Add input components 086-105; park focus off disabled controls

input/holdbutton.go

@@ -0,0 +1,99 @@
+package input
+
+import (
+	"fmt"
+	"log/slog"
+	"time"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+type HoldButtonOptions struct {
+	// Duration is the hold needed; zero means one second.
+	Duration time.Duration
+	// Danger fills in Bad instead of Accent.
+	Danger   bool
+	Disabled bool
+}
+
+type HoldButtonResult struct {
+	Element   *ui.Element
+	Confirmed bool
+}
+
+type holdButtonKey struct{}
+
+// holding is a hold's start and its last key repeat.
+type holding struct {
+	since, key time.Time
+	done       bool
+}
+
+// repeatGap outlasts a key's delay before it repeats.
+const repeatGap = 600 * time.Millisecond
+
+// HoldButton confirms only when held; its fill grows stepwise.
+func HoldButton(c *ui.Context, text string, o HoldButtonOptions) HoldButtonResult {
+	k := pixel.K(c)
+	d := o.Duration
+	if d < 0 {
+		panic(fmt.Sprintf("input: HoldButton Duration %v", d))
+	}
+	if d == 0 {
+		d = time.Second
+	}
+	shell, base, st := pixel.Shell(c, func() *ui.Element {
+		return ui.ButtonBase(c).Label(text).Description(k.Msg("hold")).Disabled(o.Disabled)
+	})
+	h := ui.Local(base, holdButtonKey{}, func() holding { return holding{} })
+	if o.Disabled {
+		*h = holding{}
+	}
+	now := k.Now()
+	// Held keys repeat; each repeat moves the hold on.
+	enter, space := base.Shortcut(0, ui.KeyEnter), base.Shortcut(0, ui.KeySpace)
+	if enter || space {
+		if now.Sub(h.key) > repeatGap {
+			h.since = now
+		}
+		h.key = now
+	}
+	keyed := now.Sub(h.key) <= repeatGap
+	var held time.Duration
+	switch {
+	case st.Press:
+		if h.since.IsZero() {
+			h.since = now
+		}
+		held = now.Sub(h.since)
+	case keyed:
+		held = h.key.Sub(h.since)
+	default:
+		*h = holding{}
+	}
+	res := HoldButtonResult{Element: shell}
+	if held >= d && !h.done {
+		h.done, res.Confirmed = true, true
+		slog.Debug("8bit: hold confirmed", "label", text)
+	}
+	if st.Press || keyed {
+		k.Tick(c, 30)
+	}
+	steps := min(8, int(held*8/d))
+	fill := pixel.Accent
+	if o.Danger {
+		fill = pixel.Bad
+	}
+	shell.Size(k.D(pixel.Measure(text)+16), k.D(pixel.LineHeight+4)).Draw(func(p *ui.Painter, r ui.Rect) {
+		g := k.Canvas(p, r)
+		ink, dy := face(g, Normal, st, false)
+		w := (g.W - 2) * steps / 8
+		g.Rect(1, 1+dy, w, g.H-2-dy, fill)
+		g.Text(8, 2+dy, text, ink, 1)
+		g.Clip(1, 0, w, g.H, func() { g.Text(8, 2+dy, text, pixel.AccentInk, 1) })
+		finish(g, st)
+	})
+	return res
+}