[fixup] cache previous state & some refactoring

include/overlay.h

@@ -4,6 +4,8 @@
 
 #include <wlr/util/box.h>
 #include "common/graphic-helpers.h"
+#include "regions.h"
+#include "view.h"
 
 struct overlay {
 	struct wlr_scene_tree *tree;
@@ -12,14 +14,23 @@ struct overlay {
 		struct multi_rect *pixman_rect;
 	};
 
-	/* For delayed overlay */
+	/* For caching previously shown overlay */
-	struct view *view;
+	struct {
-	struct wlr_box box;
+		struct region *region;
+		enum view_edge edge;
+	} active;
+
+	/* For delayed snap-to-edge overlay */
 	struct wl_event_source *timer;
+	struct {
+		struct view *view;
+		struct wlr_box box;
+	} pending;
 };
 
 /* Calls overlay_hide() internally if the view is not to be snapped */
 void overlay_show(struct seat *seat, struct view *view);
+/* This function must be called when grabbed view is destroyed */
 void overlay_hide(struct seat *seat);
 
 #endif

src/overlay.c

@@ -34,13 +34,11 @@ create_overlay(struct seat *seat)
 static void
 cancel_pending_overlay(struct overlay *overlay)
 {
-	if (!overlay->timer) {
+	if (overlay->timer) {
-		return;
+		wl_event_source_timer_update(overlay->timer, 0);
 	}
-	wl_event_source_remove(overlay->timer);
+	overlay->pending.view = NULL;
-	overlay->timer = NULL;
+	overlay->pending.box = (struct wlr_box){0};
-	overlay->view = NULL;
-	overlay->box = (struct wlr_box){0};
 }
 
 static void
@@ -72,28 +70,71 @@ show_overlay(struct seat *seat, struct view *view, struct wlr_box *box)
 	cancel_pending_overlay(&seat->overlay);
 }
 
+static void
+show_region_overlay(struct seat *seat, struct view *view, struct region *region)
+{
+	if (region == seat->overlay.active.region) {
+		return;
+	}
+	seat->overlay.active.region = region;
+	seat->overlay.active.edge = VIEW_EDGE_INVALID;
+	show_overlay(seat, view, &region->geo);
+}
+
+/* TODO: share logic with view_get_edge_snap_box() */
+static struct wlr_box get_edge_snap_box(enum view_edge edge, struct output *output)
+{
+	struct wlr_box box = output_usable_area_in_layout_coords(output);
+	switch (edge) {
+	case VIEW_EDGE_RIGHT:
+		box.x += box.width / 2;
+		/* fallthrough */
+	case VIEW_EDGE_LEFT:
+		box.width /= 2;
+		break;
+	case VIEW_EDGE_DOWN:
+		box.y += box.height / 2;
+		/* fallthrough */
+	case VIEW_EDGE_UP:
+		box.height /= 2;
+		break;
+	case VIEW_EDGE_CENTER:
+		/* <topMaximize> */
+		break;
+	default:
+		/* not reached */
+		assert(false);
+	}
+	return box;
+}
+
 static int
 handle_overlay_timeout(void *data)
 {
 	struct seat *seat = data;
-	show_overlay(seat, seat->overlay.view, &seat->overlay.box);
+	show_overlay(seat, seat->overlay.pending.view,
+		&seat->overlay.pending.box);
 	return 0;
 }
 
 static void
-show_overlay_delayed(struct seat *seat, struct view *view, struct wlr_box *box)
+show_edge_overlay_delayed(struct seat *seat, struct view *view,
+		enum view_edge edge, struct output *output)
 {
-	if (seat->overlay.timer
+	if (seat->overlay.active.edge == edge) {
-			&& seat->overlay.view == view
-			&& wlr_box_equal(box, &seat->overlay.box)) {
 		return;
 	}
-	cancel_pending_overlay(&seat->overlay);
+	seat->overlay.active.edge = edge;
-	seat->overlay.view = view;
+	seat->overlay.active.region = NULL;
-	seat->overlay.box = *box;
+
-	seat->overlay.timer = wl_event_loop_add_timer(
+	seat->overlay.pending.view = view;
-		seat->server->wl_event_loop,
+	seat->overlay.pending.box = get_edge_snap_box(edge, output);
-		handle_overlay_timeout, seat);
+	if (!seat->overlay.timer) {
+		seat->overlay.timer = wl_event_loop_add_timer(
+			seat->server->wl_event_loop,
+			handle_overlay_timeout, seat);
+	}
+	/* Delay for 150ms */
 	wl_event_source_timer_update(seat->overlay.timer, 150);
 }
 
