Fixed panic in Overflow.

ui/overflow.go

@@ -146,7 +146,7 @@ func (o *overflow) Render(ctx Context) {
 	var content = o.Content.Bounds()
 	content.Min = geom.ZeroPtF32
 	err := o.content.Update(ctx, content.Size())
-	if err != nil {
+	if err != nil && err != ErrNewBufferSize {
 		panic(err)
 	}
 	o.content.Render(ctx, o.bounds.Min, func(Context, geom.PointF32) {

ui/textbox.go

@@ -37,6 +37,8 @@ type TextBox struct {
 	Focus     bool
 	Text      string
 	Selection TextSelection
+
+	textChanged Events
 }
 
 func BuildTextBox(fn func(*TextBox)) *TextBox {
@@ -64,6 +66,8 @@ func (b *TextBox) DesiredSize(ctx Context, _ geom.PointF32) geom.PointF32 {
 	return geom.PtF32(width+pad*2, height+pad*2)
 }
 
+func (b *TextBox) TextChanged() *Events { return &b.textChanged }
+
 func (b *TextBox) mousePosToCaretPos(ctx Context, e MouseEvent) int {
 	p := b.ToControlPosition(e.Pos())
 	offset := p.X - b.box.bounds.Min.X
@@ -93,13 +97,13 @@ func (b *TextBox) mousePosToCaretPos(ctx Context, e MouseEvent) int {
 	return carets[2]
 }
 
-func (b *TextBox) cut() string {
+func (b *TextBox) cut(ctx Context) string {
 	start, end := b.selectionRange()
 	if end == 0 {
 		return ""
 	}
 	cut := b.Text[start:end]
-	b.Text = b.Text[:start] + b.Text[end:]
+	b.updateText(ctx, b.Text[:start]+b.Text[end:])
 	b.Selection.Caret = start
 	b.Selection.SetSelectionToCaret()
 	return cut
@@ -170,20 +174,20 @@ func (b *TextBox) Handle(ctx Context, e Event) bool {
 		switch {
 		case e.Key == KeyDelete:
 			if b.Selection.HasSelection() {
-				b.cut()
+				b.cut(ctx)
 			} else {
 				caret := b.Selection.Caret
 				if caret < len(b.Text) {
-					b.Text = b.Text[:caret] + b.Text[caret+1:]
+					b.updateText(ctx, b.Text[:caret]+b.Text[caret+1:])
 				}
 			}
 		case e.Key == KeyBackspace:
 			if b.Selection.HasSelection() {
-				b.cut()
+				b.cut(ctx)
 			} else {
 				caret := b.Selection.Caret
 				if caret > 0 {
-					b.Text = b.Text[:caret-1] + b.Text[caret:]
+					b.updateText(ctx, b.Text[:caret-1]+b.Text[caret:])
 					b.Selection.Caret = caret - 1
 					b.Selection.SetSelectionToCaret()
 				}
@@ -221,22 +225,22 @@ func (b *TextBox) Handle(ctx Context, e Event) bool {
 					return r
 				}, text)
 				if err == nil {
-					b.cut()
+					b.cut(ctx)
 					caret := b.Selection.Caret
-					b.Text = b.Text[:caret] + text + b.Text[caret:]
+					b.updateText(ctx, b.Text[:caret]+text+b.Text[caret:])
 					b.Selection.Caret = caret + len(text)
 				}
 			case KeyX:
-				DefaultClipboard.WriteText(b.cut())
+				DefaultClipboard.WriteText(b.cut(ctx))
 			}
 		}
 		return true
 	case *TextInputEvent:
 		if b.Selection.HasSelection() {
-			b.cut()
+			b.cut(ctx)
 		}
 		caret := b.Selection.Caret
-		b.Text = fmt.Sprintf("%s%c%s", b.Text[:caret], e.Character, b.Text[caret:])
+		b.updateText(ctx, fmt.Sprintf("%s%c%s", b.Text[:caret], e.Character, b.Text[caret:]))
 		b.Selection.Caret = caret + 1
 		b.Selection.SetSelectionToCaret()
 		return true
@@ -272,3 +276,11 @@ func (b *TextBox) Render(ctx Context) {
 		}
 	})
 }
+
+func (b *TextBox) updateText(ctx Context, text string) {
+	if b.Text == text {
+		return
+	}
+	b.Text = text
+	b.textChanged.Notify(ctx, text)
+}