drawutil

type Annotation struct {
	Offset     int
	Bytes      []byte
	NotesBytes []byte // used for arrival index
}

type AnnotationGroup struct {
	sync.RWMutex
	Anns []*Annotation
}

type ColorizeGroup struct {
	Off bool
	Ops []*ColorizeOp
}

type ColorizeOp struct {
	Offset    int
	Fg, Bg    color.Color
	ProcColor func(fg, bg color.Color) (fg2, bg2 color.Color)
	Line      bool
	SetNil    bool
}

type Decoration struct {
	Offset    int
	Kind      DecorationKind
	Fg        color.Color
	Thickness int
}

type DecorationGroup struct {
	Off     bool
	Entries []*Decoration
}

type DecorationKind uint8

type Drawer interface {
	Reader() iorw.ReaderAt
	SetReader(iorw.ReaderAt)
	ContentChanged()
	TextDrawerOptions() *TextDrawerOptions
	TextDrawerOptionsChanged()

	FontFace() *fontutil.FontFace
	SetFontFace(*fontutil.FontFace)
	LineHeight() int
	SetFg(color.Color)

	Bounds() image.Rectangle
	SetBounds(image.Rectangle)

	// rune offset  (set text view position; save/restore view in session file)
	RuneOffset() int
	SetRuneOffset(int)

	LocalPointOf(index int) image.Point
	LocalIndexOf(image.Point) int
	AnnotationsIndexOf(image.Point) (int, int, bool)

	Measure() image.Point
	Draw(img draw.Image)

	// specialized: covers editor row button margin
	FirstLineOffsetX() int
	SetFirstLineOffsetX(x int)

	// cursor
	SetCursorOffset(int)

	// scrollable utils
	ScrollOffset() image.Point
	SetScrollOffset(image.Point)
	ScrollSize() image.Point
	ScrollViewSize() image.Point
	ScrollPageSizeY(up bool) int
	ScrollWheelSizeY(up bool) int

	// visibility utils
	RangeVisible(offset, n int) bool
	RangeVisibleOffset(offset, n int, align RangeAlignment) int
}

type RangeAlignment int

type SyntaxComment struct {
	Start string
	End   string // empty for single line comment
}

type TextDrawerOptions struct {
	LineWrap struct {
		On     bool
		Fg, Bg color.Color
	}
	Cursor struct {
		On         bool
		Fg         color.Color
		AddedWidth int
	}
	IndexOf struct {
		HalfHit bool
	}
	TextContrast struct {
		On bool
		Bg color.Color
	}
	Colorize struct {
		Groups []*ColorizeGroup
	}
	Decorations struct {
		Groups []*DecorationGroup
	}
	Annotations struct {
		On       bool
		Fg, Bg   color.Color
		Selected struct {
			EntryIndex int
			Fg, Bg     color.Color
		}
		Entries *AnnotationGroup // must be ordered by offset
	}
	WordHighlight struct {
		On     bool
		Fg, Bg color.Color
		Group  ColorizeGroup
	}
	ParenthesisHighlight struct {
		On     bool
		Fg, Bg color.Color
		Group  ColorizeGroup
	}
	ContentColorize struct {
		Git struct {
			On       bool
			AddFg    color.Color
			DeleteFg color.Color
		}
		Group ColorizeGroup
	}
	SyntaxHighlight struct {
		On      bool
		Comment struct {
			SCs    []*SyntaxComment
			Fg, Bg color.Color
		}
		String struct {
			Fg, Bg color.Color
		}
		Group ColorizeGroup
	}
}