Add input components 066-085; gallery chrome on real components; deploy warms the edge

input/stepper.go

@@ -0,0 +1,103 @@
+package input
+
+import (
+	"fmt"
+	"log/slog"
+	"strconv"
+	"time"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+type StepperOptions struct {
+	Min, Max int
+	// Step is zero for 1.
+	Step     int
+	Disabled bool
+}
+
+type StepperResult struct {
+	Element *ui.Element
+	Changed bool
+}
+
+// Stepper is ◀ value ▶; held arrows repeat, keys step.
+func Stepper(c *ui.Context, text string, value *int, o StepperOptions) StepperResult {
+	if o.Max < o.Min {
+		panic(fmt.Sprintf("input: Stepper range %d to %d is empty", o.Min, o.Max))
+	}
+	k := pixel.K(c)
+	step := orDef("Stepper Step", o.Step, 1)
+	old := *value
+	set := func(v int) { *value = max(o.Min, min(o.Max, v)) }
+	w := max(pixel.Measure(strconv.Itoa(o.Min)), pixel.Measure(strconv.Itoa(o.Max))) + 8
+	e := ui.Row(c).Gap(k.D(2)).AlignItems(ui.Center).Children(func() {
+		set(*value - step*held(c, k, tinyLeft, o.Disabled))
+		shell, base, st := pixel.Shell(c, func() *ui.Element {
+			return ui.Box(c).Focusable().Role(ui.RoleStepper).Label(text).Description(strconv.Itoa(*value)).Disabled(o.Disabled)
+		})
+		if !o.Disabled {
+			if base.Shortcut(0, ui.KeyLeft) || base.Shortcut(0, ui.KeyDown) {
+				set(*value - step)
+			}
+			if base.Shortcut(0, ui.KeyRight) || base.Shortcut(0, ui.KeyUp) {
+				set(*value + step)
+			}
+		}
+		shell.Size(k.D(w), k.D(pixel.LineHeight+4)).Draw(func(p *ui.Painter, r ui.Rect) {
+			g := k.Canvas(p, r)
+			shown := strconv.Itoa(*value)
+			g.Frame(0, 0, g.W, g.H, pixel.Sunken, pixel.Well)
+			g.Text((g.W-pixel.Measure(shown))/2, 2, shown, pixel.Ink, 1)
+			finish(g, st)
+		})
+		set(*value + step*held(c, k, tinyRight, o.Disabled))
+		base.Description(strconv.Itoa(*value))
+	})
+	res := StepperResult{Element: e, Changed: *value != old}
+	if res.Changed {
+		slog.Debug("8bit: stepper", "label", text, "value", *value)
+	}
+	return res
+}
+
+type holdKey struct{}
+
+type hold struct {
+	since time.Time
+	n     int
+}
+
+// held counts an arrow's steps: one, then ten a second.
+func held(c *ui.Context, k pixel.Kit, sp *pixel.Sprite, disabled bool) int {
+	b := ui.Box(c).Size(k.D(12), k.D(pixel.LineHeight+4)).Role(ui.RoleNone)
+	down := b.Pressed() && !disabled
+	h := ui.Local(b, holdKey{}, func() hold { return hold{} })
+	b.Draw(func(p *ui.Painter, r ui.Rect) {
+		g := k.Canvas(p, r)
+		style, dy := pixel.Raised, 0
+		if down {
+			style, dy = pixel.Sunken, 1
+		}
+		g.Frame(0, 0, g.W, g.H, style, pixel.Face)
+		g.Sprite((g.W-sp.W)/2, (g.H-sp.H)/2+dy, sp, 0, pixel.Ink, 1)
+		if disabled {
+			g.Checker(0, 0, g.W, g.H, pixel.Face)
+		}
+	})
+	if !down {
+		*h = hold{}
+		return 0
+	}
+	k.Tick(c, 10)
+	if h.since.IsZero() {
+		*h = hold{since: k.Now(), n: 1}
+		return 1
+	}
+	want := 1 + max(0, int((k.Now().Sub(h.since)-400*time.Millisecond)/(100*time.Millisecond)))
+	n := want - h.n
+	h.n = want
+	return n
+}