Implement scratchpad

Implements the following commands:

* move scratchpad
* scratchpad show
* [criteria] scratchpad show

Also fixes these:

* Fix memory leak when executing command with criteria
(use `list_free(views)` instead of `free(views)`)
* Fix crash when running `move to` with no further arguments

1 files changed, 5 insertions, 0 deletions

diff --git a/include/sway/tree/container.h b/include/sway/tree/container.h
index 59c5b4c7..2a4be18c 100644
--- a/include/sway/tree/container.h
+++ b/include/sway/tree/container.h
@@ -135,6 +135,11 @@ struct sway_container {
 
         struct sway_container *parent;
 
+        // Indicates that the container is a scratchpad container.
+        // Both hidden and visible scratchpad containers have scratchpad=true.
+        // Hidden scratchpad containers have a NULL parent.
+        bool scratchpad;
+
         float alpha;
 
         struct wlr_texture *title_focused;