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
The 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.
The amount (or delta) of the event. When used for high-precision scroll events, this indicates the scroll amount (vertical or horizontal). This is only supported on some platforms; the reported sensitivity varies depending on the platform. May be [code]0[/code] 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.