widget{,/material}: rebuild label and editor with textView

This commit rebuilds the editor and label types on the common
foundation provided by textView. This enables labels to have
optional state that makes them selectable, and allows the
two widgets to share the code for managing cursor positions,
displaying selections, and soforth. Labels now have an additional
Layout function which can be invoked if they have a Selectable.
It accepts a layout.Widget used to paint their contents. Stateless
labels should still use the old Layout method.

Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>

widget/editor_test.go

@@ -121,7 +121,7 @@ func TestEditorReadOnly(t *testing.T) {
 
 	// Select everything.
 	gtx.Ops.Reset()
-	gtx.Queue.(*testQueue).events = append(gtx.Queue.(*testQueue).events, key.Event{Name: "A", Modifiers: key.ModShortcut})
+	gtx.Queue = &testQueue{events: []event.Event{key.Event{Name: "A", Modifiers: key.ModShortcut}}}
 	dims = e.Layout(gtx, cache, font, fontSize, nil)
 	textContent := e.Text()
 	cStart2, cEnd2 := e.Selection()
@@ -137,7 +137,7 @@ func TestEditorReadOnly(t *testing.T) {
 
 	// Type some new characters.
 	gtx.Ops.Reset()
-	gtx.Queue.(*testQueue).events = append(gtx.Queue.(*testQueue).events, key.EditEvent{Range: key.Range{Start: cStart2, End: cEnd2}, Text: "something else"})
+	gtx.Queue = &testQueue{events: []event.Event{key.EditEvent{Range: key.Range{Start: cStart2, End: cEnd2}, Text: "something else"}}}
 	dims = e.Layout(gtx, cache, font, fontSize, nil)
 	textContent2 := e.Text()
 	if textContent2 != textContent {
@@ -146,7 +146,7 @@ func TestEditorReadOnly(t *testing.T) {
 
 	// Try to delete selection.
 	gtx.Ops.Reset()
-	gtx.Queue.(*testQueue).events = append(gtx.Queue.(*testQueue).events, key.Event{Name: key.NameDeleteBackward})
+	gtx.Queue = &testQueue{events: []event.Event{key.Event{Name: key.NameDeleteBackward}}}
 	dims = e.Layout(gtx, cache, font, fontSize, nil)
 	textContent2 = e.Text()
 	if textContent2 != textContent {
@@ -156,7 +156,7 @@ func TestEditorReadOnly(t *testing.T) {
 	// Click and drag from the middle of the first line
 	// to the center.
 	gtx.Ops.Reset()
-	gtx.Queue.(*testQueue).events = append(gtx.Queue.(*testQueue).events,
+	gtx.Queue = &testQueue{events: []event.Event{
 		pointer.Event{
 			Type:     pointer.Press,
 			Buttons:  pointer.ButtonPrimary,
@@ -172,7 +172,8 @@ func TestEditorReadOnly(t *testing.T) {
 			Buttons:  pointer.ButtonPrimary,
 			Position: layout.FPt(dims.Size).Mul(.5),
 		},
-	)
+	}}
+	e.Layout(gtx, cache, font, fontSize, nil)
 	cStart3, cEnd3 := e.Selection()
 	if cStart3 == cStart2 || cEnd3 == cEnd2 {
 		t.Errorf("expected mouse interaction to change selection.")
@@ -246,7 +247,7 @@ func TestEditor(t *testing.T) {
 	// Regression test for bad in-cluster rune offset math.
 	e.SetText("æbc")
 	e.Layout(gtx, cache, font, fontSize, nil)
-	e.moveEnd(selectionClear)
+	e.text.MoveEnd(selectionClear)
 	assertCaret(t, e, 0, 3, len("æbc"))
 
