creator

package
v0.6.0 Latest Latest
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 Go to latest Published: Feb 24, 2026 License: MIT Imports: 24 Imported by: 0

Documentation

Overview

Package creator provides a high-level API for creating and modifying PDF documents.

Package creator provides a high-level API for creating PDF documents.

This package offers a fluent, developer-friendly interface for PDF creation, hiding the complexity of the underlying domain model.

Example: 

c := creator.New()
c.SetTitle("My Document")
c.SetAuthor("John Doe")

page, err := c.NewPageWithSize(creator.A4)
// Add content to page...

err = c.WriteToFile("output.pdf")

Package creator provides a high-level API for creating and modifying PDF documents.

Package creator provides a high-level API for creating and modifying PDF documents.

Index

Examples

Constants

View Source 
const (
	// PermissionPrint allows printing the document.
	PermissionPrint = security.PermissionPrint

	// PermissionModify allows modifying the document.
	PermissionModify = security.PermissionModify

	// PermissionCopy allows copying text and graphics.
	PermissionCopy = security.PermissionCopy

	// PermissionAnnotate allows adding or modifying annotations.
	PermissionAnnotate = security.PermissionAnnotate

	// PermissionFillForms allows filling form fields.
	PermissionFillForms = security.PermissionFillForms

	// PermissionExtract allows extracting text for accessibility.
	PermissionExtract = security.PermissionExtract

	// PermissionAssemble allows assembling the document.
	PermissionAssemble = security.PermissionAssemble

	// PermissionPrintHighQuality allows high-quality printing.
	PermissionPrintHighQuality = security.PermissionPrintHighQuality

	// PermissionAll grants all permissions.
	PermissionAll = security.PermissionAll

	// PermissionNone grants no permissions.
	PermissionNone = security.PermissionNone
)

Permission constants.

View Source 
const (
	// DefaultHeaderHeight is the default height for headers (50 points).
	DefaultHeaderHeight = 50.0

	// DefaultFooterHeight is the default height for footers (30 points).
	DefaultFooterHeight = 30.0
)

Default header and footer heights in points.

View Source 
const (
	// PointsPerInch is the number of PDF points in one inch.
	// 1 inch = 72 points (PostScript/PDF standard).
	PointsPerInch = document.PointsPerInch

	// PointsPerMM is the number of PDF points in one millimeter.
	// 1 mm = 72/25.4 ≈ 2.83465 points.
	PointsPerMM = document.PointsPerMM

	// PointsPerCM is the number of PDF points in one centimeter.
	// 1 cm = 72/2.54 ≈ 28.3465 points.
	PointsPerCM = document.PointsPerCM
)

Unit conversion constants.

Use these with the conversion helper functions to convert between real-world units and PDF points before calling NewPageWithDimensions.

View Source 
const (
	// StampApproved represents an "Approved" stamp.
	StampApproved = document.StampApproved
	// StampNotApproved represents a "Not Approved" stamp.
	StampNotApproved = document.StampNotApproved
	// StampDraft represents a "Draft" stamp.
	StampDraft = document.StampDraft
	// StampFinal represents a "Final" stamp.
	StampFinal = document.StampFinal
	// StampConfidential represents a "Confidential" stamp.
	StampConfidential = document.StampConfidential
	// StampForComment represents a "For Comment" stamp.
	StampForComment = document.StampForComment
	// StampForPublicRelease represents a "For Public Release" stamp.
	StampForPublicRelease = document.StampForPublicRelease
	// StampAsIs represents an "As Is" stamp.
	StampAsIs = document.StampAsIs
	// StampDepartmental represents a "Departmental" stamp.
	StampDepartmental = document.StampDepartmental
	// StampExperimental represents an "Experimental" stamp.
	StampExperimental = document.StampExperimental
	// StampExpired represents an "Expired" stamp.
	StampExpired = document.StampExpired
	// StampNotForPublicRelease represents a "Not For Public Release" stamp.
	StampNotForPublicRelease = document.StampNotForPublicRelease
)

Predefined stamp names (exported for user convenience).

Variables

View Source 
var (
	// ErrEmptyBookmarkTitle is returned when bookmark title is empty.
	ErrEmptyBookmarkTitle = errors.New("bookmark title cannot be empty")

	// ErrInvalidBookmarkPage is returned when page index is invalid.
	ErrInvalidBookmarkPage = errors.New("invalid bookmark page index")

	// ErrInvalidBookmarkLevel is returned when level is invalid.
	ErrInvalidBookmarkLevel = errors.New("invalid bookmark level")
)

Bookmark-related errors.

View Source 
var (
	// ErrInvalidMargins is returned when margins are negative.
	ErrInvalidMargins = errors.New("margins must be non-negative")

	// ErrWriterNotImplemented is returned when PDF writer is not yet implemented.
	ErrWriterNotImplemented = errors.New("PDF writer not yet implemented (Phase 3 TODO)")
)

Errors.

View Source 
var (
	// ErrUnsupportedImageFormat is returned for unsupported image formats.
	ErrUnsupportedImageFormat = errors.New("unsupported image format (supported: JPEG, PNG)")

	// ErrInvalidImageDimensions is returned for zero/negative dimensions.
	ErrInvalidImageDimensions = errors.New("image dimensions must be positive")
)

Errors.

View Source 
var (
	// ErrContentOutOfBounds is returned when content is positioned outside margins.
	ErrContentOutOfBounds = errors.New("content is outside page margins")

	// ErrUnsupportedFieldType is returned when an unsupported field type is added.
	ErrUnsupportedFieldType = errors.New("unsupported form field type")
)

Errors.

View Source 
var (
	// ErrPopWithoutPush is returned when Pop is called without a matching Push.
	ErrPopWithoutPush = errors.New("Pop() called without matching Push*()")

	// ErrInvalidRect is returned when a rectangle has invalid dimensions.
	ErrInvalidRect = errors.New("invalid rectangle dimensions")
)

Errors

View Source 
var (
	// Black is pure black (RGB: 0, 0, 0).
	Black = Color{0, 0, 0}

	// White is pure white (RGB: 255, 255, 255).
	White = Color{1, 1, 1}

	// Red is pure red (RGB: 255, 0, 0).
	Red = Color{1, 0, 0}

	// Green is pure green (RGB: 0, 255, 0).
	Green = Color{0, 1, 0}

	// Blue is pure blue (RGB: 0, 0, 255).
	Blue = Color{0, 0, 1}

	// Gray is 50% gray (RGB: 128, 128, 128).
	Gray = Color{0.5, 0.5, 0.5}

	// DarkGray is 25% gray (RGB: 64, 64, 64).
	DarkGray = Color{0.25, 0.25, 0.25}

	// LightGray is 75% gray (RGB: 192, 192, 192).
	LightGray = Color{0.75, 0.75, 0.75}

	// Yellow is pure yellow (RGB: 255, 255, 0).
	Yellow = Color{1, 1, 0}

	// Cyan is pure cyan (RGB: 0, 255, 255).
	Cyan = Color{0, 1, 1}

	// Magenta is pure magenta (RGB: 255, 0, 255).
	Magenta = Color{1, 0, 1}
)

Predefined colors for common use cases.

View Source 
var (
	// CMYKBlack is pure black (100% black ink).
	CMYKBlack = ColorCMYK{0, 0, 0, 1}

	// CMYKWhite is white (no ink - paper color).
	CMYKWhite = ColorCMYK{0, 0, 0, 0}

	// CMYKCyan is pure cyan (100% cyan ink).
	CMYKCyan = ColorCMYK{1, 0, 0, 0}

	// CMYKMagenta is pure magenta (100% magenta ink).
	CMYKMagenta = ColorCMYK{0, 1, 0, 0}

	// CMYKYellow is pure yellow (100% yellow ink).
	CMYKYellow = ColorCMYK{0, 0, 1, 0}

	// CMYKRed is red (magenta + yellow).
	CMYKRed = ColorCMYK{0, 1, 1, 0}

	// CMYKGreen is green (cyan + yellow).
	CMYKGreen = ColorCMYK{1, 0, 1, 0}

	// CMYKBlue is blue (cyan + magenta).
	CMYKBlue = ColorCMYK{1, 1, 0, 0}
)

Predefined CMYK colors for common print use cases.

View Source 
var (
	// TransparentBlack is fully transparent black (RGBA: 0, 0, 0, 0).
	TransparentBlack = ColorRGBA{0, 0, 0, 0}

	// SemiTransparentBlack is 50% transparent black.
	SemiTransparentBlack = ColorRGBA{0, 0, 0, 0.5}

	// TransparentWhite is fully transparent white.
	TransparentWhite = ColorRGBA{1, 1, 1, 0}

	// SemiTransparentWhite is 50% transparent white.
	SemiTransparentWhite = ColorRGBA{1, 1, 1, 0.5}

	// TransparentRed is fully transparent red.
	TransparentRed = ColorRGBA{1, 0, 0, 0}

	// SemiTransparentRed is 50% transparent red.
	SemiTransparentRed = ColorRGBA{1, 0, 0, 0.5}

	// TransparentGreen is fully transparent green.
	TransparentGreen = ColorRGBA{0, 1, 0, 0}

	// SemiTransparentGreen is 50% transparent green.
	SemiTransparentGreen = ColorRGBA{0, 1, 0, 0.5}

	// TransparentBlue is fully transparent blue.
	TransparentBlue = ColorRGBA{0, 0, 1, 0}

	// SemiTransparentBlue is 50% transparent blue.
	SemiTransparentBlue = ColorRGBA{0, 0, 1, 0.5}
)

Predefined transparent colors for common use cases.

View Source 
var (
	// ErrInvalidColor is returned when a color has invalid component values.
	ErrInvalidColor = errors.New("invalid color component values")
)

Errors

View Source 
var (
	// ErrInvalidFill is returned when a fill configuration is invalid.
	ErrInvalidFill = errors.New("invalid fill configuration")
)

Errors

View Source 
var (
	// ErrInvalidStroke is returned when a stroke configuration is invalid.
	ErrInvalidStroke = errors.New("invalid stroke configuration")
)

Errors

Functions

func CMToPoints added in v0.4.0 

func CMToPoints(cm float64) float64

CMToPoints converts centimeters to PDF points.

Example: 

width := creator.CMToPoints(21)  // ≈ 595 points (A4 width)

func InchesToPoints added in v0.4.0 

func InchesToPoints(inches float64) float64

InchesToPoints converts inches to PDF points.

Example: 

width := creator.InchesToPoints(8.5)  // 612 points (Letter width)

func MMToPoints added in v0.4.0 

func MMToPoints(mm float64) float64

MMToPoints converts millimeters to PDF points.

Example: 

width := creator.MMToPoints(210)  // ≈ 595 points (A4 width)

func Merge 

func Merge(output string, inputs ...string) error

Merge merges multiple PDF files into a single output file.

This is a convenience function that merges all pages from all input files in the order they are specified.

Parameters:

  • output: Path to the output PDF file
  • inputs: Paths to the input PDF files (must have at least 1)

Returns an error if:

  • No input files specified
  • Any input file cannot be opened or is invalid
  • Output file cannot be created

Example: 

err := creator.Merge("output.pdf", "file1.pdf", "file2.pdf", "file3.pdf")
if err != nil {
    log.Fatal(err)
}

func MergeDocuments 

func MergeDocuments(output string, docs ...*document.Document) error

MergeDocuments merges multiple already-opened Document instances.

This is useful when you already have documents loaded in memory or when you want to merge specific documents programmatically.

Parameters:

  • output: Path to the output PDF file
  • docs: Document instances to merge (must have at least 1)

Returns an error if:

  • No documents specified
  • Output file cannot be created

Example: 

doc1, _ := gxpdf.Open("file1.pdf")
doc2, _ := gxpdf.Open("file2.pdf")
err := creator.MergeDocuments("output.pdf", doc1, doc2)

func PointsToCM added in v0.4.0 

func PointsToCM(points float64) float64

PointsToCM converts PDF points to centimeters.

Example: 

cm := creator.PointsToCM(595)  // ≈ 21 cm (A4 width)

func PointsToInches added in v0.4.0 

func PointsToInches(points float64) float64

PointsToInches converts PDF points to inches.

Example: 

inches := creator.PointsToInches(612)  // 8.5 (Letter width)

func PointsToMM added in v0.4.0 

func PointsToMM(points float64) float64

PointsToMM converts PDF points to millimeters.

Example: 

mm := creator.PointsToMM(595)  // ≈ 210 mm (A4 width)

Types

type Alignment 

type Alignment int

Alignment represents text alignment within a block. 

const (
	// AlignLeft aligns text to the left edge.
	AlignLeft Alignment = iota

	// AlignCenter centers text horizontally.
	AlignCenter

	// AlignRight aligns text to the right edge.
	AlignRight

	// AlignJustify stretches text to fill the full width.
	AlignJustify
)

type Appender 

type Appender struct {
	// contains filtered or unexported fields
}

Appender provides functionality to modify existing PDF documents.

It allows you to:

  • Open an existing PDF for modification
  • Add new pages to the document
  • Add content to existing pages (watermarks, stamps, annotations)
  • Merge multiple PDFs into one
  • Save changes incrementally (append mode) or create a new file

Example - Add watermark to all pages: 

app, err := creator.NewAppender("input.pdf")
if err != nil {
    log.Fatal(err)
}
defer app.Close()

for i := 0; i < app.PageCount(); i++ {
    page, err := app.GetPage(i)
    if err != nil {
        log.Fatal(err)
    }
    page.AddText("CONFIDENTIAL", 300, 400, creator.HelveticaBold, 48)
}

err = app.WriteToFile("output.pdf")

Example - Append new page: 

app, err := creator.NewAppender("input.pdf")
if err != nil {
    log.Fatal(err)
}
defer app.Close()

newPage, err := app.AddPage(creator.A4)
if err != nil {
    log.Fatal(err)
}
newPage.AddText("New content", 100, 700, creator.Helvetica, 12)

err = app.WriteToFile("output.pdf")

func NewAppender 

func NewAppender(path string) (*Appender, error)

NewAppender opens an existing PDF file for modification.

The file is opened and parsed immediately. Remember to call Close() when done to release resources.

Returns an error if:

  • File cannot be opened
  • File is not a valid PDF
  • PDF is encrypted (not yet supported)

Example: 

app, err := creator.NewAppender("existing.pdf")
if err != nil {
    log.Fatal(err)
}
defer app.Close()

func (*Appender) AddPage 

func (a *Appender) AddPage(size PageSize) (*Page, error)

AddPage adds a new page with the specified size.

The new page is appended to the end of the document. Returns the newly created page for adding content.

Example: 

page, err := app.AddPage(creator.A4)
if err != nil {
    log.Fatal(err)
}
page.AddText("New content", 100, 700, creator.Helvetica, 12)

func (*Appender) CanFlattenForm added in v0.2.0 

func (a *Appender) CanFlattenForm() bool

CanFlattenForm returns true if the document has fields that can be flattened.

func (*Appender) Close 

func (a *Appender) Close() error

Close closes the underlying PDF file and releases resources.

It's safe to call Close() multiple times.

Example: 

app, err := creator.NewAppender("input.pdf")
if err != nil {
    log.Fatal(err)
}
defer app.Close()

func (*Appender) Document 

func (a *Appender) Document() *document.Document

Document returns the underlying domain document.

This is provided for advanced use cases where you need direct access to the domain model. Most users should use the Appender API instead.

Example: 

doc := app.Document()
// Direct domain operations...

func (*Appender) FlattenFields added in v0.2.0 

func (a *Appender) FlattenFields(names ...string) error

FlattenFields converts specific form fields to static content.

If no names are provided, all fields are flattened.

Example: 

// Flatten only specific fields
app.FlattenFields("name", "email", "signature")

func (*Appender) FlattenForm added in v0.2.0 

func (a *Appender) FlattenForm() error

FlattenForm converts all form fields to static content.

This removes interactivity by rendering field appearances directly onto pages. The resulting PDF looks the same but fields are no longer editable.

Use this when:

  • Creating final versions of filled forms
  • Preventing further editing
  • Reducing file complexity

Example: 

app, err := creator.NewAppender("filled_form.pdf")
if err != nil {
    log.Fatal(err)
}
defer app.Close()

if err := app.FlattenForm(); err != nil {
    log.Fatal(err)
}

app.WriteToFile("flattened.pdf")

func (*Appender) GetFieldValue added in v0.2.0 

func (a *Appender) GetFieldValue(name string) (interface{}, error)

GetFieldValue returns the current value of a form field.

Returns the value from pending updates if the field has been modified, otherwise returns the original value from the PDF.

Example: 

value, err := app.GetFieldValue("name")
if err != nil {
    log.Fatal(err)
}
fmt.Printf("Name: %v\n", value)

func (*Appender) GetFormFields added in v0.2.0 

func (a *Appender) GetFormFields() ([]*forms.FieldInfo, error)

GetFormFields returns all form fields from the PDF.

This includes field metadata such as name, type, current value, and options.

Example: 

fields, err := app.GetFormFields()
if err != nil {
    log.Fatal(err)
}
for _, f := range fields {
    fmt.Printf("%s (%s): %v\n", f.Name, f.Type, f.Value)
}

func (*Appender) GetPage 

func (a *Appender) GetPage(index int) (*Page, error)

GetPage returns the page at the specified index (0-based).

This allows you to add content to existing pages. The page can be modified by calling methods like AddText, DrawLine, etc.

Returns an error if the page index is out of bounds.

Example: 

page, err := app.GetPage(0)
if err != nil {
    log.Fatal(err)
}
page.AddText("Watermark", 300, 400, creator.HelveticaBold, 48)

func (*Appender) GetParserReader 

func (a *Appender) GetParserReader() *parser.Reader

GetParserReader returns the underlying parser.Reader for advanced operations.

This is useful for extracting text, images, or other content from the original PDF. Most users should not need this - use the high-level Appender methods instead.

Example: 

parserReader := app.GetParserReader()
// Advanced parser operations...

func (*Appender) HasForm added in v0.2.0 

func (a *Appender) HasForm() bool

HasForm returns true if the PDF contains an interactive form.

Example: 

if app.HasForm() {
    fields, _ := app.GetFormFields()
    fmt.Printf("Found %d form fields\n", len(fields))
}

func (*Appender) PageCount 

func (a *Appender) PageCount() int

PageCount returns the total number of pages in the document.

This includes both original pages and newly added pages.

Example: 

count := app.PageCount()
fmt.Printf("Document has %d pages\n", count)

func (*Appender) SetFieldValue added in v0.2.0 

func (a *Appender) SetFieldValue(name string, value interface{}) error

SetFieldValue sets a form field value by name.

The value type depends on the field type:

  • Text field: string
  • Checkbox: bool or string ("Yes", "Off")
  • Radio button: string (option name)
  • Choice field: string or []string (for multi-select)

Returns an error if:

  • The field is not found
  • The PDF has no interactive form
  • The value type is incompatible with the field type

Example: 

app, err := creator.NewAppender("form.pdf")
if err != nil {
    log.Fatal(err)
}
defer app.Close()

// Fill text field
if err := app.SetFieldValue("name", "John Doe"); err != nil {
    log.Fatal(err)
}

// Fill checkbox
if err := app.SetFieldValue("agree", true); err != nil {
    log.Fatal(err)
}

app.WriteToFile("filled.pdf")

func (*Appender) SetKeywords 

func (a *Appender) SetKeywords(keywords ...string)

SetKeywords sets document keywords for search/indexing.

Example: 

app.SetKeywords("modified", "watermarked", "confidential")

func (*Appender) SetMetadata 

func (a *Appender) SetMetadata(title, author, subject string)

SetMetadata updates the document metadata.

This replaces any existing metadata in the original PDF.

Example: 

app.SetMetadata("Modified Document", "John Doe", "Updated Report")

func (*Appender) WriteToFile 

func (a *Appender) WriteToFile(path string) error

WriteToFile writes the modified PDF to a file.

This creates a new PDF file with all modifications applied. The original file is not modified.

For large PDFs, consider using WriteToFileIncremental() instead, which appends only the changes (not yet implemented).

Example: 

err := app.WriteToFile("output.pdf")
if err != nil {
    log.Fatal(err)
}

func (*Appender) WriteToFileContext 

func (a *Appender) WriteToFileContext(ctx context.Context, path string) error

WriteToFileContext writes the modified PDF with context support.

This allows cancellation and timeout control.

Example: 

ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
defer cancel()

err := app.WriteToFileContext(ctx, "output.pdf")

type BezierOptions 

type BezierOptions struct {
	// Color is the curve color (RGB, 0.0 to 1.0 range).
	// If ColorCMYK is set, this field is ignored.
	Color Color

	// ColorCMYK is the curve color in CMYK color space (optional).
	// If set, this takes precedence over Color (RGB).
	ColorCMYK *ColorCMYK

	// Width is the curve width in points (default: 1.0).
	Width float64

	// Dashed enables dashed curve rendering.
	Dashed bool

	// DashArray defines the dash pattern (e.g., [3, 1] for "3 on, 1 off").
	// Only used when Dashed is true.
	DashArray []float64

	// DashPhase is the starting offset into the dash pattern.
	// Only used when Dashed is true.
	DashPhase float64

	// Closed determines if the curve path should be closed.
	// If true, a line is drawn from the last segment's end point
	// back to the first segment's start point.
	Closed bool

	// FillColor is the fill color for closed curves (nil = no fill).
	// Only used when Closed is true.
	// Mutually exclusive with FillGradient.
	FillColor *Color

	// FillGradient is the gradient fill for closed curves (nil = no gradient fill).
	// Only used when Closed is true.
	// Mutually exclusive with FillColor.
	FillGradient *Gradient

	// Opacity is the bezier curve opacity (0.0 = transparent, 1.0 = opaque).
	// Optional. If set, applies transparency via ExtGState.
	// Affects both stroke and fill (if Closed is true).
	// Range: [0.0, 1.0]
	Opacity *float64
}

BezierOptions configures Bézier curve drawing.

type BezierSegment 

type BezierSegment struct {
	// Start is the starting point (P0).
	// For the first segment, this is the curve's starting point.
	// For subsequent segments, this should match the previous segment's End point.
	Start Point

	// C1 is the first control point.
	C1 Point

	// C2 is the second control point.
	C2 Point

	// End is the ending point (P1).
	End Point
}

BezierSegment represents a cubic Bézier curve segment.

A cubic Bézier curve is defined by:

  • Start point (P0)
  • First control point (C1)
  • Second control point (C2)
  • End point (P1)

The curve starts at P0, is pulled toward C1 and C2, and ends at P1.

type BlendMode added in v0.2.0 

type BlendMode int

BlendMode defines how colors blend with the background. 

const (
	// BlendModeNormal is the default blend mode (simple alpha compositing).
	BlendModeNormal BlendMode = iota

	// BlendModeMultiply multiplies the source and destination colors.
	BlendModeMultiply

	// BlendModeScreen inverts, multiplies, and inverts again.
	BlendModeScreen

	// BlendModeOverlay combines Multiply and Screen based on destination.
	BlendModeOverlay

	// BlendModeDarken selects the darker of source and destination.
	BlendModeDarken

	// BlendModeLighten selects the lighter of source and destination.
	BlendModeLighten

	// BlendModeColorDodge brightens the destination based on source.
	BlendModeColorDodge

	// BlendModeColorBurn darkens the destination based on source.
	BlendModeColorBurn

	// BlendModeHardLight is like Overlay but uses source instead of destination.
	BlendModeHardLight

	// BlendModeSoftLight is a softer version of HardLight.
	BlendModeSoftLight

	// BlendModeDifference subtracts the darker from the lighter.
	BlendModeDifference

	// BlendModeExclusion is like Difference but with lower contrast.
	BlendModeExclusion
)

func (BlendMode) String added in v0.2.0 

func (b BlendMode) String() string

String returns the PDF blend mode name.

type Block 

type Block struct {
	// contains filtered or unexported fields
}

Block represents a rectangular area for drawing content.

Blocks are used as containers for header/footer content and provide a bounded region where Drawable elements can be placed. Content is positioned relative to the block's origin (top-left corner).

Example: 

block := NewBlock(500, 50)
block.SetMargins(Margins{Left: 10, Right: 10})
p := NewParagraph("Header Text")
block.Draw(p)

func NewBlock 

func NewBlock(width, height float64) *Block

NewBlock creates a new block with the specified dimensions.

Parameters:

  • width: Block width in points
  • height: Block height in points

Example: 

block := NewBlock(500, 50)  // 500pt wide, 50pt tall

func (*Block) Clear 

func (b *Block) Clear()

Clear removes all drawables from the block.

func (*Block) ContentHeight 

func (b *Block) ContentHeight() float64

ContentHeight returns the usable height inside the block (height minus margins).

func (*Block) ContentWidth 

func (b *Block) ContentWidth() float64

ContentWidth returns the usable width inside the block (width minus margins).

func (*Block) Draw 

func (b *Block) Draw(d Drawable) error

Draw adds a drawable element to the block at the current position.

The drawable is positioned at the block's current cursor position, which starts at (0, 0) relative to the block's content area.

Returns an error if the drawable is nil.

func (*Block) DrawAt 

func (b *Block) DrawAt(d Drawable, x, y float64) error

DrawAt adds a drawable element at a specific position within the block.

Coordinates are relative to the block's top-left corner (before margins).

Parameters:

  • d: The drawable element to add
  • x: Horizontal position from left edge of block
  • y: Vertical position from top edge of block

Returns an error if the drawable is nil.

func (*Block) GetDrawables 

func (b *Block) GetDrawables() []DrawablePosition

GetDrawables returns all drawable elements with their positions.

