Implement title_format

This implements the title_format command, with a new placeholder %shell
which gets substituted with the view type (xwayland, xdg_shell_v6 or
wl_shell).

Example config:

    for_window [title=".*"] title_format %title (class=%class instance=%instance shell=%shell)

3 files changed, 14 insertions, 3 deletions

diff --git a/include/sway/commands.h b/include/sway/commands.h
index 0732a90a..d39ac56c 100644
--- a/include/sway/commands.h
+++ b/include/sway/commands.h
@@ -144,6 +144,7 @@ sway_cmd cmd_splitt;
 sway_cmd cmd_splitv;
 sway_cmd cmd_sticky;
 sway_cmd cmd_swaybg_command;
+sway_cmd cmd_title_format;
 sway_cmd cmd_unmark;
 sway_cmd cmd_workspace;
 sway_cmd cmd_ws_auto_back_and_forth;
diff --git a/include/sway/tree/container.h b/include/sway/tree/container.h
index b07af72c..61ab7ca1 100644
--- a/include/sway/tree/container.h
+++ b/include/sway/tree/container.h
@@ -63,7 +63,8 @@ struct sway_container {
          */
         size_t id;
 
-        char *name;
+        char *name;            // 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;
@@ -204,7 +205,6 @@ void container_update_title_textures(struct sway_container *container);
  */
 void container_calculate_title_height(struct sway_container *container);
 
-void container_update_title(struct sway_container *container,
-                const char *new_title);
+void container_notify_child_title_changed(struct sway_container *container);
 
 #endif
diff --git a/include/sway/tree/view.h b/include/sway/tree/view.h
index 21127ab1..9d4256f7 100644
--- a/include/sway/tree/view.h
+++ b/include/sway/tree/view.h
@@ -48,6 +48,7 @@ struct sway_view {
 
         bool is_fullscreen;
 
+        char *title_format;
         enum sway_container_border border;
         int border_thickness;
 
@@ -164,6 +165,8 @@ const char *view_get_class(struct sway_view *view);
 
 const char *view_get_instance(struct sway_view *view);
 
+const char *view_get_type(struct sway_view *view);
+
 void view_configure(struct sway_view *view, double ox, double oy, int width,
         int height);
 
@@ -207,4 +210,11 @@ void view_child_init(struct sway_view_child *child,
 
 void view_child_destroy(struct sway_view_child *child);
 
+/**
+ * Re-read the view's title property and update any relevant title bars.
+ * The force argument makes it recreate the title bars even if the title hasn't
+ * changed.
+ */
+void view_update_title(struct sway_view *view, bool force);
+
 #endif