Implement type safe arguments and demote sway_container

This commit changes the meaning of sway_container so that it only refers
to layout containers and view containers. Workspaces, outputs and the
root are no longer known as containers. Instead, root, outputs,
workspaces and containers are all a type of node, and containers come in
two types: layout containers and view containers.

In addition to the above, this implements type safe variables. This
means we use specific types such as sway_output and sway_workspace
instead of generic containers or nodes. However, it's worth noting that
in a few places places (eg. seat focus and transactions) referring to
them in a generic way is unavoidable which is why we still use nodes in
some places.

If you want a TL;DR, look at node.h, as well as the struct definitions
for root, output, workspace and container. Note that sway_output now
contains a workspaces list, and workspaces now contain a tiling and
floating list, and containers now contain a pointer back to the
workspace.

There are now functions for seat_get_focused_workspace and
seat_get_focused_container. The latter will return NULL if a workspace
itself is focused. Most other seat functions like seat_get_focus and
seat_set_focus now accept and return nodes.

In the config->handler_context struct, current_container has been
replaced with three pointers: node, container and workspace. node is the
same as what current_container was, while workspace is the workspace
that the node resides on and container is the actual container, which
may be NULL if a workspace itself is focused.

The global root_container variable has been replaced with one simply
called root, which is a pointer to the sway_root instance.

The way outputs are created, enabled, disabled and destroyed has
changed. Previously we'd wrap the sway_output in a container when it is
enabled, but as we don't have containers any more it needs a different
approach. The output_create and output_destroy functions previously
created/destroyed the container, but now they create/destroy the
sway_output. There is a new function output_disable to disable an output
without destroying it.

Containers have a new view property. If this is populated then the
container is a view container, otherwise it's a layout container. Like
before, this property is immutable for the life of the container.

Containers have both a `sway_container *parent` and
`sway_workspace *workspace`. As we use specific types now, parent cannot
point to a workspace so it'll be NULL for containers which are direct
children of the workspace. The workspace property is set for all
containers, except those which are hidden in the scratchpad as they have
no workspace.

In some cases we need to refer to workspaces in a container-like way.
For example, workspaces have layout and children, but when using
specific types this makes it difficult. Likewise, it's difficult for a
container to get its parent's layout when the parent could be another
container or a workspace. To make it easier, some helper functions have
been created: container_parent_layout and container_get_siblings.

container_remove_child has been renamed to container_detach and
container_replace_child has been renamed to container_replace.

`container_handle_fullscreen_reparent(con, old_parent)` has had the
old_parent removed. We now unfullscreen the workspace when detaching the
container, so this function is simplified and only needs one argument
now.

container_notify_subtree_changed has been renamed to
container_update_representation. This is more descriptive of its
purpose. I also wanted to be able to call it with whatever container was
changed rather than the container's parent, which makes bubbling up to
the workspace easier.

There are now state structs per node thing. ie. sway_output_state,
sway_workspace_state and sway_container_state.

The focus, move and layout commands have been completely refactored to
work with the specific types. I considered making these a separate PR,
but I'd be backporting my changes only to replace them again, and it's
easier just to test everything at once.

1 files changed, 35 insertions, 113 deletions

diff --git a/include/sway/tree/container.h b/include/sway/tree/container.h
index e4071cfe..c51425c9 100644
--- a/include/sway/tree/container.h
+++ b/include/sway/tree/container.h
@@ -5,8 +5,7 @@
 #include <wlr/types/wlr_box.h>
 #include <wlr/types/wlr_surface.h>
 #include "list.h"
-
-extern struct sway_container root_container;
+#include "sway/tree/node.h"
 
 struct sway_view;
 struct sway_seat;
@@ -17,23 +16,6 @@ struct sway_seat;
 #define TITLEBAR_H_PADDING 3
 #define TITLEBAR_V_PADDING 4
 
