~eliasnaur/gio

16d2a3ac0a07493f4f3f43beb6b00002a1869f44 — Elias Naur 8 months ago e25b163
text: remove String, Layout and add Glyph

In preparation for using Shaper with an io.Reader, rework the API to not refer
to strings. In particular, introduce Glyph for holding the rune in addition to
the advance. For fast traversing of the underlying text, add Len to Line with
the UTF8 length.

Layout is a useless wrapper around []Line; remove it while we're
here.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
6 files changed, 95 insertions(+), 116 deletions(-)

M font/opentype/opentype.go
M text/lru.go
M text/shaper.go
M text/text.go
M widget/editor.go
M widget/label.go
M font/opentype/opentype.go => font/opentype/opentype.go +28 -30
@@ 85,11 85,11 @@ func (c *Collection) Font(i int) (*Font, error) {
	return &Font{font: fnt}, nil
}

func (f *Font) Layout(ppem fixed.Int26_6, str string, opts text.LayoutOptions) *text.Layout {
func (f *Font) Layout(ppem fixed.Int26_6, str string, opts text.LayoutOptions) []text.Line {
	return layoutText(&f.buf, ppem, str, &opentype{Font: f.font, Hinting: font.HintingFull}, opts)
}

func (f *Font) Shape(ppem fixed.Int26_6, str text.String) op.CallOp {
func (f *Font) Shape(ppem fixed.Int26_6, str []text.Glyph) op.CallOp {
	return textPath(&f.buf, ppem, &opentype{Font: f.font, Hinting: font.HintingFull}, str)
}



@@ 98,7 98,7 @@ func (f *Font) Metrics(ppem fixed.Int26_6) font.Metrics {
	return o.Metrics(&f.buf, ppem)
}

func layoutText(buf *sfnt.Buffer, ppem fixed.Int26_6, str string, f *opentype, opts text.LayoutOptions) *text.Layout {
func layoutText(buf *sfnt.Buffer, ppem fixed.Int26_6, str string, f *opentype, opts text.LayoutOptions) []text.Line {
	m := f.Metrics(buf, ppem)
	lineTmpl := text.Line{
		Ascent: m.Ascent,


@@ 110,18 110,18 @@ func layoutText(buf *sfnt.Buffer, ppem fixed.Int26_6, str string, f *opentype, o
	var lines []text.Line
	maxDotX := fixed.I(opts.MaxWidth)
	type state struct {
		r     rune
		advs  []fixed.Int26_6
		adv   fixed.Int26_6
		x     fixed.Int26_6
		idx   int
		valid bool
		r      rune
		layout []text.Glyph
		adv    fixed.Int26_6
		x      fixed.Int26_6
		idx    int
		valid  bool
	}
	var prev, word state
	endLine := func() {
		line := lineTmpl
		line.Text.Advances = prev.advs
		line.Text.String = str[:prev.idx]
		line.Layout = prev.layout
		line.Len = prev.idx
		line.Width = prev.x + prev.adv
		line.Bounds.Max.X += prev.x
		lines = append(lines, line)


@@ 133,17 133,17 @@ func layoutText(buf *sfnt.Buffer, ppem fixed.Int26_6, str string, f *opentype, o
		c, s := utf8.DecodeRuneInString(str[prev.idx:])
		a, valid := f.GlyphAdvance(buf, ppem, c)
		next := state{
			r:     c,
			advs:  prev.advs,
			idx:   prev.idx + s,
			x:     prev.x + prev.adv,
			adv:   a,
			valid: valid,
			r:      c,
			layout: prev.layout,
			idx:    prev.idx + s,
			x:      prev.x + prev.adv,
			adv:    a,
			valid:  valid,
		}
		if c == '\n' {
			// The newline is zero width; use the previous
			// character for line measurements.
			prev.advs = append(prev.advs, 0)
			prev.layout = append(prev.layout, text.Glyph{Rune: c, Advance: 0})
			prev.idx = next.idx
			endLine()
			continue


