SnapToRegion: Allow for live config updates

include/labwc.h

@@ -315,7 +315,6 @@ struct output {
 	struct wlr_box usable_area;
 
 	struct wl_list regions;  /* struct region.link */
-	struct wlr_box regions_usable_area;
 
 	struct lab_data_buffer *osd_buffer;
 

include/regions.h

@@ -33,12 +33,43 @@ struct region_overlay {
 /* Can be used as a cheap check to detect if there are any regions configured */
 bool regions_available(void);
 
-void regions_update(struct output *output);
+/**
+ * regions_reconfigure*() - re-initializes all regions from struct rc.
+ *
+ * - all views are evacuated from the given output (or all of them)
+ * - all output local regions are destroyed
+ * - new output local regions are created from struct rc
+ * - the region geometry is re-calculated
+ */
+void regions_reconfigure(struct server *server);
+void regions_reconfigure_output(struct output *output);
+
+/* re-calculate the geometry based on usable area */
+void regions_update_geometry(struct output *output);
+
+/**
+ * Mark all views which are currently region-tiled to the given output as
+ * evacuated. This means that the view->tiled_region pointer is reset to
+ * NULL but view->tiled_region_evacuate is set to a copy of the region name.
+ *
+ * The next time desktop_arrange_all_views() causes a call to
+ * view_apply_region_geometry() it will try to find a new output and then
+ * search for a region with the same name. If found, view->tiled_region will
+ * be set to the new region and view->tiled_region_evacuate will be free'd.
+ *
+ * If no region with the old name is found (e.g. the user deleted or renamed
+ * the region in rc.xml and caused a Reconfigure) the view will be reset to
+ * non-tiled state and view->tiled_region_evacuate will be free'd.
+ */
 void regions_evacuate_output(struct output *output);
+
+/* Free all regions in given wl_list pointer */
 void regions_destroy(struct seat *seat, struct wl_list *regions);
 
+/* Get output local region from cursor or name, may be NULL */
 struct region *regions_from_cursor(struct server *server);
 struct region *regions_from_name(const char *region_name, struct output *output);
+
 void regions_show_overlay(struct view *view, struct seat *seat, struct region *region);
 void regions_hide_overlay(struct seat *seat);
 

include/view.h

@@ -51,7 +51,7 @@ struct view {
 	bool maximized;
 	uint32_t tiled;  /* private, enum view_edge in src/view.c */
 
-	/* Pointer to an output owned struct region, may be NULL or already free'd */
+	/* Pointer to an output owned struct region, may be NULL */
 	struct region *tiled_region;
 	/* Set to region->name when tiled_region is free'd by a destroying output */
 	char *tiled_region_evacuate;
@@ -132,6 +132,7 @@ void view_toggle_maximize(struct view *view);
 void view_toggle_decorations(struct view *view);
 void view_toggle_always_on_top(struct view *view);
 bool view_is_always_on_top(struct view *view);
+bool view_is_tiled(struct view *view);
 void view_move_to_workspace(struct view *view, struct workspace *workspace);
 void view_set_decorations(struct view *view, bool decorations);
 void view_toggle_fullscreen(struct view *view);

src/interactive.c

@@ -45,7 +45,7 @@ interactive_begin(struct view *view, enum input_mode mode, uint32_t edges)
 			 */
 			return;
 		}
-		if (view->maximized || view->tiled || view->tiled_region) {
+		if (view->maximized || view_is_tiled(view)) {
 			/*
 			 * Un-maximize and restore natural width/height.
 			 * Don't reset tiled state yet since we may want

src/output.c

@@ -212,6 +212,9 @@ new_output_notify(struct wl_listener *listener, void *data)
 	output->scene_output = wlr_scene_get_scene_output(server->scene, wlr_output);
 	assert(output->scene_output);
 
+	/* Create regions from config */
+	regions_reconfigure_output(output);
+
 	server->pending_output_layout_change--;
 	do_output_layout_change(server);
 }
@@ -452,7 +455,7 @@ void
 output_update_usable_area(struct output *output)
 {
 	if (update_usable_area(output)) {
-		regions_update(output);
+		regions_update_geometry(output);
 		desktop_arrange_all_views(output->server);
 	}
 }
@@ -466,9 +469,9 @@ output_update_all_usable_areas(struct server *server, bool layout_changed)
 	wl_list_for_each(output, &server->outputs, link) {
 		if (update_usable_area(output)) {
 			usable_area_changed = true;
-			regions_update(output);
+			regions_update_geometry(output);
 		} else if (layout_changed) {
-			regions_update(output);
+			regions_update_geometry(output);
 		}
 	}
 	if (usable_area_changed || layout_changed) {

