Add List

README.md

@@ -22,6 +22,7 @@
   - Frame: Widget container. All child widgets are displayed at once. Child widgets are not repositioned by default.
   - Grid: Highly customizable cell-based layout. Each widget added to the Grid may span multiple cells.
   - Input: Text input widget. The Input widget is simply a Text widget that also accepts user input.
+  - List: A list of widgets as selectable items.
   - Text: Text display widget.
   - Window: Widget paging mechanism. Only one widget added to a window is displayed at a time.
 

doc.go

@@ -8,13 +8,14 @@ based on official widgets.
 
 The following official widgets are available:
 
-	Box - Building block for creating other widgets.
-	Button - Clickable button.
-	Flex - Flexible stack-based layout. Each Flex widget may be oriented horizontally or vertically.
-	Frame - Widget container. All child widgets are displayed at once. Child widgets are not repositioned by default.
-	Grid - Highly customizable cell-based layout. Widgets added to the Grid may span multiple cells.
-	Input - Text input widget. The Input widget is simply a Text widget that also accepts user input.
-	Text - Text display widget.
-	Window - Widget paging mechanism. Only one widget added to a window is displayed at a time.
+  Box - Building block for creating other widgets.
+  Button - Clickable button.
+  Flex - Flexible stack-based layout. Each Flex widget may be oriented horizontally or vertically.
+  Frame - Widget container. All child widgets are displayed at once. Child widgets are not repositioned by default.
+  Grid - Highly customizable cell-based layout. Widgets added to the Grid may span multiple cells.
+  Input - Text input widget. The Input widget is simply a Text widget that also accepts user input.
+  List - A list of widgets as selectable items.
+  Text - Text display widget.
+  Window - Widget paging mechanism. Only one widget added to a window is displayed at a time.
 */
 package etk

go.mod

@@ -3,7 +3,7 @@ module code.rocket9labs.com/tslocum/etk
 go 1.18
 
 require (
-	code.rocketnine.space/tslocum/messeji v1.0.6-0.20231128010227-689683b75174
+	code.rocketnine.space/tslocum/messeji v1.0.6-0.20231218071755-e4087431ad9f
 	github.com/hajimehoshi/ebiten/v2 v2.6.3
 	github.com/llgcode/draw2d v0.0.0-20231212091825-f55e0c776b44
 	golang.org/x/image v0.14.0
@@ -13,7 +13,7 @@ require (
 	github.com/ebitengine/purego v0.5.1 // indirect
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 // indirect
 	github.com/jezek/xgb v1.1.1 // indirect
-	golang.org/x/exp/shiny v0.0.0-20231214170342-aacd6d4b4611 // indirect
+	golang.org/x/exp/shiny v0.0.0-20231219180239-dc181d75b848 // indirect
 	golang.org/x/mobile v0.0.0-20231127183840-76ac6878050a // indirect
 	golang.org/x/sync v0.5.0 // indirect
 	golang.org/x/sys v0.15.0 // indirect

go.sum

@@ -1,5 +1,5 @@
-code.rocketnine.space/tslocum/messeji v1.0.6-0.20231128010227-689683b75174 h1:jxE3JcaE4ovMWaZHLA6MvYgkmdkdbEEUv943Bp+MoxU=
-code.rocketnine.space/tslocum/messeji v1.0.6-0.20231128010227-689683b75174/go.mod h1:yLsZtW6XgrQPpqBpQfJJkueurBUUYNnkPr68cS1MtJc=
+code.rocketnine.space/tslocum/messeji v1.0.6-0.20231218071755-e4087431ad9f h1:/6Mpu+9TfQyee7uJ1epZEEfGGCT67bvZKpVhWy8T7cs=
+code.rocketnine.space/tslocum/messeji v1.0.6-0.20231218071755-e4087431ad9f/go.mod h1:hA/frrbchjCX75HUG/GH97X3eH8xw++AKC2F+z+uXyA=
 github.com/ebitengine/purego v0.5.1 h1:hNunhThpOf1vzKl49v6YxIsXLhl92vbBEv1/2Ez3ZrY=
 github.com/ebitengine/purego v0.5.1/go.mod h1:ah1In8AOtksoNK6yk5z1HTJeUkC1Ez4Wk2idgGslMwQ=
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
@@ -12,8 +12,8 @@ github.com/jezek/xgb v1.1.1/go.mod h1:nrhwO0FX/enq75I7Y7G8iN1ubpSGZEiA3v9e9GyRFl
 github.com/llgcode/draw2d v0.0.0-20231212091825-f55e0c776b44 h1:1ad70i0s40IpMtRm2ST+Nvr03X7mlHWtdALYkFNrlxk=
 github.com/llgcode/draw2d v0.0.0-20231212091825-f55e0c776b44/go.mod h1:muweRyJCZ1mZSMiCgYbAicfnwZFoeHpNr6A6QBu+rBg=
 github.com/llgcode/ps v0.0.0-20210114104736-f4b0c5d1e02e h1:ZAvbj5hI/G/EbAYAcj4yCXUNiFKefEhH0qfImDDD0/8=
-golang.org/x/exp/shiny v0.0.0-20231214170342-aacd6d4b4611 h1:4KULGL0aJvCqUs5c7fA/eWELbK2rVfV9wpZTWW1Qs/I=
-golang.org/x/exp/shiny v0.0.0-20231214170342-aacd6d4b4611/go.mod h1:UH99kUObWAZkDnWqppdQe5ZhPYESUw8I0zVV1uWBR+0=
+golang.org/x/exp/shiny v0.0.0-20231219180239-dc181d75b848 h1:LnDWUUS+bxOesHc+QBvFFmS4v0ZH+Vtg0EncMANwN9Q=
+golang.org/x/exp/shiny v0.0.0-20231219180239-dc181d75b848/go.mod h1:UH99kUObWAZkDnWqppdQe5ZhPYESUw8I0zVV1uWBR+0=
 golang.org/x/image v0.14.0 h1:tNgSxAFe3jC4uYqvZdTr84SZoM1KfwdC9SKIFrLjFn4=
 golang.org/x/image v0.14.0/go.mod h1:HUYqC05R2ZcZ3ejNQsIHQDQiwWM4JBqmm6MKANTp4LE=
 golang.org/x/mobile v0.0.0-20231127183840-76ac6878050a h1:sYbmY3FwUWCBTodZL1S3JUuOvaW6kM2o+clDzzDNBWg=

