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/appwindow.go

@@ -0,0 +1,109 @@
+package desk
+
+import (
+	"fmt"
+	"log/slog"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/icon"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/input"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+type AppWindowOptions struct {
+	// The body's Width and Height are dots; zeros mean 160×100.
+	Width, Height int
+	// Room is its area in dots; zero leaves it open.
+	Room     [2]int
+	Disabled bool
+}
+
+type AppWindowResult struct {
+	Element *ui.Element
+	// Closed is the close box; Moved, a drag or arrow.
+	Closed, Moved bool
+}
+
+type dragKey struct{}
+
+// AppWindow floats at x, y; drag or arrow its bar.
+func AppWindow(c *ui.Context, title string, x, y *int, o AppWindowOptions, content func()) AppWindowResult {
+	k := pixel.K(c)
+	w, h := pixel.Or("AppWindow Width", o.Width, 160), pixel.Or("AppWindow Height", o.Height, 100)
+	// The bar needs room for a grip and close box.
+	if w < 40 {
+		panic(fmt.Sprintf("desk: AppWindow Width %d is under 40", w))
+	}
+	// The window is its body, bar and frame.
+	ww, wh := w+6, h+pixel.LineHeight+10
+	if o.Room[0] > 0 && o.Room[0] < ww || o.Room[1] > 0 && o.Room[1] < wh {
+		panic(fmt.Sprintf("desk: AppWindow %d×%d does not fit its Room %v", ww, wh, o.Room))
+	}
+	ox, oy := *x, *y
+	keep := func() {
+		if o.Room[0] > 0 {
+			*x = min(*x, o.Room[0]-ww)
+		}
+		if o.Room[1] > 0 {
+			*y = min(*y, o.Room[1]-wh)
+		}
+		*x, *y = max(0, *x), max(0, *y)
+	}
+	keep()
+	win := ui.Column(c).Absolute().Width(k.D(ww)).Padding(k.D(3)).Gap(k.D(2)).Role(ui.RoleGroup).Label(title)
+	// rest keeps a drag's part-dot for the next frame.
+	rest := ui.Local(win, dragKey{}, func() [2]float32 { return [2]float32{} })
+	active := win.FocusWithin()
+	if o.Disabled {
+		win.Description(k.Msg("disabled"))
+	}
+	res := AppWindowResult{Element: win}
+	win.Draw(func(p *ui.Painter, r ui.Rect) {
+		g := k.Canvas(p, r)
+		g.Frame(0, 0, g.W, g.H, pixel.Raised, pixel.Face)
+	}).Children(func() {
+		ui.Row(c).FillWidth().Gap(k.D(2)).AlignItems(ui.Center).Children(func() {
+			shell, base, st := pixel.Shell(c, func() *ui.Element {
+				return ui.Box(c).Focusable().Role(ui.RoleGroup).Label(title).Description(k.Msg("arrows_move")).Disabled(o.Disabled)
+			})
+			if !base.IsDisabled() {
+				if dx, dy, ok := base.Dragged(); ok {
+					rest[0], rest[1] = rest[0]+dx/k.Dot(), rest[1]+dy/k.Dot()
+					*x, *y = *x+int(rest[0]), *y+int(rest[1])
+					rest[0], rest[1] = rest[0]-float32(int(rest[0])), rest[1]-float32(int(rest[1]))
+				}
+				for _, m := range []struct {
+					key    ui.Key
+					dx, dy int
+				}{{ui.KeyLeft, -4, 0}, {ui.KeyRight, 4, 0}, {ui.KeyUp, 0, -4}, {ui.KeyDown, 0, 4}} {
+					if base.Shortcut(0, m.key) {
+						*x, *y = *x+m.dx, *y+m.dy
+					}
+				}
+			}
+			shell.Grow(1).Height(k.D(pixel.LineHeight + 2)).Draw(func(p *ui.Painter, r ui.Rect) {
+				g := k.Canvas(p, r)
+				barLook(g, title, active)
+				g.Finish(st)
+			})
+			res.Closed = input.IconButton(c, icon.Close, k.Msg("close"), input.IconButtonOptions{Size: input.Small, Disabled: o.Disabled}).Clicked
+		})
+		// Off, the body's controls are off too, and veiled.
+		in := pixel.Current(c)
+		in.Inert = in.Inert || o.Disabled
+		ui.Box(c).Size(k.D(w), k.D(h)).Clip().Children(func() { pixel.Scope(c, in, content) }).DrawOver(func(p *ui.Painter, r ui.Rect) {
+			if o.Disabled {
+				g := k.Canvas(p, r)
+				g.Checker(0, 0, g.W, g.H, pixel.Face)
+			}
+		})
+	})
+	keep()
+	win.Left(k.D(*x)).Top(k.D(*y))
+	res.Moved = *x != ox || *y != oy
+	if res.Moved || res.Closed {
+		slog.Debug("8bit: app window", "title", title, "x", *x, "y", *y, "closed", res.Closed)
+	}
+	return res
+}