README
¶
gvcode
gvcode is a Gio based text editor for code editing.
Key Features:
- Uses a PieceTable backed text buffer for efficient text editing.
- Optimized undo/redo operations with built-in support in the PieceTable.
- Supports tabs and tab stops, with soft tabs coming soon.
- Lines can be unwrapped, with horizontal scrolling supported.
- Syntax highlighting is available by applying text styles.
- Built-in line numbers for better readability.
- Expanded shortcut support (Work in Progress).
- Large file rendering(Planned).
Why another code editor?
I ported Gio's editor component to gioview and added a few features to support basic code editing, but it is far from a good code editor. Keep expanding the original editor seems a wise decision, but the design of the original editor makes it hard to adding more features. And it is also not performant enough for large file editing/rendering. Most importantly it lacks tab/tab stop support. When I tried to add tab stop support to it, I found it needs a new overall design, so there is gvcode.
Key Design
Gio's text shaper layout the whole document in one pass, although internally the document is processed by paragraphs. After the shaping flow, there is a iterator style API to get the shaped glyphs one by one. This is what Gio's editor does when layouting the texts.
Gvcode has chosen another way. gvcode read and layout in a paragraph by paragrah manner. The outcomes are joined together to assemble the final document view. This gives up the oppertunity to process the text only visible in the viewport, making incremental shaping possible. Besides that we can also process tab expanding & tab stops at line level, because we have full control of the paragraph layout. To achive that goal, gvcode implemented its own line wrapper.
How To Use
Gvcode exports simple APIs to ease the integration with your project. Here is a basic example:
state := &editor.Editor{}
var ops op.Ops
for {
e := ed.window.Event()
switch e := e.(type) {
case app.DestroyEvent:
return e.Err
case app.FrameEvent:
gtx := app.NewContext(&ops, e)
es := gvcode.NewEditor(th, state)
es.Font.Typeface = "monospace"
es.TextSize = unit.Sp(12)
es.LineHeightScale = 1.5
es.Layout(gtx)
e.Frame(gtx.Ops)
}
}
For a full working example, please see code in the folder ./example.
Cautions
gvcode is not intended to be a drop-in replacement for the official Editor widget as it dropped some features such as single line mode, truncator and max lines limit.
This project is a work in progress, and the APIs may change as development continues. Please use it at your own risk.
Contributing
See the contribution guide for details.
Acknowledgments
This project uses code from the Gio project, which is licensed under the Unlicense OR MIT License.
Documentation
¶
Index ¶
- type ChangeEvent
- type Editor
- func (e *Editor) CaretCoords() f32.Point
- func (e *Editor) CaretPos() (line, col int)
- func (e *Editor) ClearSelection()
- func (e *Editor) Delete(graphemeClusters int) (deletedRunes int)
- func (e *Editor) Insert(s string) (insertedRunes int)
- func (e *Editor) Layout(gtx layout.Context, lt *text.Shaper) layout.Dimensions
- func (e *Editor) Len() int
- func (e *Editor) MoveCaret(startDelta, endDelta int)
- func (e *Editor) ReplaceAll(texts []TextRange, newStr string) int
- func (e *Editor) ScrollByRatio(gtx layout.Context, ratio float32)
- func (e *Editor) SelectedText() string
- func (e *Editor) Selection() (start, end int)
- func (e *Editor) SelectionLen() int
- func (e *Editor) SetCaret(start, end int)
- func (e *Editor) SetHighlights(highlights []TextRange)
- func (e *Editor) SetText(s string)
- func (e *Editor) Text() string
- func (e *Editor) Update(gtx layout.Context) (EditorEvent, bool)
- func (e *Editor) UpdateTextStyles(styles []*TextStyle)
- func (e *Editor) ViewPortRatio() (float32, float32)
- type EditorEvent
- type Region
- type SelectEvent
- type TextRange
- type TextStyle
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type ChangeEvent ¶ added in v0.0.2
type ChangeEvent struct{}
A ChangeEvent is generated for every user change to the text.
type Editor ¶ added in v0.0.2
type Editor struct {
// Font set the font used to draw the text.
Font font.Font
// TextSize set the size of both the main text and line number.
TextSize unit.Sp
// Alignment controls the alignment of text within the editor.
Alignment text.Alignment
// LineHeight determines the gap between baselines of text. If zero, a sensible
// default will be used.
LineHeight unit.Sp
// LineHeightScale is multiplied by LineHeight to determine the final gap
// between baselines. If zero, a sensible default will be used.