 	textSample := "æbc\naøå••"
@@ -258,19 +259,19 @@ func TestEditor(t *testing.T) {
 	}
 	e.Layout(gtx, cache, font, fontSize, nil)
 	assertCaret(t, e, 0, 0, 0)
-	e.moveEnd(selectionClear)
+	e.text.MoveEnd(selectionClear)
 	assertCaret(t, e, 0, 3, len("æbc"))
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 1, 0, len("æbc\n"))
 	e.MoveCaret(-1, -1)
 	assertCaret(t, e, 0, 3, len("æbc"))
-	e.moveLines(+1, selectionClear)
+	e.text.MoveLines(+1, selectionClear)
 	assertCaret(t, e, 1, 4, len("æbc\naøå•"))
-	e.moveEnd(selectionClear)
+	e.text.MoveEnd(selectionClear)
 	assertCaret(t, e, 1, 5, len("æbc\naøå••"))
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 1, 5, len("æbc\naøå••"))
-	e.moveLines(3, selectionClear)
+	e.text.MoveLines(3, selectionClear)
 
 	e.SetCaret(0, 0)
 	assertCaret(t, e, 0, 0, 0)
@@ -282,7 +283,7 @@ func TestEditor(t *testing.T) {
 	// Ensure that password masking does not affect caret behavior
 	e.MoveCaret(-3, -3)
 	assertCaret(t, e, 1, 1, len("æbc\na"))
-	e.Mask = '*'
+	e.text.Mask = '*'
 	e.Layout(gtx, cache, font, fontSize, nil)
 	assertCaret(t, e, 1, 1, len("æbc\na"))
 	e.MoveCaret(-3, -3)
@@ -324,9 +325,9 @@ func TestEditor(t *testing.T) {
 	// Test that moveLine applies x offsets from previous moves.
 	e.SetText("long line\nshort")
 	e.SetCaret(0, 0)
-	e.moveEnd(selectionClear)
-	e.moveLines(+1, selectionClear)
-	e.moveLines(-1, selectionClear)
+	e.text.MoveEnd(selectionClear)
+	e.text.MoveLines(+1, selectionClear)
+	e.text.MoveLines(-1, selectionClear)
 	assertCaret(t, e, 0, utf8.RuneCountInString("long line"), len("long line"))
 }
 
@@ -366,14 +367,14 @@ func TestEditorRTL(t *testing.T) {
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 0, 3, len("الح"))
 	// Move to the "end" of the line. This moves to the left edge of the line.
-	e.moveEnd(selectionClear)
+	e.text.MoveEnd(selectionClear)
 	assertCaret(t, e, 0, 4, len("الحب"))
 
