Add support for WM_CLIENT_LEADER, put floating windows mapping to (0x0) to center of leader/workspace

include/data.h

@@ -341,6 +341,10 @@ struct Client {
         /** Holds the WM_CLASS, useful for matching the client in commands */
         char *window_class;
 
+        /** Holds the xcb_window_t (just an ID) for the leader window (logical
+         * parent for toolwindows and similar floating windows) */
+        xcb_window_t leader;
+
         /** fullscreen is pretty obvious */
         bool fullscreen;
 

include/handlers.h

@@ -154,4 +154,13 @@ int handle_transient_for(void *data, xcb_connection_t *conn, uint8_t state,
                          xcb_window_t window, xcb_atom_t name,
                          xcb_get_property_reply_t *reply);
 
+/**
+ * Handles changes of the WM_CLIENT_LEADER atom which specifies if this is a
+ * toolwindow (or similar) and to which window it belongs (logical parent).
+ *
+ */
+int handle_clientleader_change(void *data, xcb_connection_t *conn,
+                               uint8_t state, xcb_window_t window,
+                               xcb_atom_t name, xcb_get_property_reply_t *prop);
+
 #endif

include/i3.h

@@ -20,7 +20,7 @@
 #ifndef _I3_H
 #define _I3_H
 
-#define NUM_ATOMS 17
+#define NUM_ATOMS 18
 
 extern xcb_connection_t *global_conn;
 extern char **start_argv;

include/xcb.h

@@ -60,7 +60,8 @@ enum { _NET_SUPPORTED = 0,
         WM_PROTOCOLS,
         WM_DELETE_WINDOW,
         UTF8_STRING,
-        WM_STATE
+        WM_STATE,
+        WM_CLIENT_LEADER
 };
 
 extern unsigned int xcb_numlock_mask;