This is used internally to render the block contents to a page.

func (*Block) GetLayoutContext 

func (b *Block) GetLayoutContext() *LayoutContext

GetLayoutContext creates a LayoutContext for this block.

This allows Drawable elements to query the available space and position themselves correctly within the block.

func (*Block) Height 

func (b *Block) Height() float64

Height returns the block height in points.

func (*Block) Margins 

func (b *Block) Margins() Margins

Margins returns the block margins.

func (*Block) MoveCursor 

func (b *Block) MoveCursor(dx, dy float64)

MoveCursor moves the current drawing position by the specified delta.

func (*Block) SetCursor 

func (b *Block) SetCursor(x, y float64)

SetCursor sets the current drawing position within the block.

This affects subsequent Draw() calls.

func (*Block) SetHeight 

func (b *Block) SetHeight(height float64)

SetHeight sets the block height in points.

func (*Block) SetMargins 

func (b *Block) SetMargins(m Margins)

SetMargins sets the block margins.

Margins define the padding inside the block, reducing the available drawing area.

func (*Block) SetWidth 

func (b *Block) SetWidth(width float64)

SetWidth sets the block width in points.

func (*Block) Width 

func (b *Block) Width() float64

Width returns the block width in points.

type Bookmark 

type Bookmark struct {
	// Title is the text displayed in the bookmark tree.
	Title string

	// PageIndex is the target page (0-based index).
	// 0 = first page, 1 = second page, etc.
	PageIndex int

	// Level is the nesting level in the bookmark hierarchy.
	// 0 = top-level, 1 = child of top-level, 2 = grandchild, etc.
	Level int
}

Bookmark represents a PDF bookmark (also known as outline item).

Bookmarks provide a navigational tree structure in PDF documents. They allow users to jump to specific pages and create a table of contents.

Example: 

bookmark := Bookmark{
    Title:     "Chapter 1",
    PageIndex: 0,  // First page (0-based)
    Level:     0,  // Top-level bookmark
}

type Border 

type Border struct {
	// Width is the border line width in points.
	Width float64

	// Color is the border color (RGB, 0.0 to 1.0 range).
	Color Color
}

Border defines the border style for a division.

Border controls the appearance of a division's outline, including width and color. Individual borders can be set per side.

Example: 

border := Border{Width: 1.0, Color: Black}
div.SetBorder(border)

type Chapter 

type Chapter struct {
	// contains filtered or unexported fields
}

Chapter represents a document chapter with title and content.

Chapters provide hierarchical document structure with automatic numbering. They can contain sub-chapters (sections, subsections, etc.) up to any depth.

Example: 

ch := NewChapter("Introduction")
ch.Add(NewParagraph("This is the introduction..."))

sec := ch.NewSubChapter("Background")
sec.Add(NewParagraph("Background information..."))

func NewChapter 

func NewChapter(title string) *Chapter

NewChapter creates a new top-level chapter with the given title.

The chapter uses default styling and can have content and sub-chapters added.

Example: 

ch := NewChapter("Chapter 1: Introduction")
ch.Add(NewParagraph("Welcome to this document..."))

func (*Chapter) Add 

func (c *Chapter) Add(d Drawable) error

Add adds a content element (paragraph, table, etc.) to the chapter.

Example: 

ch.Add(NewParagraph("This is the introduction..."))
ch.Add(NewTable())

func (*Chapter) Content 

func (c *Chapter) Content() []Drawable

Content returns all content elements in the chapter.

func (*Chapter) Draw 

func (c *Chapter) Draw(ctx *LayoutContext, page *Page) error

Draw renders the chapter on the page.

This renders: 1. Chapter heading (with number if enabled) 2. All content elements 3. All sub-chapters (recursively).

func (*Chapter) FullTitle 

func (c *Chapter) FullTitle() string

FullTitle returns the title with number prefix if numbering is enabled.

For example: "1.2 Background" or just "Background" if ShowNumber is false.

func (*Chapter) GetAllChapters 

func (c *Chapter) GetAllChapters() []*Chapter

GetAllChapters returns a flat list of this chapter and all sub-chapters.

The list is in document order (depth-first traversal).

This is useful for building table of contents.

func (*Chapter) Height 

func (c *Chapter) Height(ctx *LayoutContext) float64

Height calculates the total height needed to render this chapter.

This includes the heading, all content, and all sub-chapters.

func (*Chapter) Level 

func (c *Chapter) Level() int

Level returns the nesting level of the chapter.

Top-level chapters return 0, sub-chapters return 1, etc.

func (*Chapter) NewSubChapter 

func (c *Chapter) NewSubChapter(title string) *Chapter

NewSubChapter creates a new sub-chapter (section) under this chapter.

The sub-chapter inherits styling from the parent but with smaller font size. Numbering is automatically assigned based on the position.

Example: 

ch := NewChapter("Introduction")
sec1 := ch.NewSubChapter("Background")     // 1.1 Background
sec2 := ch.NewSubChapter("Motivation")     // 1.2 Motivation
subsec := sec1.NewSubChapter("History")    // 1.1.1 History

func (*Chapter) Number 

func (c *Chapter) Number() []int

Number returns the chapter number components.

For example, section 1.2.3 returns []int{1, 2, 3}.

func (*Chapter) NumberString 

func (c *Chapter) NumberString() string

NumberString returns the formatted chapter number.

For example: "1", "1.2", "1.2.3".

func (*Chapter) PageIndex 

func (c *Chapter) PageIndex() int

PageIndex returns the page index where the chapter starts.

Returns -1 if not yet rendered.

func (*Chapter) Parent 

func (c *Chapter) Parent() *Chapter

Parent returns the parent chapter (nil for top-level).

func (*Chapter) SetStyle 

func (c *Chapter) SetStyle(style ChapterStyle)

SetStyle sets the chapter heading style.

func (*Chapter) SetTitle 

func (c *Chapter) SetTitle(title string)

SetTitle sets the chapter title.

func (*Chapter) Style 

func (c *Chapter) Style() ChapterStyle

Style returns the current chapter heading style.

func (*Chapter) SubChapters 

func (c *Chapter) SubChapters() []*Chapter

SubChapters returns all sub-chapters.

func (*Chapter) Title 

func (c *Chapter) Title() string

Title returns the chapter title.

type ChapterStyle 

type ChapterStyle struct {
	// Font for the chapter title
	Font FontName

	// FontSize for the chapter title
	FontSize float64

	// Color for the chapter title
	Color Color

	// SpaceBefore is the vertical space before the chapter heading
	SpaceBefore float64

	// SpaceAfter is the vertical space after the chapter heading
	SpaceAfter float64

	// ShowNumber indicates whether to show chapter numbers
	ShowNumber bool

	// NumberSeparator is the separator between number components (default: ".")
	NumberSeparator string
}

ChapterStyle defines the visual style for chapter headings.

func DefaultChapterStyle 

func DefaultChapterStyle() ChapterStyle

DefaultChapterStyle returns the default chapter heading style.

Default style:

  • Font: HelveticaBold
  • FontSize: 18pt (scaled down for sub-chapters)
  • Color: Black
  • SpaceBefore: 20pt
  • SpaceAfter: 10pt
  • ShowNumber: true
  • NumberSeparator: "."

type CircleOptions 

type CircleOptions struct {
	// StrokeColor is the border color (nil = no stroke).
	// If StrokeColorCMYK is set, this field is ignored.
	StrokeColor *Color

	// StrokeColorCMYK is the border color in CMYK (nil = no stroke).
	// If set, this takes precedence over StrokeColor (RGB).
	StrokeColorCMYK *ColorCMYK

	// StrokeWidth is the border width in points (default: 1.0).
	StrokeWidth float64

	// FillColor is the fill color (nil = no fill).
	// Mutually exclusive with FillGradient and FillColorCMYK.
	// If FillColorCMYK is set, this field is ignored.
	FillColor *Color

	// FillColorCMYK is the fill color in CMYK (nil = no fill).
	// If set, this takes precedence over FillColor (RGB).
	// Mutually exclusive with FillGradient.
	FillColorCMYK *ColorCMYK

	// FillGradient is the gradient fill (nil = no gradient fill).
	// Mutually exclusive with FillColor and FillColorCMYK.
	FillGradient *Gradient

	// Opacity is the circle opacity (0.0 = transparent, 1.0 = opaque).
	// Optional. If set, applies transparency via ExtGState.
	// Affects both fill and stroke.
	// Range: [0.0, 1.0]
	Opacity *float64
}

CircleOptions configures circle drawing.

type Color 

type Color struct {
	R float64 // Red component (0.0 to 1.0)
	G float64 // Green component (0.0 to 1.0)
	B float64 // Blue component (0.0 to 1.0)
}

Color represents an RGB color with values in the range [0.0, 1.0].

PDF uses RGB color space where: - 0.0 = no intensity (black for all channels) - 1.0 = full intensity (white for all channels)

Example: 

black := Color{0, 0, 0}     // RGB(0, 0, 0)
white := Color{1, 1, 1}     // RGB(255, 255, 255)
red := Color{1, 0, 0}       // RGB(255, 0, 0)
gray := Color{0.5, 0.5, 0.5} // RGB(128, 128, 128)

func GrayN added in v0.2.0 

func GrayN(value uint8) Color

GrayN creates a Color from a grayscale value (0-255).

This is a convenience function for creating gray colors from numeric values. All RGB components are set to the same value.

Note: Use the Gray variable for the predefined 50% gray color.

Parameters:

  • value: Grayscale value (0 = black, 255 = white)

Example: 

black := creator.GrayN(0)
gray := creator.GrayN(128)
white := creator.GrayN(255)

func Hex added in v0.2.0 

func Hex(hex string) (Color, error)

Hex creates a Color from a hex color string.

Supported formats:

  • "#RGB" (short form, e.g., "#F00" = red)
  • "#RRGGBB" (long form, e.g., "#FF0000" = red)
  • "RGB" (without #)
  • "RRGGBB" (without #)

Parameters:

  • hex: Hex color string

Example: 

red, _ := creator.Hex("#FF0000")
green, _ := creator.Hex("00FF00")
blue, _ := creator.Hex("#00F")

func RGB added in v0.2.0 

func RGB(r, g, b uint8) Color

RGB creates a Color from 8-bit RGB values (0-255).

This is a convenience function for creating colors from common 8-bit color values instead of normalized floats.

Parameters:

  • r: Red component (0 to 255)
  • g: Green component (0 to 255)
  • b: Blue component (0 to 255)

Example: 

red := creator.RGB(255, 0, 0)
green := creator.RGB(0, 255, 0)
gray := creator.RGB(128, 128, 128)

func (Color) ToCMYK 

func (c Color) ToCMYK() ColorCMYK

ToCMYK converts an RGB color to CMYK.

Conversion formula: 

K = 1 - max(R, G, B)
C = (1 - R - K) / (1 - K)
M = (1 - G - K) / (1 - K)
Y = (1 - B - K) / (1 - K)

Special case: Pure black (R=0, G=0, B=0) is represented as K=1, C=M=Y=0.

Note: This is a simple conversion. For precise color matching in professional printing, use ICC color profiles.

Example: 

rgb := Color{1, 0, 0}  // Red in RGB
cmyk := rgb.ToCMYK()   // Converts to CMYK{0, 1, 1, 0}

type ColorCMYK 

type ColorCMYK struct {
	C float64 // Cyan component (0.0 to 1.0)
	M float64 // Magenta component (0.0 to 1.0)
	Y float64 // Yellow component (0.0 to 1.0)
	K float64 // blacK component (0.0 to 1.0)
}

ColorCMYK represents a CMYK color with values in the range [0.0, 1.0].

CMYK (Cyan, Magenta, Yellow, blacK) is a subtractive color model used in professional printing. Unlike RGB (additive), CMYK works by subtracting colors from white.

PDF supports CMYK color space natively via DeviceCMYK.

Example: 

black := ColorCMYK{0, 0, 0, 1}       // 100% black
white := ColorCMYK{0, 0, 0, 0}       // No ink (paper white)
cyan := ColorCMYK{1, 0, 0, 0}        // 100% cyan
magenta := ColorCMYK{0, 1, 0, 0}     // 100% magenta
yellow := ColorCMYK{0, 0, 1, 0}      // 100% yellow
red := ColorCMYK{0, 1, 1, 0}         // Magenta + Yellow = Red

Reference: PDF 1.7 Specification, Section 8.6.4.4 (DeviceCMYK Color Space).

func NewColorCMYK 

func NewColorCMYK(c, m, y, k float64) ColorCMYK

NewColorCMYK creates a new CMYK color.

Parameters:

  • c: Cyan component (0.0 to 1.0)
  • m: Magenta component (0.0 to 1.0)
  • y: Yellow component (0.0 to 1.0)
  • k: blacK component (0.0 to 1.0)

Example: 

cyan := creator.NewColorCMYK(1.0, 0.0, 0.0, 0.0)
red := creator.NewColorCMYK(0.0, 1.0, 1.0, 0.0)

func (ColorCMYK) ToRGB 

func (c ColorCMYK) ToRGB() Color

ToRGB converts a CMYK color to RGB.

Conversion formula: 

R = (1 - C) * (1 - K)
G = (1 - M) * (1 - K)
B = (1 - Y) * (1 - K)

Note: This is a simple conversion. For precise color matching in professional printing, use ICC color profiles.

Example: 

cmyk := ColorCMYK{0, 1, 1, 0} // Red in CMYK
rgb := cmyk.ToRGB()            // Converts to RGB{1, 0, 0}

type ColorRGBA added in v0.2.0 

type ColorRGBA struct {
	R float64 // Red component (0.0 to 1.0)
	G float64 // Green component (0.0 to 1.0)
	B float64 // Blue component (0.0 to 1.0)
	A float64 // Alpha component (0.0 = transparent, 1.0 = opaque)
}

ColorRGBA represents an RGBA color with alpha channel (transparency).

All values are in the range [0.0, 1.0]: - R, G, B: Color components (0.0 = no intensity, 1.0 = full intensity) - A: Alpha channel (0.0 = fully transparent, 1.0 = fully opaque)

PDF uses ExtGState (Extended Graphics State) with /ca parameter to implement transparency. The alpha value controls both fill and stroke opacity.

Example: 

// Semi-transparent red
transparentRed := ColorRGBA{1, 0, 0, 0.5}

// Fully transparent (invisible)
invisible := ColorRGBA{0, 0, 0, 0}

// Fully opaque (same as Color)
opaque := ColorRGBA{1, 0, 0, 1}

Reference: PDF 1.7 Specification, Section 8.4.5 (Extended Graphics State).

func NewColorRGBA added in v0.2.0 

func NewColorRGBA(r, g, b, a float64) ColorRGBA

NewColorRGBA creates a new RGBA color with alpha channel.

Parameters:

  • r: Red component (0.0 to 1.0)
  • g: Green component (0.0 to 1.0)
  • b: Blue component (0.0 to 1.0)
  • a: Alpha component (0.0 = transparent, 1.0 = opaque)

Example: 

// 50% transparent red
red := creator.NewColorRGBA(1.0, 0.0, 0.0, 0.5)

// 30% transparent blue
blue := creator.NewColorRGBA(0.0, 0.0, 1.0, 0.3)

func RGBA added in v0.2.0 

func RGBA(r, g, b uint8, a float64) ColorRGBA

RGBA creates a ColorRGBA from 8-bit RGB values and normalized alpha.

Parameters:

  • r: Red component (0 to 255)
  • g: Green component (0 to 255)
  • b: Blue component (0 to 255)
  • a: Alpha component (0.0 = transparent, 1.0 = opaque)

Example: 

transparentRed := creator.RGBA(255, 0, 0, 0.5)
semiTransparentBlue := creator.RGBA(0, 0, 255, 0.3)

func (ColorRGBA) ToColor added in v0.2.0 

func (c ColorRGBA) ToColor() Color

ToColor converts RGBA to RGB (discards alpha channel).

Returns the RGB color without transparency.

func (ColorRGBA) WithAlpha added in v0.2.0 

func (c ColorRGBA) WithAlpha(alpha float64) ColorRGBA

WithAlpha returns a new ColorRGBA with the specified alpha value.

Parameters:

  • alpha: New alpha value (0.0 to 1.0)

Example: 

red := ColorRGBA{1, 0, 0, 1}
transparentRed := red.WithAlpha(0.5)  // 50% transparent red

type ColorSpace 

type ColorSpace string

ColorSpace represents the image color space. 

const (
	// ColorSpaceRGB is RGB color space (3 components).
	ColorSpaceRGB ColorSpace = "DeviceRGB"

	// ColorSpaceCMYK is CMYK color space (4 components).
	ColorSpaceCMYK ColorSpace = "DeviceCMYK"

	// ColorSpaceGray is grayscale (1 component).
	ColorSpaceGray ColorSpace = "DeviceGray"
)

type ColorStop 

type ColorStop struct {
	// Position is the location of this color stop in the gradient (0.0 to 1.0).
	// 0.0 = start, 1.0 = end.
	Position float64

	// Color is the RGB color at this position.
	Color Color
}

ColorStop represents a color transition point in a gradient.

A gradient is defined by multiple color stops along a [0, 1] domain. Position 0 is the start, position 1 is the end.

Example: 

stops := []ColorStop{
    {Position: 0.0, Color: Red},    // Start: red
    {Position: 0.5, Color: Yellow}, // Middle: yellow
    {Position: 1.0, Color: Green},  // End: green
}

type Creator 

type Creator struct {
	// contains filtered or unexported fields
}

Creator is a high-level API for creating PDF documents.

It provides a fluent interface for document creation with sensible defaults and simplified methods. Creator wraps the underlying domain model (Document) and provides a more intuitive API for common use cases.

Thread Safety

Creator is NOT safe for concurrent use. Each goroutine should create its own Creator instance. However, multiple Creator instances can safely be used concurrently without synchronization.

Example 

c := creator.New()
c.SetPageSize(creator.A4)
c.SetMargins(72, 72, 72, 72) // 1 inch on all sides

page := c.NewPage()
// Add content...

c.WriteToFile("output.pdf")

func New 

func New() *Creator

New creates a new Creator with default settings.

Default settings: - Page size: A4 (595 × 842 points) - Margins: 72 points (1 inch) on all sides - PDF version: 1.7

Example: 

c := creator.New()
c.SetTitle("My Document")

func (*Creator) AddBookmark 

func (c *Creator) AddBookmark(title string, pageIndex int, level int) error

AddBookmark adds a bookmark to the document.

Bookmarks create a navigational tree structure (outline) in the PDF. Use Level to create nested bookmarks (chapters → sections → subsections).

Parameters:

  • title: Text to display in the bookmark tree
  • pageIndex: Target page (0-based: 0 = first page, 1 = second, etc.)
  • level: Nesting level (0 = top-level, 1 = child, 2 = grandchild, etc.)

Returns an error if the parameters are invalid.

Example: 

c := creator.New()
page1, _ := c.NewPage()
page2, _ := c.NewPage()
page3, _ := c.NewPage()

// Add top-level bookmarks
c.AddBookmark("Chapter 1", 0, 0)  // Points to page 1
c.AddBookmark("Chapter 2", 2, 0)  // Points to page 3

// Add nested bookmarks (sections under Chapter 1)
c.AddBookmark("Section 1.1", 0, 1)  // Child of Chapter 1
c.AddBookmark("Section 1.2", 1, 1)  // Child of Chapter 1

c.WriteToFile("document.pdf")

func (*Creator) AddChapter 

func (c *Creator) AddChapter(ch *Chapter) error

AddChapter adds a chapter to the document.

Chapters provide document structure with automatic numbering and optional Table of Contents integration.

The chapter will be rendered on a new page, and all sub-chapters will be included automatically.

Example: 

c := creator.New()
c.EnableTOC()

ch1 := creator.NewChapter("Introduction")
ch1.Add(creator.NewParagraph("This is the introduction..."))
c.AddChapter(ch1)

ch2 := creator.NewChapter("Methods")
sec := ch2.NewSubChapter("Background")
c.AddChapter(ch2)

func (*Creator) Bookmarks 

func (c *Creator) Bookmarks() []Bookmark

Bookmarks returns a copy of all bookmarks in the document.

The returned slice is a copy, so modifications won't affect the document. Bookmarks are returned in the order they were added.

Example: 

c.AddBookmark("Chapter 1", 0, 0)
c.AddBookmark("Section 1.1", 0, 1)

bookmarks := c.Bookmarks()
fmt.Printf("Document has %d bookmarks\n", len(bookmarks))

func (*Creator) Bytes added in v0.2.0 

func (c *Creator) Bytes() ([]byte, error)

Bytes returns the PDF document as a byte slice.

This is a convenience method that writes to an in-memory buffer. For large documents, consider using WriteTo with a streaming writer.

Example: 

pdfBytes, err := c.Bytes()
if err != nil {
    log.Fatal(err)
}
// Use pdfBytes...

func (*Creator) Chapters 

func (c *Creator) Chapters() []*Chapter

Chapters returns all top-level chapters in the document.

func (*Creator) DisableTOC 

func (c *Creator) DisableTOC()

DisableTOC disables automatic Table of Contents generation.

func (*Creator) Document 

func (c *Creator) Document() *document.Document

Document returns the underlying domain document.

This is provided for advanced use cases where you need direct access to the domain model. Most users should use the Creator API instead.

Example: 

doc := c.Document()
// Direct domain operations...

func (*Creator) EnableTOC 

func (c *Creator) EnableTOC()

EnableTOC enables automatic Table of Contents generation.

When enabled, the TOC will be inserted at the beginning of the document and will include all chapters added via AddChapter.

The TOC includes clickable links to each chapter and section.

Example: 

c := creator.New()
c.EnableTOC()
ch1 := creator.NewChapter("Introduction")
c.AddChapter(ch1)
c.WriteToFile("document.pdf")  // TOC is automatically generated

func (*Creator) FooterHeight 

func (c *Creator) FooterHeight() float64

FooterHeight returns the current footer height in points.

func (*Creator) HeaderHeight 

func (c *Creator) HeaderHeight() float64

HeaderHeight returns the current header height in points.

func (*Creator) NewPage 

func (c *Creator) NewPage() (*Page, error)

NewPage adds a new page with the default page size.

The page uses the default page size set via SetPageSize. If no default is set, A4 is used.

Returns the newly created page for method chaining.

Example: 

page := c.NewPage()
// Add content to page...

func (*Creator) NewPageWithDimensions added in v0.4.0 

func (c *Creator) NewPageWithDimensions(widthPt, heightPt float64) (*Page, error)

NewPageWithDimensions adds a new page with explicit width and height in PDF points.

This is useful when no standard size fits your needs, or when importing content from real-world measurements (use InchesToPoints/MMToPoints to convert).

Parameters:

  • widthPt: Page width in PDF points (must be > 0)
  • heightPt: Page height in PDF points (must be > 0)

Returns the newly created page or an error if dimensions are invalid.

Example: 

// A custom 6 × 9 inch page
page, err := c.NewPageWithDimensions(
    creator.InchesToPoints(6),
    creator.InchesToPoints(9),
)

For standard sizes in landscape orientation, prefer Creator.NewPageWithSize with the Landscape option instead of swapping dimensions manually.

func (*Creator) NewPageWithSize 

func (c *Creator) NewPageWithSize(size PageSize, orientation ...Orientation) (*Page, error)

NewPageWithSize adds a new page with a specific standard size and optional orientation.

By default pages are created in portrait orientation (taller than wide). Pass Landscape to create a true landscape page with swapped width and height. This uses the industry-standard swapped-MediaBox approach — no /Rotate entry is written, so content coordinates remain natural.

Example: 

page, err := c.NewPageWithSize(creator.Letter)                    // portrait
page, err := c.NewPageWithSize(creator.A4, creator.Landscape)    // 842 × 595 pt
page, err := c.NewPageWithSize(creator.Letter, creator.Landscape) // 792 × 612 pt

func (*Creator) PageCount 

func (c *Creator) PageCount() int

PageCount returns the number of pages in the document.

func (*Creator) SetAuthor 

func (c *Creator) SetAuthor(author string)

SetAuthor sets the document author.

Example: 

c.SetAuthor("John Doe")

func (*Creator) SetEncryption 

func (c *Creator) SetEncryption(opts EncryptionOptions) error

SetEncryption enables encryption for the PDF document.

This must be called BEFORE writing the PDF to file.

Example: 

c := creator.New()
c.SetEncryption(creator.EncryptionOptions{
    UserPassword:  "userpass",
    OwnerPassword: "ownerpass",
    Permissions:   creator.PermissionPrint | creator.PermissionCopy,
    Algorithm:     creator.EncryptionAES128, // Recommended
})
c.WriteToFile("protected.pdf")

Note: Encryption is applied during WriteToFile.

Example 
c := New()

// Enable encryption with user and owner passwords.
_ = c.SetEncryption(EncryptionOptions{
	UserPassword:  "userpass",
	OwnerPassword: "ownerpass",
	Permissions:   PermissionPrint | PermissionCopy,
	KeyLength:     128,
})

// Document will be encrypted when written to file.
// (WriteToFile not shown here as it requires more setup)
Example (Aes128) 
c := New()

// Enable AES-128 encryption (recommended).
_ = c.SetEncryption(EncryptionOptions{
	UserPassword:  "userpass",
	OwnerPassword: "ownerpass",
	Permissions:   PermissionPrint | PermissionCopy,
	Algorithm:     EncryptionAES128,
})

// Document will be encrypted when written to file.
Example (Aes256) 
c := New()

// Enable AES-256 encryption (most secure).
_ = c.SetEncryption(EncryptionOptions{
	UserPassword:  "userpass",
	OwnerPassword: "ownerpass",
	Permissions:   PermissionAll,
	Algorithm:     EncryptionAES256,
})

// Document will be encrypted when written to file.

func (*Creator) SetFooterFunc 

func (c *Creator) SetFooterFunc(f FooterFunc)

SetFooterFunc sets the function to render footers on each page.

