tree/container: introduce `container_toplevel_ancestor` helper

This allows us to not have to explicitly write the same while loop
everywhere.

1 files changed, 7 insertions, 0 deletions

diff --git a/include/sway/tree/container.h b/include/sway/tree/container.h
index 8d2d8827..fd028131 100644
--- a/include/sway/tree/container.h
+++ b/include/sway/tree/container.h
@@ -273,6 +273,13 @@ void container_set_fullscreen(struct sway_container *con,
 void container_fullscreen_disable(struct sway_container *con);
 
 /**
+ * Walk up the container tree branch starting at the given container, and return
+ * its earliest ancestor.
+ */
+struct sway_container *container_toplevel_ancestor(
+		struct sway_container *container);
+
+/**
  * Return true if the container is floating, or a child of a floating split
  * container.
  */