@@ 160,33 160,32 @@ func layoutText(buf *sfnt.Buffer, ppem fixed.Int26_6, str string, f *opentype, o
			}
			next.x -= word.x + word.adv
			next.idx -= word.idx
			next.advs = next.advs[len(word.advs):]
			next.layout = next.layout[len(word.layout):]
			prev = word
			endLine()
		} else if k != 0 {
			next.advs[len(next.advs)-1] += k
			next.layout[len(next.layout)-1].Advance += k
			next.x += k
		}
		next.advs = append(next.advs, next.adv)
		if unicode.IsSpace(next.r) {
		next.layout = append(next.layout, text.Glyph{Rune: c, Advance: next.adv})
		if unicode.IsSpace(c) {
			word = next
		}
		prev = next
	}
	endLine()
	return &text.Layout{Lines: lines}
	return lines
}

func textPath(buf *sfnt.Buffer, ppem fixed.Int26_6, f *opentype, str text.String) op.CallOp {
func textPath(buf *sfnt.Buffer, ppem fixed.Int26_6, f *opentype, str []text.Glyph) op.CallOp {
	var lastPos f32.Point
	var builder clip.Path
	ops := new(op.Ops)
	var x fixed.Int26_6
	var advIdx int
	builder.Begin(ops)
	for _, r := range str.String {
		if !unicode.IsSpace(r) {
			segs, ok := f.LoadGlyph(buf, ppem, r)
	for _, g := range str {
		if !unicode.IsSpace(g.Rune) {
			segs, ok := f.LoadGlyph(buf, ppem, g.Rune)
			if !ok {
				continue
			}


@@ 232,8 231,7 @@ func textPath(buf *sfnt.Buffer, ppem fixed.Int26_6, f *opentype, str text.String
			}
			lastPos = lastPos.Add(lastArg)
		}
		x += str.Advances[advIdx]
		advIdx++
		x += g.Advance
	}
	builder.End().Add(ops)
	return op.CallOp{Ops: ops}

M text/lru.go => text/lru.go +3 -3
@@ 20,7 20,7 @@ type pathCache struct {
type layoutElem struct {
	next, prev *layoutElem
	key        layoutKey
	layout     *Layout
	layout     []Line
}

type path struct {


@@ 42,7 42,7 @@ type pathKey struct {

const maxSize = 1000

func (l *layoutCache) Get(k layoutKey) (*Layout, bool) {
func (l *layoutCache) Get(k layoutKey) ([]Line, bool) {
	if lt, ok := l.m[k]; ok {
		l.remove(lt)
		l.insert(lt)


@@ 51,7 51,7 @@ func (l *layoutCache) Get(k layoutKey) (*Layout, bool) {
	return nil, false
}

func (l *layoutCache) Put(k layoutKey, lt *Layout) {
func (l *layoutCache) Put(k layoutKey, lt []Line) {
	if l.m == nil {
		l.m = make(map[layoutKey]*layoutElem)
		l.head = new(layoutElem)

M text/shaper.go => text/shaper.go +12 -25
@@ 3,8 3,6 @@
package text

import (
	"unicode/utf8"

	"golang.org/x/image/font"

	"gioui.org/op"


@@ 14,8 12,10 @@ import (

// Shaper implements layout and shaping of text.
type Shaper interface {
	Layout(c unit.Converter, font Font, str string, opts LayoutOptions) *Layout
	Shape(c unit.Converter, font Font, str String) op.CallOp
	// Layout a text according to a set of options.
	Layout(c unit.Converter, font Font, str string, opts LayoutOptions) []Line
	// Shape a line of text previously laid out by Layout.
	Shape(c unit.Converter, font Font, str string, layout []Glyph) op.CallOp
	Metrics(c unit.Converter, font Font) font.Metrics
}



