shells: Only center tiled views on size change

The size of a tiled container cannot change in response to new buffer
sizes, so there is no need to commit a new transaction. Instead, simply
recenter the view with the new geometry, leaving the full transaction
flow for floating containers.

sway/desktop/xdg_shell.c

@@ -295,17 +295,20 @@ static void handle_commit(struct wl_listener *listener, void *data) {
 	if (new_size) {
 		// The view has unexpectedly sent a new size
 		desktop_damage_view(view);
-		view_update_size(view, new_geo.width, new_geo.height);
 		memcpy(&view->geometry, &new_geo, sizeof(struct wlr_box));
-		desktop_damage_view(view);
+		if (container_is_floating(view->container)) {
+			view_update_size(view, new_geo.width, new_geo.height);
 			transaction_commit_dirty();
+			transaction_notify_view_ready_immediately(view);
+		} else {
+			view_center_surface(view);
+		}
+		desktop_damage_view(view);
 	}
 
 	if (view->container->node.instruction) {
 		transaction_notify_view_ready_by_serial(view,
 				xdg_surface->configure_serial);
-	} else if (new_size) {
-		transaction_notify_view_ready_immediately(view);
 	}
 
 	view_damage_from(view);

sway/desktop/xwayland.c

@@ -406,22 +406,25 @@ static void handle_commit(struct wl_listener *listener, void *data) {
 	} else {
 		struct wlr_box new_geo;
 		get_geometry(view, &new_geo);
-
-		if ((new_geo.width != view->geometry.width ||
+		bool new_size = new_geo.width != view->geometry.width ||
 				new_geo.height != view->geometry.height ||
 				new_geo.x != view->geometry.x ||
-					new_geo.y != view->geometry.y)) {
+				new_geo.y != view->geometry.y;
+
+		if (new_size) {
 			// The view has unexpectedly sent a new size
 			// eg. The Firefox "Save As" dialog when downloading a file
 			desktop_damage_view(view);
-			view_update_size(view, new_geo.width, new_geo.height);
 			memcpy(&view->geometry, &new_geo, sizeof(struct wlr_box));
-			desktop_damage_view(view);
+			if (container_is_floating(view->container)) {
+				view_update_size(view, new_geo.width, new_geo.height);
 				transaction_commit_dirty();
 				transaction_notify_view_ready_by_geometry(view,
 					xsurface->x, xsurface->y, new_geo.width, new_geo.height);
 			} else {
-			memcpy(&view->geometry, &new_geo, sizeof(struct wlr_box));
+				view_center_surface(view);
+			}
+			desktop_damage_view(view);
 		}
 	}
 

sway/tree/view.c

@@ -874,17 +874,9 @@ void view_unmap(struct sway_view *view) {
 
 void view_update_size(struct sway_view *view, int width, int height) {
 	struct sway_container *con = view->container;
-
-	if (container_is_floating(con)) {
 	con->content_width = width;
 	con->content_height = height;
 	container_set_geometry_from_content(con);
-	} else {
-		con->surface_x = con->content_x + (con->content_width - width) / 2;
-		con->surface_y = con->content_y + (con->content_height - height) / 2;
-		con->surface_x = fmax(con->surface_x, con->content_x);
-		con->surface_y = fmax(con->surface_y, con->content_y);
-	}
 }
 
 void view_center_surface(struct sway_view *view) {