Improve filename truncation to fit exact number of characters

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

cmd/pad/main.go

@@ -9,6 +9,7 @@ import (
 	"gioui.org/op"
 	"gioui.org/text"
 	"gioui.org/unit"
+	"gioui.org/font/gofont"
 
 	"pad/internal/editor"
 	"pad/internal/ui"
@@ -30,7 +31,7 @@ func main() {
 func run(w *app.Window) error {
 	var ops op.Ops
 
-	shaper := text.NewShaper()
+	shaper := text.NewShaper(text.WithCollection(gofont.Collection()))
 	renderer := ui.New(ui.Theme{FontSize: 14}, shaper)
 
 	// Initial screen size

internal/editor/state.go

@@ -26,7 +26,7 @@ func NewState(screenWidth, screenHeight unit.Dp) *State {
 // It takes screen dimensions and returns []Element.
 func EditorLayout(screenWidth, screenHeight unit.Dp) []ui.Element {
 	// Margin to avoid clipping on macOS round corners
-	margin := unit.Dp(5)
+	margin := unit.Dp(10)
 
 	// Compute StatusBar region
 	// Line 1: filename (24 DP)

internal/ui/render.go

@@ -9,6 +9,7 @@ import (
 	"gioui.org/text"
 	"gioui.org/unit"
 	"gioui.org/widget/material"
+	"golang.org/x/image/math/fixed"
 )
 
 // Renderer consumes a slice of elements and draws them.
@@ -88,17 +89,31 @@ func (r *Renderer) drawStatusBar(gtx layout.Context, sb StatusBar) {
 	filenameLineY := reg.Y
 	filenameLineH := unit.Dp(24)
 
-	// Truncate filename if needed
+	// Truncate filename only if it doesn't fit
 	displayFilename := sb.Filename
-	// Simple truncation: if filename is too long, truncate it
-	if len(displayFilename) > 30 {
-		displayFilename = displayFilename[:27] + "..."
+	availableWidth := int(reg.W - unit.Dp(8) - unit.Dp(40)) // left margin + right icons in DP
+	ellipsisWidth := textWidth(gtx, th.Shaper, "...", r.theme.FontSize)
+	// Measure how wide "..." is, then find how many chars fit in availableWidth - ellipsisWidth
+	spaceForText := availableWidth - ellipsisWidth
+	widths := charWidths(gtx, th.Shaper, displayFilename, r.theme.FontSize)
+	if len(widths) > 0 && widths[len(widths)-1] > availableWidth {
+		// Find the largest index where the width fits
+		for i, w := range widths {
+			if w <= spaceForText {
+				if i+1 < len(displayFilename) {
+					displayFilename = displayFilename[:i+1] + "..."
+				} else {
+					displayFilename = displayFilename[:i] + "..."
+				}
+				break
+			}
+		}
 	}
 
 	// Position filename at (reg.X + 8, filenameLineY)
-	gtx.Constraints.Min.X = int(reg.X + unit.Dp(8))
-	gtx.Constraints.Min.Y = int(filenameLineY)
+	call1 := op.Offset(image.Point{X: int(reg.X + unit.Dp(8)), Y: int(filenameLineY)}).Push(gtx.Ops)
 	material.Label(th, r.theme.FontSize, displayFilename).Layout(gtx)
+	call1.Pop()
 
 	// Line 2: Icons
 	iconsLineY := filenameLineY + filenameLineH
@@ -108,15 +123,21 @@ func (r *Renderer) drawStatusBar(gtx layout.Context, sb StatusBar) {
 	iconY := iconsLineY
 
 	if sb.CutCopy {
-		r.drawIconButton(gtx, th, "✂", leftX, iconY)
+		call := op.Offset(image.Point{X: int(leftX), Y: int(iconY)}).Push(gtx.Ops)
+		material.Label(th, r.theme.FontSize, "✂").Layout(gtx)
+		call.Pop()
 		leftX += unit.Dp(36)
 	}
 	if sb.Copy {
-		r.drawIconButton(gtx, th, "⎘", leftX, iconY)
+		call := op.Offset(image.Point{X: int(leftX), Y: int(iconY)}).Push(gtx.Ops)
+		material.Label(th, r.theme.FontSize, "⎘").Layout(gtx)
+		call.Pop()
 		leftX += unit.Dp(36)
 	}
 	if sb.Paste {
-		r.drawIconButton(gtx, th, "⎘", leftX, iconY)
+		call := op.Offset(image.Point{X: int(leftX), Y: int(iconY)}).Push(gtx.Ops)
+		material.Label(th, r.theme.FontSize, "⎘").Layout(gtx)
+		call.Pop()
 		leftX += unit.Dp(36)
 	}
 