@@ 50,14 50,14 @@ func (s *FontRegistry) Register(font Font, tf Face) {
	}
}

func (s *FontRegistry) Layout(c unit.Converter, font Font, str string, opts LayoutOptions) *Layout {
func (s *FontRegistry) Layout(c unit.Converter, font Font, str string, opts LayoutOptions) []Line {
	tf := s.faceForFont(font)
	return tf.layout(fixed.I(c.Px(font.Size)), str, opts)
}

func (s *FontRegistry) Shape(c unit.Converter, font Font, str String) op.CallOp {
func (s *FontRegistry) Shape(c unit.Converter, font Font, str string, layout []Glyph) op.CallOp {
	tf := s.faceForFont(font)
	return tf.shape(fixed.I(c.Px(font.Size)), str)
	return tf.shape(fixed.I(c.Px(font.Size)), str, layout)
}

func (s *FontRegistry) Metrics(c unit.Converter, font Font) font.Metrics {


@@ 96,9 96,9 @@ func (s *FontRegistry) faceForFont(font Font) *face {
	return tf
}

func (t *face) layout(ppem fixed.Int26_6, str string, opts LayoutOptions) *Layout {
func (t *face) layout(ppem fixed.Int26_6, str string, opts LayoutOptions) []Line {
	if t == nil {
		return fallbackLayout(str)
		return nil
	}
	lk := layoutKey{
		ppem: ppem,


@@ 113,18 113,18 @@ func (t *face) layout(ppem fixed.Int26_6, str string, opts LayoutOptions) *Layou
	return l
}

func (t *face) shape(ppem fixed.Int26_6, str String) op.CallOp {
func (t *face) shape(ppem fixed.Int26_6, str string, layout []Glyph) op.CallOp {
	if t == nil {
		return op.CallOp{}
	}
	pk := pathKey{
		ppem: ppem,
		str:  str.String,
		str:  str,
	}
	if clip, ok := t.pathCache.Get(pk); ok {
		return clip
	}
	clip := t.face.Shape(ppem, str)
	clip := t.face.Shape(ppem, layout)
	t.pathCache.Put(pk, clip)
	return clip
}


@@ 132,16 132,3 @@ func (t *face) shape(ppem fixed.Int26_6, str String) op.CallOp {
func (t *face) metrics(ppem fixed.Int26_6) font.Metrics {
	return t.face.Metrics(ppem)
}

func fallbackLayout(str string) *Layout {
	l := &Layout{
		Lines: []Line{
			{Text: String{
				String: str,
			}},
		},
	}
	strlen := utf8.RuneCountInString(str)
	l.Lines[0].Text.Advances = make([]fixed.Int26_6, strlen)
	return l
}

M text/text.go => text/text.go +8 -13
@@ 11,7 11,9 @@ import (

// A Line contains the measurements of a line of text.
type Line struct {
	Text String
	Layout []Glyph
	// Len is the length in UTF8 bytes of the line.
	Len int
	// Width is the width of the line.
	Width fixed.Int26_6
	// Ascent is the height above the baseline.


@@ 23,16 25,9 @@ type Line struct {
	Bounds fixed.Rectangle26_6
}

type String struct {
	String string
	// Advances contain the advance of each rune in String.
	Advances []fixed.Int26_6
}

// A Layout contains the measurements of a body of text as
// a list of Lines.
type Layout struct {
	Lines []Line
type Glyph struct {
	Rune    rune
	Advance fixed.Int26_6
}

// LayoutOptions specify the constraints of a text layout.


@@ 59,8 54,8 @@ type Font struct {

// Face implements text layout and shaping for a particular font.
type Face interface {
	Layout(ppem fixed.Int26_6, str string, opts LayoutOptions) *Layout
	Shape(ppem fixed.Int26_6, str String) op.CallOp
	Layout(ppem fixed.Int26_6, str string, opts LayoutOptions) []Line
	Shape(ppem fixed.Int26_6, str []Glyph) op.CallOp
	Metrics(ppem fixed.Int26_6) font.Metrics
}


M widget/editor.go => widget/editor.go +23 -25
@@ 273,11 273,13 @@ func (e *Editor) layout(gtx *layout.Context, sh text.Shaper) {
	}
	e.shapes = e.shapes[:0]
	for {
		str, off, ok := it.Next()
		start, end, layout, off, ok := it.Next()
		if !ok {
			break
		}
		path := sh.Shape(gtx, e.font, str)
		// TODO: remove
		str := e.rr.String()[start:end]
		path := sh.Shape(gtx, e.font, str, layout)
		e.shapes = append(e.shapes, line{off, path})
	}



