desktop-shell: resize background and panel surfaces on output resize v4

When an output is resized (permanent mode switch), we should also notify the
shell client so that the panel and background fits to the new screen dimensions.

Signed-off-by: David Fort <contact@hardening-consulting.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

desktop-shell/shell.c

@@ -4365,6 +4365,20 @@ configure_static_view(struct weston_view *ev, struct weston_layer *layer)
 	}
 }
 
+
+static struct shell_output *
+find_shell_output_from_weston_output(struct desktop_shell *shell, struct weston_output *output)
+{
+	struct shell_output *shell_output;
+
+	wl_list_for_each(shell_output, &shell->output_list, link) {
+		if (shell_output->output == output)
+			return shell_output;
+	}
+
+	return NULL;
+}
+
 static int
 background_get_label(struct weston_surface *surface, char *buf, size_t len)
 {
@@ -4383,6 +4397,16 @@ background_configure(struct weston_surface *es, int32_t sx, int32_t sy)
 	configure_static_view(view, &shell->background_layer);
 }
 
+static void
+handle_background_surface_destroy(struct wl_listener *listener, void *data)
+{
+	struct shell_output *output =
+	    container_of(listener, struct shell_output, background_surface_listener);
+
+	weston_log("background surface gone\n");
+	output->background_surface = NULL;
+}
+
 static void
 desktop_shell_set_background(struct wl_client *client,
 			     struct wl_resource *resource,
@@ -4392,6 +4416,7 @@ desktop_shell_set_background(struct wl_client *client,
 	struct desktop_shell *shell = wl_resource_get_user_data(resource);
 	struct weston_surface *surface =
 		wl_resource_get_user_data(surface_resource);
+	struct shell_output *sh_output;
 	struct weston_view *view, *next;
 
 	if (surface->configure) {
@@ -4414,6 +4439,12 @@ desktop_shell_set_background(struct wl_client *client,
 					    surface_resource,
 					    surface->output->width,
 					    surface->output->height);
+
+	sh_output = find_shell_output_from_weston_output(shell, surface->output);
+	sh_output->background_surface = surface;
+
+	sh_output->background_surface_listener.notify = handle_background_surface_destroy;
+	wl_signal_add(&surface->destroy_signal, &sh_output->background_surface_listener);
 }
 
 static int
@@ -4434,6 +4465,17 @@ panel_configure(struct weston_surface *es, int32_t sx, int32_t sy)
 	configure_static_view(view, &shell->panel_layer);
 }
 
+static void
+handle_panel_surface_destroy(struct wl_listener *listener, void *data)
+{
+	struct shell_output *output =
+	    container_of(listener, struct shell_output, panel_surface_listener);
+
+	weston_log("panel surface gone\n");
+	output->panel_surface = NULL;
+}
+
+
 static void
 desktop_shell_set_panel(struct wl_client *client,
 			struct wl_resource *resource,
@@ -4444,6 +4486,7 @@ desktop_shell_set_panel(struct wl_client *client,
 	struct weston_surface *surface =
 		wl_resource_get_user_data(surface_resource);
 	struct weston_view *view, *next;
+	struct shell_output *sh_output;
 
 	if (surface->configure) {
 		wl_resource_post_error(surface_resource,
@@ -4465,6 +4508,12 @@ desktop_shell_set_panel(struct wl_client *client,
 					    surface_resource,
 					    surface->output->width,
 					    surface->output->height);
+
+	sh_output = find_shell_output_from_weston_output(shell, surface->output);
+	sh_output->panel_surface = surface;
+
+	sh_output->panel_surface_listener.notify = handle_panel_surface_destroy;
+	wl_signal_add(&surface->destroy_signal, &sh_output->panel_surface_listener);
 }
 
 static int
@@ -6381,6 +6430,33 @@ handle_output_destroy(struct wl_listener *listener, void *data)
 	free(output_listener);
 }
 
+static void
+shell_resize_surface_to_output(struct desktop_shell *shell,
+				struct weston_surface *surface,
+				const struct weston_output *output)
+{
+	if (!surface)
+		return;
+
+	weston_desktop_shell_send_configure(shell->child.desktop_shell, 0,
+					surface->resource,
+					output->width,
+					output->height);
+}
+
+
+static void
+handle_output_resized(struct wl_listener *listener, void *data)
+{
+	struct desktop_shell *shell =
+		container_of(listener, struct desktop_shell, resized_listener);
+	struct weston_output *output = (struct weston_output *)data;
+	struct shell_output *sh_output = find_shell_output_from_weston_output(shell, output);
+
+	shell_resize_surface_to_output(shell, sh_output->background_surface, output);
+	shell_resize_surface_to_output(shell, sh_output->panel_surface, output);
+}
+
 static void
 create_shell_output(struct desktop_shell *shell,
 					struct weston_output *output)
@@ -6488,6 +6564,7 @@ shell_destroy(struct wl_listener *listener, void *data)
 
 	wl_list_remove(&shell->output_create_listener.link);
 	wl_list_remove(&shell->output_move_listener.link);
+	wl_list_remove(&shell->resized_listener.link);
 
 	wl_array_for_each(ws, &shell->workspaces.array)
 		workspace_destroy(*ws);
@@ -6704,6 +6781,9 @@ module_init(struct weston_compositor *ec,
 	shell->seat_create_listener.notify = handle_seat_created;
 	wl_signal_add(&ec->seat_created_signal, &shell->seat_create_listener);
 
+	shell->resized_listener.notify = handle_output_resized;
+	wl_signal_add(&ec->output_resized_signal, &shell->resized_listener);
+
 	screenshooter_create(ec);
 
 	shell_add_bindings(ec, shell);

desktop-shell/shell.h

@@ -114,6 +114,12 @@ struct shell_output {
 	struct exposay_output eoutput;
 	struct wl_listener    destroy_listener;
 	struct wl_list        link;
+
+	struct weston_surface *panel_surface;
+	struct wl_listener panel_surface_listener;
+
+	struct weston_surface *background_surface;
+	struct wl_listener background_surface_listener;
 };
 
 struct desktop_shell {
@@ -122,6 +128,7 @@ struct desktop_shell {
 	struct wl_listener idle_listener;
 	struct wl_listener wake_listener;
 	struct wl_listener transform_listener;
+	struct wl_listener resized_listener;
 	struct wl_listener destroy_listener;
 	struct wl_listener show_input_panel_listener;
 	struct wl_listener hide_input_panel_listener;