The function is called once for each page during PDF generation. It receives page information and a Block to draw footer content into.

Example: 

c.SetFooterFunc(func(args FooterFunctionArgs) {
    text := fmt.Sprintf("Page %d of %d", args.PageNum, args.TotalPages)
    p := NewParagraph(text)
    p.SetAlignment(AlignCenter)
    args.Block.Draw(p)
})

func (*Creator) SetFooterHeight 

func (c *Creator) SetFooterHeight(h float64)

SetFooterHeight sets the height reserved for footers in points.

Default: 30 points.

Example: 

c.SetFooterHeight(25)  // 25 points for footer

func (*Creator) SetHeaderFunc 

func (c *Creator) SetHeaderFunc(f HeaderFunc)

SetHeaderFunc sets the function to render headers on each page.

The function is called once for each page during PDF generation. It receives page information and a Block to draw header content into.

Example: 

c.SetHeaderFunc(func(args HeaderFunctionArgs) {
    p := NewParagraph("Document Title")
    p.SetFont(HelveticaBold, 10)
    args.Block.Draw(p)
})

func (*Creator) SetHeaderHeight 

func (c *Creator) SetHeaderHeight(h float64)

SetHeaderHeight sets the height reserved for headers in points.

Default: 50 points.

Example: 

c.SetHeaderHeight(40)  // 40 points for header

func (*Creator) SetKeywords 

func (c *Creator) SetKeywords(keywords ...string)

SetKeywords sets document keywords for search/indexing.

Example: 

c.SetKeywords("report", "2025", "finance", "annual")

func (*Creator) SetMargins 

func (c *Creator) SetMargins(top, right, bottom, left float64) error

SetMargins sets the default margins for new pages.

Margins are specified in points (1 point = 1/72 inch).

Example: 

c.SetMargins(72, 72, 72, 72) // 1 inch on all sides
c.SetMargins(36, 36, 36, 36) // 0.5 inch on all sides

func (*Creator) SetMetadata 

func (c *Creator) SetMetadata(title, author, subject string)

SetMetadata sets all document metadata at once.

Example: 

c.SetMetadata("My Document", "John Doe", "Annual Report")

func (*Creator) SetPageSize 

func (c *Creator) SetPageSize(size PageSize)

SetPageSize sets the default page size for new pages.

This affects all pages added after calling this method. Existing pages are not affected.

Example: 

c.SetPageSize(creator.Letter) // 8.5 × 11 inches
c.NewPage() // Uses Letter size

func (*Creator) SetSkipFooterOnFirstPage 

func (c *Creator) SetSkipFooterOnFirstPage(skip bool)

SetSkipFooterOnFirstPage sets whether to skip the footer on the first page.

This is useful for documents with a title page that should not have a footer.

Example: 

c.SetSkipFooterOnFirstPage(true)  // No footer on page 1

func (*Creator) SetSkipHeaderOnFirstPage 

func (c *Creator) SetSkipHeaderOnFirstPage(skip bool)

SetSkipHeaderOnFirstPage sets whether to skip the header on the first page.

This is useful for documents with a title page that should not have a header.

Example: 

c.SetSkipHeaderOnFirstPage(true)  // No header on page 1

func (*Creator) SetSubject 

func (c *Creator) SetSubject(subject string)

SetSubject sets the document subject.

Example: 

c.SetSubject("Financial Report")

func (*Creator) SetTitle 

func (c *Creator) SetTitle(title string)

SetTitle sets the document title.

Example: 

c.SetTitle("Annual Report 2025")

func (*Creator) SkipFooterOnFirstPage 

func (c *Creator) SkipFooterOnFirstPage() bool

SkipFooterOnFirstPage returns whether footers are skipped on the first page.

func (*Creator) SkipHeaderOnFirstPage 

func (c *Creator) SkipHeaderOnFirstPage() bool

SkipHeaderOnFirstPage returns whether headers are skipped on the first page.

func (*Creator) TOC 

func (c *Creator) TOC() *TOC

TOC returns the Table of Contents instance for customization.

This allows customizing TOC appearance before rendering.

Example: 

c.EnableTOC()
toc := c.TOC()
toc.SetTitle("Contents")
style := toc.Style()
style.TitleSize = 28
toc.SetStyle(style)

func (*Creator) TOCEnabled 

func (c *Creator) TOCEnabled() bool

TOCEnabled returns whether TOC generation is enabled.

func (*Creator) Validate 

func (c *Creator) Validate() error

Validate checks if the document is valid and ready to be written.

Returns an error if: - Document has no pages - Any page validation fails

It's recommended to call this before WriteToFile to catch errors early.

func (*Creator) WriteTo added in v0.2.0 

func (c *Creator) WriteTo(w io.Writer) (int64, error)

WriteTo writes the PDF document to an io.Writer.

This implements io.WriterTo and is useful for:

  • Writing to HTTP responses
  • Writing to memory buffers
  • Writing to network connections
  • Any other io.Writer implementation

Example: 

var buf bytes.Buffer
n, err := c.WriteTo(&buf)
if err != nil {
    log.Fatal(err)
}
fmt.Printf("Wrote %d bytes\n", n)

func (*Creator) WriteToContext added in v0.2.0 

func (c *Creator) WriteToContext(ctx context.Context, w io.Writer) (int64, error)

WriteToContext writes the PDF document to an io.Writer with context support.

This allows cancellation and timeout control during PDF generation.

Example: 

ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
defer cancel()

var buf bytes.Buffer
n, err := c.WriteToContext(ctx, &buf)

func (*Creator) WriteToFile 

func (c *Creator) WriteToFile(path string) error

WriteToFile writes the PDF document to a file.

This will: 1. Validate the document 2. Generate the PDF structure 3. Write to the specified file

Returns an error if validation or writing fails.

Example: 

err := c.WriteToFile("output.pdf")
if err != nil {
    log.Fatal(err)
}

func (*Creator) WriteToFileContext 

func (c *Creator) WriteToFileContext(ctx context.Context, path string) error

WriteToFileContext writes the PDF document to a file with context support.

This allows cancellation and timeout control. The context is checked at multiple points during PDF generation:

  • Before rendering TOC and chapters
  • Before validation
  • Before writing to file

Example: 

ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
defer cancel()

err := c.WriteToFileContext(ctx, "output.pdf")

type CustomFont 

type CustomFont struct {
	// contains filtered or unexported fields
}

CustomFont represents an embedded TrueType/OpenType font.

Custom fonts allow you to use any TTF/OTF font file in your PDFs, including fonts with Unicode support (Cyrillic, CJK, etc.).

The font is embedded as a subset containing only the glyphs used in the document, reducing file size.

Example: 

font, err := LoadFont("fonts/OpenSans-Regular.ttf")
if err != nil {
    log.Fatal(err)
}

p := NewParagraph("Текст на русском")
p.SetCustomFont(font, 12)

func LoadFont 

func LoadFont(path string) (*CustomFont, error)

LoadFont loads a TrueType/OpenType font file.

Supported formats:

  • TrueType (.ttf)
  • OpenType with TrueType outlines (.otf)

Not yet supported:

  • OpenType with CFF outlines (.otf with PostScript outlines)
  • TrueType Collections (.ttc)

Returns an error if the file cannot be read or is not a valid font.

func (*CustomFont) Build 

func (f *CustomFont) Build() error

Build builds the font subset.

This must be called before writing the PDF. It's automatically called by the Creator when finalizing the document.

func (*CustomFont) GetSubset 

func (f *CustomFont) GetSubset() *fonts.FontSubset

GetSubset returns the font subset (for internal use).

func (*CustomFont) GetTTF added in v0.1.1 

func (f *CustomFont) GetTTF() *fonts.TTFFont

GetTTF returns the parsed TrueType font (for internal use).

func (*CustomFont) ID added in v0.1.1 

func (f *CustomFont) ID() string

ID returns a unique identifier for this font instance.

The ID is used to track fonts across pages and avoid duplicates.

func (*CustomFont) MeasureString 

func (f *CustomFont) MeasureString(text string, size float64) float64

MeasureString returns the width of a string in points at the given size.

This is used for layout calculations (word wrapping, alignment, etc.).

func (*CustomFont) PostScriptName 

func (f *CustomFont) PostScriptName() string

PostScriptName returns the PostScript name of the font.

This is used as the font name in the PDF.

func (*CustomFont) UnitsPerEm 

func (f *CustomFont) UnitsPerEm() uint16

UnitsPerEm returns the units per em for this font.

func (*CustomFont) UseChar 

func (f *CustomFont) UseChar(ch rune)

UseChar marks a character as used (for subsetting).

This is called automatically by text rendering functions. You don't need to call this manually.

func (*CustomFont) UseString 

func (f *CustomFont) UseString(text string)

UseString marks all characters in a string as used.

This is called automatically by text rendering functions. You don't need to call this manually.

type Division 

type Division struct {
	// contains filtered or unexported fields
}

Division is a container for grouping multiple Drawables.

Division provides a box model with support for: - Background color - Borders (all sides or individual) - Padding (inner spacing) - Margins (outer spacing) - Width and minimum height control

Example: 

div := NewDivision()
div.SetBackground(White)
div.SetBorder(Border{Width: 1, Color: Gray})
div.SetPaddingAll(10)
div.Add(NewParagraph("Content"))
page.Draw(div)

func NewDivision 

func NewDivision() *Division

NewDivision creates a new empty division.

The division starts with no content, transparent background, no borders, no padding, and no margins.

Example: 

div := NewDivision()
div.Add(NewParagraph("Hello"))

func (*Division) Add 

func (d *Division) Add(drawable Drawable) *Division

Add adds a drawable element to the division.

Elements are drawn in the order they are added.

Example: 

div.Add(NewParagraph("First"))
div.Add(NewParagraph("Second"))

func (*Division) Background 

func (d *Division) Background() *Color

Background returns the background color, or nil if transparent.

func (*Division) Clear 

func (d *Division) Clear() *Division

Clear removes all drawable elements from the division.

This does not affect styling (background, borders, padding, margins).

Example: 

div.Clear() // Remove all content

func (*Division) ContentWidth 

func (d *Division) ContentWidth(ctx *LayoutContext) float64

ContentWidth calculates the available width for content.

This accounts for padding and border widths.

func (*Division) Draw 

func (d *Division) Draw(ctx *LayoutContext, page *Page) error

Draw renders the division and its contents on the page.

Drawing sequence: 1. Apply margins (adjust cursor) 2. Draw background 3. Draw borders 4. Draw content (with padding) 5. Update cursor position.

func (*Division) Drawables 

func (d *Division) Drawables() []Drawable

Drawables returns all drawable elements in the division.

The returned slice is a direct reference, not a copy.

func (*Division) Height 

func (d *Division) Height(ctx *LayoutContext) float64

Height calculates the total height of the division.

This includes content height, padding, and borders.

func (*Division) Padding 

func (d *Division) Padding() Margins

Padding returns the padding margins.

func (*Division) SetBackground 

func (d *Division) SetBackground(c Color) *Division

SetBackground sets the background color for the division.

The background fills the entire division area (including padding, but excluding margins).

Example: 

div.SetBackground(White)

func (*Division) SetBorder 

func (d *Division) SetBorder(b Border) *Division

SetBorder sets the border for all sides of the division.

Individual borders (top, right, bottom, left) can override this if set separately.

Example: 

div.SetBorder(Border{Width: 2, Color: Black})

func (*Division) SetBorderBottom 

func (d *Division) SetBorderBottom(b Border) *Division

SetBorderBottom sets the bottom border, overriding the default border.

Example: 

div.SetBorderBottom(Border{Width: 3, Color: Red})

func (*Division) SetBorderLeft 

func (d *Division) SetBorderLeft(b Border) *Division

SetBorderLeft sets the left border, overriding the default border.

Example: 

div.SetBorderLeft(Border{Width: 4, Color: Blue})

func (*Division) SetBorderRight 

func (d *Division) SetBorderRight(b Border) *Division

SetBorderRight sets the right border, overriding the default border.

Example: 

div.SetBorderRight(Border{Width: 1, Color: Gray})

func (*Division) SetBorderTop 

func (d *Division) SetBorderTop(b Border) *Division

SetBorderTop sets the top border, overriding the default border.

Example: 

div.SetBorderTop(Border{Width: 3, Color: Red})

func (*Division) SetMargins 

func (d *Division) SetMargins(m Margins) *Division

SetMargins sets margins for the division.

Margins are the outer spacing around the division (outside the border).

Example: 

div.SetMargins(Margins{Top: 10, Right: 5, Bottom: 10, Left: 5})

func (*Division) SetMinHeight 

func (d *Division) SetMinHeight(h float64) *Division

SetMinHeight sets the minimum height for the division.

The division will be at least this tall, even if content is shorter.

Example: 

div.SetMinHeight(100) // At least 100 points tall

func (*Division) SetPadding 

func (d *Division) SetPadding(top, right, bottom, left float64) *Division

SetPadding sets padding for all sides individually.

Padding is the inner spacing between the border and content.

Example: 

div.SetPadding(10, 15, 10, 15) // top, right, bottom, left

func (*Division) SetPaddingAll 

func (d *Division) SetPaddingAll(p float64) *Division

SetPaddingAll sets the same padding for all sides.

This is a convenience method for uniform padding.

Example: 

div.SetPaddingAll(15) // 15 points on all sides

func (*Division) SetWidth 

func (d *Division) SetWidth(w float64) *Division

SetWidth sets an explicit width for the division.

If width is 0, the division uses the full available width.

Example: 

div.SetWidth(300) // 300 points wide

type Drawable 

type Drawable interface {
	// Draw renders the element on the page using the layout context.
	// The context's cursor position is updated after drawing.
	Draw(ctx *LayoutContext, page *Page) error

	// Height returns the pre-calculated height of the element.
	// This is used for page break detection and layout planning.
	Height(ctx *LayoutContext) float64
}

Drawable is an interface for elements that can be drawn on a page.

Elements implementing this interface can be used with Page.Draw() for automatic layout and positioning.

type DrawablePosition 

type DrawablePosition struct {
	Drawable Drawable
	X        float64
	Y        float64
}

DrawablePosition stores a drawable with its position within the block.

type EllipseOptions 

type EllipseOptions struct {
	// StrokeColor is the border color (nil = no stroke).
	// If StrokeColorCMYK is set, this field is ignored.
	StrokeColor *Color

	// StrokeColorCMYK is the border color in CMYK (nil = no stroke).
	// If set, this takes precedence over StrokeColor (RGB).
	StrokeColorCMYK *ColorCMYK

	// StrokeWidth is the border width in points (default: 1.0).
	StrokeWidth float64

	// FillColor is the fill color (nil = no fill).
	// Mutually exclusive with FillGradient and FillColorCMYK.
	// If FillColorCMYK is set, this field is ignored.
	FillColor *Color

	// FillColorCMYK is the fill color in CMYK (nil = no fill).
	// If set, this takes precedence over FillColor (RGB).
	// Mutually exclusive with FillGradient.
	FillColorCMYK *ColorCMYK

	// FillGradient is the gradient fill (nil = no gradient fill).
	// Mutually exclusive with FillColor and FillColorCMYK.
	FillGradient *Gradient

	// Opacity is the ellipse opacity (0.0 = transparent, 1.0 = opaque).
	// Optional. If set, applies transparency via ExtGState.
	// Affects both fill and stroke.
	// Range: [0.0, 1.0]
	Opacity *float64
}

EllipseOptions configures ellipse drawing.

type EncryptionAlgorithm 

type EncryptionAlgorithm int

EncryptionAlgorithm specifies the encryption algorithm to use. 

const (
	// EncryptionRC4_40 uses RC4 with 40-bit keys (PDF 1.1+, legacy).
	EncryptionRC4_40 EncryptionAlgorithm = iota

	// EncryptionRC4_128 uses RC4 with 128-bit keys (PDF 1.4+, legacy).
	EncryptionRC4_128

	// EncryptionAES128 uses AES-128 encryption (PDF 1.5+, recommended).
	EncryptionAES128

	// EncryptionAES256 uses AES-256 encryption (PDF 1.7+, most secure).
	EncryptionAES256
)

type EncryptionOptions 

type EncryptionOptions struct {
	// UserPassword allows opening the document with restrictions.
	// If empty, document can be opened without password (but with restrictions).
	UserPassword string

	// OwnerPassword allows opening the document with full access.
	// If empty, defaults to UserPassword.
	OwnerPassword string

	// Permissions specifies what operations are allowed.
	// Use Permission constants (PermissionPrint, PermissionCopy, etc.).
	Permissions Permission

	// Algorithm specifies the encryption algorithm.
	// Valid values: EncryptionRC4_40, EncryptionRC4_128, EncryptionAES128, EncryptionAES256.
	// Default: EncryptionAES128.
	Algorithm EncryptionAlgorithm

	// KeyLength specifies the encryption key length in bits (deprecated, use Algorithm instead).
	// Valid values: 40 (PDF 1.1+), 128 (PDF 1.4+), 256 (PDF 1.7+).
	// If Algorithm is set, KeyLength is ignored.
	// Default: 128 (for backward compatibility).
	KeyLength int
}

EncryptionOptions holds the encryption settings for PDF creation.

Use SetEncryption to enable password protection and permissions control.

Example: 

c := creator.New()
c.SetEncryption(creator.EncryptionOptions{
    UserPassword:  "userpass",
    OwnerPassword: "ownerpass",
    Permissions:   creator.PermissionPrint | creator.PermissionCopy,
    Algorithm:     creator.EncryptionAES128, // or EncryptionAES256
})
Example (Permissions) 
c := New()

// Allow only printing, no modifications.
_ = c.SetEncryption(EncryptionOptions{
	UserPassword: "secret",
	Permissions:  PermissionPrint,
	KeyLength:    128,
})

// Allow print and copy, but no modify.
_ = c.SetEncryption(EncryptionOptions{
	UserPassword: "secret",
	Permissions:  PermissionPrint | PermissionCopy,
	KeyLength:    128,
})

// Allow all operations.
_ = c.SetEncryption(EncryptionOptions{
	UserPassword: "secret",
	Permissions:  PermissionAll,
	KeyLength:    128,
})

type Fill added in v0.2.0 

type Fill struct {
	// Paint is the paint source (Color, ColorRGBA, ColorCMYK, or Gradient).
	Paint Paint

	// Opacity is the fill opacity (0.0 = transparent, 1.0 = opaque).
	// This is multiplied with the paint's alpha if using ColorRGBA.
	Opacity float64

	// Rule is the fill rule (NonZero or EvenOdd).
	// Determines which areas are "inside" the path for complex shapes.
	Rule FillRule
}

Fill represents fill configuration for shapes.

Fill controls how shapes are filled with paint (color or gradient). It includes the paint source, opacity, and fill rule.

Example: 

// Solid color fill
fill := &Fill{
    Paint:   Red,
    Opacity: 1.0,
    Rule:    FillRuleNonZero,
}

// Gradient fill with transparency
grad := NewLinearGradient(0, 0, 100, 0)
grad.AddColorStop(0, Red)
grad.AddColorStop(1, Blue)
fill := &Fill{
    Paint:   grad,
    Opacity: 0.8,
    Rule:    FillRuleNonZero,
}

func NewFill added in v0.2.0 

func NewFill(paint Paint) *Fill

NewFill creates a new Fill with the specified paint.

Default values:

  • Opacity: 1.0 (fully opaque)
  • Rule: FillRuleNonZero

Parameters:

  • paint: Paint source (Color, ColorRGBA, ColorCMYK, or Gradient)

Example: 

fill := NewFill(Red)
fill := NewFill(NewLinearGradient(0, 0, 100, 0))

func (*Fill) Validate added in v0.2.0 

func (f *Fill) Validate() error

Validate validates the fill configuration.

Checks:

  • Paint is not nil
  • Opacity is in range [0, 1]
  • If paint is a Gradient, validate gradient

Returns an error if validation fails.

func (*Fill) WithOpacity added in v0.2.0 

func (f *Fill) WithOpacity(opacity float64) *Fill

WithOpacity returns a new Fill with the specified opacity.

Parameters:

  • opacity: Opacity value (0.0 = transparent, 1.0 = opaque)

Example: 

fill := NewFill(Red).WithOpacity(0.5)

func (*Fill) WithRule added in v0.2.0 

func (f *Fill) WithRule(rule FillRule) *Fill

WithRule returns a new Fill with the specified fill rule.

Parameters:

  • rule: Fill rule (FillRuleNonZero or FillRuleEvenOdd)

Example: 

fill := NewFill(Red).WithRule(FillRuleEvenOdd)

type FillRule added in v0.2.0 

type FillRule int

FillRule defines how to determine which areas are "inside" a path.

PDF supports two fill rules:

  • NonZero winding rule (default): Counts path direction crossings
  • EvenOdd rule: Counts total path crossings

Reference: PDF 1.7 Specification, Section 8.5.3.3 (Filling). 

const (
	// FillRuleNonZero uses the non-zero winding rule.
	//
	// A point is inside if the winding number is non-zero.
	// Winding number counts +1 for left-to-right crossings,
	// -1 for right-to-left crossings.
	//
	// PDF operator: f (fill) or F (deprecated).
	FillRuleNonZero FillRule = iota

	// FillRuleEvenOdd uses the even-odd rule.
	//
	// A point is inside if a ray from the point crosses
	// the path an odd number of times.
	//
	// PDF operator: f* (eofill).
	FillRuleEvenOdd
)

func (FillRule) String added in v0.2.0 

func (r FillRule) String() string

String returns the PDF fill rule name.

type FontName 

type FontName string

FontName represents one of the Standard 14 fonts built into all PDF readers.

These fonts do not require embedding and are guaranteed to be available in all PDF viewers.

Reference: PDF 1.7 Specification, Section 9.6.2.2 (Standard Type 1 Fonts). 

const (
	// TimesRoman is Times Roman (serif, regular weight, normal style).
	TimesRoman FontName = "Times-Roman"

	// TimesBold is Times Bold (serif, bold weight, normal style).
	TimesBold FontName = "Times-Bold"

	// TimesItalic is Times Italic (serif, regular weight, italic style).
	TimesItalic FontName = "Times-Italic"

	// TimesBoldItalic is Times Bold Italic (serif, bold weight, italic style).
	TimesBoldItalic FontName = "Times-BoldItalic"
)

Standard 14 fonts - Serif family (Times). 

const (
	// Helvetica is Helvetica (sans-serif, regular weight, normal style).
	Helvetica FontName = "Helvetica"

	// HelveticaBold is Helvetica Bold (sans-serif, bold weight, normal style).
	HelveticaBold FontName = "Helvetica-Bold"

	// HelveticaOblique is Helvetica Oblique (sans-serif, regular weight, oblique style).
	HelveticaOblique FontName = "Helvetica-Oblique"

	// HelveticaBoldOblique is Helvetica Bold Oblique (sans-serif, bold weight, oblique style).
	HelveticaBoldOblique FontName = "Helvetica-BoldOblique"
)

Standard 14 fonts - Sans-serif family (Helvetica). 

const (
	// Courier is Courier (monospace, regular weight, normal style).
	Courier FontName = "Courier"

	// CourierBold is Courier Bold (monospace, bold weight, normal style).
	CourierBold FontName = "Courier-Bold"

	// CourierOblique is Courier Oblique (monospace, regular weight, oblique style).
	CourierOblique FontName = "Courier-Oblique"

	// CourierBoldOblique is Courier Bold Oblique (monospace, bold weight, oblique style).
	CourierBoldOblique FontName = "Courier-BoldOblique"
)

Standard 14 fonts - Monospace family (Courier). 

const (
	// Symbol is Symbol font (symbolic characters, mathematical symbols).
	Symbol FontName = "Symbol"

	// ZapfDingbats is ZapfDingbats font (symbolic characters, dingbats).
	ZapfDingbats FontName = "ZapfDingbats"
)

Standard 14 fonts - Symbolic fonts.

type FooterFunc 

type FooterFunc func(args FooterFunctionArgs)

FooterFunc is the function signature for footer rendering.

The function receives a FooterFunctionArgs struct containing page information and a Block to draw the footer content into. The function should add any desired content to the Block using Draw() or DrawAt().

Example: 

var footerFunc FooterFunc = func(args FooterFunctionArgs) {
    text := fmt.Sprintf("Page %d of %d", args.PageNum, args.TotalPages)
    p := NewParagraph(text)
    p.SetAlignment(AlignCenter)
    args.Block.Draw(p)
}

type FooterFunctionArgs 

type FooterFunctionArgs struct {
	// PageNum is the current page number (1-based).
	PageNum int

	// TotalPages is the total number of pages in the document.
	// This is known because footers are rendered after all content is generated.
	TotalPages int

	// PageWidth is the page width in points.
	PageWidth float64

	// PageHeight is the page height in points.
	PageHeight float64

	// Block is the block to draw footer content into.
	// The block is positioned at the bottom of the page within the margins.
	Block *Block
}

FooterFunctionArgs contains information passed to the footer function.

This struct provides context about the current page and a Block to draw the footer content into. The footer function is called once for each page.