-/**
- * Different kinds of containers.
- *
- * This enum is in order. A container will never be inside of a container below
- * it on this list.
- */
-enum sway_container_type {
-	C_ROOT,
-	C_OUTPUT,
-	C_WORKSPACE,
-	C_CONTAINER,
-	C_VIEW,
-
-	// Keep last
-	C_TYPES,
-};
-
 enum sway_container_layout {
 	L_NONE,
 	L_HORIZ,
@@ -57,18 +39,14 @@ enum movement_direction;
 enum wlr_direction;
 
 struct sway_container_state {
-	// Container/swayc properties
+	// Container properties
 	enum sway_container_layout layout;
-	double swayc_x, swayc_y;
-	double swayc_width, swayc_height;
+	double con_x, con_y;
+	double con_width, con_height;
 
 	bool is_fullscreen;
 
-	bool has_gaps;
-	double current_gaps;
-	double gaps_inner;
-	double gaps_outer;
-
+	struct sway_workspace *workspace;
 	struct sway_container *parent;
 	list_t *children;
 
@@ -86,35 +64,19 @@ struct sway_container_state {
 	bool border_left;
 	bool border_right;
 	bool using_csd;
-
-	// Workspace properties
-	struct sway_container *ws_fullscreen;
-	list_t *ws_floating;
 };
 
 struct sway_container {
-	union {
-		// TODO: Encapsulate state for other node types as well like C_CONTAINER
-		struct sway_root *sway_root;
-		struct sway_output *sway_output;
-		struct sway_workspace *sway_workspace;
-		struct sway_view *sway_view;
-	};
-
-	/**
-	 * A unique ID to identify this container. Primarily used in the
-	 * get_tree JSON output.
-	 */
-	size_t id;
+	struct sway_node node;
+	struct sway_view *view;
 
 	// The pending state is the main container properties, and the current state is in the below struct.
 	// This means most places of the code can refer to the main variables (pending state) and it'll just work.
 	struct sway_container_state current;
 
-	char *name;            // The view's title (unformatted)
+	char *title;           // The view's title (unformatted)
 	char *formatted_title; // The title displayed in the title bar
 
-	enum sway_container_type type;
 	enum sway_container_layout layout;
 	enum sway_container_layout prev_split_layout;
 
@@ -132,14 +94,13 @@ struct sway_container {
 
 	// The gaps currently applied to the container.
 	double current_gaps;
-
 	bool has_gaps;
 	double gaps_inner;
 	double gaps_outer;
 
-	list_t *children;
-
-	struct sway_container *parent;
+	struct sway_workspace *workspace; // NULL when hidden in the scratchpad
+	struct sway_container *parent;    // NULL if container in root of workspace
+	list_t *children;                 // struct sway_container
 
 	// Outputs currently being intersected
 	list_t *outputs; // struct sway_output
@@ -157,42 +118,17 @@ struct sway_container {
 	struct wlr_texture *title_urgent;
 	size_t title_height;
 
-	// The number of transactions which reference this container.
-	size_t ntxnrefs;
-
-	// If this container is a view and is waiting for the client to respond to a
-	// configure then this will be populated, otherwise NULL.
-	struct sway_transaction_instruction *instruction;
-
-	bool destroying;
-
-	// If true, indicates that the container has pending state that differs from
-	// the current.
-	bool dirty;
-
 	struct {
 		struct wl_signal destroy;
 	} events;
 };
 
-struct sway_container *container_create(enum sway_container_type type);
-
-const char *container_type_to_str(enum sway_container_type type);
-
-/*
- * Create a new view container. A view can be a child of a workspace container
- * or a container container and are rendered in the order and structure of
- * how they are attached to the tree.
- */
-struct sway_container *container_view_create(
-		struct sway_container *sibling, struct sway_view *sway_view);
+struct sway_container *container_create(struct sway_view *view);
 
 void container_destroy(struct sway_container *con);
 
 void container_begin_destroy(struct sway_container *con);
 
-struct sway_container *container_close(struct sway_container *container);
-
 /**
  * Search a container's descendants a container based on test criteria. Returns
  * the first container that passes the test.
@@ -201,22 +137,16 @@ struct sway_container *container_find_child(struct sway_container *container,
 		bool (*test)(struct sway_container *view, void *data), void *data);
 
