The view class for a Game application.
You may need to access an instance of this class to draw GObject instances. However, you will never need to construct one. You should only use the one provided in the view attribute of Game. See class Game for more information.
Initializer: creates a new GView
The current (x,y) coordinate of the mouse, if pressed.
This method only returns coordinates if the mouse button is pressed. If the mouse button is not pressed it returns None. The origin (0,0) corresponds to the bottom left corner of the application window.
There is currently no way to get the location of the mouse when the button is not preseed. This a limitation of Kivy.
Invariant: Either a GPoint or None (if there is no touch).
There are no publically accessible methods in GView.