Example: 

c.SetFooterFunc(func(args FooterFunctionArgs) {
    p := NewParagraph(fmt.Sprintf("Page %d", args.PageNum))
    p.SetAlignment(AlignCenter)
    args.Block.Draw(p)
})

type Gradient 

type Gradient struct {
	// Type is the gradient type (linear or radial).
	Type GradientType

	// ColorStops define the color transitions (minimum 2 required).
	// Stops must be sorted by Position (0.0 to 1.0).
	ColorStops []ColorStop

	// Linear gradient fields (Type == GradientTypeLinear)
	// Coordinates define the gradient axis from (X1, Y1) to (X2, Y2).
	X1, Y1 float64 // Start point
	X2, Y2 float64 // End point

	// Radial gradient fields (Type == GradientTypeRadial)
	// Coordinates define two circles: (X0, Y0, R0) and (X1, Y1, R1).
	// Gradient transitions from inner circle to outer circle.
	X0, Y0, R0 float64 // Starting circle (center + radius)
	// X1, Y1 already defined above (reused for radial end center)
	R1 float64 // Ending radius

	// Extend flags control what happens outside the gradient domain.
	// If true, colors extend beyond the gradient boundaries.
	ExtendStart bool // Extend before the first color stop
	ExtendEnd   bool // Extend after the last color stop
}

Gradient represents a color gradient (linear or radial).

Gradients can be used to fill shapes with smooth color transitions. Two types are supported:

  • Linear (axial): Color transitions along a straight line
  • Radial: Color radiates from a center point

Gradients are defined by color stops at specific positions. The PDF renderer interpolates colors between stops.

func NewLinearGradient 

func NewLinearGradient(x1, y1, x2, y2 float64) *Gradient

NewLinearGradient creates a new linear (axial) gradient.

The gradient transitions along a line from (x1, y1) to (x2, y2). Color stops must be added separately using AddColorStop().

Parameters:

  • x1, y1: Start point of gradient axis
  • x2, y2: End point of gradient axis

Example: 

grad := creator.NewLinearGradient(0, 0, 100, 0) // Horizontal gradient
grad.AddColorStop(0, creator.Red)
grad.AddColorStop(1, creator.Blue)

PDF Reference: ShadingType 2 (Axial Shading).

func NewRadialGradient 

func NewRadialGradient(x0, y0, r0, x1, y1, r1 float64) *Gradient

NewRadialGradient creates a new radial gradient.

The gradient radiates from an inner circle (x0, y0, r0) to an outer circle (x1, y1, r1). For a simple radial gradient from center outward, use same center for both circles and set r0 = 0.

Parameters:

  • x0, y0, r0: Center and radius of starting circle
  • x1, y1, r1: Center and radius of ending circle

Example: 

// Simple radial gradient from center
grad := creator.NewRadialGradient(150, 550, 0, 150, 550, 50)
grad.AddColorStop(0, creator.White) // Center: white
grad.AddColorStop(1, creator.Blue)  // Edge: blue

PDF Reference: ShadingType 3 (Radial Shading).

func (*Gradient) AddColorStop 

func (g *Gradient) AddColorStop(position float64, color Color) error

AddColorStop adds a color stop to the gradient.

Color stops define the color at specific positions along the gradient. Position must be in range [0.0, 1.0] where 0 is start and 1 is end.

Stops can be added in any order; they will be sorted automatically.

Parameters:

  • position: Position in gradient (0.0 = start, 1.0 = end)
  • color: RGB color at this position

Example: 

grad := creator.NewLinearGradient(0, 0, 100, 0)
grad.AddColorStop(0.0, creator.Red)
grad.AddColorStop(0.5, creator.Yellow)
grad.AddColorStop(1.0, creator.Green)

func (*Gradient) Validate 

func (g *Gradient) Validate() error

Validate validates the gradient configuration.

Checks:

  • At least 2 color stops are defined
  • Color stops are in range [0, 1]
  • For linear gradients: start and end points are different
  • For radial gradients: radii are non-negative

Returns an error if validation fails.

type GradientType 

type GradientType int

GradientType represents the type of gradient. 

const (
	// GradientTypeLinear represents an axial (linear) gradient.
	// PDF ShadingType 2: gradient along a straight line from start to end point.
	GradientTypeLinear GradientType = 2

	// GradientTypeRadial represents a radial gradient.
	// PDF ShadingType 3: gradient radiating from center point.
	GradientTypeRadial GradientType = 3
)

type GraphicsOpType 

type GraphicsOpType int

GraphicsOpType represents the type of graphics operation. 

const (
	// GraphicsOpLine draws a line from (X,Y) to (X2,Y2).
	GraphicsOpLine GraphicsOpType = iota

	// GraphicsOpRect draws a rectangle (stroke only, fill only, or both).
	GraphicsOpRect

	// GraphicsOpCircle draws a circle at center (X,Y) with Radius.
	GraphicsOpCircle

	// GraphicsOpImage draws an image at (X,Y) with Width,Height.
	GraphicsOpImage

	// GraphicsOpWatermark draws a text watermark at (X,Y) with rotation and opacity.
	GraphicsOpWatermark

	// GraphicsOpPolygon draws a closed polygon through N vertices.
	GraphicsOpPolygon

	// GraphicsOpPolyline draws an open path through N vertices.
	GraphicsOpPolyline

	// GraphicsOpEllipse draws an ellipse at center (X,Y) with radii RX and RY.
	GraphicsOpEllipse

	// GraphicsOpBezier draws a complex curve composed of Bézier segments.
	GraphicsOpBezier

	// GraphicsOpBeginClip begins a rectangular clipping region.
	// All subsequent drawing is clipped to the rectangle (X, Y, Width, Height).
	// Must be followed by GraphicsOpEndClip to restore the previous clipping state.
	GraphicsOpBeginClip GraphicsOpType = 20

	// GraphicsOpEndClip ends a clipping region started by GraphicsOpBeginClip.
	GraphicsOpEndClip GraphicsOpType = 21

	// GraphicsOpTextBlock renders text inline with graphics operations.
	// Used for clipped text where ordering matters.
	GraphicsOpTextBlock GraphicsOpType = 22
)

type GraphicsOperation 

type GraphicsOperation struct {
	// Type is the graphics operation type.
	Type GraphicsOpType

	// X is the x-coordinate (start point for line, lower-left for rect/image, center for circle/ellipse).
	X float64

	// Y is the y-coordinate (start point for line, lower-left for rect/image, center for circle/ellipse).
	Y float64

	// X2 is the end x-coordinate (only for line).
	X2 float64

	// Y2 is the end y-coordinate (only for line).
	Y2 float64

	// Width is the rectangle/image width (only for rect/image).
	Width float64

	// Height is the rectangle/image height (only for rect/image).
	Height float64

	// Radius is the circle radius (only for circle).
	Radius float64

	// RX is the horizontal radius (only for ellipse).
	RX float64

	// RY is the vertical radius (only for ellipse).
	RY float64

	// Vertices is the array of points (only for polygon/polyline).
	Vertices []Point

	// BezierSegs is the array of Bézier segments (only for bezier).
	BezierSegs []BezierSegment

	// LineOpts are line options (only for line).
	LineOpts *LineOptions

	// RectOpts are rectangle options (only for rect).
	RectOpts *RectOptions

	// CircleOpts are circle options (only for circle).
	CircleOpts *CircleOptions

	// PolygonOpts are polygon options (only for polygon).
	PolygonOpts *PolygonOptions

	// PolylineOpts are polyline options (only for polyline).
	PolylineOpts *PolylineOptions

	// EllipseOpts are ellipse options (only for ellipse).
	EllipseOpts *EllipseOptions

	// BezierOpts are Bézier curve options (only for bezier).
	BezierOpts *BezierOptions

	// Image is the image to draw (only for image).
	Image *Image

	// WatermarkOp is the watermark operation (only for watermark).
	WatermarkOp *TextWatermark

	// TextBlock fields (only for GraphicsOpTextBlock).
	Text      string      // Text content
	TextFont  *CustomFont // Custom font for text
	TextSize  float64     // Font size
	TextColor *Color      // Text color (RGB)
}

GraphicsOperation represents a graphics drawing operation.

The fields used depend on the Type: - GraphicsOpLine: X, Y, X2, Y2, LineOpts. - GraphicsOpRect: X, Y, Width, Height, RectOpts. - GraphicsOpCircle: X, Y, Radius, CircleOpts. - GraphicsOpImage: X, Y, Width, Height, Image. - GraphicsOpWatermark: X, Y, WatermarkOp. - GraphicsOpPolygon: Vertices, PolygonOpts. - GraphicsOpPolyline: Vertices, PolylineOpts. - GraphicsOpEllipse: X, Y, RX, RY, EllipseOpts. - GraphicsOpBezier: BezierSegs, BezierOpts.

type GraphicsState added in v0.2.0 

type GraphicsState struct {
	// Transform is the current transformation matrix (CTM).
	Transform Transform

	// Opacity is the overall transparency (0.0 = invisible, 1.0 = opaque).
	// This affects both fill and stroke operations.
	Opacity float64

	// BlendMode controls how colors blend with the background.
	BlendMode BlendMode

	// ClipPath is the active clipping path (nil = no clipping).
	// Drawing operations are clipped to this path.
	ClipPath *Path

	// ClipRule is the fill rule for the clipping path.
	// Only used when ClipPath is not nil.
	ClipRule FillRule

	// Fill is the current fill configuration.
	Fill *Fill

	// Stroke is the current stroke configuration.
	Stroke *Stroke
}

GraphicsState represents the complete graphics state at a point in time.

This includes transformation, opacity, blend mode, clipping path, fill, and stroke. The state is saved/restored using the PDF graphics state stack (q/Q operators).

func NewGraphicsState added in v0.2.0 

func NewGraphicsState() GraphicsState

NewGraphicsState creates a new graphics state with default values.

func (GraphicsState) Clone added in v0.2.0 

func (g GraphicsState) Clone() GraphicsState

Clone creates a copy of the graphics state.

This is used when pushing state onto the stack. Fill, Stroke, and ClipPath pointers are copied (shallow copy), so modifications to the pointed-to objects will affect both states. However, replacing the pointer (e.g., SetFill) only affects the current state.

type HeaderFunc 

type HeaderFunc func(args HeaderFunctionArgs)

HeaderFunc is the function signature for header rendering.

The function receives a HeaderFunctionArgs struct containing page information and a Block to draw the header content into. The function should add any desired content to the Block using Draw() or DrawAt().

Example: 

var headerFunc HeaderFunc = func(args HeaderFunctionArgs) {
    p := NewParagraph("Company Name")
    p.SetFont(HelveticaBold, 10)
    args.Block.Draw(p)
}

type HeaderFunctionArgs 

type HeaderFunctionArgs struct {
	// PageNum is the current page number (1-based).
	PageNum int

	// TotalPages is the total number of pages in the document.
	// This is known because headers are rendered after all content is generated.
	TotalPages int

	// PageWidth is the page width in points.
	PageWidth float64

	// PageHeight is the page height in points.
	PageHeight float64

	// Block is the block to draw header content into.
	// The block is positioned at the top of the page within the margins.
	Block *Block
}

HeaderFunctionArgs contains information passed to the header function.

This struct provides context about the current page and a Block to draw the header content into. The header function is called once for each page.

Example: 

c.SetHeaderFunc(func(args HeaderFunctionArgs) {
    p := NewParagraph(fmt.Sprintf("Page %d of %d", args.PageNum, args.TotalPages))
    p.SetAlignment(AlignRight)
    args.Block.Draw(p)
})

type HighlightAnnotation 

type HighlightAnnotation struct {
	// contains filtered or unexported fields
}

HighlightAnnotation represents a highlight markup annotation.

Highlight annotations mark text with a colored overlay (typically yellow).

Example: 

highlight := creator.NewHighlightAnnotation(100, 650, 300, 670)
highlight.SetColor(creator.Yellow)
highlight.SetAuthor("John Doe")
page.AddHighlightAnnotation(highlight)

func NewHighlightAnnotation 

func NewHighlightAnnotation(x1, y1, x2, y2 float64) *HighlightAnnotation

NewHighlightAnnotation creates a new highlight annotation.

The highlight covers the rectangular area from (x1, y1) to (x2, y2).

Parameters:

  • x1: Left X coordinate (from left edge)
  • y1: Bottom Y coordinate (from bottom edge)
  • x2: Right X coordinate (from left edge)
  • y2: Top Y coordinate (from bottom edge)

Example: 

// Highlight text from (100, 650) to (300, 670)
highlight := creator.NewHighlightAnnotation(100, 650, 300, 670)
highlight.SetColor(creator.Yellow)

func (*HighlightAnnotation) SetAuthor 

func (a *HighlightAnnotation) SetAuthor(author string) *HighlightAnnotation

SetAuthor sets the author name.

Example: 

highlight.SetAuthor("John Doe")

func (*HighlightAnnotation) SetColor 

func (a *HighlightAnnotation) SetColor(color Color) *HighlightAnnotation

SetColor sets the highlight color.

Common highlight colors:

  • Yellow (default)
  • Cyan (informational)
  • Magenta (important)
  • Green (approved)

Example: 

highlight.SetColor(creator.Yellow)

func (*HighlightAnnotation) SetNote 

func (a *HighlightAnnotation) SetNote(note string) *HighlightAnnotation

SetNote sets an optional note text.

This text appears when the user hovers over or clicks the highlight.

Example: 

highlight.SetNote("Important point")

type Image 

type Image struct {
	// contains filtered or unexported fields
}

Image represents an image that can be embedded in a PDF document.

Currently supports:

  • JPEG images (RGB and CMYK color spaces)
  • PNG images (RGB, RGBA, grayscale, paletted)

The image data is stored as:

  • JPEG: Raw JPEG bytes (DCTDecode)
  • PNG: Raw pixel data compressed with FlateDecode

For RGBA PNG with transparency, the alpha channel is stored separately as an SMask (soft mask) for proper PDF rendering.

Example: 

img, err := creator.LoadImage("photo.jpg")  // or "photo.png"
if err != nil {
    return err
}
page.DrawImage(img, 100, 500, 200, 150)

func LoadImage 

func LoadImage(path string) (*Image, error)

LoadImage loads an image from a file.

Supported formats: JPEG, PNG. For JPEG: RGB and CMYK color spaces. For PNG: RGB, RGBA (with alpha mask), grayscale, paletted.

Example: 

img, err := creator.LoadImage("photo.jpg")  // or "photo.png"
if err != nil {
    return err
}

func LoadImageFromReader 

func LoadImageFromReader(r io.Reader) (*Image, error)

LoadImageFromReader loads an image from an io.Reader.

Supported formats: JPEG, PNG. This allows loading images from various sources (files, HTTP responses, etc.).

Example: 

resp, _ := http.Get("https://example.com/image.png")
defer resp.Body.Close()
img, _ := creator.LoadImageFromReader(resp.Body)

func (*Image) AlphaMask 

func (img *Image) AlphaMask() []byte

AlphaMask returns the alpha mask data (nil if no transparency).

For RGBA PNG images with transparency, this contains the compressed alpha channel data used for the SMask (soft mask) in PDF.

func (*Image) BitsPerComponent 

func (img *Image) BitsPerComponent() int

BitsPerComponent returns the bits per component (typically 8).

func (*Image) ColorSpace 

func (img *Image) ColorSpace() ColorSpace

ColorSpace returns the image color space.

func (*Image) Components 

func (img *Image) Components() int

Components returns the number of color components.

Returns:

  • 1 for grayscale
  • 3 for RGB
  • 4 for CMYK

func (*Image) Data 

func (img *Image) Data() []byte

Data returns the raw JPEG data.

This is used internally by the PDF writer to embed the image.

func (*Image) Format 

func (img *Image) Format() string

Format returns the image format (jpeg or png).

func (*Image) HasAlpha 

func (img *Image) HasAlpha() bool

HasAlpha returns true if the image has transparency data.

func (*Image) Height 

func (img *Image) Height() int

Height returns the image height in pixels.

func (*Image) Width 

func (img *Image) Width() int

Width returns the image width in pixels.

type LayoutContext 

type LayoutContext struct {
	// Page dimensions (in points).
	PageWidth  float64
	PageHeight float64

	// Page margins (in points).
	Margins Margins

	// CursorX is the current horizontal position (from left edge).
	CursorX float64

	// CursorY is the current vertical position from top of content area.
	// 0 = top of content area (below top margin)
	// Increases downward.
	CursorY float64
}

LayoutContext provides positioning information for layout operations.

It tracks the current cursor position and available space within the page margins. The cursor Y is measured from the top of the content area (intuitive "document flow" model).

Example: 

ctx := page.GetLayoutContext()
paragraph.Draw(ctx, page)  // Draws at cursor position
// Cursor automatically advances after drawing

func (*LayoutContext) AvailableHeight 

func (ctx *LayoutContext) AvailableHeight() float64

AvailableHeight returns the height remaining from cursor to bottom margin.

func (*LayoutContext) AvailableWidth 

func (ctx *LayoutContext) AvailableWidth() float64

AvailableWidth returns the width available for content (excluding margins).

func (*LayoutContext) CanFit 

func (ctx *LayoutContext) CanFit(height float64) bool

CanFit checks if an element of the given height fits in the remaining space.

func (*LayoutContext) ContentBottom 

func (ctx *LayoutContext) ContentBottom() float64

ContentBottom returns the Y coordinate (PDF coordinates) of the bottom content edge.

func (*LayoutContext) ContentLeft 

func (ctx *LayoutContext) ContentLeft() float64

ContentLeft returns the X coordinate of the left content edge.

func (*LayoutContext) ContentRight 

func (ctx *LayoutContext) ContentRight() float64

ContentRight returns the X coordinate of the right content edge.

func (*LayoutContext) ContentTop 

func (ctx *LayoutContext) ContentTop() float64

ContentTop returns the Y coordinate (PDF coordinates) of the top content edge.

func (*LayoutContext) CurrentPDFY 

func (ctx *LayoutContext) CurrentPDFY() float64

CurrentPDFY converts the cursor Y (from top) to PDF Y coordinate (from bottom).

func (*LayoutContext) MoveCursor 

func (ctx *LayoutContext) MoveCursor(dx, dy float64)

MoveCursor moves the cursor by the specified delta values.

Positive dx moves right, positive dy moves down.

func (*LayoutContext) NewLine 

func (ctx *LayoutContext) NewLine(lineHeight float64)

NewLine moves the cursor to the start of the next line.

The cursor X is reset to the left content edge. The cursor Y advances by the specified line height.

func (*LayoutContext) ResetX 

func (ctx *LayoutContext) ResetX()

ResetX moves the cursor X back to the left content edge.

func (*LayoutContext) SetCursor 

func (ctx *LayoutContext) SetCursor(x, y float64)

SetCursor sets the cursor to specific coordinates.

x is measured from the left edge of the page. y is measured from the top of the content area (below top margin).

type LineCap added in v0.2.0 

type LineCap int

LineCap defines how line ends are rendered.

PDF supports three line cap styles. Reference: PDF 1.7 Specification, Section 8.4.3.3 (Line Cap Style). 

const (
	// LineCapButt ends exactly at the endpoint.
	//
	// The line terminates squarely at the endpoint.
	// PDF value: 0
	LineCapButt LineCap = iota

	// LineCapRound adds a semicircular cap.
	//
	// A semicircle with diameter equal to line width is added.
	// PDF value: 1
	LineCapRound

	// LineCapSquare adds a square cap extending past the endpoint.
	//
	// A square extending half the line width beyond the endpoint.
	// PDF value: 2
	LineCapSquare
)

func (LineCap) String added in v0.2.0 

func (c LineCap) String() string

String returns the PDF line cap name.

type LineJoin added in v0.2.0 

type LineJoin int

LineJoin defines how corners are rendered.

PDF supports three line join styles. Reference: PDF 1.7 Specification, Section 8.4.3.4 (Line Join Style). 

const (
	// LineJoinMiter extends lines to form a sharp corner.
	//
	// Lines are extended until they meet at an angle.
	// If miter length exceeds MiterLimit, a bevel is used.
	// PDF value: 0
	LineJoinMiter LineJoin = iota

	// LineJoinRound rounds the corner.
	//
	// A circular arc with radius equal to half line width.
	// PDF value: 1
	LineJoinRound

	// LineJoinBevel cuts off the corner.
	//
	// A straight line connects the outer endpoints.
	// PDF value: 2
	LineJoinBevel
)

func (LineJoin) String added in v0.2.0 

func (j LineJoin) String() string

String returns the PDF line join name.

type LineOptions 

type LineOptions struct {
	// Color is the line color (RGB, 0.0 to 1.0 range).
	// If ColorCMYK is set, this field is ignored.
	Color Color

	// ColorCMYK is the line color in CMYK color space (optional).
	// If set, this takes precedence over Color (RGB).
	ColorCMYK *ColorCMYK

	// Width is the line width in points (default: 1.0).
	Width float64

	// Dashed enables dashed line rendering.
	Dashed bool

	// DashArray defines the dash pattern (e.g., [3, 1] for "3 on, 1 off").
	// Only used when Dashed is true.
	DashArray []float64

	// DashPhase is the starting offset into the dash pattern.
	// Only used when Dashed is true.
	DashPhase float64

	// Opacity is the line opacity (0.0 = transparent, 1.0 = opaque).
	// Optional. If set, applies transparency via ExtGState.
	// Range: [0.0, 1.0]
	Opacity *float64
}

LineOptions configures line drawing.

type LinkStyle 

type LinkStyle struct {
	// Font to use for the link text.
	Font FontName

	// Size of the font in points.
	Size float64

	// Color of the link text (RGB, 0.0 to 1.0 range).
	Color Color

	// Underline indicates whether to draw a line under the link text.
	// Default: true (like web browsers).
	Underline bool
}

LinkStyle defines the visual style for a link.

This controls how clickable links appear in the PDF. By default, links are displayed in blue with underline (like in web browsers).

Example: 

// Default style (blue, underlined)
style := DefaultLinkStyle()

// Custom style (red, bold, no underline)
custom := LinkStyle{
    Font:      HelveticaBold,
    Size:      14,
    Color:     Red,
    Underline: false,
}

func DefaultLinkStyle 

func DefaultLinkStyle() LinkStyle

DefaultLinkStyle returns the default link style.

Default style:

  • Font: Helvetica
  • Size: 12pt
  • Color: Blue (0, 0, 1)
  • Underline: true

This matches the typical appearance of links in web browsers.

Example: 

style := DefaultLinkStyle()
page.AddLinkStyled("Click here", "https://example.com", 100, 700, style)

type List 

type List struct {
	// contains filtered or unexported fields
}

List represents a bullet or numbered list.

Lists support nested sublists, custom markers, and automatic text wrapping.

Example: 

list := NewList()
list.SetBulletChar("•")
list.Add("First item")
list.Add("Second item with long text that will wrap")
page.Draw(list)

func NewList 

func NewList() *List

NewList creates a new bullet list with default settings.

Default settings:

  • Marker: Bullet ("•")
  • Font: Helvetica, 12pt
  • Color: Black
  • Line spacing: 1.2 (120%)
  • Indent: 20pt per level
  • Marker indent: 10pt
  • Start number: 1

func NewNumberedList 

func NewNumberedList() *List

NewNumberedList creates a new numbered list with default settings.

Default settings:

  • Marker: Number (1. 2. 3.)
  • Font: Helvetica, 12pt
  • Color: Black
  • Line spacing: 1.2 (120%)
  • Indent: 20pt per level
  • Marker indent: 10pt
  • Start number: 1

func (*List) Add 

func (l *List) Add(text string) *List

Add adds a text item to the list. Returns the list for method chaining.

func (*List) AddItem 

func (l *List) AddItem(item ListItem) *List

AddItem adds a ListItem to the list. Returns the list for method chaining.

func (*List) AddSubList 

func (l *List) AddSubList(subList *List) *List

AddSubList adds a nested sublist as the last item. Returns the list for method chaining.

func (*List) Draw 

func (l *List) Draw(ctx *LayoutContext, page *Page) error

Draw renders the list on the page at the current cursor position.

func (*List) Height 

func (l *List) Height(ctx *LayoutContext) float64

Height calculates the total height of the list when rendered.

func (*List) SetBulletChar 

func (l *List) SetBulletChar(char string) *List

SetBulletChar sets the bullet character for bullet lists. Returns the list for method chaining.

func (*List) SetColor 

func (l *List) SetColor(c Color) *List

SetColor sets the text color. Returns the list for method chaining.

func (*List) SetFont 

func (l *List) SetFont(font FontName, size float64) *List

SetFont sets the font and size for the list. Returns the list for method chaining.

func (*List) SetIndent 

func (l *List) SetIndent(indent float64) *List

SetIndent sets the indentation per nesting level. Returns the list for method chaining.

func (*List) SetLineSpacing 

func (l *List) SetLineSpacing(spacing float64) *List

SetLineSpacing sets the line spacing multiplier. 1.0 = single spacing, 1.5 = 150% spacing, 2.0 = double spacing. Returns the list for method chaining.

func (*List) SetMarkerIndent 

func (l *List) SetMarkerIndent(indent float64) *List

SetMarkerIndent sets the space between marker and text. Returns the list for method chaining.

func (*List) SetMarkerType 

func (l *List) SetMarkerType(t MarkerType) *List

SetMarkerType sets the marker type (bullet or number). Returns the list for method chaining.

func (*List) SetNumberFormat 

func (l *List) SetNumberFormat(f NumberFormat) *List

SetNumberFormat sets the numbering format for numbered lists. Returns the list for method chaining.

func (*List) SetStartNumber 

func (l *List) SetStartNumber(n int) *List

SetStartNumber sets the starting number for numbered lists. Returns the list for method chaining.

type ListItem 

type ListItem struct {
	// contains filtered or unexported fields
}

ListItem represents a single item in a list.

func NewListItem 

func NewListItem(text string) ListItem

NewListItem creates a new list item with the given text.

func NewListItemWithSubList 

func NewListItemWithSubList(text string, subList *List) ListItem

NewListItemWithSubList creates a new list item with a nested list.

type Margins 

type Margins struct {
	Top    float64
	Right  float64
	Bottom float64
	Left   float64
}

Margins represents page margins in points (1 point = 1/72 inch).

type MarkerType 

type MarkerType int

MarkerType defines the type of list marker. 

const (
	// BulletMarker represents a bullet list (•, -, *, etc.).
	BulletMarker MarkerType = iota

	// NumberMarker represents a numbered list (1., 2., 3. or a), b), c) etc.).
	NumberMarker
)

type Merger 

type Merger struct {
	// contains filtered or unexported fields
}

Merger provides flexible page selection when merging PDFs.

