[PATCH weston] input: set the focus to NULL when the focus's resource is destroyed

[Giulio Camuffo]

with the surface ref-count feature a surface may live on after its
resource was destroyed. so listen for the resource destroy signal
and set the focus to NULL.
---
 src/compositor.c |  4 ++++
 src/compositor.h |  3 +++
 src/input.c      | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/src/compositor.c b/src/compositor.c
index 9757a75..6b38e38 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -1148,6 +1148,10 @@ destroy_surface(struct wl_resource *resource)
 {
 	struct weston_surface *surface = wl_resource_get_user_data(resource);
 
+	/* Set the resource to NULL, since we don't want to leave a
+	 * dangling pointer if the surface was refcounted and survives
+	 * the weston_surface_destroy() call. */
+	surface->resource = NULL;
 	weston_surface_destroy(surface);
 }
 
diff --git a/src/compositor.h b/src/compositor.h
index 5257356..1408110 100644
--- a/src/compositor.h
+++ b/src/compositor.h
@@ -312,6 +312,7 @@ struct weston_pointer {
 	struct wl_list resource_list;
 	struct wl_list focus_resource_list;
 	struct weston_surface *focus;
+	struct wl_listener focus_listener;
 	uint32_t focus_serial;
 	struct wl_signal focus_signal;
 
@@ -337,6 +338,7 @@ struct weston_touch {
 	struct wl_list resource_list;
 	struct wl_list focus_resource_list;
 	struct weston_surface *focus;
+	struct wl_listener focus_listener;
 	uint32_t focus_serial;
 	struct wl_signal focus_signal;
 
@@ -431,6 +433,7 @@ struct weston_keyboard {
 	struct wl_list resource_list;
 	struct wl_list focus_resource_list;
 	struct weston_surface *focus;
+	struct wl_listener focus_listener;
 	uint32_t focus_serial;
 	struct wl_signal focus_signal;
 
diff --git a/src/input.c b/src/input.c
index 1313b52..644f30a 100644
--- a/src/input.c
+++ b/src/input.c
@@ -71,6 +71,33 @@ weston_compositor_idle_release(struct weston_compositor *compositor)
 }
 
 static void
+lose_pointer_focus(struct wl_listener *listener, void *data)
+{
+	struct weston_pointer *pointer =
+		container_of(listener, struct weston_pointer, focus_listener);
+
+	weston_pointer_set_focus(pointer, NULL, 0, 0);
+}
+
+static void
+lose_keyboard_focus(struct wl_listener *listener, void *data)
+{
+	struct weston_keyboard *keyboard =
+		container_of(listener, struct weston_keyboard, focus_listener);
+
+	weston_keyboard_set_focus(keyboard, NULL);
+}
+
+static void
+lose_touch_focus(struct wl_listener *listener, void *data)
+{
+	struct weston_touch *touch =
+		container_of(listener, struct weston_touch, focus_listener);
+
+	weston_touch_set_focus(touch->seat, NULL);
+}
+
+static void
 move_resources(struct wl_list *destination, struct wl_list *source)
 {
 	wl_list_insert_list(destination, source);
@@ -360,6 +387,8 @@ weston_pointer_create(void)
 
 	wl_list_init(&pointer->resource_list);
 	wl_list_init(&pointer->focus_resource_list);
+	wl_list_init(&pointer->focus_listener.link);
+	pointer->focus_listener.notify = lose_pointer_focus;
 	pointer->default_grab.interface = &default_pointer_grab_interface;
 	pointer->default_grab.pointer = pointer;
 	pointer->grab = &pointer->default_grab;
@@ -381,7 +410,7 @@ weston_pointer_destroy(struct weston_pointer *pointer)
 		pointer_unmap_sprite(pointer);
 
 	/* XXX: What about pointer->resource_list? */
-
+	wl_list_remove(&pointer->focus_listener.link);
 	free(pointer);
 }
 