grid.go

@@ -142,13 +142,6 @@ func (g *Grid) Draw(screen *ebiten.Image) error {
 		g.updated = false
 	}
 
-	for _, child := range g.children {
-		err := child.Draw(screen)
-		if err != nil {
-			return err
-		}
-	}
-
 	return nil
 }
 

list.go

@@ -0,0 +1,276 @@
+package etk
+
+import (
+	"image"
+	"image/color"
+	"sync"
+
+	"github.com/hajimehoshi/ebiten/v2"
+)
+
+// SelectionMode represents a mode of selection.
+type SelectionMode int
+
+// Selection modes.
+const (
+	// SelectNone disables selection.
+	SelectNone SelectionMode = iota
+
+	// SelectRow enables selection by row.
+	SelectRow
+
+	// SelectColumn enables selection by column.
+	SelectColumn
+)
+
+// List is a list of widgets. Rows or cells may optionally be selectable.
+type List struct {
+	grid                 *Grid
+	itemHeight           int
+	highlightColor       color.RGBA
+	maxY                 int
+	selectionMode        SelectionMode
+	selectedX, selectedY int
+	selectedFunc         func(index int) (accept bool)
+	sync.Mutex
+}
+
+// NewList returns a new List widget.
+func NewList(itemHeight int, onSelected func(index int) (accept bool)) *List {
+	return &List{
+		grid:           NewGrid(),
+		itemHeight:     itemHeight,
+		highlightColor: color.RGBA{255, 255, 255, 255},
+		maxY:           -1,
+		selectedY:      -1,
+		selectedFunc:   onSelected,
+	}
+}
+
+// Rect returns the position and size of the widget.
+func (l *List) Rect() image.Rectangle {
+	l.Lock()
+	defer l.Unlock()
+
+	return l.grid.Rect()
+}
+
+// SetRect sets the position and size of the widget.
+func (l *List) SetRect(r image.Rectangle) {
+	l.Lock()
+	defer l.Unlock()
+
+	l.grid.SetRect(r)
+}
+
+// Background returns the background color of the widget.
+func (l *List) Background() color.RGBA {
+	l.Lock()
+	defer l.Unlock()
+
+	return l.grid.Background()
+}
+
+// SetBackground sets the background color of the widget.
+func (l *List) SetBackground(background color.RGBA) {
+	l.Lock()
+	defer l.Unlock()
+
+	l.grid.SetBackground(background)
+}
+
+// Focus returns the focus state of the widget.
+func (l *List) Focus() bool {
+	l.Lock()
+	defer l.Unlock()
+
+	return l.grid.Focus()
+}
+
+// SetFocus sets the focus state of the widget.
+func (l *List) SetFocus(focus bool) (accept bool) {
+	l.Lock()
+	defer l.Unlock()
+
+	return l.grid.SetFocus(focus)
+}
+
+// Visible returns the visibility of the widget.
+func (l *List) Visible() bool {
+	l.Lock()
+	defer l.Unlock()
+
+	return l.grid.Visible()
+}
+
+// SetVisible sets the visibility of the widget.
+func (l *List) SetVisible(visible bool) {
+	l.Lock()
+	defer l.Unlock()
+
+	l.grid.SetVisible(visible)
+}
+
+// SetColumnSizes sets the size of each column. A size of -1 represents an equal
+// proportion of the available space.
+func (l *List) SetColumnSizes(size ...int) {
+	l.Lock()
+	defer l.Unlock()
+
+	l.grid.SetColumnSizes(size...)
+}
+
+// SetItemHeight sets the height of the list items.
+func (l *List) SetItemHeight(itemHeight int) {
+	l.Lock()
+	defer l.Unlock()
+
+	if l.itemHeight == itemHeight {
+		return
+	}
+	l.itemHeight = itemHeight
+
+	if l.maxY == -1 {
+		return
+	}
+	rowSizes := make([]int, l.maxY+1)
+	for i := range rowSizes {
+		rowSizes[i] = l.itemHeight
+	}
+	l.grid.SetRowSizes(rowSizes...)
+}
+
+// SetSelectionMode sets the selection mode of the list.
+func (l *List) SetSelectionMode(selectionMode SelectionMode) {
+	l.Lock()
+	defer l.Unlock()
+
+	if l.selectionMode == selectionMode {
+		return
+	}
+	l.selectionMode = selectionMode
+}
+
+// SetHighlightColor sets the color used to highlight the currently selected item.
