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.

4 files changed, 35 insertions, 9 deletions

diff --git a/include/sway/output.h b/include/sway/output.h
index 8bdd1919..d0d034b3 100644
--- a/include/sway/output.h
+++ b/include/sway/output.h
@@ -95,4 +95,16 @@ void output_drag_icons_for_each_surface(struct sway_output *output,
         struct wl_list *drag_icons, sway_surface_iterator_func_t iterator,
         void *user_data);
 
+void output_for_each_workspace(struct sway_container *output,
+                void (*f)(struct sway_container *con, void *data), void *data);
+
+void output_for_each_container(struct sway_container *output,
+                void (*f)(struct sway_container *con, void *data), void *data);
+
+struct sway_container *output_find_workspace(struct sway_container *output,
+                bool (*test)(struct sway_container *con, void *data), void *data);
+
+struct sway_container *output_find_container(struct sway_container *output,
+                bool (*test)(struct sway_container *con, void *data), void *data);
+
 #endif
diff --git a/include/sway/tree/container.h b/include/sway/tree/container.h
index d866ec03..c8410801 100644
--- a/include/sway/tree/container.h
+++ b/include/sway/tree/container.h
@@ -214,15 +214,11 @@ struct sway_container *container_destroy(struct sway_container *container);
 
 struct sway_container *container_close(struct sway_container *container);
 
-void container_descendants(struct sway_container *root,
-                enum sway_container_type type,
-                void (*func)(struct sway_container *item, void *data), void *data);
-
 /**
  * Search a container's descendants a container based on test criteria. Returns
  * the first container that passes the test.
  */
-struct sway_container *container_find(struct sway_container *container,
+struct sway_container *container_find_child(struct sway_container *container,
                 bool (*test)(struct sway_container *view, void *data), void *data);
 
 /**
@@ -244,10 +240,7 @@ struct sway_container *tiling_container_at(
                 struct sway_container *con, double lx, double ly,
                 struct wlr_surface **surface, double *sx, double *sy);
 
-/**
- * Apply the function for each child of the container depth first.
- */
-void container_for_each_descendant(struct sway_container *container,
+void container_for_each_child(struct sway_container *container,
                 void (*f)(struct sway_container *container, void *data), void *data);
 
 /**
diff --git a/include/sway/tree/root.h b/include/sway/tree/root.h
index edb7c817..d1f04a96 100644
--- a/include/sway/tree/root.h
+++ b/include/sway/tree/root.h
@@ -58,4 +58,19 @@ struct sway_container *root_workspace_for_pid(pid_t pid);
 
 void root_record_workspace_pid(pid_t pid);
 
+void root_for_each_workspace(void (*f)(struct sway_container *con, void *data),
+                void *data);
+
+void root_for_each_container(void (*f)(struct sway_container *con, void *data),
+                void *data);
+
+struct sway_container *root_find_output(
+                bool (*test)(struct sway_container *con, void *data), void *data);
+
+struct sway_container *root_find_workspace(
+                bool (*test)(struct sway_container *con, void *data), void *data);
+
+struct sway_container *root_find_container(
+                bool (*test)(struct sway_container *con, void *data), void *data);
+
 #endif
diff --git a/include/sway/tree/workspace.h b/include/sway/tree/workspace.h
index 5b43ae87..c9dbb538 100644
--- a/include/sway/tree/workspace.h
+++ b/include/sway/tree/workspace.h
@@ -50,6 +50,12 @@ struct sway_container *workspace_output_get_highest_available(
 
 void workspace_detect_urgent(struct sway_container *workspace);
 
+void workspace_for_each_container(struct sway_container *ws,
+                void (*f)(struct sway_container *con, void *data), void *data);
+
+struct sway_container *workspace_find_container(struct sway_container *ws,
+                bool (*test)(struct sway_container *con, void *data), void *data);
+
 /**
  * Wrap the workspace's tiling children in a new container.
  * The new container will be the only direct tiling child of the workspace.