Use Merger when you need fine-grained control over which pages to include in the merged output.

Example - Merge specific pages: 

merger := creator.NewMerger()
merger.AddPages("file1.pdf", 1, 2, 3)     // Pages 1-3
merger.AddPages("file2.pdf", 5, 10)       // Pages 5-10
merger.AddAllPages("file3.pdf")           // All pages
err := merger.Write("output.pdf")

Example - Merge with page range: 

merger := creator.NewMerger()
merger.AddPageRange("input.pdf", 1, 5)   // Pages 1-5
err := merger.Write("output.pdf")

func NewMerger 

func NewMerger() *Merger

NewMerger creates a new Merger instance.

Example: 

merger := creator.NewMerger()
// Add pages...
merger.Write("output.pdf")

func (*Merger) AddAllPages 

func (m *Merger) AddAllPages(path string) error

AddAllPages adds all pages from a PDF file.

Parameters:

  • path: Path to the PDF file

Returns an error if file cannot be opened.

Example: 

merger.AddAllPages("input.pdf")  // Add all pages

func (*Merger) AddPageRange 

func (m *Merger) AddPageRange(path string, start, end int) error

AddPageRange adds a range of pages from a PDF file.

Page numbers are 1-based and inclusive (start and end are both included).

Parameters:

  • path: Path to the PDF file
  • start: First page number (1-based, inclusive)
  • end: Last page number (1-based, inclusive)

Returns an error if:

  • File cannot be opened
  • Range is invalid (start > end, or out of bounds)

Example: 

merger.AddPageRange("input.pdf", 1, 5)  // Add pages 1-5

func (*Merger) AddPages 

func (m *Merger) AddPages(path string, pageNums ...int) error

AddPages adds specific pages from a PDF file.

Page numbers are 1-based (1 = first page, 2 = second page, etc.). Pages are added in the order specified.

Parameters:

  • path: Path to the PDF file
  • pageNums: Page numbers to add (1-based)

Returns an error if:

  • File cannot be opened
  • Any page number is invalid (< 1 or > page count)

Example: 

merger.AddPages("input.pdf", 1, 3, 5)  // Add pages 1, 3, 5

func (*Merger) Close 

func (m *Merger) Close() error

Close closes all opened PDF readers and releases resources.

This is automatically called by Write(), but can be called manually if you need to release resources before writing.

func (*Merger) Write 

func (m *Merger) Write(path string) error

Write writes the merged PDF to a file.

This copies all selected pages to the output document and writes it.

Parameters:

  • path: Path to the output PDF file

Returns an error if:

  • No pages have been added
  • Page content cannot be copied
  • Output file cannot be created or written

Example: 

err := merger.Write("output.pdf")

func (*Merger) WriteContext 

func (m *Merger) WriteContext(ctx context.Context, path string) error

WriteContext writes the merged PDF with context support.

This allows cancellation and timeout control.

Example: 

ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
defer cancel()
err := merger.WriteContext(ctx, "output.pdf")

type NumberFormat 

type NumberFormat int

NumberFormat defines the numbering style. 

const (
	// NumberFormatArabic uses Arabic numerals (1. 2. 3.).
	NumberFormatArabic NumberFormat = iota

	// NumberFormatLowerAlpha uses lowercase letters (a. b. c.).
	NumberFormatLowerAlpha

	// NumberFormatUpperAlpha uses uppercase letters (A. B. C.).
	NumberFormatUpperAlpha

	// NumberFormatLowerRoman uses lowercase Roman numerals (i. ii. iii.).
	NumberFormatLowerRoman

	// NumberFormatUpperRoman uses uppercase Roman numerals (I. II. III.).
	NumberFormatUpperRoman
)

type Orientation added in v0.4.0 

type Orientation int

Orientation represents page orientation (portrait or landscape).

Use as an optional parameter to Creator.NewPageWithSize to control page orientation. Portrait is the default — width < height. Landscape swaps width and height so that the page is wider than it is tall.

This uses the industry-standard swapped-MediaBox approach (not /Rotate), so content coordinates remain natural: (0,0) is bottom-left of the page.

Note: Presentation sizes (Slide16x9, Slide4x3) are already landscape-oriented (width > height). Passing Landscape to Creator.NewPageWithSize with these sizes will swap them to portrait orientation, which is rarely desired for slides. 

const (
	// Portrait is the default page orientation (taller than wide).
	Portrait Orientation = iota

	// Landscape rotates the page so it is wider than tall.
	// Internally this swaps MediaBox width and height — no /Rotate entry is used,
	// so content coordinates remain natural.
	Landscape
)

type Page 

type Page struct {
	// contains filtered or unexported fields
}

Page represents a page in the PDF document being created.

This is a high-level wrapper around the domain Page entity, providing a simplified API for adding content.

Example: 

page := creator.NewPage()
// Add text, images, etc. to page...

func (*Page) AddField 

func (p *Page) AddField(field interface{}) error

AddField adds a form field to the page.

Form fields allow user input and interaction in PDF documents. This is part of the AcroForm (Interactive Forms) system.

Supported field types:

  • TextField: Single-line or multi-line text input
  • (Future: CheckBox, RadioButton, ComboBox, ListBox, PushButton)

Example: 

field := forms.NewTextField("username", 100, 700, 200, 20)
field.SetValue("John Doe").SetRequired(true)
page.AddField(field)

func (*Page) AddHighlightAnnotation 

func (p *Page) AddHighlightAnnotation(annotation *HighlightAnnotation) error

AddHighlightAnnotation adds a highlight annotation to the page.

The highlight marks text with a colored overlay.

Example: 

highlight := creator.NewHighlightAnnotation(100, 650, 300, 670)
highlight.SetColor(creator.Yellow).SetAuthor("Bob")
page.AddHighlightAnnotation(highlight)

func (p *Page) AddInternalLink(text string, destPage int, x, y float64, font FontName, size float64) error

AddInternalLink adds a link to another page in the document.

The destPage parameter is 0-based (0 = first page, 1 = second page, etc.).

Parameters:

  • text: The link text to display
  • destPage: Target page number (0-based)
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • font: Font to use for the link text
  • size: Font size in points

Example: 

page.AddInternalLink("See page 3", 2, 100, 600, creator.Helvetica, 12)

func (p *Page) AddLink(text, url string, x, y float64, font FontName, size float64) error

AddLink adds a clickable URL link with default styling (blue, underlined).

The text is rendered at the specified position and made clickable. A clickable annotation is created that covers the text area.

Parameters:

  • text: The link text to display
  • url: The target URL (e.g., "https://example.com")
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • font: Font to use for the link text
  • size: Font size in points

Example: 

page.AddLink("Visit Google", "https://google.com", 100, 700, creator.Helvetica, 12)

func (*Page) AddLinkStyled 

func (p *Page) AddLinkStyled(text, url string, x, y float64, style LinkStyle) error

AddLinkStyled adds a clickable URL link with custom styling.

This gives full control over the link appearance (font, size, color, underline).

Parameters:

  • text: The link text to display
  • url: The target URL (e.g., "https://example.com")
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • style: Visual style for the link

Example: 

style := creator.LinkStyle{
    Font:      creator.HelveticaBold,
    Size:      14,
    Color:     creator.Red,
    Underline: false,
}
page.AddLinkStyled("Click here", "https://example.com", 100, 700, style)

func (*Page) AddStampAnnotation 

func (p *Page) AddStampAnnotation(annotation *StampAnnotation) error

AddStampAnnotation adds a stamp annotation to the page.

The stamp displays predefined text like "Approved", "Draft", etc.

Example: 

stamp := creator.NewStampAnnotation(300, 700, 100, 50, creator.StampApproved)
stamp.SetColor(creator.Green).SetAuthor("Manager")
page.AddStampAnnotation(stamp)

func (*Page) AddStrikeOutAnnotation 

func (p *Page) AddStrikeOutAnnotation(annotation *StrikeOutAnnotation) error

AddStrikeOutAnnotation adds a strikeout annotation to the page.

The strikeout draws a line through text.

Example: 

strikeout := creator.NewStrikeOutAnnotation(100, 650, 300, 670)
strikeout.SetColor(creator.Red)
page.AddStrikeOutAnnotation(strikeout)

func (*Page) AddText 

func (p *Page) AddText(text string, x, y float64, font FontName, size float64) error

AddText adds text to the page at the specified position with default black color.

Parameters:

  • text: The string to display
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • font: Font to use (one of the Standard 14 fonts)
  • size: Font size in points

Example: 

err := page.AddText("Hello World", 100, 700, creator.Helvetica, 24)

func (*Page) AddTextAnnotation 

func (p *Page) AddTextAnnotation(annotation *TextAnnotation) error

AddTextAnnotation adds a text (sticky note) annotation to the page.

The annotation appears as a small icon at the specified position. When clicked, it displays the contents in a pop-up.

Example: 

note := creator.NewTextAnnotation(100, 700, "Review this section")
note.SetAuthor("Alice").SetColor(creator.Yellow)
page.AddTextAnnotation(note)

func (*Page) AddTextColor 

func (p *Page) AddTextColor(text string, x, y float64, font FontName, size float64, color Color) error

AddTextColor adds colored text to the page at the specified position.

Parameters:

  • text: The string to display
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • font: Font to use (one of the Standard 14 fonts)
  • size: Font size in points
  • color: Text color (RGB, 0.0 to 1.0 range)

Example: 

err := page.AddTextColor("Error!", 100, 700, creator.HelveticaBold, 18, creator.Red)

func (*Page) AddTextColorAlpha added in v0.5.0 

func (p *Page) AddTextColorAlpha(text string, x, y float64, font FontName, size float64, color Color, opacity float64) error

AddTextColorAlpha adds colored text with opacity to the page.

Opacity controls the transparency level of the text (ISO 32000 §11.6.4.4):

  • 1.0 = fully opaque (default)
  • 0.5 = 50% transparent
  • 0.0 = fully transparent

The opacity is implemented via an ExtGState resource with /ca (fill alpha) and /CA (stroke alpha) keys. Values are clamped to [0.0, 1.0].

Parameters:

  • text: The string to display
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • font: Font to use (one of the Standard 14 fonts)
  • size: Font size in points
  • color: Text color (RGB, 0.0 to 1.0 range)
  • opacity: Transparency level (0.0 to 1.0)

Example: 

// Semi-transparent watermark text
err := page.AddTextColorAlpha("DRAFT", 200, 400, creator.HelveticaBold, 48, creator.Gray, 0.3)

func (*Page) AddTextColorCMYK 

func (p *Page) AddTextColorCMYK(text string, x, y float64, font FontName, size float64, color ColorCMYK) error

AddTextColorCMYK adds CMYK-colored text to the page at the specified position.

CMYK (Cyan, Magenta, Yellow, blacK) is a subtractive color model used in professional printing. This method should be used when precise color control is needed for print production.

Parameters:

  • text: The string to display
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • font: Font to use (one of the Standard 14 fonts)
  • size: Font size in points
  • color: Text color (CMYK, 0.0 to 1.0 range)

Example: 

// Pure cyan for printing
cyan := creator.NewColorCMYK(1.0, 0.0, 0.0, 0.0)
err := page.AddTextColorCMYK("Print-ready text", 100, 700, creator.Helvetica, 12, cyan)

func (*Page) AddTextColorRotated added in v0.4.0 

func (p *Page) AddTextColorRotated(text string, x, y float64, font FontName, size float64, color Color, rotation float64) error

AddTextColorRotated adds colored rotated text to the page at the specified position.

Rotation follows the PDF/PostScript mathematical convention (ISO 32000 §8.3): positive angles rotate counter-clockwise, negative angles rotate clockwise. Angles are normalized to [0, 360) internally — for example, -90 and 270 produce identical output. Fractional angles are fully supported.

Parameters:

  • text: The string to display
  • x: Horizontal position in points (from left edge) — also the rotation pivot
  • y: Vertical position in points (from bottom edge) — also the rotation pivot
  • font: Font to use (one of the Standard 14 fonts)
  • size: Font size in points
  • color: Text color (RGB, 0.0 to 1.0 range)
  • rotation: Rotation angle in degrees (counter-clockwise positive)

Example: 

// Diagonal red label at 45 degrees
err := page.AddTextColorRotated("DRAFT", 300, 400, creator.HelveticaBold, 48, creator.Red, 45)

func (*Page) AddTextColorRotatedAlpha added in v0.5.0 

func (p *Page) AddTextColorRotatedAlpha(text string, x, y float64, font FontName, size float64, color Color, rotation, opacity float64) error

AddTextColorRotatedAlpha adds colored rotated text with opacity to the page.

Combines rotation (ISO 32000 §8.3) and opacity (ISO 32000 §11.6.4.4). Rotation angles are normalized to [0, 360). Opacity is clamped to [0.0, 1.0].

Parameters:

  • text: The string to display
  • x: Horizontal position in points (from left edge) — also the rotation pivot
  • y: Vertical position in points (from bottom edge) — also the rotation pivot
  • font: Font to use (one of the Standard 14 fonts)
  • size: Font size in points
  • color: Text color (RGB, 0.0 to 1.0 range)
  • rotation: Rotation angle in degrees (counter-clockwise positive)
  • opacity: Transparency level (0.0 to 1.0)

Example: 

// Diagonal semi-transparent watermark
err := page.AddTextColorRotatedAlpha("CONFIDENTIAL", 300, 400, creator.HelveticaBold, 36, creator.Red, 45, 0.2)

func (*Page) AddTextCustomFont added in v0.1.1 

func (p *Page) AddTextCustomFont(text string, x, y float64, font *CustomFont, size float64) error

AddTextCustomFont adds text using an embedded TrueType/OpenType font.

This method supports Unicode text including Cyrillic, CJK, Arabic, and symbols. The font is automatically subset to include only the glyphs used in the document.

Parameters:

  • text: The string to display (supports Unicode)
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • font: Custom font loaded via LoadFont()
  • size: Font size in points

Example: 

font, _ := creator.LoadFont("fonts/OpenSans-Regular.ttf")
err := page.AddTextCustomFont("Привет мир! 你好世界!", 100, 700, font, 24)

func (*Page) AddTextCustomFontColor added in v0.1.1 

func (p *Page) AddTextCustomFontColor(text string, x, y float64, font *CustomFont, size float64, color Color) error

AddTextCustomFontColor adds colored text using an embedded TrueType/OpenType font.

This method supports Unicode text including Cyrillic, CJK, Arabic, and symbols. The font is automatically subset to include only the glyphs used in the document.

Parameters:

  • text: The string to display (supports Unicode)
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • font: Custom font loaded via LoadFont()
  • size: Font size in points
  • color: Text color (RGB, 0.0 to 1.0 range)

Example: 

font, _ := creator.LoadFont("fonts/OpenSans-Bold.ttf")
err := page.AddTextCustomFontColor("重要!", 100, 700, font, 24, creator.Red)

func (*Page) AddTextCustomFontColorAlpha added in v0.5.0 

func (p *Page) AddTextCustomFontColorAlpha(text string, x, y float64, font *CustomFont, size float64, color Color, opacity float64) error

AddTextCustomFontColorAlpha adds colored text with opacity using an embedded TrueType/OpenType font.

Supports Unicode text (Cyrillic, CJK, Arabic, symbols) with transparency. Opacity is implemented via ExtGState (ISO 32000 §11.6.4.4).

Parameters:

  • text: The string to display (supports Unicode)
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • font: Custom font loaded via LoadFont()
  • size: Font size in points
  • color: Text color (RGB, 0.0 to 1.0 range)
  • opacity: Transparency level (0.0 to 1.0)

Example: 

font, _ := creator.LoadFont("fonts/OpenSans-Regular.ttf")
err := page.AddTextCustomFontColorAlpha("Полупрозрачный", 100, 700, font, 24, creator.Blue, 0.5)

func (*Page) AddTextCustomFontColorRotated added in v0.4.0 

func (p *Page) AddTextCustomFontColorRotated(text string, x, y float64, font *CustomFont, size float64, color Color, rotation float64) error

AddTextCustomFontColorRotated adds colored rotated text using an embedded TrueType/OpenType font.

Rotation follows the PDF/PostScript mathematical convention (ISO 32000 §8.3): positive angles rotate counter-clockwise, negative angles rotate clockwise. Angles are normalized to [0, 360) internally. Fractional angles are supported. This is the custom font equivalent of Page.AddTextColorRotated.

Example: 

err := page.AddTextCustomFontColorRotated("DRAFT", 300, 400, font, 48, creator.Red, 45)

func (*Page) AddTextCustomFontColorRotatedAlpha added in v0.5.0 

func (p *Page) AddTextCustomFontColorRotatedAlpha(text string, x, y float64, font *CustomFont, size float64, color Color, rotation, opacity float64) error

AddTextCustomFontColorRotatedAlpha adds colored rotated text with opacity using an embedded font.

Combines custom font support, rotation, and opacity. This is the most flexible text method, supporting Unicode, rotation (ISO 32000 §8.3), and transparency (ISO 32000 §11.6.4.4) simultaneously.

Parameters:

  • text: The string to display (supports Unicode)
  • x: Horizontal position in points (from left edge) — also the rotation pivot
  • y: Vertical position in points (from bottom edge) — also the rotation pivot
  • font: Custom font loaded via LoadFont()
  • size: Font size in points
  • color: Text color (RGB, 0.0 to 1.0 range)
  • rotation: Rotation angle in degrees (counter-clockwise positive)
  • opacity: Transparency level (0.0 to 1.0)

Example: 

font, _ := creator.LoadFont("fonts/OpenSans-Bold.ttf")
err := page.AddTextCustomFontColorRotatedAlpha("DRAFT", 300, 400, font, 48, creator.Red, 45, 0.3)

func (*Page) AddTextCustomFontRotated added in v0.4.0 

func (p *Page) AddTextCustomFontRotated(text string, x, y float64, font *CustomFont, size float64, rotation float64) error

AddTextCustomFontRotated adds rotated text using an embedded TrueType/OpenType font.

Rotation follows the PDF/PostScript mathematical convention (ISO 32000 §8.3): positive angles rotate counter-clockwise, negative angles rotate clockwise. Angles are normalized to [0, 360) internally. Fractional angles are supported. This is the custom font equivalent of Page.AddTextRotated.

Example: 

err := page.AddTextCustomFontRotated("Sidebar", 50, 400, font, 14, 90)

func (*Page) AddTextRotated added in v0.4.0 

func (p *Page) AddTextRotated(text string, x, y float64, font FontName, size float64, rotation float64) error

AddTextRotated adds rotated text to the page at the specified position with default black color.

Rotation follows the PDF/PostScript mathematical convention (ISO 32000 §8.3): positive angles rotate counter-clockwise, negative angles rotate clockwise. Angles are normalized to [0, 360) internally — for example, -90 and 270 produce identical output.

Common angles:

  • 90: vertical text running bottom-to-top
  • 270 (or -90): vertical text running top-to-bottom
  • 180: upside-down text
  • 45: diagonal text

Fractional angles (e.g. 22.5, 33.3) are fully supported.

Parameters:

  • text: The string to display
  • x: Horizontal position in points (from left edge) — also the rotation pivot
  • y: Vertical position in points (from bottom edge) — also the rotation pivot
  • font: Font to use (one of the Standard 14 fonts)
  • size: Font size in points
  • rotation: Rotation angle in degrees (counter-clockwise positive)

Example: 

// Vertical text running bottom-to-top
err := page.AddTextRotated("Sideways", 100, 400, creator.Helvetica, 14, 90)

func (*Page) AddUnderlineAnnotation 

func (p *Page) AddUnderlineAnnotation(annotation *UnderlineAnnotation) error

AddUnderlineAnnotation adds an underline annotation to the page.

The underline draws a line under text.

Example: 

underline := creator.NewUnderlineAnnotation(100, 650, 300, 670)
underline.SetColor(creator.Blue)
page.AddUnderlineAnnotation(underline)

func (*Page) BeginClipRect added in v0.1.1 

func (p *Page) BeginClipRect(x, y, width, height float64) error

BeginClipRect begins a rectangular clipping region.

All subsequent drawing operations (shapes, text, images) will be clipped to the specified rectangle. Content outside the rectangle will not be visible.

This is useful for tables where text should not overflow cell boundaries.

You MUST call EndClip() after drawing the clipped content to restore the previous graphics state. Clipping regions can be nested.

Parameters:

  • x, y: Lower-left corner of the clipping rectangle
  • width, height: Size of the clipping rectangle

Example: 

// Clip text to a cell boundary
page.BeginClipRect(100, 500, 200, 30)
page.AddText("Very long text that would overflow...", 105, 510, opts)
page.EndClip()

func (*Page) ContentHeight 

func (p *Page) ContentHeight() float64

ContentHeight returns the usable height (page height minus top and bottom margins).

func (*Page) ContentWidth 

func (p *Page) ContentWidth() float64

ContentWidth returns the usable width (page width minus left and right margins).

func (*Page) Draw 

func (p *Page) Draw(d Drawable) error

Draw renders a Drawable element on the page.

This uses the page's layout context and automatically positions the element. The cursor advances after drawing.

Example: 

p := NewParagraph("Hello World")
page.Draw(p)

func (*Page) DrawAt 

func (p *Page) DrawAt(d Drawable, x, y float64) error

DrawAt renders a Drawable element at a specific position.

x is measured from the left edge of the page. y is measured from the top of the content area (below top margin).

Example: 

p := NewParagraph("Hello World")
page.DrawAt(p, 100, 50)  // 100 points from left, 50 from top

func (*Page) DrawBezierCurve 

func (p *Page) DrawBezierCurve(segments []BezierSegment, opts *BezierOptions) error

DrawBezierCurve draws a complex curve composed of one or more cubic Bézier segments.

A Bézier curve provides smooth, flowing curves that are widely used in vector graphics. Multiple segments can be connected to create complex paths.

Parameters:

  • segments: Array of Bézier curve segments (minimum 1 segment)
  • opts: Curve options (color, width, dash pattern, closed path)

Example (simple S-curve): 

opts := &creator.BezierOptions{
    Color: creator.Blue,
    Width: 2.0,
}
segments := []creator.BezierSegment{
    {
        Start: creator.Point{X: 100, Y: 100},
        C1:    creator.Point{X: 150, Y: 200},
        C2:    creator.Point{X: 200, Y: 200},
        End:   creator.Point{X: 250, Y: 100},
    },
}
err := page.DrawBezierCurve(segments, opts)

Example (closed filled shape): 

opts := &creator.BezierOptions{
    Color:     creator.Black,
    Width:     1.0,
    Closed:    true,
    FillColor: &creator.Yellow,
}
segments := []creator.BezierSegment{
    // ... multiple segments forming a closed shape
}
err := page.DrawBezierCurve(segments, opts)

func (*Page) DrawCircle 

func (p *Page) DrawCircle(cx, cy, radius float64, opts *CircleOptions) error

DrawCircle draws a circle at center (cx,cy) with given radius.

The circle can be stroked, filled, or both, depending on the options. The circle is approximated using 4 cubic Bézier curves.

Parameters:

  • cx, cy: Center coordinates
  • radius: Circle radius
  • opts: Circle options (stroke color, fill color, stroke width)

Example: 

opts := &creator.CircleOptions{
    StrokeColor: &creator.Red,
    StrokeWidth: 2.0,
    FillColor:   &creator.Yellow,
}
err := page.DrawCircle(300, 400, 50, opts)

func (*Page) DrawEllipse 

func (p *Page) DrawEllipse(cx, cy, rx, ry float64, opts *EllipseOptions) error

DrawEllipse draws an ellipse at center (cx, cy) with horizontal radius rx and vertical radius ry.

An ellipse is approximated using 4 cubic Bézier curves. For a circle, set rx = ry.

The ellipse can be stroked, filled, or both, depending on the options.

Parameters:

  • cx, cy: Center coordinates
  • rx: Horizontal radius (half-width)
  • ry: Vertical radius (half-height)
  • opts: Ellipse options (stroke color, fill color, stroke width)

Example: 

opts := &creator.EllipseOptions{
    StrokeColor: &creator.Black,
    StrokeWidth: 2.0,
    FillColor:   &creator.Green,
}
err := page.DrawEllipse(150, 200, 100, 50, opts)  // Horizontal ellipse

func (*Page) DrawImage 

func (p *Page) DrawImage(img *Image, x, y, width, height float64) error

DrawImage draws an image at the specified position and size.

The image is scaled to fit the specified width and height. No aspect ratio preservation - the image is stretched to fit.