LineHeightScale float32
// WrapLine configures whether the displayed text will be broken into lines or not.
WrapLine bool
// ReadOnly controls whether the contents of the editor can be altered by
// user interaction. If set to true, the editor will allow selecting text
// and copying it interactively, but not modifying it.
ReadOnly bool
// InputHint specifies the type of on-screen keyboard to be displayed.
InputHint key.InputHint
// SoftTab controls the behaviour when user try to insert a Tab character.
// If set to true, the editor will insert the amount of space characters specified by
// TabWidth, else the editor insert a \t character.
SoftTab bool
// TabWidth set how many spaces to represent a tab character. In the case of
// soft tab, this determines the number of space characters to insert into the editor.
// While for hard tab, this controls the maximum width of the 'tab' glyph to expand to.
TabWidth int
// LineNumberGutter specifies the gap between the line number and the main text.
LineNumberGutter unit.Dp
// Color used to paint text
TextMaterial op.CallOp
// Color used to highlight the selections.
SelectMaterial op.CallOp
// Color used to highlight the current paragraph.
LineMaterial op.CallOp
// Color used to paint the line number
LineNumberMaterial op.CallOp
// Color used to highlight the text snippets, such as search matches.
TextHighlightMaterial op.CallOp
// WordSeperators configures a set of characters that will be used as word separators
// when doing word related operations, like navigating or deleting by word.
WordSeperators string
// contains filtered or unexported fields
}
Editor implements an editable and scrollable text area.
func (*Editor) CaretCoords ¶ added in v0.0.2
CaretCoords returns the coordinates of the caret, relative to the editor itself.
func (*Editor) ClearSelection ¶ added in v0.0.2
func (e *Editor) ClearSelection()
ClearSelection clears the selection, by setting the selection end equal to the selection start.
func (*Editor) Delete ¶ added in v0.0.2
Delete runes from the caret position. The sign of the argument specifies the direction to delete: positive is forward, negative is backward.
If there is a selection, it is deleted and counts as a single grapheme cluster.
func (*Editor) MoveCaret ¶ added in v0.0.2
MoveCaret moves the caret (aka selection start) and the selection end relative to their current positions. Positive distances moves forward, negative distances moves backward. Distances are in grapheme clusters, which closely match what users perceive as "characters" even when the characters are multiple code points long.
func (*Editor) ReplaceAll ¶ added in v0.0.2
ReplaceAll replaces all texts specifed in TextRange with newStr. It returns the number of occurrences replaced.
func (*Editor) ScrollByRatio ¶ added in v0.0.2
func (*Editor) SelectedText ¶ added in v0.0.2
SelectedText returns the currently selected text (if any) from the editor.
func (*Editor) Selection ¶ added in v0.0.2
Selection returns the start and end of the selection, as rune offsets. start can be > end.
func (*Editor) SelectionLen ¶ added in v0.0.2
SelectionLen returns the length of the selection, in runes; it is equivalent to utf8.RuneCountInString(e.SelectedText()).
func (*Editor) SetCaret ¶ added in v0.0.2
SetCaret moves the caret to start, and sets the selection end to end. start and end are in runes, and represent offsets into the editor text.
func (*Editor) SetHighlights ¶ added in v0.0.2
SetHighlights sets the texts to be highlighted.
func (*Editor) Update ¶ added in v0.0.2
func (e *Editor) Update(gtx layout.Context) (EditorEvent, bool)
Update the state of the editor in response to input events. Update consumes editor input events until there are no remaining events or an editor event is generated. To fully update the state of the editor, callers should call Update until it returns false.
func (*Editor) UpdateTextStyles ¶ added in v0.0.2
func (*Editor) ViewPortRatio ¶ added in v0.0.2
returns start and end offset ratio of viewport
type EditorEvent ¶ added in v0.0.2
type EditorEvent interface {
// contains filtered or unexported methods
}
type Region ¶ added in v0.0.2
type Region struct {
// Bounds is the coordinates of the bounding box relative to the containing
// widget.
Bounds image.Rectangle
// Baseline is the quantity of vertical pixels between the baseline and
// the bottom of bounds.
Baseline int
}
Region describes the position and baseline of an area of interest within shaped text.
type SelectEvent ¶ added in v0.0.2
type SelectEvent struct{}
A SelectEvent is generated when the user selects some text, or changes the selection (e.g. with a shift-click), including if they remove the selection. The selected text is not part of the event, on the theory that it could be a relatively expensive operation (for a large editor), most applications won't actually care about it, and those that do can call Editor.SelectedText() (which can be empty).
Source Files
Directories