 	sentence := "الحب سماء لا\nتمط غير الأحلام"
 	e.SetText(sentence)
 	e.Layout(gtx, cache, font, fontSize, nil)
 	assertCaret(t, e, 0, 0, 0)
-	e.moveEnd(selectionClear)
+	e.text.MoveEnd(selectionClear)
 	assertCaret(t, e, 0, 12, len("الحب سماء لا"))
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 1, 0, len("الحب سماء لا\n"))
@@ -383,13 +384,13 @@ func TestEditorRTL(t *testing.T) {
 	assertCaret(t, e, 1, 0, len("الحب سماء لا\n"))
 	e.MoveCaret(-1, -1)
 	assertCaret(t, e, 0, 12, len("الحب سماء لا"))
-	e.moveLines(+1, selectionClear)
+	e.text.MoveLines(+1, selectionClear)
 	assertCaret(t, e, 1, 14, len("الحب سماء لا\nتمط غير الأحلا"))
-	e.moveEnd(selectionClear)
+	e.text.MoveEnd(selectionClear)
 	assertCaret(t, e, 1, 15, len("الحب سماء لا\nتمط غير الأحلام"))
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 1, 15, len("الحب سماء لا\nتمط غير الأحلام"))
-	e.moveLines(3, selectionClear)
+	e.text.MoveLines(3, selectionClear)
 	assertCaret(t, e, 1, 15, len("الحب سماء لا\nتمط غير الأحلام"))
 	e.SetCaret(utf8.RuneCountInString(sentence), 0)
 	assertCaret(t, e, 1, 15, len("الحب سماء لا\nتمط غير الأحلام"))
@@ -440,7 +441,7 @@ func TestEditorLigature(t *testing.T) {
 	assertCaret(t, e, 0, 0, 0)
 	e.SetText("fl") // just a ligature
 	e.Layout(gtx, cache, font, fontSize, nil)
-	e.moveEnd(selectionClear)
+	e.text.MoveEnd(selectionClear)
 	assertCaret(t, e, 0, 2, len("fl"))
 	e.MoveCaret(-1, -1)
 	assertCaret(t, e, 0, 1, len("f"))
@@ -451,7 +452,7 @@ func TestEditorLigature(t *testing.T) {
 	e.SetText("flaffl•ffi\n•fflfi") // 3 ligatures on line 0, 2 on line 1
 	e.Layout(gtx, cache, font, fontSize, nil)
 	assertCaret(t, e, 0, 0, 0)
-	e.moveEnd(selectionClear)
+	e.text.MoveEnd(selectionClear)
 	assertCaret(t, e, 0, 10, len("ffaffl•ffi"))
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 1, 0, len("ffaffl•ffi\n"))
@@ -504,13 +505,13 @@ func TestEditorLigature(t *testing.T) {
 	e.Layout(gtx, cache, font, fontSize, nil)
 	// Ensure that all runes in the final cluster of a line are properly
 	// decoded when moving to the end of the line. This is a regression test.
-	e.moveEnd(selectionClear)
+	e.text.MoveEnd(selectionClear)
 	// The first line was broken by line wrapping, not a newline character. As such,
 	// the cursor can reach the position after the final glyph (a space).
 	assertCaret(t, e, 0, 14, len("fflffl fflffl "))
-	e.moveLines(1, selectionClear)
+	e.text.MoveLines(1, selectionClear)
 	assertCaret(t, e, 1, 13, len("fflffl fflffl fflffl fflffl"))
-	e.moveLines(-1, selectionClear)
+	e.text.MoveLines(-1, selectionClear)
 	assertCaret(t, e, 0, 14, len("fflffl fflffl "))
 
 	// Absurdly narrow constraints to force each ligature onto its own line.
@@ -554,7 +555,7 @@ func assertCaret(t *testing.T, e *Editor, line, col, bytes int) {
 	if gotLine != line || gotCol != col {
 		t.Errorf("caret at (%d, %d), expected (%d, %d)", gotLine, gotCol, line, col)
 	}
-	caretBytes := e.runeOffset(e.caret.start)
+	caretBytes := e.text.runeOffset(e.text.caret.start)
 	if bytes != caretBytes {
 		t.Errorf("caret at buffer position %d, expected %d", caretBytes, bytes)
 	}
@@ -588,9 +589,8 @@ func TestEditorCaretConsistency(t *testing.T) {
 	fontSize := unit.Sp(10)
 	font := text.Font{}
 	for _, a := range []text.Alignment{text.Start, text.Middle, text.End} {
-		e := &Editor{
-			Alignment: a,
-		}
+		e := &Editor{}
+		e.Alignment = a
 		e.Layout(gtx, cache, font, fontSize, nil)
 