Parameters:

  • img: The image to draw
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • width: Display width in points
  • height: Display height in points

Example: 

img, _ := creator.LoadImage("photo.jpg")
page.DrawImage(img, 100, 500, 200, 150)

func (*Page) DrawImageFit 

func (p *Page) DrawImageFit(img *Image, x, y, maxWidth, maxHeight float64) error

DrawImageFit draws an image scaled to fit within the specified dimensions.

The image is scaled to fit within the width/height while maintaining its aspect ratio. The image is centered in the available space.

Parameters:

  • img: The image to draw
  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • maxWidth: Maximum width in points
  • maxHeight: Maximum height in points

Example: 

img, _ := creator.LoadImage("photo.jpg")
page.DrawImageFit(img, 100, 500, 200, 200)  // Fit in 200x200 box

func (*Page) DrawLine 

func (p *Page) DrawLine(x1, y1, x2, y2 float64, opts *LineOptions) error

DrawLine draws a line from (x1,y1) to (x2,y2).

Parameters:

  • x1, y1: Starting point coordinates
  • x2, y2: Ending point coordinates
  • opts: Line options (color, width, dash pattern)

Example: 

opts := &creator.LineOptions{
    Color: creator.Black,
    Width: 2.0,
}
err := page.DrawLine(100, 700, 500, 700, opts)

func (*Page) DrawPolygon 

func (p *Page) DrawPolygon(vertices []Point, opts *PolygonOptions) error

DrawPolygon draws a closed polygon through the specified vertices.

A polygon is a closed shape with N vertices. The path automatically closes from the last vertex back to the first.

The polygon can be stroked, filled, or both, depending on the options.

Parameters:

  • vertices: Array of points defining the polygon vertices (minimum 3 points)
  • opts: Polygon options (stroke color, fill color, width, dash pattern)

Example: 

opts := &creator.PolygonOptions{
    StrokeColor: &creator.Black,
    StrokeWidth: 2.0,
    FillColor:   &creator.Blue,
}
vertices := []creator.Point{
    {X: 100, Y: 100},
    {X: 150, Y: 50},
    {X: 200, Y: 100},
    {X: 175, Y: 150},
    {X: 125, Y: 150},
}
err := page.DrawPolygon(vertices, opts)

func (*Page) DrawPolyline 

func (p *Page) DrawPolyline(vertices []Point, opts *PolylineOptions) error

DrawPolyline draws an open path through the specified vertices.

A polyline is an open path (not closed) that connects N vertices. Unlike a polygon, the path does NOT automatically close back to the first point.

Parameters:

  • vertices: Array of points defining the polyline path (minimum 2 points)
  • opts: Polyline options (color, width, dash pattern)

Example: 

opts := &creator.PolylineOptions{
    Color: creator.Red,
    Width: 2.0,
}
vertices := []creator.Point{
    {X: 100, Y: 100},
    {X: 150, Y: 50},
    {X: 200, Y: 100},
    {X: 250, Y: 75},
}
err := page.DrawPolyline(vertices, opts)

func (*Page) DrawQuadBezierCurve added in v0.5.0 

func (p *Page) DrawQuadBezierCurve(segments []QuadBezierSegment, opts *BezierOptions) error

DrawQuadBezierCurve draws a curve composed of one or more quadratic Bézier segments.

Quadratic Bézier curves are defined by a single control point per segment (compared to two control points for cubic Bézier curves). They are the curve primitive used in TrueType font outlines and the SVG "Q" command.

Because the PDF specification (ISO 32000, section 8.5.2) only supports cubic Bézier curves via the "c" content-stream operator, each quadratic segment is converted to an exact cubic equivalent using degree elevation before writing to the PDF. The conversion is lossless — the rendered curve is identical to the original quadratic specification.

Multiple segments are connected end-to-end to form a compound path. Each segment's Start point must match the previous segment's End point (within a floating-point epsilon of 0.001). This mirrors the continuity requirement of [DrawBezierCurve].

All BezierOptions apply equally to quadratic and cubic curves: stroke color, width, dash patterns, closed paths, fill colors, and opacity.

Parameters:

  • segments: One or more quadratic Bézier segments (minimum 1).
  • opts: Curve drawing options (must not be nil).

Example (simple quadratic arc): 

opts := &creator.BezierOptions{
    Color: creator.Blue,
    Width: 2.0,
}
segments := []creator.QuadBezierSegment{
    {
        Start:   creator.Point{X: 100, Y: 100},
        Control: creator.Point{X: 175, Y: 200},
        End:     creator.Point{X: 250, Y: 100},
    },
}
err := page.DrawQuadBezierCurve(segments, opts)

Example (multi-segment wave): 

segments := []creator.QuadBezierSegment{
    {Start: creator.Point{X: 50, Y: 100}, Control: creator.Point{X: 100, Y: 150}, End: creator.Point{X: 150, Y: 100}},
    {Start: creator.Point{X: 150, Y: 100}, Control: creator.Point{X: 200, Y: 50}, End: creator.Point{X: 250, Y: 100}},
}
err := page.DrawQuadBezierCurve(segments, opts)

func (*Page) DrawRect 

func (p *Page) DrawRect(x, y, width, height float64, opts *RectOptions) error

DrawRect draws a rectangle at (x,y) with given width and height.

The rectangle can be stroked, filled, or both, depending on the options.

Parameters:

  • x, y: Lower-left corner coordinates
  • width, height: Rectangle dimensions
  • opts: Rectangle options (stroke color, fill color, width, dash pattern)

Example: 

opts := &creator.RectOptions{
    StrokeColor: &creator.Black,
    StrokeWidth: 1.0,
    FillColor:   &creator.LightGray,
}
err := page.DrawRect(100, 600, 200, 100, opts)

func (*Page) DrawRectFilled 

func (p *Page) DrawRectFilled(x, y, width, height float64, fillColor Color) error

DrawRectFilled draws a filled rectangle (convenience method).

This is a shorthand for DrawRect with only fill color.

Parameters:

  • x, y: Lower-left corner coordinates
  • width, height: Rectangle dimensions
  • fillColor: Fill color

Example: 

err := page.DrawRectFilled(100, 600, 200, 100, creator.LightGray)

func (*Page) DrawTextClipped added in v0.1.1 

func (p *Page) DrawTextClipped(text string, textX, textY, clipX, clipY, clipW, clipH float64, font *CustomFont, fontSize float64, color Color) error

DrawTextClipped draws text that is clipped to a rectangular region.

This is useful for table cells where text should not overflow the cell boundary. Text that extends beyond the clipping rectangle will be cut off (not visible).

Parameters:

  • text: The text to render
  • textX, textY: Position of the text baseline
  • clipX, clipY, clipW, clipH: Clipping rectangle (text outside is hidden)
  • font: Custom font to use
  • fontSize: Font size in points
  • color: Text color

Example: 

// Draw text clipped to a 100pt wide cell
page.DrawTextClipped("Very long text...", 55, 510, 50, 500, 100, 30, font, 10, Black)

func (*Page) DrawWatermark 

func (p *Page) DrawWatermark(wm *TextWatermark) error

DrawWatermark applies a text watermark to the page.

The watermark is rendered as semi-transparent text positioned according to the watermark's settings.

Example: 

wm := creator.NewTextWatermark("CONFIDENTIAL")
wm.SetOpacity(0.3)
page.DrawWatermark(wm)

func (*Page) EndClip added in v0.1.1 

func (p *Page) EndClip() error

EndClip ends a clipping region started by BeginClipRect.

This restores the graphics state to what it was before BeginClipRect was called. Every BeginClipRect MUST have a matching EndClip.

func (*Page) GetLayoutContext 

func (p *Page) GetLayoutContext() *LayoutContext

GetLayoutContext creates a LayoutContext for this page.

The context is initialized with the cursor at the top-left of the content area (inside margins).

Example: 

ctx := page.GetLayoutContext()
paragraph := NewParagraph("Hello World")
paragraph.Draw(ctx, page)

func (*Page) GraphicsOperations 

func (p *Page) GraphicsOperations() []GraphicsOperation

GraphicsOperations returns all graphics operations for this page.

This is used by the writer infrastructure to generate the content stream.

func (*Page) Height 

func (p *Page) Height() float64

Height returns the page height in points.

If the page is rotated 90 or 270 degrees, width and height are swapped.

func (*Page) Margins 

func (p *Page) Margins() Margins

Margins returns the page margins.

func (*Page) MoveCursor 

func (p *Page) MoveCursor(x, y float64)

MoveCursor moves the page's layout cursor to the specified position.

This affects subsequent Draw() calls that use the default layout context. Note: This creates a new context each time, so for multiple sequential draws, use GetLayoutContext() and pass it to Draw() on the Drawable directly.

x is measured from the left edge of the page. y is measured from the top of the content area (below top margin).

func (*Page) Rotate 

func (p *Page) Rotate(degrees int) error

Rotate rotates the page by the specified degrees (clockwise).

Valid values are 0, 90, 180, and 270 degrees. This method sets the absolute rotation, not cumulative.

This is an alias for Page.SetRotation for API convenience. For true landscape pages, prefer Creator.NewPageWithSize with Landscape.

Example: 

page.Rotate(90)  // viewer rotates 90° clockwise
page.Rotate(180) // upside down
page.Rotate(270) // viewer rotates 270° clockwise

func (*Page) Rotation 

func (p *Page) Rotation() int

Rotation returns the current page rotation in degrees.

func (*Page) SetMargins 

func (p *Page) SetMargins(top, right, bottom, left float64) error

SetMargins sets page-specific margins.

This overrides the default margins from the Creator.

Example: 

page.SetMargins(36, 36, 36, 36) // 0.5 inch margins

func (*Page) SetRotation 

func (p *Page) SetRotation(degrees int) error

SetRotation sets the page /Rotate entry.

Valid values are 0, 90, 180, and 270 degrees (clockwise). This writes a /Rotate key into the page dictionary, which tells the viewer to rotate the rendered page. Content coordinates are NOT affected — text placed at (100, 700) will still appear at (100, 700) in the unrotated coordinate system.

For true landscape pages (swapped width/height, natural coordinates), use Creator.NewPageWithSize with Landscape instead.

Example: 

page.SetRotation(90) // viewer rotates the page 90° clockwise

func (*Page) Surface added in v0.2.0 

func (p *Page) Surface() *Surface

Surface creates a new drawing surface for this page.

Surface provides Skia-like Push/Pop semantics for graphics state management. This allows composable transformations, opacity, blend modes, and clipping.

Example: 

surface := page.Surface()
surface.PushTransform(Rotate(45))
surface.PushOpacity(0.5)
// ... draw operations ...
surface.Pop()
surface.Pop()

func (*Page) TextOperations 

func (p *Page) TextOperations() []TextOperation

TextOperations returns all text operations for this page.

This is used by the writer infrastructure to generate the content stream.

func (*Page) Width 

func (p *Page) Width() float64

Width returns the page width in points.

If the page is rotated 90 or 270 degrees, width and height are swapped.

type PageRange 

type PageRange struct {
	Start  int    // First page (1-based, inclusive)
	End    int    // Last page (1-based, inclusive)
	Output string // Output file path
}

PageRange defines a range of pages to extract.

Page numbers are 1-based (1 = first page). Start and End are inclusive.

type PageSize 

type PageSize int

PageSize represents standard PDF page sizes.

Common page sizes are provided as constants (A4, Letter, etc.). For custom dimensions use NewPageWithDimensions on the Creator.

The iota values mirror document.PageSize exactly so that casting between creator.PageSize and document.PageSize is always valid. 

const (

	// A4 paper size (210 × 297 mm or 595 × 842 points).
	// This is the most common paper size worldwide.
	A4 PageSize = iota

	// A3 paper size (297 × 420 mm or 842 × 1191 points).
	// Twice the size of A4.
	A3

	// A5 paper size (148 × 210 mm or 420 × 595 points).
	// Half the size of A4.
	A5

	// B4 paper size (250 × 353 mm or 709 × 1001 points).
	B4

	// B5 paper size (176 × 250 mm or 499 × 709 points).
	B5

	// Letter paper size (8.5 × 11 inches or 612 × 792 points).
	// This is the standard size in North America.
	Letter

	// Legal paper size (8.5 × 14 inches or 612 × 1008 points).
	Legal

	// Tabloid paper size (11 × 17 inches or 792 × 1224 points).
	// Also known as Ledger when in landscape orientation.
	Tabloid

	// A0 paper size (841 × 1189 mm or 2384 × 3370 points).
	// Largest common A-series size.
	A0

	// A1 paper size (594 × 841 mm or 1684 × 2384 points).
	A1

	// A2 paper size (420 × 594 mm or 1191 × 1684 points).
	A2

	// A6 paper size (105 × 148 mm or 298 × 420 points). Postcard size.
	A6

	// A7 paper size (74 × 105 mm or 210 × 298 points).
	A7

	// A8 paper size (52 × 74 mm or 147 × 210 points).
	A8

	// B0 paper size (1000 × 1414 mm or 2835 × 4008 points).
	B0

	// B1 paper size (707 × 1000 mm or 2004 × 2835 points).
	B1

	// B2 paper size (500 × 707 mm or 1417 × 2004 points).
	B2

	// B3 paper size (353 × 500 mm or 1001 × 1417 points).
	B3

	// B6 paper size (125 × 176 mm or 354 × 499 points).
	B6

	// C4 envelope (229 × 324 mm or 649 × 918 points). Fits A4 unfolded.
	C4

	// C5 envelope (162 × 229 mm or 459 × 649 points). Fits A5 unfolded or A4 folded in half.
	C5

	// C6 envelope (114 × 162 mm or 323 × 459 points). Fits A6 unfolded or A4 folded in quarters.
	C6

	// DL envelope (110 × 220 mm or 312 × 624 points). Fits A4 folded in thirds.
	DL

	// Executive paper size (7.25 × 10.5 inches or 522 × 756 points).
	Executive

	// HalfLetter paper size (5.5 × 8.5 inches or 396 × 612 points).
	HalfLetter

	// ANSIC engineering drawing (17 × 22 inches or 1224 × 1584 points).
	ANSIC

	// ANSID engineering drawing (22 × 34 inches or 1584 × 2448 points).
	ANSID

	// ANSIE engineering drawing (34 × 44 inches or 2448 × 3168 points).
	ANSIE

	// Photo4x6 is a standard 4 × 6 inch photo (288 × 432 points).
	Photo4x6

	// Photo5x7 is a standard 5 × 7 inch photo (360 × 504 points).
	Photo5x7

	// Photo8x10 is a standard 8 × 10 inch photo (576 × 720 points).
	Photo8x10

	// Digest is digest magazine size (5.5 × 8.5 inches or 396 × 612 points).
	Digest

	// USTradeBook is standard US trade book size (6 × 9 inches or 432 × 648 points).
	USTradeBook

	// Slide16x9 is a widescreen presentation slide at 16:9 aspect ratio (960 × 540 points).
	// Equivalent to 13.33 × 7.5 inches — matches PowerPoint/Keynote widescreen default.
	// This size is already landscape-oriented (width > height).
	// When exported at 2× DPI (144 dpi), this produces a 1920 × 1080 pixel image.
	Slide16x9

	// Slide4x3 is a standard presentation slide at 4:3 aspect ratio (720 × 540 points).
	// Equivalent to 10 × 7.5 inches — matches the traditional slide format.
	// This size is already landscape-oriented (width > height).
	Slide4x3

	// Envelope10 is a #10 commercial envelope (4.125 × 9.5 inches or 297 × 684 points).
	Envelope10

	// JISB4 is Japanese B4 (257 × 364 mm or 729 × 1032 points).
	JISB4

	// JISB5 is Japanese B5 (182 × 257 mm or 516 × 729 points).
	JISB5
)

func (PageSize) String 

func (ps PageSize) String() string

String returns the human-readable name of the page size.

type Paint added in v0.2.0 

type Paint interface {
	// contains filtered or unexported methods
}

Paint represents a paint source for fill and stroke operations.

Paint can be a solid color, a gradient, or a pattern (future). This interface allows uniform handling of different paint types.

Implemented by:

  • Color (RGB solid color)
  • ColorRGBA (RGB with alpha)
  • ColorCMYK (CMYK solid color)
  • Gradient (linear/radial gradient)

Example: 

var paint Paint
paint = Red                    // Solid color
paint = NewColorRGBA(1, 0, 0, 0.5) // Transparent red
paint = NewLinearGradient(0, 0, 100, 0) // Gradient

type Paragraph 

type Paragraph struct {
	// contains filtered or unexported fields
}

Paragraph represents a block of text with automatic word wrapping.

Paragraphs automatically wrap text based on the available width, handle alignment, and track their height for layout purposes.

Example: 

p := NewParagraph("This is a long text that will be wrapped automatically.")
p.SetFont(Helvetica, 12)
p.SetAlignment(AlignJustify)
page.Draw(p)

func NewParagraph 

func NewParagraph(text string) *Paragraph

NewParagraph creates a new paragraph with the given text.

Default settings:

  • Font: Helvetica, 12pt
  • Color: Black
  • Alignment: Left
  • Line spacing: 1.2 (120%)

func (*Paragraph) Alignment 

func (p *Paragraph) Alignment() Alignment

Alignment returns the current text alignment.

func (*Paragraph) Color 

func (p *Paragraph) Color() Color

Color returns the current text color.

func (*Paragraph) Draw 

func (p *Paragraph) Draw(ctx *LayoutContext, page *Page) error

Draw renders the paragraph on the page at the current cursor position.

func (*Paragraph) Font 

func (p *Paragraph) Font() FontName

Font returns the current font name.

func (*Paragraph) FontSize 

func (p *Paragraph) FontSize() float64

FontSize returns the current font size.

func (*Paragraph) Height 

func (p *Paragraph) Height(ctx *LayoutContext) float64

Height calculates the total height of the paragraph when rendered.

func (*Paragraph) LineSpacing 

func (p *Paragraph) LineSpacing() float64

LineSpacing returns the current line spacing multiplier.

func (*Paragraph) SetAlignment 

func (p *Paragraph) SetAlignment(a Alignment) *Paragraph

SetAlignment sets the text alignment. Returns the paragraph for method chaining.

func (*Paragraph) SetColor 

func (p *Paragraph) SetColor(c Color) *Paragraph

SetColor sets the text color. Returns the paragraph for method chaining.

func (*Paragraph) SetFont 

func (p *Paragraph) SetFont(font FontName, size float64) *Paragraph

SetFont sets the font and size for the paragraph. Returns the paragraph for method chaining.

func (*Paragraph) SetLineSpacing 

func (p *Paragraph) SetLineSpacing(spacing float64) *Paragraph

SetLineSpacing sets the line spacing multiplier. 1.0 = single spacing, 1.5 = 150% spacing, 2.0 = double spacing. Returns the paragraph for method chaining.

func (*Paragraph) SetText 

func (p *Paragraph) SetText(text string) *Paragraph

SetText sets the paragraph text. Returns the paragraph for method chaining.

func (*Paragraph) Text 

func (p *Paragraph) Text() string

Text returns the paragraph text.

func (*Paragraph) WrapTextLines 

func (p *Paragraph) WrapTextLines(availableWidth float64) []string

WrapTextLines returns the lines after wrapping (for testing/debugging).

type Path added in v0.2.0 

type Path struct {
	// contains filtered or unexported fields
}

Path represents a vector path for drawing, filling, and clipping.

A Path consists of one or more subpaths, where each subpath is a sequence of connected lines and curves. Subpaths can be open or closed.

Path uses a fluent builder API for easy construction: 

path := NewPath().
    MoveTo(100, 100).
    LineTo(200, 100).
    QuadraticTo(250, 150, 200, 200).
    CubicTo(150, 250, 100, 250, 100, 200).
    Close()

Shape helpers provide shortcuts for common shapes: 

circle := NewPath().AddCircle(Point{150, 150}, 50)
rect := NewPath().AddRect(Rect{X: 10, Y: 10, Width: 100, Height: 50})

Reference: PDF 1.7 Specification, Section 8.5 (Path Construction).

func NewPath added in v0.2.0 

func NewPath() *Path

NewPath creates a new empty path.

The path starts with no current point. Use MoveTo to start a new subpath.

Example: 

path := NewPath()
path.MoveTo(100, 100)
path.LineTo(200, 200)

func (*Path) AddArc added in v0.2.0 

func (p *Path) AddArc(center Point, radius, startAngle, endAngle float64) *Path

AddArc adds a circular arc to the path.

The arc is centered at 'center' with the specified radius. It spans from startAngle to endAngle (in degrees). Angles are measured counterclockwise from the positive X axis.

If there is a current point, a line is drawn from the current point to the arc start. Otherwise, MoveTo is used to start at the arc.

Parameters:

  • center: Arc center point
  • radius: Arc radius (must be positive)
  • startAngle: Starting angle in degrees (0 = right, 90 = top)
  • endAngle: Ending angle in degrees

Example: 

// Quarter circle arc (90 degrees)
path := NewPath().
    MoveTo(150, 150).
    AddArc(Point{150, 150}, 50, 0, 90)

func (*Path) AddCircle added in v0.2.0 

func (p *Path) AddCircle(center Point, radius float64) *Path

AddCircle adds a circle to the path.

The circle is approximated using 4 cubic Bézier curves. This provides a very accurate approximation (error < 0.06% of radius).

Parameters:

  • center: Circle center point
  • radius: Circle radius (must be positive)

Example: 

path := NewPath().AddCircle(Point{150, 150}, 50)

func (*Path) AddEllipse added in v0.2.0 

func (p *Path) AddEllipse(rect Rect) *Path

AddEllipse adds an ellipse to the path.

The ellipse is inscribed in the specified rectangle. It is approximated using 4 cubic Bézier curves.

Parameters:

  • rect: Bounding rectangle of the ellipse

Example: 

// Horizontal ellipse
path := NewPath().AddEllipse(Rect{X: 10, Y: 10, Width: 200, Height: 100})

func (*Path) AddRect added in v0.2.0 

func (p *Path) AddRect(rect Rect) *Path

AddRect adds a rectangle to the path.

This is a convenience method that adds a closed rectangular subpath. The rectangle is drawn counterclockwise (for NonZero fill rule).

PDF operator: x y width height re

Parameters:

  • rect: Rectangle to add

Example: 

path := NewPath().
    AddRect(Rect{X: 10, Y: 10, Width: 100, Height: 50}).
    AddRect(Rect{X: 150, Y: 10, Width: 100, Height: 50})

func (*Path) AddRoundedRect added in v0.2.0 

func (p *Path) AddRoundedRect(rect Rect, radius float64) *Path

AddRoundedRect adds a rounded rectangle to the path.

The rectangle has rounded corners with the specified radius. Corners are drawn as quarter-circle arcs.

Parameters:

  • rect: Rectangle bounds
  • radius: Corner radius (must be non-negative)

Example: 

// Rounded rectangle with 10-unit radius corners
path := NewPath().AddRoundedRect(
    Rect{X: 10, Y: 10, Width: 100, Height: 50},
    10,
)

func (*Path) Bounds added in v0.2.0 

func (p *Path) Bounds() Rect

Bounds returns the bounding box of the path.

The bounding box is the smallest rectangle that contains all points in the path. This includes line endpoints and Bézier curve control points (which may be outside the actual curve).

Returns a zero Rect if the path is empty.

Example: 

path := NewPath().
    MoveTo(10, 10).
    LineTo(100, 50).
    LineTo(10, 90)
bounds := path.Bounds() // Rect{X: 10, Y: 10, Width: 90, Height: 80}

func (*Path) Clone added in v0.2.0 

func (p *Path) Clone() *Path

Clone creates a deep copy of the path.

The cloned path is independent of the original.

Example: 

original := NewPath().MoveTo(0, 0).LineTo(100, 100)
clone := original.Clone()
clone.LineTo(200, 0) // Does not affect original

func (*Path) Close added in v0.2.0 

func (p *Path) Close() *Path

Close closes the current subpath.

A straight line is appended from the current point to the subpath start. The subpath is marked as closed for filling purposes.

PDF operator: h

After Close(), there is no current point (call MoveTo to start a new subpath).

Example: 

// Closed triangle
path := NewPath().
    MoveTo(100, 100).
    LineTo(200, 100).
    LineTo(150, 200).
    Close()

func (*Path) CubicTo added in v0.2.0 

func (p *Path) CubicTo(c1x, c1y, c2x, c2y, x, y float64) *Path

CubicTo appends a cubic Bézier curve to the path.

The curve goes from the current point to (x, y) using (c1x, c1y) and (c2x, c2y) as control points.

PDF operator: c1x c1y c2x c2y x y c

Panics if there is no current point (call MoveTo first).

Parameters:

  • c1x, c1y: First control point
  • c2x, c2y: Second control point
  • x, y: Endpoint of the curve

Example: 

// Smooth S-curve
path := NewPath().
    MoveTo(100, 100).
    CubicTo(150, 50, 200, 150, 250, 100)

func (*Path) IsEmpty added in v0.2.0 

func (p *Path) IsEmpty() bool

IsEmpty returns true if the path has no commands.

Example: 

path := NewPath()
fmt.Println(path.IsEmpty()) // true
path.MoveTo(0, 0)
fmt.Println(path.IsEmpty()) // false

func (*Path) LineTo added in v0.2.0 

func (p *Path) LineTo(x, y float64) *Path

LineTo appends a straight line to the path.

The line goes from the current point to the specified point. The specified point becomes the new current point.

PDF operator: x y l

Panics if there is no current point (call MoveTo first).

