WIP essentials 3

hold_to_confirm.go

@@ -0,0 +1,113 @@
+package mujica
+
+import (
+	"fmt"
+	"log/slog"
+	"time"
+
+	"github.com/egoist/mygo/ui"
+
+	"mujicaui/internal"
+	"mujicaui/theme"
+)
+
+// HoldToConfirmOptions configure a HoldToConfirm.
+type HoldToConfirmOptions struct {
+	// Duration is how long to hold; zero is 1.5 s.
+	Duration time.Duration
+	Disabled bool
+}
+
+// holdToConfirmState tracks one hold: by key or pointer, since start.
+type holdToConfirmState struct {
+	key, done bool
+	start     time.Time
+}
+
+// step advances the hold to now; it reports completion once per hold.
+func (s *holdToConfirmState) step(held bool, now time.Time, d time.Duration) (progress float64, confirmed bool) {
+	switch {
+	case !held:
+		s.start, s.done = time.Time{}, false
+		return 0, false
+	case s.done:
+		return 1, false
+	case s.start.IsZero():
+		s.start = now
+	}
+	progress = min(1, float64(now.Sub(s.start))/float64(d))
+	if progress >= 1 {
+		s.done = true
+		return 1, true
+	}
+	return progress, false
+}
+
+// HoldToConfirm runs a dangerous action only after the pointer or Space is held for Duration.
+func HoldToConfirm(c *ui.Context, label string, opts HoldToConfirmOptions) ChoiceResult {
+	if label == "" {
+		panic("mujica: HoldToConfirm needs a label")
+	}
+	if opts.Duration < 0 {
+		panic("mujica: negative HoldToConfirm Duration")
+	}
+	d := opts.Duration
+	if d == 0 {
+		d = 1500 * time.Millisecond
+	}
+	k := Tokens(c)
+	den := Density(c)
+	b := ui.ButtonBase(c).MinHeight(den.ControlHeight()).MinWidth(theme.MinHitSize).Padding(0, den.Unit()*4).
+		Radius(theme.ControlRadius).Disabled(opts.Disabled).Description(msg(c, "hold_to_confirm.hint")).Clip()
+	internal.Ring(b, k.Focus, theme.ControlRadius)
+	st := ui.Local(b, "hold_to_confirm", func() *holdToConfirmState { return &holdToConfirmState{} })
+	s := *st
+	// Space holds; Enter and Space never click, so no single key press confirms.
+	b.HandleInput(func(ev ui.InputEvent) bool {
+		if ev.Key != ui.KeySpace && ev.Key != ui.KeyEnter || b.IsDisabled() {
+			return false
+		}
+		if ev.Key == ui.KeySpace && (ev.Kind == ui.InputKeyDown || ev.Kind == ui.InputKeyUp) {
+			s.key = ev.Kind == ui.InputKeyDown
+		}
+		return true
+	})
+	_ = b.Clicked() // a click alone does nothing; it keeps the base pressable
+	disabled := b.IsDisabled()
+	held := !disabled && (s.key || b.Pressed())
+	if !b.Focused() {
+		s.key = false
+		held = !disabled && b.Pressed()
+	}
+	progress, confirmed := s.step(held, c.Now(), d)
+	still := c.Preferences().ReduceMotion
+	if held && !confirmed && progress < 1 {
+		if still {
+			c.After(100 * time.Millisecond)
+		} else {
+			c.AnimationFrame()
+		}
+	}
+	bg, fg, _ := buttonColors(k, Danger, b.Hovered() && !disabled, false)
+	b.Background(bg).TextColor(fg)
+	text := label
+	if held && still && progress < 1 {
+		left := d - time.Duration(progress*float64(d))
+		text = fmt.Sprintf(msg(c, "hold_to_confirm.left"), left.Seconds())
+	}
+	b.Draw(func(p *ui.Painter, r ui.Rect) {
+		if progress > 0 && !still {
+			p.Fill(ui.Rect{X: r.X, Y: r.Y, W: r.W * float32(progress), H: r.H}, k.OnDanger.Alpha(0.28), 0)
+		}
+	})
+	// Room for the countdown, so the width holds.
+	w1, _ := c.MeasureText(0, ui.Span{Text: label})
+	w2, _ := c.MeasureText(0, ui.Span{Text: fmt.Sprintf(msg(c, "hold_to_confirm.left"), d.Seconds())})
+	b.MinWidth(max(w1, w2) + den.Unit()*8)
+	b.Children(func() { ui.Text(c, text).SingleLine() })
+	if confirmed {
+		c.Announce(msg(c, "hold_to_confirm.done"))
+		slog.Debug("mujica: hold_to_confirm confirmed", "label", label)
+	}
+	return ChoiceResult{b, confirmed}
+}