+func (l *List) SetHighlightColor(c color.RGBA) {
+	l.Lock()
+	defer l.Unlock()
+
+	l.highlightColor = c
+}
+
+// SelectedItem returns the selected list item.
+func (l *List) SelectedItem() (x int, y int) {
+	l.Lock()
+	defer l.Unlock()
+
+	return l.selectedX, l.selectedY
+}
+
+// SetSelectedItem sets the selected list item.
+func (l *List) SetSelectedItem(x int, y int) {
+	l.Lock()
+	defer l.Unlock()
+
+	l.selectedX, l.selectedY = x, y
+}
+
+// SetSelectedFunc sets a handler which is called when a list item is selected.
+// Providing a nil function value will remove the existing handler (if set).
+// The handler may return false to return the selection to its original state.
+func (l *List) SetSelectedFunc(f func(index int) (accept bool)) {
+	l.Lock()
+	defer l.Unlock()
+
+	l.selectedFunc = f
+}
+
+// Children returns the children of the widget. Children are drawn in the
+// order they are returned. Keyboard and mouse events are passed to children
+// in reverse order.
+func (l *List) Children() []Widget {
+	l.Lock()
+	defer l.Unlock()
+
+	return l.grid.Children()
+}
+
+// AddChildAt adds a widget to the list at the specified position.
+func (l *List) AddChildAt(w Widget, x int, y int) {
+	l.Lock()
+	defer l.Unlock()
+
+	l.grid.AddChildAt(&ignoreMouse{w}, x, y, 1, 1)
+	if y > l.maxY {
+		l.maxY = y
+		rowSizes := make([]int, l.maxY+1)
+		for i := range rowSizes {
+			rowSizes[i] = l.itemHeight
+		}
+		l.grid.SetRowSizes(rowSizes...)
+	}
+}
+
+// HandleKeyboard is called when a keyboard event occurs.
+func (l *List) HandleKeyboard(key ebiten.Key, r rune) (handled bool, err error) {
+	l.Lock()
+	defer l.Unlock()
+
+	return l.grid.HandleKeyboard(key, r)
+}
+
+// HandleMouse is called when a mouse event occurs. Only mouse events that
+// are on top of the widget are passed to the widget.
+func (l *List) HandleMouse(cursor image.Point, pressed bool, clicked bool) (handled bool, err error) {
+	l.Lock()
+	defer l.Unlock()
+
+	if !clicked || (cursor.X == 0 && cursor.Y == 0) {
+		return true, nil
+	}
+	selected := (cursor.Y - l.grid.rect.Min.Y) / l.itemHeight
+	if selected >= 0 && selected <= l.maxY {
+		lastSelected := l.selectedY
+		l.selectedY = selected
+		if l.selectedFunc != nil {
+			accept := l.selectedFunc(l.selectedY)
+			if !accept {
+				l.selectedY = lastSelected
+			}
+		}
+	}
+	return true, nil
+}
+
+// Draw draws the widget on the screen.
+func (l *List) Draw(screen *ebiten.Image) error {
+	l.Lock()
+	defer l.Unlock()
+
+	// Draw grid.
+	err := l.grid.Draw(screen)
+	if err != nil {
+		return err
+	}
+
+	// Highlight selection.
+	if l.selectionMode == SelectNone || l.selectedY < 0 {
+		return nil
+	}
+
+	x, y := l.grid.rect.Min.X, l.grid.rect.Min.Y+l.selectedY*l.itemHeight
+	w, h := l.grid.rect.Dx(), l.itemHeight
+	r := image.Rect(x, y, x+w, y+h)
+	screen.SubImage(r).(*ebiten.Image).Fill(l.highlightColor)
+	return nil
+}
+
+// Clear clears all items from the list.
+func (l *List) Clear() {
+	l.Lock()
+	defer l.Unlock()
+
+	l.grid.Clear()
+	l.maxY = -1
+	l.selectedX, l.selectedY = 0, -1
+}

widget.go

@@ -49,3 +49,14 @@ type Widget interface {
 	// in reverse order.
 	Children() []Widget
 }
+
+// ignoreMouse wraps a widget to ignore mouse events.
+type ignoreMouse struct {
+	Widget
+}
+
+// HandleMouse is called when a mouse event occurs. Only mouse events that
+// are on top of the widget are passed to the widget.
+func (i *ignoreMouse) HandleMouse(cursor image.Point, pressed bool, clicked bool) (handled bool, err error) {
+	return false, nil
+}