Parameters:

  • x, y: Coordinates of the line endpoint

Example: 

path := NewPath().
    MoveTo(100, 100).
    LineTo(200, 100).
    LineTo(200, 200)

func (*Path) MoveTo added in v0.2.0 

func (p *Path) MoveTo(x, y float64) *Path

MoveTo starts a new subpath at the specified point.

If there is a current subpath, it is left open (not closed). The specified point becomes the current point and the subpath start.

PDF operator: x y m

Parameters:

  • x, y: Coordinates of the new subpath start

Example: 

path := NewPath().MoveTo(100, 100)

func (*Path) QuadraticTo added in v0.2.0 

func (p *Path) QuadraticTo(cx, cy, x, y float64) *Path

QuadraticTo appends a quadratic Bézier curve to the path.

The curve goes from the current point to (x, y) using (cx, cy) as the control point.

PDF does not support quadratic Bézier curves directly, so this method converts the quadratic curve to a cubic curve using the standard algorithm: 

CP1 = P0 + 2/3 * (CP - P0)
CP2 = P1 + 2/3 * (CP - P1)

Where P0 is the current point, CP is (cx, cy), and P1 is (x, y).

Panics if there is no current point (call MoveTo first).

Parameters:

  • cx, cy: Control point
  • x, y: Endpoint of the curve

Example: 

// Smooth parabolic curve
path := NewPath().
    MoveTo(100, 100).
    QuadraticTo(150, 50, 200, 100)

Reference: Converting between quadratic and cubic curves.

type Permission 

type Permission = security.Permission

Permission represents PDF document permissions.

Multiple permissions can be combined using the OR operator (|).

Example: 

perms := PermissionPrint | PermissionCopy

type Point 

type Point struct {
	X float64 // Horizontal position (points from left)
	Y float64 // Vertical position (points from bottom)
}

Point represents a 2D point in PDF coordinate space.

type PolygonOptions 

type PolygonOptions struct {
	// StrokeColor is the border color (nil = no stroke).
	// If StrokeColorCMYK is set, this field is ignored.
	StrokeColor *Color

	// StrokeColorCMYK is the border color in CMYK (nil = no stroke).
	// If set, this takes precedence over StrokeColor (RGB).
	StrokeColorCMYK *ColorCMYK

	// StrokeWidth is the border width in points (default: 1.0).
	StrokeWidth float64

	// FillColor is the fill color (nil = no fill).
	// Mutually exclusive with FillGradient and FillColorCMYK.
	// If FillColorCMYK is set, this field is ignored.
	FillColor *Color

	// FillColorCMYK is the fill color in CMYK (nil = no fill).
	// If set, this takes precedence over FillColor (RGB).
	// Mutually exclusive with FillGradient.
	FillColorCMYK *ColorCMYK

	// FillGradient is the gradient fill (nil = no gradient fill).
	// Mutually exclusive with FillColor and FillColorCMYK.
	FillGradient *Gradient

	// Dashed enables dashed border rendering.
	Dashed bool

	// DashArray defines the dash pattern for the border.
	// Only used when Dashed is true.
	DashArray []float64

	// DashPhase is the starting offset into the dash pattern.
	// Only used when Dashed is true.
	DashPhase float64

	// Opacity is the polygon opacity (0.0 = transparent, 1.0 = opaque).
	// Optional. If set, applies transparency via ExtGState.
	// Affects both fill and stroke.
	// Range: [0.0, 1.0]
	Opacity *float64
}

PolygonOptions configures polygon drawing.

type PolylineOptions 

type PolylineOptions struct {
	// Color is the line color (RGB, 0.0 to 1.0 range).
	// If ColorCMYK is set, this field is ignored.
	Color Color

	// ColorCMYK is the line color in CMYK color space (optional).
	// If set, this takes precedence over Color (RGB).
	ColorCMYK *ColorCMYK

	// Width is the line width in points (default: 1.0).
	Width float64

	// Dashed enables dashed line rendering.
	Dashed bool

	// DashArray defines the dash pattern (e.g., [3, 1] for "3 on, 1 off").
	// Only used when Dashed is true.
	DashArray []float64

	// DashPhase is the starting offset into the dash pattern.
	// Only used when Dashed is true.
	DashPhase float64

	// Opacity is the polyline opacity (0.0 = transparent, 1.0 = opaque).
	// Optional. If set, applies transparency via ExtGState.
	// Range: [0.0, 1.0]
	Opacity *float64
}

PolylineOptions configures polyline drawing.

type QuadBezierSegment added in v0.5.0 

type QuadBezierSegment struct {
	// Start is the starting anchor point (P0).
	// For the first segment this is the curve's entry point.
	// For subsequent segments this should match the previous segment's End point.
	Start Point

	// Control is the single quadratic control point (P1).
	// The curve does not pass through this point; it is attracted toward it.
	Control Point

	// End is the ending anchor point (P2).
	End Point
}

QuadBezierSegment represents a quadratic Bézier curve segment.

A quadratic Bézier curve is defined by three points:

  • Start point (P0): the curve's starting anchor
  • Control point (P1): the single control point that shapes the curve
  • End point (P2): the curve's ending anchor

Quadratic Bézier curves are the native curve primitive of TrueType font outlines and the SVG "Q" command. They offer one fewer degree of freedom than cubic Bézier curves and are therefore simpler to parameterize.

Because the PDF specification (ISO 32000) only supports cubic Bézier curves (the "c" operator), GxPDF converts each quadratic segment to an equivalent cubic segment using exact degree elevation via QuadBezierSegment.ToCubic. The conversion is mathematically exact — it is not an approximation.

func (QuadBezierSegment) ToCubic added in v0.5.0 

func (q QuadBezierSegment) ToCubic() BezierSegment

ToCubic converts the quadratic Bézier segment to an equivalent cubic Bézier segment using degree elevation.

The conversion formula (exact, not an approximation) is: 

Q0 = P0
Q1 = P0 + (2/3) * (P1 - P0)
Q2 = P2 + (2/3) * (P1 - P2)
Q3 = P2

where P0, P1, P2 are the quadratic start, control, and end points and Q0..Q3 are the resulting cubic start, first control, second control, and end points.

This identity is derived from the de Casteljau algorithm: a degree-n polynomial can always be expressed exactly as a degree-(n+1) polynomial by splitting its control polygon in the ratio 2:1 from each endpoint.

Reference: Farin, "Curves and Surfaces for CAGD", §5.2 — Degree Elevation.

type Rect added in v0.2.0 

type Rect struct {
	X      float64 // Left edge
	Y      float64 // Bottom edge
	Width  float64 // Width
	Height float64 // Height
}

Rect represents a rectangle in user space.

type RectOptions 

type RectOptions struct {
	// StrokeColor is the border color (nil = no stroke).
	// If StrokeColorCMYK is set, this field is ignored.
	StrokeColor *Color

	// StrokeColorCMYK is the border color in CMYK (nil = no stroke).
	// If set, this takes precedence over StrokeColor (RGB).
	StrokeColorCMYK *ColorCMYK

	// StrokeWidth is the border width in points (default: 1.0).
	StrokeWidth float64

	// FillColor is the fill color (nil = no fill).
	// Mutually exclusive with FillGradient and FillColorCMYK.
	// If FillColorCMYK is set, this field is ignored.
	FillColor *Color

	// FillColorCMYK is the fill color in CMYK (nil = no fill).
	// If set, this takes precedence over FillColor (RGB).
	// Mutually exclusive with FillGradient.
	FillColorCMYK *ColorCMYK

	// FillGradient is the gradient fill (nil = no gradient fill).
	// Mutually exclusive with FillColor and FillColorCMYK.
	FillGradient *Gradient

	// Dashed enables dashed border rendering.
	Dashed bool

	// DashArray defines the dash pattern for the border.
	// Only used when Dashed is true.
	DashArray []float64

	// DashPhase is the starting offset into the dash pattern.
	// Only used when Dashed is true.
	DashPhase float64

	// Opacity is the rectangle opacity (0.0 = transparent, 1.0 = opaque).
	// Optional. If set, applies transparency via ExtGState.
	// Affects both fill and stroke.
	// Range: [0.0, 1.0]
	Opacity *float64
}

RectOptions configures rectangle drawing.

type Splitter 

type Splitter struct {
	// contains filtered or unexported fields
}

Splitter provides functionality to split PDF files into smaller parts.

Use Splitter when you need to: - Split a PDF into individual pages (one file per page) - Split a PDF into multiple files based on page ranges - Extract specific pages into a new document

Example - Split into individual pages: 

splitter, _ := creator.NewSplitter("large.pdf")
defer splitter.Close()
splitter.Split("output/") // Creates page_001.pdf, page_002.pdf, etc.

Example - Split by ranges: 

splitter, _ := creator.NewSplitter("large.pdf")
defer splitter.Close()
splitter.SplitByRanges(
    creator.PageRange{Start: 1, End: 5, Output: "part1.pdf"},
    creator.PageRange{Start: 6, End: 10, Output: "part2.pdf"},
)

Example - Extract specific pages: 

splitter, _ := creator.NewSplitter("large.pdf")
doc, _ := splitter.ExtractPages(1, 3, 5, 7)

func NewSplitter 

func NewSplitter(path string) (*Splitter, error)

NewSplitter creates a new Splitter for the specified PDF file.

Parameters:

  • path: Path to the PDF file to split

Returns an error if:

  • File cannot be opened
  • File is not a valid PDF

Example: 

splitter, err := creator.NewSplitter("large.pdf")
if err != nil {
    log.Fatal(err)
}
defer splitter.Close()

func (*Splitter) Close 

func (s *Splitter) Close() error

Close closes the splitter and releases resources.

This should be called when done with the splitter (use defer).

func (*Splitter) ExtractPages 

func (s *Splitter) ExtractPages(pages ...int) (*document.Document, error)

ExtractPages extracts specific pages into a new document.

This creates a new in-memory document with only the specified pages. The returned document can be modified or written to a file.

Page numbers are 1-based.

Parameters:

  • pages: Page numbers to extract (1-based)

Returns an error if:

  • No pages specified
  • Any page number is invalid

Example: 

doc, err := splitter.ExtractPages(1, 3, 5, 7)
if err != nil {
    log.Fatal(err)
}
// Use document...

func (*Splitter) SetFilenamePattern 

func (s *Splitter) SetFilenamePattern(pattern string)

SetFilenamePattern sets the output filename pattern.

The pattern must contain a single %d or %03d formatter for page number.

Default pattern: "page_%03d.pdf"

Example: 

splitter.SetFilenamePattern("output_%04d.pdf")
// Produces: output_0001.pdf, output_0002.pdf, etc.

func (*Splitter) Split 

func (s *Splitter) Split(outputDir string) error

Split splits the PDF into individual page files.

Each page is written to a separate PDF file in the specified directory. Filenames are generated using the filename pattern (default: page_001.pdf).

Parameters:

  • outputDir: Directory where individual page files will be written

Returns an error if:

  • Output directory cannot be created
  • Any page cannot be written

Example: 

splitter.Split("output/") // Creates page_001.pdf, page_002.pdf, etc.

func (*Splitter) SplitByRanges 

func (s *Splitter) SplitByRanges(ranges ...PageRange) error

SplitByRanges splits the PDF by page ranges.

Each range is written to the specified output file. Page numbers are 1-based and inclusive.

Parameters:

  • ranges: One or more PageRange specifications

Returns an error if:

  • No ranges specified
  • Any range is invalid
  • Any output file cannot be written

Example: 

splitter.SplitByRanges(
    creator.PageRange{Start: 1, End: 5, Output: "part1.pdf"},
    creator.PageRange{Start: 6, End: 10, Output: "part2.pdf"},
)

func (*Splitter) SplitByRangesContext 

func (s *Splitter) SplitByRangesContext(ctx context.Context, ranges ...PageRange) error

SplitByRangesContext splits by ranges with context support.

func (*Splitter) SplitContext 

func (s *Splitter) SplitContext(ctx context.Context, outputDir string) error

SplitContext splits with context support.

Example: 

ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
defer cancel()
splitter.SplitContext(ctx, "output/")

type StampAnnotation 

type StampAnnotation struct {
	// contains filtered or unexported fields
}

StampAnnotation represents a rubber stamp annotation.

Stamp annotations display predefined stamps like "Approved", "Draft", etc.

Example: 

stamp := creator.NewStampAnnotation(300, 700, 100, 50, creator.StampApproved)
stamp.SetColor(creator.Green)
stamp.SetAuthor("John Doe")
page.AddStampAnnotation(stamp)

func NewStampAnnotation 

func NewStampAnnotation(x, y, width, height float64, name document.StampName) *StampAnnotation

NewStampAnnotation creates a new stamp annotation.

The stamp appears at (x, y) with the specified width and height.

Parameters:

  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • width: Stamp width in points
  • height: Stamp height in points
  • name: Stamp name (e.g., creator.StampApproved)

Example: 

// Create an "Approved" stamp at (300, 700), 100x50 points
stamp := creator.NewStampAnnotation(300, 700, 100, 50, creator.StampApproved)
stamp.SetColor(creator.Green)

func (*StampAnnotation) SetAuthor 

func (a *StampAnnotation) SetAuthor(author string) *StampAnnotation

SetAuthor sets the author name.

Example: 

stamp.SetAuthor("John Doe")

func (*StampAnnotation) SetColor 

func (a *StampAnnotation) SetColor(color Color) *StampAnnotation

SetColor sets the stamp color.

Common stamp colors:

  • Red (default, for important/rejected)
  • Green (approved/ok)
  • Blue (informational)
  • Yellow (warning)

Example: 

stamp.SetColor(creator.Green) // Approved

func (*StampAnnotation) SetNote 

func (a *StampAnnotation) SetNote(note string) *StampAnnotation

SetNote sets an optional note text.

This text appears when the user hovers over or clicks the stamp.

Example: 

stamp.SetNote("Approved on 2025-01-06")

type StrikeOutAnnotation 

type StrikeOutAnnotation struct {
	// contains filtered or unexported fields
}

StrikeOutAnnotation represents a strikeout markup annotation.

StrikeOut annotations draw a line through text.

Example: 

strikeout := creator.NewStrikeOutAnnotation(100, 650, 300, 670)
strikeout.SetColor(creator.Red)
page.AddStrikeOutAnnotation(strikeout)

func NewStrikeOutAnnotation 

func NewStrikeOutAnnotation(x1, y1, x2, y2 float64) *StrikeOutAnnotation

NewStrikeOutAnnotation creates a new strikeout annotation.

The strikeout line is drawn through the rectangular area from (x1, y1) to (x2, y2).

Parameters:

  • x1: Left X coordinate (from left edge)
  • y1: Bottom Y coordinate (from bottom edge)
  • x2: Right X coordinate (from left edge)
  • y2: Top Y coordinate (from bottom edge)

Example: 

strikeout := creator.NewStrikeOutAnnotation(100, 650, 300, 670)
strikeout.SetColor(creator.Red)

func (*StrikeOutAnnotation) SetAuthor 

func (a *StrikeOutAnnotation) SetAuthor(author string) *StrikeOutAnnotation

SetAuthor sets the author name.

Example: 

strikeout.SetAuthor("John Doe")

func (*StrikeOutAnnotation) SetColor 

func (a *StrikeOutAnnotation) SetColor(color Color) *StrikeOutAnnotation

SetColor sets the strikeout color.

Example: 

strikeout.SetColor(creator.Red)

func (*StrikeOutAnnotation) SetNote 

func (a *StrikeOutAnnotation) SetNote(note string) *StrikeOutAnnotation

SetNote sets an optional note text.

Example: 

strikeout.SetNote("Obsolete")

type Stroke added in v0.2.0 

type Stroke struct {
	// Paint is the paint source (Color, ColorRGBA, ColorCMYK, or Gradient).
	Paint Paint

	// Width is the line width in user space units.
	// Default: 1.0
	Width float64

	// LineCap defines how line ends are rendered.
	// Default: LineCapButt
	LineCap LineCap

	// LineJoin defines how corners are rendered.
	// Default: LineJoinMiter
	LineJoin LineJoin

	// MiterLimit is the maximum miter length for LineJoinMiter.
	// When miter length exceeds this, a bevel join is used instead.
	// Default: 10.0
	MiterLimit float64

	// DashArray defines the dash pattern.
	// Alternating on/off lengths: [on1, off1, on2, off2, ...]
	// Empty array = solid line (no dashing).
	DashArray []float64

	// DashPhase is the offset into the dash pattern.
	// Default: 0
	DashPhase float64
}

Stroke represents stroke configuration for shapes.

Stroke controls how shape outlines are drawn with paint (color or gradient). It includes the paint source, line width, cap style, join style, and dash pattern.

Example: 

// Solid color stroke
stroke := &Stroke{
    Paint:      Black,
    Width:      2.0,
    LineCap:    LineCapRound,
    LineJoin:   LineJoinMiter,
    MiterLimit: 10.0,
}

// Dashed stroke
stroke := &Stroke{
    Paint:     Black,
    Width:     1.0,
    DashArray: []float64{5, 3},
    DashPhase: 0,
}

func NewStroke added in v0.2.0 

func NewStroke(paint Paint) *Stroke

NewStroke creates a new Stroke with the specified paint.

Default values:

  • Width: 1.0
  • LineCap: LineCapButt
  • LineJoin: LineJoinMiter
  • MiterLimit: 10.0
  • DashArray: nil (solid line)
  • DashPhase: 0

Parameters:

  • paint: Paint source (Color, ColorRGBA, ColorCMYK, or Gradient)

Example: 

stroke := NewStroke(Black)
stroke := NewStroke(NewLinearGradient(0, 0, 100, 0))

func (*Stroke) Validate added in v0.2.0 

func (s *Stroke) Validate() error

Validate validates the stroke configuration.

Checks:

  • Paint is not nil
  • Width is positive
  • MiterLimit is >= 1.0
  • DashArray values are all positive
  • If paint is a Gradient, validate gradient

Returns an error if validation fails.

func (*Stroke) WithDash added in v0.2.0 

func (s *Stroke) WithDash(dashArray []float64, dashPhase float64) *Stroke

WithDash returns a new Stroke with the specified dash pattern.

Parameters:

  • dashArray: Alternating on/off lengths
  • dashPhase: Offset into the dash pattern

Example: 

// Dash: 5 on, 3 off
stroke := NewStroke(Black).WithDash([]float64{5, 3}, 0)

// Dash: 10 on, 5 off, 2 on, 5 off
stroke := NewStroke(Black).WithDash([]float64{10, 5, 2, 5}, 0)

func (*Stroke) WithLineCap added in v0.2.0 

func (s *Stroke) WithLineCap(cap LineCap) *Stroke

WithLineCap returns a new Stroke with the specified line cap style.

Parameters:

  • cap: Line cap style (LineCapButt, LineCapRound, LineCapSquare)

Example: 

stroke := NewStroke(Black).WithLineCap(LineCapRound)

func (*Stroke) WithLineJoin added in v0.2.0 

func (s *Stroke) WithLineJoin(join LineJoin) *Stroke

WithLineJoin returns a new Stroke with the specified line join style.

Parameters:

  • join: Line join style (LineJoinMiter, LineJoinRound, LineJoinBevel)

Example: 

stroke := NewStroke(Black).WithLineJoin(LineJoinRound)

func (*Stroke) WithMiterLimit added in v0.2.0 

func (s *Stroke) WithMiterLimit(limit float64) *Stroke

WithMiterLimit returns a new Stroke with the specified miter limit.

Parameters:

  • limit: Maximum miter length (must be >= 1.0)

Example: 

stroke := NewStroke(Black).WithMiterLimit(5.0)

func (*Stroke) WithWidth added in v0.2.0 

func (s *Stroke) WithWidth(width float64) *Stroke

WithWidth returns a new Stroke with the specified width.

Parameters:

  • width: Line width in user space units (must be positive)

Example: 

stroke := NewStroke(Black).WithWidth(2.0)

type StyledParagraph 

type StyledParagraph struct {
	// contains filtered or unexported fields
}

StyledParagraph is a paragraph with multiple text styles.

Unlike a simple Paragraph that has one style for all text, StyledParagraph allows mixing different fonts, sizes, and colors within the same paragraph while maintaining proper text wrapping and alignment.

Example: 

sp := NewStyledParagraph()
sp.Append("This is ")
sp.AppendStyled("bold", TextStyle{Font: HelveticaBold, Size: 12, Color: Black})
sp.Append(" and this is ")
sp.AppendStyled("red", TextStyle{Font: Helvetica, Size: 12, Color: Red})
sp.Append(" text.")
sp.SetAlignment(AlignJustify)
page.Draw(sp)

func NewStyledParagraph 

func NewStyledParagraph() *StyledParagraph

NewStyledParagraph creates a new styled paragraph.

Default settings:

  • Alignment: Left
  • Line spacing: 1.2 (120%)
  • No text chunks initially

func (*StyledParagraph) Append 

func (sp *StyledParagraph) Append(text string) *StyledParagraph

Append adds text using the default style. Returns the paragraph for method chaining.

func (*StyledParagraph) AppendStyled 

func (sp *StyledParagraph) AppendStyled(text string, style TextStyle) *StyledParagraph

AppendStyled adds text with a specific style. Returns the paragraph for method chaining.

func (*StyledParagraph) Draw 

func (sp *StyledParagraph) Draw(ctx *LayoutContext, page *Page) error

Draw renders the styled paragraph on the page at the current cursor position.

func (*StyledParagraph) Height 

func (sp *StyledParagraph) Height(ctx *LayoutContext) float64

Height calculates the total height of the styled paragraph when rendered.

func (*StyledParagraph) SetAlignment 

func (sp *StyledParagraph) SetAlignment(a Alignment) *StyledParagraph

SetAlignment sets the text alignment. Returns the paragraph for method chaining.

func (*StyledParagraph) SetLineSpacing 

func (sp *StyledParagraph) SetLineSpacing(spacing float64) *StyledParagraph

SetLineSpacing sets the line spacing multiplier. 1.0 = single spacing, 1.5 = 150% spacing, 2.0 = double spacing. Returns the paragraph for method chaining.

type Surface added in v0.2.0 

type Surface struct {
	// contains filtered or unexported fields
}

Surface represents a drawing surface with a graphics state stack.

Surface provides Skia-like Push/Pop semantics for graphics state management. This allows composable transformations, opacity, blend modes, and clipping.

Example: 

surface := page.Surface()

// Draw with transform and opacity
surface.PushTransform(Rotate(45))
surface.PushOpacity(0.5)
surface.DrawRect(rect)
surface.Pop()  // Restore opacity
surface.Pop()  // Restore transform

func NewSurface added in v0.2.0 

func NewSurface(page *Page) *Surface

NewSurface creates a new drawing surface for a page.

The surface starts with an empty state stack and default graphics state.

func (*Surface) CurrentBlendMode added in v0.2.0 

func (s *Surface) CurrentBlendMode() BlendMode

CurrentBlendMode returns the current blend mode.

func (*Surface) CurrentClipPath added in v0.2.0 

func (s *Surface) CurrentClipPath() *Path

CurrentClipPath returns the current clipping path (nil if no clipping).

func (*Surface) CurrentFill added in v0.2.0 

func (s *Surface) CurrentFill() *Fill

CurrentFill returns the current fill configuration.

func (*Surface) CurrentOpacity added in v0.2.0 

func (s *Surface) CurrentOpacity() float64

CurrentOpacity returns the current opacity value.

func (*Surface) CurrentStroke added in v0.2.0 

func (s *Surface) CurrentStroke() *Stroke

CurrentStroke returns the current stroke configuration.

func (*Surface) CurrentTransform added in v0.2.0 

func (s *Surface) CurrentTransform() Transform

CurrentTransform returns the current transformation matrix.

func (*Surface) DrawPath added in v0.2.0 

func (s *Surface) DrawPath(path *Path) error

DrawPath draws a path with the current fill and stroke.

The path is drawn using the current graphics state. If both fill and stroke are set, the path is filled then stroked (B operator). If only fill is set, the path is filled (f operator). If only stroke is set, the path is stroked (S operator). If neither is set, no drawing occurs (but path is constructed).

Parameters:

  • path: Path to draw

Example: 

path := NewPath()
path.MoveTo(0, 0)
path.LineTo(100, 0)
path.LineTo(50, 100)
path.Close()

surface.SetFill(NewFill(Red))
surface.SetStroke(NewStroke(Black).WithWidth(2))
surface.DrawPath(path)

func (*Surface) DrawRect added in v0.2.0 

func (s *Surface) DrawRect(rect Rect) error

DrawRect draws a rectangle with the current fill and stroke.

The rectangle is drawn using the current graphics state. If both fill and stroke are set, the rectangle is filled then stroked.

Parameters:

  • rect: Rectangle to draw

Example: 

surface.SetFill(NewFill(Red))
surface.SetStroke(NewStroke(Black).WithWidth(2))
surface.DrawRect(Rect{X: 50, Y: 50, Width: 100, Height: 100})

func (*Surface) FillPath added in v0.2.0 

func (s *Surface) FillPath(path *Path) error

FillPath fills a path using the current fill configuration.

The path is filled using the current fill color/gradient and fill rule. Stroke configuration is ignored (even if set).

PDF operators: f (NonZero) or f* (EvenOdd)

Parameters:

  • path: Path to fill

Example: 

path := NewPath().
    AddCircle(Point{150, 150}, 50)

surface.SetFill(NewFill(Red))
surface.FillPath(path)

func (*Surface) Pop added in v0.2.0 

func (s *Surface) Pop()

Pop restores the previous graphics state.

Each Pop must match a previous Push* call. Panics if Pop is called more times than Push.

