Choices: components 031-040 (wip)

toggle.go

@@ -0,0 +1,72 @@
+package mujica
+
+import (
+	"log/slog"
+
+	"github.com/egoist/mygo/ui"
+
+	"mujicaui/internal"
+	"mujicaui/theme"
+)
+
+// ToggleOptions configure a Toggle.
+type ToggleOptions struct {
+	// Icon goes before the label.
+	Icon     *ui.SVG
+	Disabled bool
+	// Label names an icon-only toggle for assistive technology.
+	Label string
+}
+
+// Toggle is a button that stays pressed while *on. Click or Space flips it; Changed reports it.
+func Toggle(c *ui.Context, on *bool, label string, opts ToggleOptions) *ui.Element {
+	if label == "" && opts.Label == "" {
+		panic("mujica: Toggle needs a label or Label")
+	}
+	b := ui.ToggleBase(c, on).Disabled(opts.Disabled)
+	if b.Changed() {
+		slog.Debug("mujica: toggle changed", "label", label+opts.Label, "on", *on)
+	}
+	toggleLook(c, b, *on, label, opts.Icon)
+	if opts.Label != "" {
+		b.Label(opts.Label)
+	}
+	return b
+}
+
+// toggleLook styles a pressed-or-not button and builds its content.
+func toggleLook(c *ui.Context, b *ui.Element, on bool, label string, icon *ui.SVG) {
+	k := Tokens(c)
+	d := Density(c)
+	b.MinHeight(d.ControlHeight()).MinWidth(d.ControlHeight()).Padding(0, d.Unit()*3).Gap(d.Unit() * 2).
+		Radius(theme.ControlRadius)
+	internal.Ring(b, k.Focus, theme.ControlRadius)
+	bg, fg, border := k.Surface, k.Text, k.ControlBorder
+	switch {
+	case on:
+		bg, fg, border = k.Selection, k.AccentText, k.AccentText
+	case b.Pressed():
+		bg = k.Selection
+	case b.Hovered():
+		bg = k.SurfaceHover
+	}
+	b.Background(bg).TextColor(fg).Border(theme.BorderWidth, border)
+	if on {
+		toggleMark(b, k)
+	}
+	b.Children(func() {
+		if icon != nil {
+			ui.Icon(c, icon).Size(16, 16)
+		}
+		if label != "" {
+			ui.Text(c, label).SingleLine()
+		}
+	})
+}
+
+// toggleMark draws a bar under the content: the pressed state beside the color.
+func toggleMark(b *ui.Element, k theme.Tokens) {
+	b.Draw(func(p *ui.Painter, r ui.Rect) {
+		p.Fill(ui.Rect{X: r.X + r.W*0.25, Y: r.Y + r.H - 4, W: r.W * 0.5, H: 2}, k.AccentText, 1)
+	})
+}