The following events are generated if a keyboard is present and supported by the render manager.
A key is in the pressed state
gre.keydown events with control as a destination require focus.
uint32_t code uint32_t modifiers
This is the UTF-8 key value
A set of modifiers applied to the key
GR_EVENT_KEYMOD_ALT GR_EVENT_KEYMOD_CTRL GR_EVENT_KEYMOD_SHIFT