@@ 433,15 435,13 @@ func (e *Editor) moveCoord(c unit.Converter, pos image.Point) {
func (e *Editor) layoutText(c unit.Converter, s text.Shaper, font text.Font) ([]text.Line, layout.Dimensions) {
	txt := e.rr.String()
	opts := text.LayoutOptions{MaxWidth: e.maxWidth}
	textLayout := s.Layout(c, font, txt, opts)
	lines := textLayout.Lines
	lines := s.Layout(c, font, txt, opts)
	dims := linesDimens(lines)
	for i := 0; i < len(lines)-1; i++ {
		s := lines[i].Text.String
		// To avoid layout flickering while editing, assume a soft newline takes
		// up all available space.
		if len(s) > 0 {
			r, _ := utf8.DecodeLastRuneInString(s)
		if layout := lines[i].Layout; len(layout) > 0 {
			r := layout[len(layout)-1].Rune
			if r != '\n' {
				dims.Size.X = e.maxWidth
				break


@@ 459,21 459,18 @@ loop:
		l := e.lines[carLine]
		y += (prevDesc + l.Ascent).Ceil()
		prevDesc = l.Descent
		if carLine == len(e.lines)-1 || idx+len(l.Text.String) > e.rr.caret {
			str := l.Text.String
			for _, adv := range l.Text.Advances {
		if carLine == len(e.lines)-1 || idx+len(l.Layout) > e.rr.caret {
			for _, g := range l.Layout {
				if idx == e.rr.caret {
					break loop
				}
				x += adv
				_, s := utf8.DecodeRuneInString(str)
				idx += s
				str = str[s:]
				x += g.Advance
				idx += utf8.RuneLen(g.Rune)
				carCol++
			}
			break
		}
		idx += len(l.Text.String)
		idx += l.Len
	}
	x += align(e.Alignment, e.lines[carLine].Width, e.viewSize.X)
	return


@@ 553,11 550,11 @@ func (e *Editor) moveToLine(carX fixed.Int26_6, carLine2 int) fixed.Int26_6 {
		// Move to start of line2.
		if carLine2 > carLine {
			for i := carLine; i < carLine2; i++ {
				e.rr.caret += len(e.lines[i].Text.String)
				e.rr.caret += e.lines[i].Len
			}
		} else {
			for i := carLine - 1; i >= carLine2; i-- {
				e.rr.caret -= len(e.lines[i].Text.String)
				e.rr.caret -= e.lines[i].Len
			}
		}
	}


@@ 569,15 566,15 @@ func (e *Editor) moveToLine(carX fixed.Int26_6, carLine2 int) fixed.Int26_6 {
		end = 1
	}
	// Move to rune closest to previous horizontal position.
	for i := 0; i < len(l2.Text.Advances)-end; i++ {
		adv := l2.Text.Advances[i]
	for i := 0; i < len(l2.Layout)-end; i++ {
		g := l2.Layout[i]
		if carX2 >= carX {
			break
		}
		if carX2+adv-carX >= carX-carX2 {
		if carX2+g.Advance-carX >= carX-carX2 {
			break
		}
		carX2 += adv
		carX2 += g.Advance
		_, s := e.rr.runeAt(e.rr.caret)
		e.rr.caret += s
	}


@@ 593,11 590,11 @@ func (e *Editor) Move(distance int) {

func (e *Editor) moveStart() {
	carLine, carCol, x, _ := e.layoutCaret()
	advances := e.lines[carLine].Text.Advances
	layout := e.lines[carLine].Layout
	for i := carCol - 1; i >= 0; i-- {
		_, s := e.rr.runeBefore(e.rr.caret)
		e.rr.caret -= s
		x -= advances[i]
		x -= layout[i].Advance
	}
	e.carXOff = -x
}


