Add desk components 466-485 and icon.Bomb

Twenty pieces of a retro desktop: Desktop, DesktopIcon, Taskbar,
StartMenu, AppWindow, Calculator, Notepad, Minesweeper, ControlPanel,
TrayIcons, ShutdownScreen, BootScreen, Screensaver, Snake, Dock,
RunDialog, DiskDefrag, WallpaperPicker, ClipboardPanel and LockScreen.

The calculator really adds up and calls division by zero GAME OVER;
Minesweeper and Snake are playable, first click always safe; START
cascades its submenus without moving the rows already open; windows
drag by whole dots; the screensaver's logo changes color at each wall
and sparkles in a corner; the defragmenter is oddly soothing. Clocks
that step back hold at zero, and typed or copied text never reaches
the log.

icon.Bomb is the new 12x12 mine.

desk/dock.go

@@ -0,0 +1,96 @@
+package desk
+
+import (
+	"fmt"
+	"log/slog"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+// DockApp is an app on the dock.
+type DockApp struct {
+	Name string
+	Icon *pixel.Sprite
+}
+
+type DockOptions struct {
+	Disabled bool
+}
+
+type DockResult struct {
+	Element *ui.Element
+	// Launched is the app pressed this frame, else -1.
+	Launched int
+}
+
+type dockKey struct{}
+
+const dockCell = 30
+
+// Dock: a shelf of apps; the pointed or focused rises.
+func Dock(c *ui.Context, text string, apps []DockApp, o DockOptions) DockResult {
+	k := pixel.K(c)
+	if len(apps) == 0 {
+		panic("desk: Dock has no apps")
+	}
+	seen := map[string]bool{}
+	for i, a := range apps {
+		sprite("Dock", a.Icon)
+		if a.Name == "" || seen[a.Name] {
+			panic(fmt.Sprintf("desk: Dock app %d %q is nameless or twice", i, a.Name))
+		}
+		seen[a.Name] = true
+	}
+	w := len(apps) * dockCell
+	col := ui.Column(c).Width(k.D(w + 8)).AlignItems(ui.Center)
+	// lit is the risen app, read when the names paint.
+	lit := ui.Local(col, dockKey{}, func() int { return -1 })
+	*lit = -1
+	res := DockResult{Launched: -1}
+	res.Element = col.Children(func() {
+		ui.Box(c).Size(k.D(w+8), k.D(pixel.LineHeight)).Role(ui.RoleNone).Draw(func(p *ui.Painter, r ui.Rect) {
+			if *lit < 0 {
+				return
+			}
+			g := k.Canvas(p, r)
+			name := pixel.Wrap(apps[*lit].Name, w+8, 1)[0]
+			x := max(0, min(g.W-pixel.Measure(name), 4+*lit*dockCell+dockCell/2-pixel.Measure(name)/2))
+			g.Text(x, 0, name, pixel.Ink, 1)
+		})
+		ui.Row(c).Padding(0, k.D(4)).FocusGroup(ui.Horizontal).Role(ui.RoleToolbar).Label(text).Draw(func(p *ui.Painter, r ui.Rect) {
+			g := k.Canvas(p, r)
+			g.Rect(0, g.H-6, g.W, 6, pixel.Face)
+			g.HLine(0, g.H-6, g.W, pixel.Lit)
+			g.HLine(0, g.H-1, g.W, pixel.Edge)
+		}).Children(func() {
+			for i, a := range apps {
+				// Keyed by name: apps come and go.
+				ui.Box(c).Key(a.Name).Children(func() {
+					shell, base, st := pixel.Shell(c, func() *ui.Element {
+						return ui.Box(c).Focusable().Role(ui.RoleButton).Label(a.Name).Disabled(o.Disabled)
+					})
+					up := st.Hover || st.Focus
+					if up {
+						*lit = i
+					}
+					// It rises eight dots in four steps, and sinks back.
+					rise := 2 * k.Toward(c, shell, up, 15, 4)
+					if !base.IsDisabled() && base.Clicked() {
+						res.Launched = i
+					}
+					shell.Size(k.D(dockCell), k.D(40)).Draw(func(p *ui.Painter, r ui.Rect) {
+						g := k.Canvas(p, r)
+						g.Sprite((dockCell-2*a.Icon.W)/2, 10-rise+2*(12-a.Icon.H), a.Icon, 0, pixel.Ink, 2)
+						g.Finish(st)
+					})
+				})
+			}
+		})
+	})
+	if res.Launched >= 0 {
+		slog.Debug("8bit: dock launched", "label", text, "app", apps[res.Launched].Name)
+	}
+	return res
+}