Update top layer visiblity on workspace switch

Fixes: #1158

include/labwc.h

@@ -393,6 +393,12 @@ void desktop_arrange_all_views(struct server *server);
 void desktop_focus_output(struct output *output);
 struct view *desktop_topmost_focusable_view(struct server *server);
 
+/**
+ * Toggles the (output local) visibility of the layershell top layer
+ * based on the existence of a fullscreen window on the current workspace.
+ */
+void desktop_update_top_layer_visiblity(struct server *server);
+
 enum lab_cycle_dir {
 	LAB_CYCLE_DIR_NONE,
 	LAB_CYCLE_DIR_FORWARD,

include/view.h

@@ -225,8 +225,9 @@ struct xdg_toplevel_view {
 enum lab_view_criteria {
 	LAB_VIEW_CRITERIA_NONE = 0,
 	LAB_VIEW_CRITERIA_CURRENT_WORKSPACE = 1 << 0,
-	LAB_VIEW_CRITERIA_NO_ALWAYS_ON_TOP = 1 << 1,
-	LAB_VIEW_CRITERIA_NO_SKIP_WINDOW_SWITCHER = 1 << 2,
+	LAB_VIEW_CRITERIA_FULLSCREEN = 1 << 1,
+	LAB_VIEW_CRITERIA_NO_ALWAYS_ON_TOP = 1 << 2,
+	LAB_VIEW_CRITERIA_NO_SKIP_WINDOW_SWITCHER = 1 << 3,
 };
 
 /**

src/desktop.c

@@ -289,6 +289,32 @@ desktop_focus_output(struct output *output)
 	cursor_update_focus(output->server);
 }
 
+void
+desktop_update_top_layer_visiblity(struct server *server)
+{
+	struct view *view;
+	struct output *output;
+	uint32_t top = ZWLR_LAYER_SHELL_V1_LAYER_TOP;
+
+	/* Enable all top layers */
+	wl_list_for_each(output, &server->outputs, link) {
+		if (!output_is_usable(output)) {
+			continue;
+		}
+		wlr_scene_node_set_enabled(&output->layer_tree[top]->node, true);
+	}
+
+	/* And disable them again when there is a view in fullscreen */
+	enum lab_view_criteria criteria =
+		LAB_VIEW_CRITERIA_CURRENT_WORKSPACE | LAB_VIEW_CRITERIA_FULLSCREEN;
+	for_each_view(view, &server->views, criteria) {
+		if (!output_is_usable(view->output)) {
+			continue;
+		}
+		wlr_scene_node_set_enabled(&view->output->layer_tree[top]->node, false);
+	}
+}
+
 static struct wlr_surface *
 get_surface_from_layer_node(struct wlr_scene_node *node)
 {

src/view.c

@@ -100,6 +100,11 @@ matches_criteria(struct view *view, enum lab_view_criteria criteria)
 			return false;
 		}
 	}
+	if (criteria & LAB_VIEW_CRITERIA_FULLSCREEN) {
+		if (!view->fullscreen) {
+			return false;
+		}
+	}
 	if (criteria & LAB_VIEW_CRITERIA_NO_ALWAYS_ON_TOP) {
 		if (view_is_always_on_top(view)) {
 			return false;
@@ -1122,9 +1127,7 @@ set_fullscreen(struct view *view, bool fullscreen)
 
 	/* Show fullscreen views above top-layer */
 	if (view->output) {
-		uint32_t top = ZWLR_LAYER_SHELL_V1_LAYER_TOP;
-		wlr_scene_node_set_enabled(&view->output->layer_tree[top]->node,
-			!fullscreen);
+		desktop_update_top_layer_visiblity(view->server);
 	}
 }
 
@@ -1662,13 +1665,12 @@ view_destroy(struct view *view)
 
 	/*
 	 * The layer-shell top-layer is disabled when an application is running
-	 * in fullscreen mode, so if that's the case, we have to re-enable it
-	 * here.
+	 * in fullscreen mode, so if that's the case, we may have to re-enable
+	 * it here.
 	 */
 	if (view->fullscreen && view->output) {
-		uint32_t top = ZWLR_LAYER_SHELL_V1_LAYER_TOP;
-		wlr_scene_node_set_enabled(&view->output->layer_tree[top]->node,
-			true);
+		view->fullscreen = false;
+		desktop_update_top_layer_visiblity(server);
 	}
 
 	/* If we spawned a window menu, close it */
@@ -1685,4 +1687,3 @@ view_destroy(struct view *view)
 		cursor_update_focus(server);
 	}
 }
-

src/workspaces.c

@@ -302,6 +302,9 @@ workspaces_switch_to(struct workspace *target, bool update_focus)
 	 * cursor image from the previous desktop
 	 */
 	cursor_update_focus(server);
+
+	/* Ensure that only currently visible fullscreen windows hide the top layer */
+	desktop_update_top_layer_visiblity(server);
 }
 
 void