Add focus change event for seats

include/wlr/types/wlr_seat.h

@@ -146,6 +146,10 @@ struct wlr_seat_pointer_state {
 	uint32_t grab_time;
 
 	struct wl_listener surface_destroy;
+
+	struct {
+		struct wl_signal focus_change;
+	} events;
 };
 
 // TODO: May be useful to be able to simulate keyboard input events
@@ -164,6 +168,10 @@ struct wlr_seat_keyboard_state {
 
 	struct wlr_seat_keyboard_grab *grab;
 	struct wlr_seat_keyboard_grab *default_grab;
+
+	struct {
+		struct wl_signal focus_change;
+	} events;
 };
 
 struct wlr_seat_touch_state {
@@ -238,6 +246,20 @@ struct wlr_seat_pointer_request_set_cursor_event {
 	int32_t hotspot_x, hotspot_y;
 };
 
+struct wlr_seat_pointer_focus_change_event {
+	struct wlr_seat *seat;
+	struct wlr_surface *old_surface, *new_surface;
+	double sx, sy;
+};
+
+struct wlr_seat_keyboard_focus_change_event {
+	struct wlr_seat *seat;
+	struct wlr_surface *old_surface, *new_surface;
+	size_t num_keycodes;
+	uint32_t *keycodes;
+	struct wlr_keyboard_modifiers *modifiers;
+};
+
 /**
  * Allocates a new wlr_seat and adds a wl_seat global to the display.
  */

types/seat/wlr_seat.c

@@ -225,6 +225,8 @@ struct wlr_seat *wlr_seat_create(struct wl_display *display, const char *name) {
 	seat->pointer_state.default_grab = pointer_grab;
 	seat->pointer_state.grab = pointer_grab;
 
+	wl_signal_init(&seat->pointer_state.events.focus_change);
+
 	// keyboard state
 	struct wlr_seat_keyboard_grab *keyboard_grab =
 		calloc(1, sizeof(struct wlr_seat_keyboard_grab));
@@ -241,6 +243,8 @@ struct wlr_seat *wlr_seat_create(struct wl_display *display, const char *name) {
 	seat->keyboard_state.seat = seat;
 	wl_list_init(&seat->keyboard_state.surface_destroy.link);
 
+	wl_signal_init(&seat->keyboard_state.events.focus_change);
+
 	// touch state
 	struct wlr_seat_touch_grab *touch_grab =
 		calloc(1, sizeof(struct wlr_seat_touch_grab));

types/seat/wlr_seat_keyboard.c

@@ -291,6 +291,16 @@ void wlr_seat_keyboard_enter(struct wlr_seat *seat,
 		// as it targets seat->keyboard_state.focused_client
 		wlr_seat_keyboard_send_modifiers(seat, modifiers);
 	}
+
+	struct wlr_seat_keyboard_focus_change_event event = {
+		.seat = seat,
+		.new_surface = surface,
+		.old_surface = focused_surface,
+		.num_keycodes = num_keycodes,
+		.keycodes = keycodes,
+		.modifiers = modifiers,
+	};
+	wlr_signal_emit_safe(&seat->keyboard_state.events.focus_change, &event);
 }
 
 void wlr_seat_keyboard_notify_enter(struct wlr_seat *seat,

types/seat/wlr_seat_pointer.c

@@ -183,7 +183,14 @@ void wlr_seat_pointer_enter(struct wlr_seat *wlr_seat,
 	wlr_seat->pointer_state.focused_client = client;
 	wlr_seat->pointer_state.focused_surface = surface;
 
-	// TODO: send focus change event
+	struct wlr_seat_pointer_focus_change_event event = {
+		.seat = wlr_seat,
+		.new_surface = surface,
+		.old_surface = focused_surface,
+		.sx = sx,
+		.sy = sy,
+	};
+	wlr_signal_emit_safe(&wlr_seat->pointer_state.events.focus_change, &event);
 }
 
 void wlr_seat_pointer_clear_focus(struct wlr_seat *wlr_seat) {