@@ 610,8 607,9 @@ func (e *Editor) moveEnd() {
	if carLine < len(e.lines)-1 {
		end = 1
	}
	for i := carCol; i < len(l.Text.Advances)-end; i++ {
		adv := l.Text.Advances[i]
	layout := l.Layout
	for i := carCol; i < len(layout)-end; i++ {
		adv := layout[i].Advance
		_, s := e.rr.runeAt(e.rr.caret)
		e.rr.caret += s
		x += adv

M widget/label.go => widget/label.go +21 -20
@@ 32,11 32,12 @@ type lineIterator struct {
	Offset    image.Point

	y, prevDesc fixed.Int26_6
	txtOff      int
}

const inf = 1e6

func (l *lineIterator) Next() (text.String, f32.Point, bool) {
func (l *lineIterator) Next() (int, int, []text.Glyph, f32.Point, bool) {
	for len(l.Lines) > 0 {
		line := l.Lines[0]
		l.Lines = l.Lines[1:]


@@ 50,42 51,41 @@ func (l *lineIterator) Next() (text.String, f32.Point, bool) {
		if (off.Y + line.Bounds.Min.Y).Floor() > l.Clip.Max.Y {
			break
		}
		layout := line.Layout
		start := l.txtOff
		l.txtOff += line.Len
		if (off.Y + line.Bounds.Max.Y).Ceil() < l.Clip.Min.Y {
			continue
		}
		str := line.Text
		for len(str.Advances) > 0 {
			adv := str.Advances[0]
		for len(layout) > 0 {
			g := layout[0]
			adv := g.Advance
			if (off.X + adv + line.Bounds.Max.X - line.Width).Ceil() >= l.Clip.Min.X {
				break
			}
			off.X += adv
			_, s := utf8.DecodeRuneInString(str.String)
			str.String = str.String[s:]
			str.Advances = str.Advances[1:]
			layout = layout[1:]
			start += utf8.RuneLen(g.Rune)
		}
		n := 0
		end := start
		endx := off.X
		for i, adv := range str.Advances {
		for i, g := range layout {
			if (endx + line.Bounds.Min.X).Floor() > l.Clip.Max.X {
				str.String = str.String[:n]
				str.Advances = str.Advances[:i]
				layout = layout[:i]
				break
			}
			_, s := utf8.DecodeRuneInString(str.String[n:])
			n += s
			endx += adv
			end += utf8.RuneLen(g.Rune)
			endx += g.Advance
		}
		offf := f32.Point{X: float32(off.X) / 64, Y: float32(off.Y) / 64}
		return str, offf, true
		return start, end, layout, offf, true
	}
	return text.String{}, f32.Point{}, false
	return 0, 0, nil, f32.Point{}, false
}

func (l Label) Layout(gtx *layout.Context, s text.Shaper, font text.Font, txt string) {
	cs := gtx.Constraints
	textLayout := s.Layout(gtx, font, txt, text.LayoutOptions{MaxWidth: cs.Width.Max})
	lines := textLayout.Lines
	lines := s.Layout(gtx, font, txt, text.LayoutOptions{MaxWidth: cs.Width.Max})
	if max := l.MaxLines; max > 0 && len(lines) > max {
		lines = lines[:max]
	}


@@ 100,7 100,7 @@ func (l Label) Layout(gtx *layout.Context, s text.Shaper, font text.Font, txt st
		Width:     dims.Size.X,
	}
	for {
		str, off, ok := it.Next()
		start, end, layout, off, ok := it.Next()
		if !ok {
			break
		}


@@ 108,7 108,8 @@ func (l Label) Layout(gtx *layout.Context, s text.Shaper, font text.Font, txt st
		var stack op.StackOp
		stack.Push(gtx.Ops)
		op.TransformOp{}.Offset(off).Add(gtx.Ops)
		s.Shape(gtx, font, str).Add(gtx.Ops)
		str := txt[start:end]
		s.Shape(gtx, font, str, layout).Add(gtx.Ops)
		paint.PaintOp{Rect: lclip}.Add(gtx.Ops)
		stack.Pop()
	}