create waveform seekbar widget; still more to do

ui/widgets/playercontrols.go

@@ -1,6 +1,7 @@
 package widgets
 
 import (
+	"github.com/dweymouth/supersonic/backend"
 	"github.com/dweymouth/supersonic/ui/util"
 
 	"fyne.io/fyne/v2"
@@ -82,6 +83,7 @@ type PlayerControls struct {
 	widget.BaseWidget
 
 	slider         *TrackPosSlider
+	waveform       *WaveformSeekbar
 	curTimeLabel   *labelMinSize
 	totalTimeLabel *labelMinSize
 	prev           *IconButton
@@ -116,6 +118,8 @@ func NewPlayerControls() *PlayerControls {
 
 	pc.slider = NewTrackPosSlider()
 	pc.slider.Disable()
+	pc.slider.Hide()
+	pc.waveform = NewWaveformSeekbar()
 	pc.curTimeLabel = NewLabelMinSize(util.SecondsToMMSS(0), 55)
 	pc.curTimeLabel.Alignment = fyne.TextAlignTrailing
 	pc.totalTimeLabel = NewLabelMinSize(util.SecondsToMMSS(0), 55)
@@ -138,7 +142,11 @@ func NewPlayerControls() *PlayerControls {
 
 	buttons := container.NewHBox(layout.NewSpacer(), pc.prev, pc.playpause, pc.next, layout.NewSpacer())
 
-	c := container.NewBorder(nil, nil, pc.curTimeLabel, pc.totalTimeLabel, pc.slider)
+	seekCtrl := container.NewStack(
+		pc.slider,
+		pc.waveform,
+	)
+	c := container.NewBorder(nil, nil, pc.curTimeLabel, pc.totalTimeLabel, seekCtrl)
 	pc.container = container.New(layout.NewCustomPaddedVBoxLayout(0), c, buttons)
 
 	return pc
@@ -203,10 +211,15 @@ func (pc *PlayerControls) UpdatePlayTime(curTime, totalTime float64) {
 		if updated {
 			// Only update slider once a second when time label changes
 			pc.slider.SetValue(v)
+			pc.waveform.SetProgress(v)
 		}
 	}
 }
 
+func (p *PlayerControls) UpdateWaveformImg(img *backend.WaveformImage) {
+	p.waveform.UpdateImage(img)
+}
+
 func (p *PlayerControls) CreateRenderer() fyne.WidgetRenderer {
 	return widget.NewSimpleRenderer(p.container)
 }

ui/widgets/waveformseekbar.go

@@ -0,0 +1,109 @@
+package widgets
+
+import (
+	"image"
+	"image/color"
+	"log"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/canvas"
+	"fyne.io/fyne/v2/container"
+	"fyne.io/fyne/v2/layout"
+	"fyne.io/fyne/v2/theme"
+	"fyne.io/fyne/v2/widget"
+	"github.com/dweymouth/supersonic/backend"
+)
+
+type WaveformSeekbar struct {
+	widget.BaseWidget
+
+	imgColorL   color.Color
+	imgColorR   color.Color
+	imgProgress float64
+
+	img *canvas.Image
+}
+
+func NewWaveformSeekbar() *WaveformSeekbar {
+	w := &WaveformSeekbar{
+		img: canvas.NewImageFromImage(nil),
+	}
+	w.ExtendBaseWidget(w)
+	return w
+}
+
+func (w *WaveformSeekbar) UpdateImage(img *backend.WaveformImage) {
+	w.img.Image = img
+	w.Refresh()
+}
+
+func (w *WaveformSeekbar) Refresh() {
+	prm, fg := w.getThemeColors()
+	w.recolorImage(prm, fg, w.imgProgress)
+	w.img.Refresh()
+	//w.BaseWidget.Refresh()
+}
+
+func (w *WaveformSeekbar) CreateRenderer() fyne.WidgetRenderer {
+	return widget.NewSimpleRenderer(
+		container.New(layout.NewCustomPaddedLayout(4, 4, 0, 0), w.img),
+	)
+}
+
+// SetProgress sets how much of the seekbar has been played
+// (ratio from 0 to 1)
+func (w *WaveformSeekbar) SetProgress(v float64) {
+	prm, fg := w.getThemeColors()
+	w.recolorImage(prm, fg, v)
+	w.Refresh()
+}
+
+func (w *WaveformSeekbar) getThemeColors() (primary, foreground color.Color) {
+	th := w.Theme()
+	vnt := fyne.CurrentApp().Settings().ThemeVariant()
+	primary = th.Color(theme.ColorNamePrimary, vnt)
+	foreground = th.Color(theme.ColorNameForeground, vnt)
+	return primary, foreground
+}
+
+func (w *WaveformSeekbar) recolorImage(cL, cR color.Color, progress float64) {
+	if w.img.Image == nil {
+		return
+	}
+	if w.imgColorL == cL && w.imgColorR == cR && w.imgProgress == progress {
+		return
+	}
+
+	_r, _g, _b, _ := cL.RGBA()
+	rL, gL, bL := byte(_r>>8), byte(_g>>8), byte(_b>>8)
+	_r, _g, _b, _ = cR.RGBA()
+	rR, gR, bR := byte(_r>>8), byte(_g>>8), byte(_b>>8)
+
+	// TODO- smartly figure out which pixels we need
+	// to update for different scenarios (e.g. progress update only)
+	// and not iterate the whole thing every time
+	img := w.img.Image.(*image.NRGBA)
+	bnds := img.Rect.Bounds()
+	thresholdPixel := int(float64(bnds.Dx()) * progress)
+	log.Println("progress = ", progress, " bounds Dx = ", bnds.Dx())
+	log.Println("thresholdPixel = ", thresholdPixel)
+	for x := 0; x < bnds.Dx(); x++ {
+		for y := 0; y < bnds.Dy(); y++ {
+			if x < thresholdPixel {
+				setPixelRGB(img, x, y, rL, gL, bL)
+			} else {
+				setPixelRGB(img, x, y, rR, gR, bR)
+			}
+		}
+	}
+
+	w.imgColorL, w.imgColorR = cL, cR
+	w.imgProgress = progress
+}
+
+func setPixelRGB(img *image.NRGBA, x, y int, r, g, b byte) {
+	offset := img.PixOffset(x, y)
+	img.Pix[offset+0] = r
+	img.Pix[offset+1] = g
+	img.Pix[offset+2] = b
+}