10.8 Key Map State Notification Events

The X server can report KeymapNotify events to clients that want information about changes in their keyboard state.

To receive KeymapNotify events, set the KeymapStateMask bit in the event-mask attribute of the window. The X server generates this event immediately after every EnterNotify and FocusIn event.

The structure for this event type contains:


/* generated on EnterWindow and FocusIn when KeymapState selected */
typedef struct {
	int type;		/* KeymapNotify */
	unsigned long serial;	/* # of last request processed by server */
	Bool send_event;	/* true if this came from a SendEvent request */
	Display *display;	/* Display the event was read from */
	Window window;
	char key_vector[32];
} XKeymapEvent;

The window member is not used but is present to aid some toolkits. The key_vector member is set to the bit vector of the keyboard. Each bit set to 1 indicates that the corresponding key is currently pressed. The vector is represented as 32 bytes. Byte N (from 0) contains the bits for keys 8N to 8N + 7 with the least-significant bit in the byte representing key 8N.

Next: Exposure events

Christophe Tronche, [email protected]