Input event type for mouse button events.
Contains mouse click information. See [method Node._input].
http://docs.godotengine.org/en/3.0/tutorials/inputs/mouse_and_input_coordinates.html
- Mouse button identifier, one of the BUTTON_* or BUTTON_WHEEL_* constants in [@GlobalScope].
- If [code]true[/code] the mouse button's state is a double-click. If [code]false[/code] the mouse button's state is released.
- Magnitude. Amount (or delta) of the event. Used for scroll events, indicates scroll amount (vertically or horizontally). Only supported on some platforms, sensitivity varies by platform. May be 0 if not supported.
- If [code]true[/code] the mouse button's state is pressed. If [code]false[/code] the mouse button's state is released.