Drop sway_output.events.disable

In general wl_signal isn't well-suited for Sway: Sway doesn't need
any modularity, and signals make it trickier to track down exactly
what happens down the stack.

Replace Sway's output disable signal with a simple list tracking
for the only user.

Author: emersion

include/sway/layers.h

@@ -19,6 +19,8 @@ struct sway_layer_surface {
 	struct sway_popup_desc desc;
 
 	struct sway_output *output;
+	struct wl_list link; // sway_output.layer_surfaces
+
 	struct wlr_scene_layer_surface_v1 *scene;
 	struct wlr_scene_tree *tree;
 	struct wlr_layer_surface_v1 *layer_surface;
@@ -41,4 +43,6 @@ struct wlr_layer_surface_v1 *toplevel_layer_surface_from_surface(
 
 void arrange_layers(struct sway_output *output);
 
+void destroy_layers(struct sway_output *output);
+
 #endif

include/sway/output.h

@@ -52,6 +52,7 @@ struct sway_output {
 
 	bool enabled;
 	list_t *workspaces;
+	struct wl_list layer_surfaces; // sway_layer_surface.link
 
 	struct sway_output_state current;
 
@@ -61,10 +62,6 @@ struct sway_output {
 	struct wl_listener frame;
 	struct wl_listener request_state;
 
-	struct {
-		struct wl_signal disable;
-	} events;
-
 	struct wlr_color_transform *color_transform;
 
 	struct timespec last_presentation;

sway/desktop/layer_shell.c

@@ -216,14 +216,6 @@ static struct sway_layer_surface *find_mapped_layer_by_client(
 	return NULL;
 }
 
-static void handle_output_destroy(struct wl_listener *listener, void *data) {
-	struct sway_layer_surface *layer =
-		wl_container_of(listener, layer, output_destroy);
-
-	layer->output = NULL;
-	wlr_layer_surface_v1_destroy(layer->layer_surface);
-}
-
 static void handle_node_destroy(struct wl_listener *listener, void *data) {
 	struct sway_layer_surface *layer =
 		wl_container_of(listener, layer, node_destroy);
@@ -479,6 +471,7 @@ void handle_layer_shell_surface(struct wl_listener *listener, void *data) {
 	}
 
 	surface->output = output;
+	wl_list_insert(&output->layer_surfaces, &surface->link);
 
 	// now that the surface's output is known, we can advertise its scale
 	wlr_fractional_scale_v1_notify_scale(surface->layer_surface->surface,
@@ -496,9 +489,14 @@ void handle_layer_shell_surface(struct wl_listener *listener, void *data) {
 	surface->new_popup.notify = handle_new_popup;
 	wl_signal_add(&layer_surface->events.new_popup, &surface->new_popup);
 
-	surface->output_destroy.notify = handle_output_destroy;
-	wl_signal_add(&output->events.disable, &surface->output_destroy);
-
 	surface->node_destroy.notify = handle_node_destroy;
 	wl_signal_add(&scene_surface->tree->node.events.destroy, &surface->node_destroy);
 }
+
+void destroy_layers(struct sway_output *output) {
+	struct sway_layer_surface *layer, *layer_tmp;
+	wl_list_for_each_safe(layer, layer_tmp, &output->layer_surfaces, link) {
+		layer->output = NULL;
+		wlr_layer_surface_v1_destroy(layer->layer_surface);
+	}
+}

sway/tree/output.c

@@ -136,12 +136,11 @@ struct sway_output *output_create(struct wlr_output *wlr_output) {
 	output->detected_subpixel = wlr_output->subpixel;
 	output->scale_filter = SCALE_FILTER_NEAREST;
 
-	wl_signal_init(&output->events.disable);
-
 	wl_list_insert(&root->all_outputs, &output->link);
 
 	output->workspaces = create_list();
 	output->current.workspaces = create_list();
+	wl_list_init(&output->layer_surfaces);
 
 	return output;
 }
@@ -287,8 +286,8 @@ void output_disable(struct sway_output *output) {
 	}
 
 	sway_log(SWAY_DEBUG, "Disabling output '%s'", output->wlr_output->name);
-	wl_signal_emit_mutable(&output->events.disable, output);
 
+	destroy_layers(output);
 	output_evacuate(output);
 
 	list_del(root->outputs, index);