cycle: use dummy node to remember the scene position of previewed window

With this approach, we only need to store cycle->dummy_node instead of
cycle->preview_anchor and cycle->preview_parent and we don't need to care
about annoying cases like when the previewed window has no siblings or
when a window tracked by cycle->preview_anchor is destroyed.

diff --git a/include/labwc.h b/include/labwc.h
index 62863defa4f15f5e22c67529ff99a95fc610704b..abe07a49723d21c7e623c5f6e7eaae6844bee6e0 100644 (file)
--- a/include/labwc.h
+++ b/include/labwc.h
@@ -306,8 +306,7 @@ struct server {
                bool preview_was_shaded;
                bool preview_was_enabled;
                struct wlr_scene_node *preview_node;
-               struct wlr_scene_tree *preview_parent;
-               struct wlr_scene_node *preview_anchor;
+               struct wlr_scene_node *preview_dummy;
                struct lab_scene_rect *preview_outline;
        } cycle;
 

diff --git a/src/cycle/cycle.c b/src/cycle/cycle.c
index d49b5497119b3a4de707a965ec92314b9f87297b..306607dd72d793d7ea3b4aab1084ecb0113110a9 100644 (file)
--- a/src/cycle/cycle.c
+++ b/src/cycle/cycle.c
@@ -133,17 +133,6 @@ cycle_on_view_destroy(struct view *view)
                destroy_osd_scenes(server);
                update_cycle(server);
        }
-
-       if (view->scene_tree) {
-               struct wlr_scene_node *node = &view->scene_tree->node;
-               if (cycle->preview_anchor == node) {
-                       /*
-                        * If we are the anchor for the current OSD selected view,
-                        * replace the anchor with the node before us.
-                        */
-                       cycle->preview_anchor = lab_wlr_scene_get_prev_node(node);
-               }
-       }
 }
 
 void
@@ -161,15 +150,10 @@ restore_preview_node(struct server *server)
 {
        if (server->cycle.preview_node) {
                wlr_scene_node_reparent(server->cycle.preview_node,
-                       server->cycle.preview_parent);
-
-               if (server->cycle.preview_anchor) {
-                       wlr_scene_node_place_above(server->cycle.preview_node,
-                               server->cycle.preview_anchor);
-               } else {
-                       /* Selected view was the first node */
-                       wlr_scene_node_lower_to_bottom(server->cycle.preview_node);
-               }
+                       server->cycle.preview_dummy->parent);
+               wlr_scene_node_place_above(server->cycle.preview_node,
+                       server->cycle.preview_dummy);
+               wlr_scene_node_destroy(server->cycle.preview_dummy);
 
                /* Node was disabled / minimized before, disable again */
                if (!server->cycle.preview_was_enabled) {
@@ -180,8 +164,7 @@ restore_preview_node(struct server *server)
                        view_set_shade(view, true);
                }
                server->cycle.preview_node = NULL;
-               server->cycle.preview_parent = NULL;
-               server->cycle.preview_anchor = NULL;
+               server->cycle.preview_dummy = NULL;
                server->cycle.preview_was_shaded = false;
        }
 }
@@ -227,7 +210,7 @@ cycle_finish(struct server *server, bool switch_focus)
 
        struct view *selected_view = server->cycle.selected_view;
        server->cycle.preview_node = NULL;
-       server->cycle.preview_anchor = NULL;
+       server->cycle.preview_dummy = NULL;
        server->cycle.selected_view = NULL;
        server->cycle.preview_was_shaded = false;
 
@@ -261,22 +244,18 @@ preview_selected_view(struct view *view)
        /* Move previous selected node back to its original place */
        restore_preview_node(server);
 
-       /* Store some pointers so we can reset the preview later on */
        cycle->preview_node = &view->scene_tree->node;
-       cycle->preview_parent = view->scene_tree->node.parent;
-
-       /* Remember the sibling right before the selected node */
-       cycle->preview_anchor = lab_wlr_scene_get_prev_node(
-               cycle->preview_node);
-       while (cycle->preview_anchor && !cycle->preview_anchor->data) {
-               /* Ignore non-view nodes */
-               cycle->preview_anchor = lab_wlr_scene_get_prev_node(
-                       cycle->preview_anchor);
-       }
+
+       /* Create a dummy node at the original place of the previewed window */
+       struct wlr_scene_rect *dummy_rect = wlr_scene_rect_create(
+               cycle->preview_node->parent, 0, 0, (float [4]) {0});
+       wlr_scene_node_place_below(&dummy_rect->node, cycle->preview_node);
+       wlr_scene_node_set_enabled(&dummy_rect->node, false);
+       cycle->preview_dummy = &dummy_rect->node;
 
        /* Store node enabled / minimized state and force-enable if disabled */
        cycle->preview_was_enabled = cycle->preview_node->enabled;
-               wlr_scene_node_set_enabled(cycle->preview_node, true);
+       wlr_scene_node_set_enabled(cycle->preview_node, true);
        if (rc.window_switcher.unshade && view->shaded) {
                view_set_shade(view, false);
                cycle->preview_was_shaded = true;