 /**
- * Finds a parent container with the given struct sway_containerype.
- */
-struct sway_container *container_parent(struct sway_container *container,
-		enum sway_container_type type);
-
-/**
  * Find a container at the given coordinates. Returns the the surface and
  * surface-local coordinates of the given layout coordinates if the container
  * is a view and the view contains a surface at those coordinates.
  */
-struct sway_container *container_at(struct sway_container *workspace,
+struct sway_container *container_at(struct sway_workspace *workspace,
 		double lx, double ly, struct wlr_surface **surface,
 		double *sx, double *sy);
 
 struct sway_container *tiling_container_at(
-		struct sway_container *con, double lx, double ly,
+		struct sway_node *parent, double lx, double ly,
 		struct wlr_surface **surface, double *sx, double *sy);
 
 void container_for_each_child(struct sway_container *container,
@@ -228,16 +158,11 @@ void container_for_each_child(struct sway_container *container,
 bool container_has_ancestor(struct sway_container *container,
 		struct sway_container *ancestor);
 
-int container_count_descendants_of_type(struct sway_container *con,
-		enum sway_container_type type);
-
-void container_create_notify(struct sway_container *container);
-
 void container_update_textures_recursive(struct sway_container *con);
 
 void container_damage_whole(struct sway_container *container);
 
-struct sway_container *container_reap_empty(struct sway_container *con);
+void container_reap_empty(struct sway_container *con);
 
 struct sway_container *container_flatten(struct sway_container *container);
 
@@ -248,11 +173,10 @@ void container_update_title_textures(struct sway_container *container);
  */
 void container_calculate_title_height(struct sway_container *container);
 
-/**
- * Notify a container that a tree modification has changed in its children,
- * so the container can update its tree representation.
- */
-void container_notify_subtree_changed(struct sway_container *container);
+size_t container_build_representation(enum sway_container_layout layout,
+		list_t *children, char *buffer);
+
+void container_update_representation(struct sway_container *container);
 
 /**
  * Return the height of a regular title bar.
@@ -288,8 +212,7 @@ void container_floating_translate(struct sway_container *con,
 /**
  * Choose an output for the floating container's new position.
  */
-struct sway_container *container_floating_find_output(
-		struct sway_container *con);
+struct sway_output *container_floating_find_output(struct sway_container *con);
 
 /**
  * Move a floating container to a new layout-local position.
@@ -302,12 +225,6 @@ void container_floating_move_to(struct sway_container *con,
  */
 void container_floating_move_to_center(struct sway_container *con);
 
-/**
- * Mark a container as dirty if it isn't already. Dirty containers will be
- * included in the next transaction then unmarked as dirty.
- */
-void container_set_dirty(struct sway_container *container);
-
 bool container_has_urgent_child(struct sway_container *container);
 
 /**
@@ -342,10 +259,18 @@ void container_remove_gaps(struct sway_container *container);
 
 void container_add_gaps(struct sway_container *container);
 
+enum sway_container_layout container_parent_layout(struct sway_container *con);
+
+enum sway_container_layout container_current_parent_layout(
+		struct sway_container *con);
+
+list_t *container_get_siblings(const struct sway_container *container);
+
 int container_sibling_index(const struct sway_container *child);
 
-void container_handle_fullscreen_reparent(struct sway_container *con,
-		struct sway_container *old_parent);
+list_t *container_get_current_siblings(struct sway_container *container);
+
+void container_handle_fullscreen_reparent(struct sway_container *con);
 
 void container_add_child(struct sway_container *parent,
 		struct sway_container *child);
@@ -353,19 +278,16 @@ void container_add_child(struct sway_container *parent,
 void container_insert_child(struct sway_container *parent,
 		struct sway_container *child, int i);
 
-struct sway_container *container_add_sibling(struct sway_container *parent,
-		struct sway_container *child);
+void container_add_sibling(struct sway_container *parent,
+		struct sway_container *child, int offset);
 
-struct sway_container *container_remove_child(struct sway_container *child);
+void container_detach(struct sway_container *child);
 
-struct sway_container *container_replace_child(struct sway_container *child,
-		struct sway_container *new_child);
+void container_replace(struct sway_container *container,
+		struct sway_container *replacement);
 
 bool sway_dir_to_wlr(enum movement_direction dir, enum wlr_direction *out);
 
-enum sway_container_layout container_get_default_layout(
-		struct sway_container *con);
-
 struct sway_container *container_split(struct sway_container *child,
 		enum sway_container_layout layout);