Popup Menu
fun PopupMenu(vararg children: Drawable, size: Vec2? = null, align: Align = AlignDefault, polyUI: PolyUI?, openNow: Boolean = true, position: Point = Point.At): Block
Spawn a menu at the mouse position.
Parameters
poly UI
an instance of PolyUI. If null, openNow must be false, or else an exception will be thrown.
open Now
if true, the menu is opened immediately. else, call PolyUI.focus on the return value to open it.