xwm: supply wlr_xwayland pointer to user_event_handler callback

Previously it was supplying a pointer to private struct wlr_xwm
which was useless for compositors. The wlr_xwayland pointer in
contrast does have a generic data field and thus can be used by
compositors to attach their own pointer.

Additionally change the return value from int to bool.

include/wlr/xwayland/xwayland.h

@@ -57,11 +57,11 @@ struct wlr_xwayland {
 	} events;
 
 	/**
-	 * Add a custom event handler to xwayland. Return 1 if the event was
-	 * handled or 0 to use the default wlr-xwayland handler. wlr-xwayland will
+	 * Add a custom event handler to xwayland. Return true if the event was
+	 * handled or false to use the default wlr-xwayland handler. wlr-xwayland will
 	 * free the event.
 	 */
-	int (*user_event_handler)(struct wlr_xwm *xwm, xcb_generic_event_t *event);
+	bool (*user_event_handler)(struct wlr_xwayland *wlr_xwayland, xcb_generic_event_t *event);
 
 	void *data;
 

xwayland/xwm.c

@@ -1747,7 +1747,7 @@ static int x11_event_handler(int fd, uint32_t mask, void *data) {
 		count++;
 
 		if (xwm->xwayland->user_event_handler &&
-				xwm->xwayland->user_event_handler(xwm, event)) {
+				xwm->xwayland->user_event_handler(xwm->xwayland, event)) {
 			free(event);
 			continue;
 		}