 		consistent := func() error {
@@ -598,8 +598,8 @@ func TestEditorCaretConsistency(t *testing.T) {
 			gotLine, gotCol := e.CaretPos()
 			gotCoords := e.CaretCoords()
 			// Blow away index to re-compute position from scratch.
-			e.invalidate()
-			want := e.closestToRune(e.caret.start)
+			e.text.invalidate()
+			want := e.text.closestToRune(e.text.caret.start)
 			wantCoords := f32.Pt(float32(want.x)/64, float32(want.y))
 			if want.lineCol.line != gotLine || int(want.lineCol.col) != gotCol || gotCoords != wantCoords {
 				return fmt.Errorf("caret (%d,%d) pos %s, want (%d,%d) pos %s",
@@ -619,17 +619,17 @@ func TestEditorCaretConsistency(t *testing.T) {
 			case moveRune:
 				e.MoveCaret(int(distance), int(distance))
 			case moveLine:
-				e.moveLines(int(distance), selectionClear)
+				e.text.MoveLines(int(distance), selectionClear)
 			case movePage:
-				e.movePages(int(distance), selectionClear)
+				e.text.MovePages(int(distance), selectionClear)
 			case moveStart:
-				e.moveStart(selectionClear)
+				e.text.MoveStart(selectionClear)
 			case moveEnd:
-				e.moveEnd(selectionClear)
+				e.text.MoveEnd(selectionClear)
 			case moveCoord:
-				e.moveCoord(image.Pt(int(x), int(y)))
+				e.text.MoveCoord(image.Pt(int(x), int(y)))
 			case moveWord:
-				e.moveWord(int(distance), selectionClear)
+				e.text.MoveWord(int(distance), selectionClear)
 			case deleteWord:
 				e.deleteWord(int(distance))
 			default:
@@ -687,8 +687,8 @@ func TestEditorMoveWord(t *testing.T) {
 	for ii, tt := range tests {
 		e := setup(tt.Text)
 		e.MoveCaret(tt.Start, tt.Start)
-		e.moveWord(tt.Skip, selectionClear)
-		caretBytes := e.runeOffset(e.caret.start)
+		e.text.MoveWord(tt.Skip, selectionClear)
+		caretBytes := e.text.runeOffset(e.text.caret.start)
 		if caretBytes != tt.Want {
 			t.Fatalf("[%d] moveWord: bad caret position: got %d, want %d", ii, caretBytes, tt.Want)
 		}
@@ -884,7 +884,7 @@ func TestEditorDeleteWord(t *testing.T) {
 		e.MoveCaret(tt.Start, tt.Start)
 		e.MoveCaret(0, tt.Selection)
 		e.deleteWord(tt.Delete)
-		caretBytes := e.runeOffset(e.caret.start)
+		caretBytes := e.text.runeOffset(e.text.caret.start)
 		if caretBytes != tt.Want {
 			t.Fatalf("[%d] deleteWord: bad caret position: got %d, want %d", ii, caretBytes, tt.Want)
 		}
@@ -938,8 +938,8 @@ g 2 4 6 8 g
 		_ = e.Events() // throw away any events from this layout
 
 		// Build the selection events
-		startPos := e.closestToRune(start)
-		endPos := e.closestToRune(end)
+		startPos := e.text.closestToRune(start)
+		endPos := e.text.closestToRune(end)
 		tq := &testQueue{
 			events: []event.Event{
 				pointer.Event{
@@ -1008,8 +1008,8 @@ g 2 4 6 8 g
 		gtx.Queue = nil
 		e.Layout(gtx, cache, font, fontSize, nil)
 
-		caretStart := e.closestToRune(e.caret.start)
-		caretEnd := e.closestToRune(e.caret.end)
+		caretStart := e.text.closestToRune(e.text.caret.start)
+		caretEnd := e.text.closestToRune(e.text.caret.end)
 		logicalPosMatch(t, n, "start", tst.startPos, caretEnd)
 		logicalPosMatch(t, n, "end", tst.endPos, caretStart)
 	}
@@ -1189,8 +1189,8 @@ func TestEditor_Submit(t *testing.T) {
 // It assumes single-run lines, which isn't safe with non-test text
 // data.
 func textWidth(e *Editor, lineNum, colStart, colEnd int) float32 {
-	start := e.closestToLineCol(lineNum, colStart)
-	end := e.closestToLineCol(lineNum, colEnd)
+	start := e.text.closestToLineCol(lineNum, colStart)
+	end := e.text.closestToLineCol(lineNum, colEnd)
 	delta := start.x - end.x
 	if delta < 0 {
 		delta = -delta
@@ -1201,7 +1201,7 @@ func textWidth(e *Editor, lineNum, colStart, colEnd int) float32 {
 // testBaseline returns the y coordinate of the baseline for the
 // given line number.
 func textBaseline(e *Editor, lineNum int) float32 {
-	start := e.closestToLineCol(lineNum, 0)
+	start := e.text.closestToLineCol(lineNum, 0)
 	return float32(start.y)
 }