sway_view_child: add listener for view unmap

Since not all child views's have an unmap event, it is possible for it
to still be mapped (default state) in the destruction handler. When
the destruction handler is called, the corresponding view may have
already been freed and the memory location reallocated. This adds a
listener for the view unmapping and removes the mapped status. This
ensures that the child view is damaged due to destruction while the
view still exists and not after.

1 files changed, 1 insertions, 0 deletions

diff --git a/include/sway/tree/view.h b/include/sway/tree/view.h
index 5cc9777b..ac203ac7 100644
--- a/include/sway/tree/view.h
+++ b/include/sway/tree/view.h
@@ -202,6 +202,7 @@ struct sway_view_child {
         struct wl_listener surface_map;
         struct wl_listener surface_unmap;
         struct wl_listener surface_destroy;
+        struct wl_listener view_unmap;
 };
 
 struct sway_subsurface {