Input event type for mouse button events.
Contains mouse click information. See [method Node._input].
https://docs.godotengine.org/en/latest/tutorials/inputs/mouse_and_input_coordinates.html
Mouse button identifier, one of the [enum ButtonList] button or button wheel constants.
If [code]true[/code], the mouse button's state is a double-click.
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.