Foundation: tokens, theme, icons, i18n, Button, Spinner, gallery scaffold

button.go

@@ -0,0 +1,92 @@
+package mujica
+
+import (
+	"github.com/egoist/mygo/ui"
+
+	"mujicaui/internal"
+	"mujicaui/theme"
+)
+
+// ButtonVariant is a button's emphasis. The zero value is Primary.
+type ButtonVariant int
+
+const (
+	Primary ButtonVariant = iota
+	Secondary
+	Outline
+	Ghost
+	Danger
+)
+
+// ButtonOptions configure a Button.
+type ButtonOptions struct {
+	Variant ButtonVariant
+	// Icon goes before the label.
+	Icon     *ui.SVG
+	Loading  bool
+	Disabled bool
+	// Label names an icon-only button for assistive technology.
+	Label string
+}
+
+// Button is a push button. Loading keeps its size and blocks clicks.
+func Button(c *ui.Context, label string, opts ButtonOptions) *ui.Element {
+	k := Tokens(c)
+	d := Density(c)
+	b := ui.ButtonBase(c).MinHeight(d.ControlHeight()).MinWidth(theme.MinHitSize).
+		Padding(0, d.Unit()*4).Gap(d.Unit()*2).Radius(theme.ControlRadius).
+		Disabled(opts.Disabled || opts.Loading)
+	internal.Ring(b, k.Focus, theme.ControlRadius)
+	if opts.Label != "" {
+		b.Label(opts.Label)
+	}
+	bg, fg, border := buttonColors(k, opts.Variant, b.Hovered() && !opts.Disabled, b.Pressed())
+	b.Background(bg).TextColor(fg)
+	if border.A > 0 {
+		b.Border(theme.BorderWidth, border)
+	}
+	b.Children(func() {
+		if opts.Loading {
+			Spinner(c, SpinnerOptions{Size: 14, Color: fg})
+		} else if opts.Icon != nil {
+			ui.Icon(c, opts.Icon).Size(16, 16)
+		}
+		if label != "" {
+			ui.Text(c, label).SingleLine()
+		}
+	})
+	return b
+}
+
+func buttonColors(k theme.Tokens, v ButtonVariant, hover, pressed bool) (bg, fg, border ui.Color) {
+	switch v {
+	case Secondary:
+		bg, fg, border = k.Surface, k.Text, k.ControlBorder
+	case Outline:
+		bg, fg, border = ui.Transparent, k.AccentText, k.AccentText
+	case Ghost:
+		bg, fg = ui.Transparent, k.AccentText
+	case Danger:
+		bg, fg = k.DangerFill, k.OnDanger
+		if pressed {
+			bg = k.DangerFill.Mix(ui.RGB(0, 0, 0), 0.25)
+		} else if hover {
+			bg = k.DangerFill.Mix(ui.RGB(0, 0, 0), 0.12)
+		}
+		return
+	default:
+		bg, fg = k.Accent, k.OnAccent
+		if pressed {
+			bg = k.AccentPressed
+		} else if hover {
+			bg = k.AccentHover
+		}
+		return
+	}
+	if pressed {
+		bg = k.Selection
+	} else if hover {
+		bg = k.SurfaceHover
+	}
+	return
+}