Input event type for keyboard events.
Stores key presses on the keyboard. Supports key presses, key releases and [member echo] events.
http://docs.godotengine.org/en/3.0/learning/features/inputs/inputevent.html
If [code]true[/code] the key was already pressed before this event. It means the user is holding the key down.
If [code]true[/code] the key's state is pressed. If [code]false[/code] the key's state is released.
Key scancode, one of the [code]KEY_*[/code] constants in [@global Scope].
Key unicode identifier when relevant.