Implement iterators per container type

This introduces the following `for_each` functions:

* root_for_each_workspace
* root_for_each_container
* output_for_each_workspace
* output_for_each_container
* workspace_for_each_container

And introduces the following `find` functions:

* root_find_output
* root_find_workspace
* root_find_container
* output_find_workspace
* output_find_container
* workspace_find_container
* container_find_child

And removes the following functions:

* container_descendants
* container_for_each_descendant
* container_find

This change is preparing the way for demoting sway_container. Eventually
these functions will accept and return sway_outputs, sway_workspaces and
sway_containers (meaning a C_CONTAINER or C_VIEW).

This change also makes it easy to handle abnormalities like the
workspace floating list, root's scratchpad list and (once implemented)
root's saved workspaces list for when there's no connected outputs.

1 files changed, 4 insertions, 5 deletions

diff --git a/sway/desktop/output.c b/sway/desktop/output.c
index 66747a3f..43ed9793 100644
--- a/sway/desktop/output.c
+++ b/sway/desktop/output.c
@@ -303,15 +303,14 @@ struct send_frame_done_data {
 
 static void send_frame_done_container_iterator(struct sway_container *con,
                 void *_data) {
-        struct send_frame_done_data *data = _data;
-        if (!sway_assert(con->type == C_VIEW, "expected a view")) {
+        if (con->type != C_VIEW) {
                 return;
         }
-
         if (!view_is_visible(con->sway_view)) {
                 return;
         }
 
+        struct send_frame_done_data *data = _data;
         output_view_for_each_surface(data->output, con->sway_view,
                 send_frame_done_iterator, data->when);
 }
@@ -322,8 +321,8 @@ static void send_frame_done_container(struct sway_output *output,
                 .output = output,
                 .when = when,
         };
-        container_descendants(con, C_VIEW,
-                send_frame_done_container_iterator, &data);
+        output_for_each_container(output->swayc,
+                        send_frame_done_container_iterator, &data);
 }
 
 static void send_frame_done(struct sway_output *output, struct timespec *when) {