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.
Contructor: creates a new GView. Size is handled by the controller.
The current (x,y) coordinate of the mouse, if pressed.
This attribute is either a GPoint object or None. It is only a GPoint if the mouse button is currently pressed. There is currently no way to get the location of the mouse when the button is not preseed. This a limitation of Kivy.
In determining the mouse coordinates, the origin (0,0) corresponds to the bottom left corner of the application window.
Invariant: Either a GPoint object or None.
There are no publically accessible methods in GView.