Refactor destroy functions and save workspaces when there's no outputs

This changes the destroy functions to the following:

* output_begin_destroy
* output_destroy
* workspace_begin_destroy
* workspace_destroy
* container_begin_destroy
* container_destroy
* view_begin_destroy
* view_destroy

The terminology was `destroy` and `free`, and it has been changed to
`begin_destroy` and `destroy` respectively.

When the last output is disconnected, its workspaces will now be stashed
in the root. Upon connection of a new output they will be restored.

There is a new function `workspace_consider_destroy` which decides
whether the given workspace should be destroyed or not (ie. empty and
not visible).

Calling container_begin_destroy will no longer automatically reap the
parents. In some places we want to reap the parents and in some we
don't, so this is left to the caller.

container_reap_empty_recursive and container_reap_empty have been
combined into one function and it will recurse up the tree.

1 files changed, 6 insertions, 0 deletions

diff --git a/include/sway/output.h b/include/sway/output.h
index d0d034b3..098540fb 100644
--- a/include/sway/output.h
+++ b/include/sway/output.h
@@ -39,6 +39,12 @@ struct sway_output {
         } events;
 };
 
+struct sway_container *output_create(struct sway_output *sway_output);
+
+void output_destroy(struct sway_container *output);
+
+void output_begin_destroy(struct sway_container *output);
+
 typedef void (*sway_surface_iterator_func_t)(struct sway_output *output,
         struct wlr_surface *surface, struct wlr_box *box, float rotation,
         void *user_data);