MouseButtons
All possible mouse button values that are currently pressed.
Auxiliary = 4
The auxiliary button. In general, the middle button, often combined with a mouse wheel.
None = 0
No buttons currently pressed.
Primary = 0
The primary button of the device. In general, the left button or the only button on single-button
devices, used to activate a user interface control or select text.
Secondary = 2
The secondary button. In general, the right button, often used to display a context menu.