Mouse Events

Notes:

The constants LeftButton, RightButton and MiddleButton can be used to see which mouse buttons are currently held down.
The buttons parameter in the callback functions is a bit-field.
Use setmousedown to intercept mouse button clicks.
Use setmouseup to intercept mouse button releases.
Use setmousedrag to handle moving the mouse with one or more buttons held down.
Use setmousemove to handle moving the mouse with no buttons held down.
See also: mousevnt.c