adding tracklist widget and columns layout

ui/layout/columnslayout.go

@@ -0,0 +1,66 @@
+package layout
+
+import "fyne.io/fyne/v2"
+
+type ColumnsLayout struct {
+	ColumnWidths []float32
+}
+
+func NewColumnsLayout(widths []float32) *ColumnsLayout {
+	return &ColumnsLayout{ColumnWidths: widths}
+}
+
+func (c *ColumnsLayout) MinSize(objects []fyne.CanvasObject) fyne.Size {
+	var width float32
+	var height float32
+	for i := 0; i < len(objects); i++ {
+		if !objects[i].Visible() {
+			continue
+		}
+		height = fyne.Max(height, objects[i].MinSize().Height)
+		w := objects[i].MinSize().Width
+		if i < len(c.ColumnWidths) && c.ColumnWidths[i] > w {
+			w = c.ColumnWidths[i]
+		}
+		width += w
+	}
+	return fyne.NewSize(width, height)
+}
+
+func (c *ColumnsLayout) Layout(objects []fyne.CanvasObject, size fyne.Size) {
+	var fixedW float32
+	var expandObjCount int
+	for i := 0; i < min(len(objects), len(c.ColumnWidths)); i++ {
+		if !objects[i].Visible() {
+			continue
+		}
+		if c.ColumnWidths[i] < 0 {
+			expandObjCount++
+		} else {
+			itemW := objects[i].MinSize().Width
+			fixedW += fyne.Max(itemW, c.ColumnWidths[i])
+		}
+	}
+	extraW := size.Width - fixedW
+	expandObjW := extraW / float32(expandObjCount)
+
+	var x float32
+	for i := 0; i < len(objects); i++ {
+		w := objects[i].MinSize().Width
+		if i < len(c.ColumnWidths) && c.ColumnWidths[i] > w {
+			w = c.ColumnWidths[i]
+		} else if c.ColumnWidths[i] < 0 && expandObjW > w {
+			w = expandObjW
+		}
+		objects[i].Resize(fyne.NewSize(w, size.Height))
+		objects[i].Move(fyne.NewPos(x, 0))
+		x += w
+	}
+}
+
+func min(x, y int) int {
+	if x < y {
+		return x
+	}
+	return y
+}

ui/widgets/tracklist.go

@@ -0,0 +1,102 @@
+package widgets
+
+import (
+	"strconv"
+	"supersonic/ui/layout"
+	"supersonic/ui/util"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/container"
+	"fyne.io/fyne/v2/widget"
+	"github.com/dweymouth/go-subsonic"
+)
+
+type TrackRow struct {
+	widget.BaseWidget
+
+	trackID     string
+	prevTrackID string
+
+	num    *widget.RichText
+	name   *widget.RichText
+	artist *widget.RichText
+	dur    *widget.RichText
+
+	OnDoubleTapped func()
+
+	container *fyne.Container
+}
+
+var _ fyne.DoubleTappable = (*TrackRow)(nil)
+
+func NewTrackRow() *TrackRow {
+	t := &TrackRow{}
+	t.ExtendBaseWidget(t)
+	t.num = widget.NewRichTextWithText("")
+	t.name = widget.NewRichTextWithText("")
+	t.name.Wrapping = fyne.TextTruncate
+	t.artist = widget.NewRichTextWithText("")
+	t.artist.Wrapping = fyne.TextTruncate
+	t.dur = widget.NewRichTextWithText("")
+
+	t.container = container.New(layout.NewColumnsLayout([]float32{30, -1, -1, 50}),
+		t.num, t.name, t.artist, t.dur)
+	return t
+}
+
+func (t *TrackRow) Update(tr *subsonic.Child) {
+	if tr.ID == t.prevTrackID {
+		return
+	}
+	t.prevTrackID = t.trackID
+	t.trackID = tr.ID
+	t.num.Segments[0].(*widget.TextSegment).Text = strconv.Itoa(tr.Track)
+	t.name.Segments[0].(*widget.TextSegment).Text = tr.Title
+	t.artist.Segments[0].(*widget.TextSegment).Text = tr.Artist
+	t.dur.Segments[0].(*widget.TextSegment).Text = util.SecondsToTimeString(float64(tr.Duration))
+
+	t.Refresh()
+}
+
+func (t *TrackRow) CreateRenderer() fyne.WidgetRenderer {
+	return widget.NewSimpleRenderer(t.container)
+}
+
+func (t *TrackRow) DoubleTapped(*fyne.PointEvent) {
+	if t.OnDoubleTapped != nil {
+		t.OnDoubleTapped()
+	}
+}
+
+type Tracklist struct {
+	widget.BaseWidget
+
+	tracks []*subsonic.Child
+	list   *widget.List
+
+	OnPlayTrackAt func(int)
+}
+
+func NewTracklist(tracks []*subsonic.Child) *Tracklist {
+	t := &Tracklist{tracks: tracks}
+	t.ExtendBaseWidget(t)
+	t.list = widget.NewList(
+		func() int { return len(t.tracks) },
+		func() fyne.CanvasObject { return NewTrackRow() },
+		func(itemID widget.ListItemID, item fyne.CanvasObject) {
+			tr := item.(*TrackRow)
+			tr.OnDoubleTapped = func() { t.onPlayTrackAt(itemID) }
+			tr.Update(t.tracks[itemID])
+		})
+	return t
+}
+
+func (t *Tracklist) CreateRenderer() fyne.WidgetRenderer {
+	return widget.NewSimpleRenderer(t.list)
+}
+
+func (t *Tracklist) onPlayTrackAt(idx int) {
+	if t.OnPlayTrackAt != nil {
+		t.OnPlayTrackAt(idx)
+	}
+}