Add navigation components 131-150; pixel Pad, Finish, Park, Since

pixel/pad.go

@@ -0,0 +1,43 @@
+package pixel
+
+import "github.com/egoist/mygo/ui"
+
+// Pad is a focusable grid; it returns the picked cell.
+func Pad(c *ui.Context, text string, cols, n, cw, ch int, cur *int, disabled bool) (shell, base *ui.Element, st State, picked int) {
+	k := K(c)
+	shell, base, st = Shell(c, func() *ui.Element {
+		return ui.Box(c).Focusable().Role(ui.RoleGroup).Label(text).Disabled(disabled)
+	})
+	shell.Size(k.D(cols*cw), k.D((n+cols-1)/cols*ch))
+	for _, m := range []struct {
+		key ui.Key
+		to  func() int
+	}{
+		{ui.KeyLeft, func() int { return *cur - 1 }}, {ui.KeyRight, func() int { return *cur + 1 }},
+		{ui.KeyUp, func() int { return *cur - cols }}, {ui.KeyDown, func() int { return *cur + cols }},
+		{ui.KeyHome, func() int { return 0 }}, {ui.KeyEnd, func() int { return n - 1 }},
+	} {
+		if to := m.to(); base.Shortcut(0, m.key) && to >= 0 && to < n {
+			*cur = to
+		}
+	}
+	picked = -1
+	enter, space := base.Shortcut(0, ui.KeyEnter), base.Shortcut(0, ui.KeySpace)
+	if enter || space {
+		picked = *cur
+	}
+	// Enter and Space are taken, so clicks come from pointers.
+	if base.Clicked() {
+		x, y, _ := base.PointerPosition()
+		if col, i := int(x/k.D(cw)), int(y/k.D(ch))*cols+int(x/k.D(cw)); x >= 0 && y >= 0 && col < cols && i < n {
+			*cur, picked = i, i
+		}
+	}
+	return shell, base, st, picked
+}
+
+// Cursor lights a cell with an Accent ring.
+func (g Canvas) Cursor(x, y, w, h int) {
+	g.Rect(x, y, w, h, Accent)
+	g.Rect(x+1, y+1, w-2, h-2, Lit)
+}