Improvements to menus

Major progress on #4

menu.go

@@ -18,23 +18,28 @@ type Menu struct {
 }
 
 // NewMenu creates a new menu with the specified items. The menu will appear
-// directly under the anchor Object. If the anchor is nil, it will appear
-// directly under the mouse pointer instead.
-func NewMenu (anchor tomo.Object, items ...tomo.Object) (*Menu, error) {
-	menu := &Menu { }
-	if anchor == nil {
-		// TODO: *actually* put it under the mouse
-		window, err := tomo.NewWindow(menu.bounds)
-		if err != nil { return nil, err }
-		menu.Window = window
-	} else {
-		menu.bounds = menuBoundsFromAnchor(anchor)
-		menu.parent = anchor.GetBox().Window()
-		window, err := menu.parent.NewMenu(menu.bounds)
-		if err != nil { return nil, err }
-		menu.Window = window
-	}
+// directly under the mouse pointer.
+func NewMenu (parent tomo.Window, items ...tomo.Object) (*Menu, error) {
+	bounds := (image.Rectangle { }).Add(parent.MousePosition())
+	return newMenu(parent, bounds, items...)
+}
 
+// NewAnchoredMenu creates a new menu with the specified items. The menu will
+// appear directly under the anchor.
+func NewAnchoredMenu (anchor tomo.Object, items ...tomo.Object) (*Menu, error) {
+	parent := anchor.GetBox().Window()
+	bounds := menuBoundsFromAnchor(anchor)
+	return newMenu(parent, bounds, items...)
+}
+
+func newMenu (parent tomo.Window, bounds image.Rectangle, items ...tomo.Object) (*Menu, error) {
+	menu := &Menu { }
+	menu.bounds = bounds
+	menu.parent = parent
+	window, err := menu.parent.NewMenu(menu.bounds)
+	if err != nil { return nil, err }
+	menu.Window = window
+	
 	menu.rootContainer = tomo.NewContainerBox()
 	menu.rootContainer.SetAttr(tomo.ALayout(layouts.ContractVertical))
 
@@ -74,6 +79,7 @@ func (this *Menu) TearOff () {
 	this.Window.Close()
 
 	this.rootContainer.Remove(this.tearLine)
+	this.rootContainer.SetTag("torn", true)
 	
 	this.Window = window
 	this.Window.SetRoot(this.rootContainer)