Example: 

surface.PushOpacity(0.5)
surface.DrawRect(rect)
surface.Pop()  // OK
surface.Pop()  // PANIC: no matching Push

func (*Surface) PushBlendMode added in v0.2.0 

func (s *Surface) PushBlendMode(mode BlendMode)

PushBlendMode saves the current state and applies a blend mode.

The blend mode controls how colors blend with the background. Call Pop() to restore the previous blend mode.

Example: 

surface.PushBlendMode(BlendModeMultiply)
surface.DrawRect(rect)
surface.Pop()

func (*Surface) PushClipCircle added in v0.2.0 

func (s *Surface) PushClipCircle(center Point, radius float64) error

PushClipCircle saves the current state and clips to a circle.

This is a convenience method equivalent to: 

path := NewPath().AddCircle(center, radius)
surface.PushClipPath(path, FillRuleNonZero)

Parameters:

  • center: Circle center point
  • radius: Circle radius (must be positive)

Example: 

surface.PushClipCircle(Point{150, 150}, 50)
surface.DrawRect(Rect{X: 100, Y: 100, Width: 100, Height: 100}) // Circle-clipped
surface.Pop()

func (*Surface) PushClipEllipse added in v0.2.0 

func (s *Surface) PushClipEllipse(rect Rect) error

PushClipEllipse saves the current state and clips to an ellipse.

The ellipse is inscribed in the specified rectangle.

Parameters:

  • rect: Bounding rectangle of the ellipse

Example: 

surface.PushClipEllipse(Rect{X: 50, Y: 50, Width: 200, Height: 100})
surface.DrawRect(Rect{X: 0, Y: 0, Width: 300, Height: 200}) // Ellipse-clipped
surface.Pop()

func (*Surface) PushClipPath added in v0.2.0 

func (s *Surface) PushClipPath(path *Path, rule FillRule) error

PushClipPath saves the current state and applies a clipping path.

All subsequent drawing is clipped to the path. The fill rule determines which areas are "inside" the path:

  • FillRuleNonZero: Non-zero winding rule (default)
  • FillRuleEvenOdd: Even-odd rule

Clipping paths are intersected with any existing clip path. Call Pop() to restore the previous clipping state.

PDF operators:

  • W (clip with NonZero rule)
  • W* (clip with EvenOdd rule)
  • n (end path without painting)

Example: 

path := NewPath()
path.MoveTo(0, 0)
path.LineTo(100, 0)
path.LineTo(100, 100)
path.Close()

surface.PushClipPath(path, FillRuleNonZero)
surface.DrawRect(rect)  // Clipped to triangle
surface.Pop()

Reference: PDF 1.7 Specification, Section 8.5.4 (Clipping Path).

func (*Surface) PushClipRect added in v0.2.0 

func (s *Surface) PushClipRect(rect Rect) error

PushClipRect saves the current state and clips to a rectangle.

This is a convenience method equivalent to: 

path := NewPath().AddRect(rect)
surface.PushClipPath(path, FillRuleNonZero)

Parameters:

  • rect: Rectangle to clip to

Example: 

surface.PushClipRect(Rect{X: 10, Y: 10, Width: 100, Height: 100})
surface.DrawRect(Rect{X: 0, Y: 0, Width: 200, Height: 200}) // Only 10-110 visible
surface.Pop()

func (*Surface) PushOpacity added in v0.2.0 

func (s *Surface) PushOpacity(opacity float64) error

PushOpacity saves the current state and applies an opacity.

The opacity is multiplicative with the current opacity. Call Pop() to restore the previous opacity.

Example: 

surface.PushOpacity(0.5)
surface.PushOpacity(0.5)  // Combined opacity = 0.25
surface.DrawRect(rect)
surface.Pop()  // opacity = 0.5
surface.Pop()  // opacity = 1.0

func (*Surface) PushTransform added in v0.2.0 

func (s *Surface) PushTransform(t Transform)

PushTransform saves the current state and applies a transformation.

The transformation is applied to all subsequent drawing operations. Call Pop() to restore the previous state.

Example: 

surface.PushTransform(Rotate(45))
surface.DrawRect(rect)  // Drawn rotated
surface.Pop()           // Restore rotation

func (*Surface) SetFill added in v0.2.0 

func (s *Surface) SetFill(fill *Fill)

SetFill sets the current fill configuration.

All subsequent drawing operations will use this fill. Pass nil to disable filling.

Example: 

fill := NewFill(Red).WithOpacity(0.8)
surface.SetFill(fill)
surface.DrawRect(rect)  // Filled with red at 80% opacity

func (*Surface) SetStroke added in v0.2.0 

func (s *Surface) SetStroke(stroke *Stroke)

SetStroke sets the current stroke configuration.

All subsequent drawing operations will use this stroke. Pass nil to disable stroking.

Example: 

stroke := NewStroke(Black).WithWidth(2.0)
surface.SetStroke(stroke)
surface.DrawRect(rect)  // Stroked with black 2pt line

func (*Surface) StackDepth added in v0.2.0 

func (s *Surface) StackDepth() int

StackDepth returns the number of saved states on the stack.

This is useful for debugging and ensuring Push/Pop are balanced.

func (*Surface) StrokePath added in v0.2.0 

func (s *Surface) StrokePath(path *Path) error

StrokePath strokes a path using the current stroke configuration.

The path is stroked using the current stroke color/gradient, line width, cap style, join style, and dash pattern. Fill configuration is ignored (even if set).

PDF operator: S

Parameters:

  • path: Path to stroke

Example: 

path := NewPath().
    MoveTo(50, 50).
    LineTo(150, 50).
    LineTo(100, 150).
    Close()

stroke := NewStroke(Black).
    WithWidth(3.0).
    WithLineCap(LineCapRound).
    WithLineJoin(LineJoinRound)
surface.SetStroke(stroke)
surface.StrokePath(path)

type TOC 

type TOC struct {
	// contains filtered or unexported fields
}

TOC represents a Table of Contents for the document.

The TOC is automatically generated from document chapters and includes clickable links to each chapter/section.

Example: 

c := creator.New()
c.EnableTOC()
// Add chapters...
c.WriteToFile("document.pdf")  // TOC is automatically generated

func NewTOC 

func NewTOC() *TOC

NewTOC creates a new Table of Contents.

The TOC will be populated with chapters when the document is rendered.

Example: 

toc := NewTOC()
toc.SetTitle("Contents")

func (*TOC) Draw 

func (t *TOC) Draw(ctx *LayoutContext, page *Page) error

Draw renders the Table of Contents.

func (*TOC) GetEntries 

func (t *TOC) GetEntries() []TOCEntry

GetEntries returns all TOC entries in document order.

This is useful for custom TOC rendering or testing.

func (*TOC) Height 

func (t *TOC) Height(ctx *LayoutContext) float64

Height calculates the total height needed for the TOC.

func (*TOC) Leader 

func (t *TOC) Leader() string

Leader returns the current leader character.

func (*TOC) SetLeader 

func (t *TOC) SetLeader(leader string)

SetLeader sets the leader character (default: ".").

Example: 

toc.SetLeader(".")  // Introduction .............. 1
toc.SetLeader("-")  // Introduction ------------- 1

func (*TOC) SetShowPageNumbers 

func (t *TOC) SetShowPageNumbers(show bool)

SetShowPageNumbers enables/disables page number display.

func (*TOC) SetStyle 

func (t *TOC) SetStyle(style TOCStyle)

SetStyle sets the TOC visual style.

func (*TOC) SetTitle 

func (t *TOC) SetTitle(title string)

SetTitle sets the TOC heading title.

func (*TOC) ShowPageNumbers 

func (t *TOC) ShowPageNumbers() bool

ShowPageNumbers returns whether page numbers are displayed.

func (*TOC) Style 

func (t *TOC) Style() TOCStyle

Style returns the current TOC style.

func (*TOC) Title 

func (t *TOC) Title() string

Title returns the TOC heading title.

type TOCEntry 

type TOCEntry struct {
	// Title of the chapter/section
	Title string

	// Number of the chapter (e.g., "1.2.3")
	Number string

	// Level of nesting (0 = top-level)
	Level int

	// PageIndex where the chapter starts (0-based)
	PageIndex int
}

TOCEntry represents a single entry in the Table of Contents.

This is used internally for rendering and testing.

type TOCStyle 

type TOCStyle struct {
	// TitleFont for the "Table of Contents" heading
	TitleFont FontName

	// TitleSize for the heading
	TitleSize float64

	// TitleColor for the heading
	TitleColor Color

	// EntryFont for TOC entries
	EntryFont FontName

	// EntrySize for TOC entries (base size, reduced for sub-levels)
	EntrySize float64

	// EntryColor for TOC entries
	EntryColor Color

	// IndentPerLevel is the indentation in points for each sub-level
	IndentPerLevel float64

	// LineSpacing between TOC entries
	LineSpacing float64

	// SpaceAfterTitle is the space after the TOC heading
	SpaceAfterTitle float64

	// LeaderFont for the leader dots (...)
	LeaderFont FontName

	// LeaderSize for the leader dots
	LeaderSize float64

	// LeaderColor for the leader dots
	LeaderColor Color
}

TOCStyle defines the visual style for the Table of Contents.

func DefaultTOCStyle 

func DefaultTOCStyle() TOCStyle

DefaultTOCStyle returns the default TOC style.

Default style:

  • TitleFont: HelveticaBold, 24pt, Black
  • EntryFont: Helvetica, 12pt, Black
  • IndentPerLevel: 20pt
  • LineSpacing: 1.5
  • SpaceAfterTitle: 20pt
  • LeaderFont: Helvetica, 12pt, Gray

type TableCell 

type TableCell struct {
	// Content is the text content of the cell.
	Content string

	// Font is the font for the cell content.
	Font FontName

	// FontSize is the font size in points.
	FontSize float64

	// Color is the text color.
	Color Color

	// Align is the horizontal alignment within the cell.
	Align Alignment

	// ColSpan is the number of columns this cell spans (future use).
	ColSpan int
}

TableCell represents a cell in a table.

func NewTableCell 

func NewTableCell(content string) TableCell

NewTableCell creates a new table cell with text content and default styling.

type TableLayout 

type TableLayout struct {
	// contains filtered or unexported fields
}

TableLayout represents a table that can be drawn on a page.

Tables support automatic column width calculation, borders, and header rows with bold styling.

Example: 

table := NewTableLayout(3)
table.SetBorder(0.5, Black)
table.AddHeaderRow("Name", "Age", "City")
table.AddRow("Alice", "30", "New York")
table.AddRow("Bob", "25", "Los Angeles")
page.Draw(table)

func NewTableLayout 

func NewTableLayout(columns int) *TableLayout

NewTableLayout creates a new table with the specified number of columns.

func (*TableLayout) AddHeaderRow 

func (t *TableLayout) AddHeaderRow(cells ...string) *TableLayout

AddHeaderRow adds a header row with the given cell texts. Header rows use bold font by default. Returns the table for method chaining.

func (*TableLayout) AddRow 

func (t *TableLayout) AddRow(cells ...string) *TableLayout

AddRow adds a row with the given cell texts using default styling. Returns the table for method chaining.

func (*TableLayout) AddRowCells 

func (t *TableLayout) AddRowCells(cells ...TableCell) *TableLayout

AddRowCells adds a row with fully-configured cells. Returns the table for method chaining.

func (*TableLayout) ColumnCount 

func (t *TableLayout) ColumnCount() int

ColumnCount returns the number of columns.

func (*TableLayout) Draw 

func (t *TableLayout) Draw(ctx *LayoutContext, page *Page) error

Draw renders the table on the page at the current cursor position.

func (*TableLayout) HeaderRowCount 

func (t *TableLayout) HeaderRowCount() int

HeaderRowCount returns the number of header rows.

func (*TableLayout) Height 

func (t *TableLayout) Height(_ *LayoutContext) float64

Height calculates the total height of the table when rendered.

func (*TableLayout) RowCount 

func (t *TableLayout) RowCount() int

RowCount returns the number of rows (including header rows).

func (*TableLayout) SetBorder 

func (t *TableLayout) SetBorder(width float64, color Color) *TableLayout

SetBorder enables table borders with the specified width and color. Returns the table for method chaining.

func (*TableLayout) SetCellPadding 

func (t *TableLayout) SetCellPadding(padding float64) *TableLayout

SetCellPadding sets the padding inside cells. Returns the table for method chaining.

func (*TableLayout) SetColumnWidths 

func (t *TableLayout) SetColumnWidths(widths ...float64) *TableLayout

SetColumnWidths sets explicit widths for each column. If not all widths are provided, remaining columns use auto width. Returns the table for method chaining.

type TableRow 

type TableRow struct {
	Cells []TableCell
}

TableRow represents a row in a table.

type TextAnnotation 

type TextAnnotation struct {
	// contains filtered or unexported fields
}

TextAnnotation represents a sticky note annotation in the Creator API.

Text annotations appear as icons (sticky notes) on PDF pages. When clicked, they display pop-up text.

Example: 

note := creator.NewTextAnnotation(100, 700, "This is a comment")
note.SetAuthor("John Doe")
note.SetColor(creator.Yellow)
note.SetOpen(true)
page.AddTextAnnotation(note)

func NewTextAnnotation 

func NewTextAnnotation(x, y float64, contents string) *TextAnnotation

NewTextAnnotation creates a new text annotation (sticky note).

The annotation appears as a small icon (typically 20x20 points) at (x, y). When clicked, it displays the contents text in a pop-up.

Parameters:

  • x: Horizontal position in points (from left edge)
  • y: Vertical position in points (from bottom edge)
  • contents: Text to display in the pop-up

Example: 

note := creator.NewTextAnnotation(100, 700, "Review this section")
note.SetAuthor("Alice")
note.SetColor(creator.Yellow)

func (*TextAnnotation) SetAuthor 

func (a *TextAnnotation) SetAuthor(author string) *TextAnnotation

SetAuthor sets the author name for the annotation.

This appears in the annotation properties and can be used to track who added the comment.

Example: 

note.SetAuthor("John Doe")

func (*TextAnnotation) SetColor 

func (a *TextAnnotation) SetColor(color Color) *TextAnnotation

SetColor sets the annotation color.

Common colors for sticky notes:

  • Yellow (default)
  • Red (important)
  • Green (ok/approved)
  • Blue (informational)

Example: 

note.SetColor(creator.Red) // Mark as important

func (*TextAnnotation) SetOpen 

func (a *TextAnnotation) SetOpen(open bool) *TextAnnotation

SetOpen sets whether the pop-up should be open by default.

If true, the pop-up is visible when the PDF is opened. If false, the user must click the icon to see the text.

Example: 

note.SetOpen(true) // Show immediately

type TextChunk 

type TextChunk struct {
	// Text is the text content.
	Text string

	// Style is the styling to apply to this chunk.
	Style TextStyle
}

TextChunk represents a piece of text with specific styling.

TextChunks are combined to create a StyledParagraph with multiple text styles within the same paragraph.

Example: 

chunk := TextChunk{
    Text:  "Hello World",
    Style: DefaultTextStyle(),
}

type TextOperation 

type TextOperation struct {
	// Text is the string to display.
	Text string

	// X is the horizontal position in points (from left edge of page).
	X float64

	// Y is the vertical position in points (from bottom edge of page).
	Y float64

	// Font is the font to use (one of the Standard 14 fonts).
	// Ignored if CustomFont is set.
	Font FontName

	// CustomFont is an embedded TrueType/OpenType font (optional).
	// When set, this takes precedence over Font field.
	// Use for Unicode text (Cyrillic, CJK, symbols, etc.).
	CustomFont *CustomFont

	// Size is the font size in points.
	Size float64

	// Color is the text color (RGB, 0.0 to 1.0 range).
	// If ColorCMYK is set, this field is ignored.
	Color Color

	// ColorCMYK is the text color in CMYK color space (optional).
	// If set, this takes precedence over Color (RGB).
	// Used for professional printing workflows.
	ColorCMYK *ColorCMYK

	// Opacity is the text opacity (0.0 = transparent, 1.0 = opaque).
	// Optional. If set, applies transparency via ExtGState.
	// Works with both Color and ColorCMYK.
	// Range: [0.0, 1.0]
	Opacity *float64

	// Rotation is the text rotation in degrees, counter-clockwise.
	// The rotation pivot is the text origin point (X, Y).
	// Zero means no rotation (default horizontal text).
	// Positive values rotate counter-clockwise; negative values rotate clockwise.
	//
	// Example: 90 degrees rotates text to read bottom-to-top.
	Rotation float64
}

TextOperation represents a text drawing operation to be added to a page.

Each TextOperation describes how to render a single text string at a specific position with a specific font, size, and color.

Example: 

op := TextOperation{
    Text:  "Hello World",
    X:     100,
    Y:     700,
    Font:  Helvetica,
    Size:  24,
    Color: Black,
}

type TextStyle 

type TextStyle struct {
	// Font is the font to use (one of the Standard 14 fonts).
	Font FontName

	// Size is the font size in points.
	Size float64

	// Color is the text color (RGB, 0.0 to 1.0 range).
	Color Color
}

TextStyle defines styling for a text chunk.

TextStyle combines font, size, and color into a single style definition that can be applied to text chunks in a StyledParagraph.

Example: 

boldRed := TextStyle{
    Font:  HelveticaBold,
    Size:  14,
    Color: Red,
}

func DefaultTextStyle 

func DefaultTextStyle() TextStyle

DefaultTextStyle returns the default text style.

Default style:

  • Font: Helvetica
  • Size: 12pt
  • Color: Black

type TextWatermark 

type TextWatermark struct {
	// contains filtered or unexported fields
}

TextWatermark represents a text watermark to be applied to PDF pages.

A watermark is semi-transparent text (typically "CONFIDENTIAL", "DRAFT", etc.) rendered on a page, often rotated diagonally.

Example: 

wm := creator.NewTextWatermark("CONFIDENTIAL")
wm.SetFont(creator.HelveticaBold, 72)
wm.SetColor(creator.Gray)
wm.SetOpacity(0.3)
wm.SetRotation(45)
page.DrawWatermark(wm)

func NewTextWatermark 

func NewTextWatermark(text string) *TextWatermark

NewTextWatermark creates a new text watermark with default settings.

Default settings:

  • Font: HelveticaBold
  • Font size: 48 points
  • Color: Gray (0.5, 0.5, 0.5)
  • Opacity: 0.5 (50% transparent)
  • Rotation: 45 degrees (diagonal)
  • Position: Center

Example: 

wm := creator.NewTextWatermark("DRAFT")

func (*TextWatermark) Color 

func (w *TextWatermark) Color() Color

Color returns the watermark color.

func (*TextWatermark) Font 

func (w *TextWatermark) Font() FontName

Font returns the watermark font.

func (*TextWatermark) FontSize 

func (w *TextWatermark) FontSize() float64

FontSize returns the watermark font size.

func (*TextWatermark) Opacity 

func (w *TextWatermark) Opacity() float64

Opacity returns the watermark opacity.

func (*TextWatermark) Position 

func (w *TextWatermark) Position() WatermarkPosition

Position returns the watermark position.

func (*TextWatermark) Rotation 

func (w *TextWatermark) Rotation() float64

Rotation returns the watermark rotation in degrees.

func (*TextWatermark) SetColor 

func (w *TextWatermark) SetColor(color Color) error

SetColor sets the watermark text color.

Color components must be in the range [0.0, 1.0].

Example: 

wm.SetColor(creator.Red)
wm.SetColor(creator.Color{R: 0.8, G: 0.0, B: 0.0})

func (*TextWatermark) SetFont 

func (w *TextWatermark) SetFont(font FontName, size float64) error

SetFont sets the watermark font and size.

Parameters:

  • font: Font name (one of the Standard 14 fonts)
  • size: Font size in points (must be > 0)

Example: 

wm.SetFont(creator.HelveticaBold, 72)

func (*TextWatermark) SetOpacity 

func (w *TextWatermark) SetOpacity(opacity float64) error

SetOpacity sets the watermark transparency.

Opacity must be in the range [0.0, 1.0]:

  • 0.0 = fully transparent (invisible)
  • 1.0 = fully opaque (no transparency)
  • 0.3-0.5 = typical watermark range

Example: 

wm.SetOpacity(0.3) // 30% opaque, 70% transparent

func (*TextWatermark) SetPosition 

func (w *TextWatermark) SetPosition(position WatermarkPosition) error

SetPosition sets the watermark position on the page.

Example: 

wm.SetPosition(creator.WatermarkCenter)
wm.SetPosition(creator.WatermarkTopRight)

func (*TextWatermark) SetRotation 

func (w *TextWatermark) SetRotation(degrees float64) error

SetRotation sets the watermark rotation angle in degrees (clockwise).

Common values:

  • 0 = horizontal
  • 45 = diagonal (typical for "CONFIDENTIAL")
  • 90 = vertical

Example: 

wm.SetRotation(45) // Diagonal

func (*TextWatermark) Text 

func (w *TextWatermark) Text() string

Text returns the watermark text.

type Transform added in v0.2.0 

type Transform struct {
	A, B, C, D, E, F float64
}

Transform represents a 2D affine transformation matrix.

PDF uses column-major matrix notation: 

[ a  b  0 ]
[ c  d  0 ]
[ e  f  1 ]

Where: 

a, d: Scale
b, c: Skew/Rotation
e, f: Translation

func Identity added in v0.2.0 

func Identity() Transform

Identity returns the identity transformation (no change).

func Rotate added in v0.2.0 

func Rotate(degrees float64) Transform

Rotate returns a rotation transformation.

The angle is in degrees, clockwise.

Example: 

t := Rotate(45)   // Rotate 45° clockwise
t := Rotate(-90)  // Rotate 90° counter-clockwise

func RotateAround added in v0.2.0 

func RotateAround(degrees, cx, cy float64) Transform

RotateAround returns a rotation transformation around a specific point.

Example: 

t := RotateAround(45, 100, 200)  // Rotate 45° around point (100, 200)

func Scale added in v0.2.0 

func Scale(sx, sy float64) Transform

Scale returns a scaling transformation.

Example: 

t := Scale(2, 2)     // Double size
t := Scale(1, -1)    // Flip vertically

func Skew added in v0.2.0 

func Skew(angleX, angleY float64) Transform

Skew returns a skew transformation.

Example: 

t := Skew(15, 0)  // Skew horizontally by 15°

func Translate added in v0.2.0 

func Translate(tx, ty float64) Transform

Translate returns a translation transformation.

Example: 

t := Translate(100, 200)  // Move right 100, up 200

func (Transform) Then added in v0.2.0 

func (t Transform) Then(other Transform) Transform

Then combines this transformation with another.

The result is equivalent to applying this transform first, then the other.

Example: 

t := Translate(100, 0).Then(Rotate(45))  // Move, then rotate

func (Transform) ToPDFMatrix added in v0.2.0 

func (t Transform) ToPDFMatrix() [6]float64

ToPDFMatrix returns the transformation as a PDF CTM (Current Transformation Matrix).

Returns 6 values: [a b c d e f]

func (Transform) TransformPoint added in v0.2.0 

func (t Transform) TransformPoint(x, y float64) (float64, float64)

TransformPoint applies the transformation to a point.

Returns the transformed coordinates.

type UnderlineAnnotation 

type UnderlineAnnotation struct {
	// contains filtered or unexported fields
}

UnderlineAnnotation represents an underline markup annotation.

Underline annotations draw a line under text.

Example: 

underline := creator.NewUnderlineAnnotation(100, 650, 300, 670)
underline.SetColor(creator.Blue)
page.AddUnderlineAnnotation(underline)

func NewUnderlineAnnotation 

func NewUnderlineAnnotation(x1, y1, x2, y2 float64) *UnderlineAnnotation

NewUnderlineAnnotation creates a new underline annotation.

The underline is drawn under the rectangular area from (x1, y1) to (x2, y2).

Parameters:

  • x1: Left X coordinate (from left edge)
  • y1: Bottom Y coordinate (from bottom edge)
  • x2: Right X coordinate (from left edge)
  • y2: Top Y coordinate (from bottom edge)

Example: 

underline := creator.NewUnderlineAnnotation(100, 650, 300, 670)
underline.SetColor(creator.Blue)

func (*UnderlineAnnotation) SetAuthor 

func (a *UnderlineAnnotation) SetAuthor(author string) *UnderlineAnnotation

SetAuthor sets the author name.

Example: 

underline.SetAuthor("John Doe")

func (*UnderlineAnnotation) SetColor 

func (a *UnderlineAnnotation) SetColor(color Color) *UnderlineAnnotation

SetColor sets the underline color.

Example: 

underline.SetColor(creator.Blue)

func (*UnderlineAnnotation) SetNote 

func (a *UnderlineAnnotation) SetNote(note string) *UnderlineAnnotation

SetNote sets an optional note text.

Example: 

underline.SetNote("Check this")

type WatermarkPosition 

type WatermarkPosition int

WatermarkPosition defines the position of a watermark on a page. 

const (
	// WatermarkCenter positions the watermark at the page center.
	WatermarkCenter WatermarkPosition = iota

	// WatermarkTopLeft positions the watermark at the top-left corner.
	WatermarkTopLeft

	// WatermarkTopRight positions the watermark at the top-right corner.
	WatermarkTopRight

	// WatermarkBottomLeft positions the watermark at the bottom-left corner.
	WatermarkBottomLeft

	// WatermarkBottomRight positions the watermark at the bottom-right corner.
	WatermarkBottomRight
)

Source Files

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Directories

Path Synopsis
Package forms provides interactive form field support for PDF documents.
 Package forms provides interactive form field support for PDF documents.

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