src/regions.c

@@ -149,30 +149,52 @@ regions_hide_overlay(struct seat *seat)
 }
 
 void
-regions_update(struct output *output)
+regions_reconfigure_output(struct output *output)
+{
+	assert(output);
+
+	/* Evacuate views and destroy current regions */
+	if (!wl_list_empty(&output->regions)) {
+		regions_evacuate_output(output);
+		regions_destroy(&output->server->seat, &output->regions);
+	}
+
+	/* Initialize regions from config */
+	struct region *region;
+	wl_list_for_each(region, &rc.regions, link) {
+		struct region *region_new = znew(*region_new);
+		/* Create a copy */
+		region_new->name = xstrdup(region->name);
+		region_new->percentage = region->percentage;
+		wl_list_append(&output->regions, &region_new->link);
+	}
+
+	/* Update region geometries */
+	regions_update_geometry(output);
+}
+
+void
+regions_reconfigure(struct server *server)
+{
+	struct output *output;
+
+	/* Evacuate views and initialize regions from config */
+	wl_list_for_each(output, &server->outputs, link) {
+		regions_reconfigure_output(output);
+	}
+
+	/* Tries to match the evacuated views to the new regions */
+	desktop_arrange_all_views(server);
+}
+
+void
+regions_update_geometry(struct output *output)
 {
 	assert(output);
 
 	struct region *region;
 	struct wlr_box usable = output_usable_area_in_layout_coords(output);
 
-	/* Initialize regions */
-	if (wl_list_empty(&output->regions)) {
-		wl_list_for_each(region, &rc.regions, link) {
-			struct region *region_new = znew(*region_new);
-			/* Create a copy */
-			region_new->name = xstrdup(region->name);
-			region_new->percentage = region->percentage;
-			wl_list_append(&output->regions, &region_new->link);
-		}
-	}
-
-	if (wlr_box_equal(&output->regions_usable_area, &usable)) {
-		/* Nothing changed */
-		return;
-	}
-	output->regions_usable_area = usable;
-
 	/* Update regions */
 	struct wlr_box *perc, *geo;
 	wl_list_for_each(region, &output->regions, link) {
@@ -201,6 +223,8 @@ regions_evacuate_output(struct output *output)
 					view->tiled_region_evacuate =
 						xstrdup(region->name);
 				}
+				/* Prevent carrying around a dangling pointer */
+				view->tiled_region = NULL;
 				break;
 			}
 		}

src/server.c

@@ -20,6 +20,7 @@
 #include "labwc.h"
 #include "layers.h"
 #include "menu/menu.h"
+#include "regions.h"
 #include "theme.h"
 #include "view.h"
 #include "workspaces.h"
@@ -49,6 +50,7 @@ reload_config_and_theme(void)
 
 	menu_reconfigure(g_server);
 	seat_reconfigure(g_server);
+	regions_reconfigure(g_server);
 }
 
 static int

src/view.c

@@ -295,7 +295,7 @@ void
 view_store_natural_geometry(struct view *view)
 {
 	assert(view);
-	if (view->maximized || view->tiled || view->tiled_region) {
+	if (view->maximized || view_is_tiled(view)) {
 		/* Do not overwrite the stored geometry with special cases */
 		return;
 	}
@@ -347,7 +347,7 @@ static void
 view_apply_region_geometry(struct view *view)
 {
 	assert(view);
-	assert(view->tiled_region);
+	assert(view->tiled_region || view->tiled_region_evacuate);
 
 	if (view->tiled_region_evacuate) {
 		/* View was evacuated from a destroying output */
@@ -357,7 +357,7 @@ view_apply_region_geometry(struct view *view)
 			return;
 		}
 
-		/* Get new output local region */
+		/* Get new output local region, may be NULL */
 		view->tiled_region = regions_from_name(
 			view->tiled_region_evacuate, output);
 
@@ -500,7 +500,7 @@ view_apply_special_geometry(struct view *view)
 		view_apply_maximized_geometry(view);
 	} else if (view->tiled) {
 		view_apply_tiled_geometry(view, NULL);
-	} else if (view->tiled_region) {
+	} else if (view->tiled_region || view->tiled_region_evacuate) {
 		view_apply_region_geometry(view);
 	} else {
 		return false;
@@ -538,6 +538,15 @@ view_restore_to(struct view *view, struct wlr_box geometry)
 	view_move_resize(view, geometry);
 }
 
+bool
+view_is_tiled(struct view *view)
+{
+	if (!view) {
+		return false;
+	}
+	return view->tiled || view->tiled_region || view->tiled_region_evacuate;
+}
+
 /* Reset tiled state of view without changing geometry */
 void
 view_set_untiled(struct view *view)
@@ -545,6 +554,7 @@ view_set_untiled(struct view *view)
 	assert(view);
 	view->tiled = VIEW_EDGE_INVALID;
 	view->tiled_region = NULL;
+	zfree(view->tiled_region_evacuate);
 }
 
 void