@@ -396,6 +425,8 @@ weston_keyboard_create(void)
 
 	wl_list_init(&keyboard->resource_list);
 	wl_list_init(&keyboard->focus_resource_list);
+	wl_list_init(&keyboard->focus_listener.link);
+	keyboard->focus_listener.notify = lose_keyboard_focus;
 	wl_array_init(&keyboard->keys);
 	keyboard->default_grab.interface = &default_keyboard_grab_interface;
 	keyboard->default_grab.keyboard = keyboard;
@@ -411,6 +442,7 @@ weston_keyboard_destroy(struct weston_keyboard *keyboard)
 	/* XXX: What about keyboard->resource_list? */
 
 	wl_array_release(&keyboard->keys);
+	wl_list_remove(&keyboard->focus_listener.link);
 	free(keyboard);
 }
 
@@ -425,6 +457,8 @@ weston_touch_create(void)
 
 	wl_list_init(&touch->resource_list);
 	wl_list_init(&touch->focus_resource_list);
+	wl_list_init(&touch->focus_listener.link);
+	touch->focus_listener.notify = lose_touch_focus;
 	touch->default_grab.interface = &default_touch_grab_interface;
 	touch->default_grab.touch = touch;
 	touch->grab = &touch->default_grab;
@@ -438,6 +472,7 @@ weston_touch_destroy(struct weston_touch *touch)
 {
 	/* XXX: What about touch->resource_list? */
 
+	wl_list_remove(&touch->focus_listener.link);
 	free(touch);
 }
 
@@ -479,6 +514,8 @@ weston_pointer_set_focus(struct weston_pointer *pointer,
 					      pointer->focus->resource);
 		}
 
+		wl_list_remove(&pointer->focus_listener.link);
+		wl_list_init(&pointer->focus_listener.link);
 		move_resources(&pointer->resource_list, focus_resource_list);
 	}
 
@@ -501,6 +538,8 @@ weston_pointer_set_focus(struct weston_pointer *pointer,
 		}
 
 		pointer->focus_serial = serial;
+		wl_resource_add_destroy_listener(surface->resource,
+						 &pointer->focus_listener);
 	}
 
 	if (kbd && surface && surface->resource && kbd->focus != pointer->focus) {
@@ -549,6 +588,8 @@ weston_keyboard_set_focus(struct weston_keyboard *keyboard,
 			wl_keyboard_send_leave(resource, serial,
 					keyboard->focus->resource);
 		}
+		wl_list_remove(&keyboard->focus_listener.link);
+		wl_list_init(&keyboard->focus_listener.link);
 		move_resources(&keyboard->resource_list, focus_resource_list);
 	}
 
@@ -567,6 +608,8 @@ weston_keyboard_set_focus(struct weston_keyboard *keyboard,
 					    surface,
 					    serial);
 		keyboard->focus_serial = serial;
+		wl_resource_add_destroy_listener(surface->resource,
+						 &keyboard->focus_listener);
 	}
 
 	keyboard->focus = surface;
@@ -1059,6 +1102,11 @@ weston_touch_set_focus(struct weston_seat *seat, struct weston_surface *surface)
 	if (seat->touch->focus == surface)
 		return;
 
+	if (seat->touch->focus) {
+		wl_list_remove(&seat->touch->focus_listener.link);
+		wl_list_init(&seat->touch->focus_listener.link);
+	}
+
 	if (!wl_list_empty(focus_resource_list)) {
 		move_resources(&seat->touch->resource_list,
 			       focus_resource_list);
@@ -1070,6 +1118,8 @@ weston_touch_set_focus(struct weston_seat *seat, struct weston_surface *surface)
 		move_resources_for_client(focus_resource_list,
 					  &seat->touch->resource_list,
 					  surface_client);
+		wl_resource_add_destroy_listener(surface->resource,
+						 &seat->touch->focus_listener);
 	}
 	seat->touch->focus = surface;
 }
-- 
1.8.4