@@ -124,11 +145,15 @@ func (r *Renderer) drawStatusBar(gtx layout.Context, sb StatusBar) {
 	rightX := reg.X + reg.W - unit.Dp(8)
 	if sb.Search {
 		rightX -= unit.Dp(36)
-		r.drawIconButton(gtx, th, "🔍", rightX, iconY)
+		call := op.Offset(image.Point{X: int(rightX), Y: int(iconY)}).Push(gtx.Ops)
+		material.Label(th, r.theme.FontSize, "🔍").Layout(gtx)
+		call.Pop()
 	}
 	if sb.ConflictIcon {
 		rightX -= unit.Dp(36)
-		r.drawIconButton(gtx, th, "⚠", rightX, iconY)
+		call := op.Offset(image.Point{X: int(rightX), Y: int(iconY)}).Push(gtx.Ops)
+		material.Label(th, r.theme.FontSize, "⚠").Layout(gtx)
+		call.Pop()
 	}
 
 	c.Pop()
@@ -139,12 +164,6 @@ func (r *Renderer) drawBottomBar(gtx layout.Context, bb BottomBar) {
 	th := material.NewTheme()
 	th.Shaper = r.shp
 
-	// Clip to bottom bar region
-	c := clip.Rect{
-		Min: image.Point{X: int(reg.X), Y: int(reg.Y)},
-		Max: image.Point{X: int(reg.X + reg.W), Y: int(reg.Y + reg.H)},
-	}.Push(gtx.Ops)
-
 	// Left: Cursor position
 	cursorX := reg.X + unit.Dp(8)
 	call1 := op.Offset(image.Point{X: int(cursorX), Y: int(reg.Y)}).Push(gtx.Ops)
@@ -158,12 +177,10 @@ func (r *Renderer) drawBottomBar(gtx layout.Context, bb BottomBar) {
 	call2.Pop()
 
 	// Right: Word wrap button
-	wordWrapX := reg.X + reg.W - unit.Dp(120)
+	wordWrapX := reg.X + reg.W - unit.Dp(80)
 	call3 := op.Offset(image.Point{X: int(wordWrapX), Y: int(reg.Y)}).Push(gtx.Ops)
-	material.Label(th, r.theme.FontSize, "[Word Wrap: "+boolToString(bb.WordWrap)+"]").Layout(gtx)
+	material.Label(th, r.theme.FontSize, "W:"+boolToString(bb.WordWrap)).Layout(gtx)
 	call3.Pop()
-
-	c.Pop()
 }
 
 func (r *Renderer) drawButton(gtx layout.Context, btn Button) {
@@ -190,3 +207,41 @@ func boolToString(b bool) string {
 	}
 	return "Off"
 }
+
+// textWidth measures the total width of a string using the shaper.
+func textWidth(gtx layout.Context, shp *text.Shaper, str string, size unit.Sp) int {
+	shp.LayoutString(text.Parameters{PxPerEm: 1024}, str)
+	var lastX fixed.Int26_6
+	for {
+		g, ok := shp.NextGlyph()
+		if !ok {
+			break
+		}
+		x := g.X + g.Advance
+		if x > lastX {
+			lastX = x
+		}
+	}
+	return int(lastX)
+}
+
+// charWidths returns the cumulative width after each rune in str.
+func charWidths(gtx layout.Context, shp *text.Shaper, str string, size unit.Sp) []int {
+	shp.LayoutString(text.Parameters{PxPerEm: 1024}, str)
+	var widths []int
+	var cumX fixed.Int26_6
+	var runeIdx int
+	for {
+		g, ok := shp.NextGlyph()
+		if !ok {
+			break
+		}
+		cumX = g.X + g.Advance
+		// Each glyph corresponds to one rune in our simple ASCII case
+		if runeIdx < len(str) {
+			widths = append(widths, int(cumX))
+			runeIdx++
+		}
+	}
+	return widths
+}