initial commit

progressbar.go

@@ -0,0 +1,83 @@
+package gel
+
+import (
+	"image"
+	"image/color"
+
+	l "github.com/p9c/p9/pkg/gel/gio/layout"
+	"github.com/p9c/p9/pkg/gel/gio/op/clip"
+	"github.com/p9c/p9/pkg/gel/gio/op/paint"
+	"github.com/p9c/p9/pkg/gel/gio/unit"
+
+	"github.com/p9c/p9/pkg/gel/f32color"
+)
+
+type ProgressBar struct {
+	*Window
+	color    color.NRGBA
+	progress int
+}
+
+// ProgressBar renders a horizontal bar with an indication of completion of a process
+func (w *Window) ProgressBar() *ProgressBar {
+	return &ProgressBar{
+		Window:   w,
+		progress: 0,
+		color:    w.Colors.GetNRGBAFromName("Primary"),
+	}
+}
+
+// SetProgress sets the progress of the progress bar
+func (p *ProgressBar) SetProgress(progress int) *ProgressBar {
+	p.progress = progress
+	return p
+}
+
+// Color sets the color to render the bar in
+func (p *ProgressBar) Color(c string) *ProgressBar {
+	p.color = p.Theme.Colors.GetNRGBAFromName(c)
+	return p
+}
+
+// Fn renders the progress bar as it is currently configured
+func (p *ProgressBar) Fn(gtx l.Context) l.Dimensions {
+	shader := func(width float32, col color.NRGBA) l.Dimensions {
+		maxHeight := unit.Dp(4)
+		rr := gtx.Dp(unit.Dp(2))
+
+		d := image.Point{X: int(width), Y: gtx.Dp(maxHeight)}
+
+		defer clip.UniformRRect(image.Rectangle{Max: image.Pt(int(width), gtx.Dp(maxHeight))}, rr).Push(gtx.Ops).Pop()
+
+		paint.ColorOp{Color: col}.Add(gtx.Ops)
+		paint.PaintOp{}.Add(gtx.Ops)
+
+		return l.Dimensions{Size: d}
+	}
+
+	progress := p.progress
+	if progress > 100 {
+		progress = 100
+	} else if progress < 0 {
+		progress = 0
+	}
+
+	progressBarWidth := float32(gtx.Constraints.Max.X)
+
+	return l.Stack{Alignment: l.W}.Layout(gtx,
+		l.Stacked(func(gtx l.Context) l.Dimensions {
+			// Use a transparent equivalent of progress color.
+			bgCol := f32color.MulAlpha(p.color, 150)
+
+			return shader(progressBarWidth, bgCol)
+		}),
+		l.Stacked(func(gtx l.Context) l.Dimensions {
+			fillWidth := (progressBarWidth / 100) * float32(progress)
+			fillColor := p.color
+			if !gtx.Source.Enabled() {
+				fillColor = f32color.MulAlpha(fillColor, 200)
+			}
+			return shader(fillWidth, fillColor)
+		}),
+	)
+}