@@ -102,55 +143,28 @@ overlay_show(struct seat *seat, struct view *view)
 {
 	struct server *server = seat->server;
 
-	/*
+	/* Region overlay */
-	 * TODO: cache return value of regions_from_cursor() or
-	 * edge_from_cursor() to eliminate duplicated calls to show_overlay() /
-	 * show_overlay_delayed().
-	 */
 	if (regions_should_snap(server)) {
-		/* Region overlay */
 		struct region *region = regions_from_cursor(server);
 		if (region) {
-			show_overlay(seat, view, &region->geo);
+			show_region_overlay(seat, view, region);
-			return;
-		}
-	} else {
-		/* Snap-to-edge overlay */
-		struct output *output;
-		enum view_edge edge = edge_from_cursor(seat, &output);
-		if (edge != VIEW_EDGE_INVALID) {
-			/* TODO: share logic with view_get_edge_snap_box() */
-			struct wlr_box box =
-				output_usable_area_in_layout_coords(output);
-			switch (edge) {
-			case VIEW_EDGE_RIGHT:
-				box.x += box.width / 2;
-				/* fallthrough */
-			case VIEW_EDGE_LEFT:
-				box.width /= 2;
-				break;
-			case VIEW_EDGE_DOWN:
-				box.y += box.height / 2;
-				/* fallthrough */
-			case VIEW_EDGE_UP:
-				box.height /= 2;
-				break;
-			case VIEW_EDGE_CENTER:
-				/* <topMaximize> */
-				break;
-			case VIEW_EDGE_INVALID:
-				/* not reached */
-				assert(false);
-			}
-			/*
-			 * Delay showing overlay to prevent flickering when
-			 * dragging view across output edges in multi-monitor
-			 * setup
-			 */
-			show_overlay_delayed(seat, view, &box);
 			return;
 		}
 	}
+
+	/* Snap-to-edge overlay */
+	struct output *output;
+	enum view_edge edge = edge_from_cursor(seat, &output);
+	if (edge != VIEW_EDGE_INVALID) {
+		/*
+		 * Snap-to-edge overlay is delayed for 150ms to prevent
+		 * flickering when dragging view across output edges in
+		 * multi-monitor setup.
+		 */
+		show_edge_overlay_delayed(seat, view, edge, output);
+		return;
+	}
+
 	overlay_hide(seat);
 }
 
@@ -158,12 +172,14 @@ void
 overlay_hide(struct seat *seat)
 {
 	cancel_pending_overlay(&seat->overlay);
+	seat->overlay.active.edge = VIEW_EDGE_INVALID;
+	seat->overlay.active.region = NULL;
 
-	struct server *server = seat->server;
+	if (!seat->overlay.tree) {
-	struct wlr_scene_node *node = &seat->overlay.tree->node;
-	if (!node) {
 		return;
 	}
+	struct server *server = seat->server;
+	struct wlr_scene_node *node = &seat->overlay.tree->node;
 
 	wlr_scene_node_set_enabled(node, false);
 	if (node->parent != &server->scene->tree) {

src/regions.c

@@ -163,6 +163,9 @@ regions_destroy(struct seat *seat, struct wl_list *regions)
 	struct region *region, *region_tmp;
 	wl_list_for_each_safe(region, region_tmp, regions, link) {
 		wl_list_remove(&region->link);
+		if (seat && seat->overlay.active.region == region) {
+			seat->overlay.active.region = NULL;
+		}
 		zfree(region->name);
 		zfree(region);
 	}