client: Expose leader_id.

Signed-off-by: Maarten Maathuis <madman2003@gmail.com>
Signed-off-by: Julien Danjou <julien@danjou.info>

client.c

@@ -465,6 +465,7 @@ client_manage(xcb_window_t w, xcb_get_geometry_reply_t *wgeom, int phys_screen,
     property_update_wm_normal_hints(c, NULL);
     property_update_wm_hints(c, NULL);
     property_update_wm_transient_for(c, NULL);
+    property_update_wm_client_leader(c, NULL);
 
     if(c->transient_for)
         screen = c->transient_for->screen;
@@ -1478,6 +1479,7 @@ luaA_client_newindex(lua_State *L)
  * \lfield maximized_vertical The client is maximized vertically or not.
  * \lfield transient_for Return the client the window is transient for.
  * \lfield group_id Identification unique to a group of windows.
+ * \lfield leader_id Identification unique to windows spawned by the same command.
  * \lfield size_hints A table with size hints of the client: user_position,
  *         user_size, program_position and program_size.
  */
@@ -1577,6 +1579,9 @@ luaA_client_index(lua_State *L)
             return 0;
         }
         break;
+      case A_TK_LEADER_ID:
+        lua_pushnumber(L, (*c)->leader_win);
+        break;
       case A_TK_MACHINE:
         if(!xutil_text_prop_get(globalconf.connection, (*c)->win,
                                 WM_CLIENT_MACHINE, &value, &slen))

common/atoms.list

@@ -53,3 +53,4 @@ _NET_WM_WINDOW_OPACITY
 _NET_SYSTEM_TRAY_ORIENTATION
 WM_CHANGE_STATE
 WM_WINDOW_ROLE
+WM_CLIENT_LEADER

common/tokenize.gperf

@@ -37,6 +37,7 @@ icon
 icon_name
 image
 instance
+leader_id
 left
 len
 line

property.c

@@ -69,6 +69,50 @@ property_handle_wm_transient_for(void *data,
     return 0;
 }
 
+
+/** Update leader hint of a client.
+ * \param c The client.
+ * \param reply (Optional) An existing reply.
+ */
+void
+property_update_wm_client_leader(client_t *c, xcb_get_property_reply_t *reply)
+{
+    xcb_get_property_cookie_t client_leader_q;
+    void *data;
+    bool no_reply = !reply;
+
+    if(no_reply)
+    {
+        client_leader_q = xcb_get_property_unchecked(globalconf.connection, false, c->win,
+                                                     WM_CLIENT_LEADER, WINDOW, 0, 32);
+
+        reply = xcb_get_property_reply(globalconf.connection, client_leader_q, NULL);
+    }
+
+    if(reply && reply->value_len && (data = xcb_get_property_value(reply)))
+        c->leader_win = *(xcb_window_t *) data;
+
+    /* Only free when we created a reply ourselves. */
+    if(no_reply)
+        p_delete(&reply);
+}
+
+static int
+property_handle_wm_client_leader(void *data,
+                                xcb_connection_t *connection,
+                                uint8_t state,
+                                xcb_window_t window,
+                                xcb_atom_t name,
+                                xcb_get_property_reply_t *reply)
+{
+    client_t *c = client_getbywin(window);
+
+    if(c)
+        property_update_wm_client_leader(c, reply);
+
+    return 0;
+}
+
 /** Update the size hints of a client.
  * \param c The client.
  */
@@ -394,6 +438,8 @@ void a_xcb_set_property_handlers(void)
     /* ICCCM stuff */
     xcb_property_set_handler(&globalconf.prophs, WM_TRANSIENT_FOR, UINT_MAX,
                              property_handle_wm_transient_for, NULL);
+    xcb_property_set_handler(&globalconf.prophs, WM_CLIENT_LEADER, UINT_MAX,
+                             property_handle_wm_client_leader, NULL);
     xcb_property_set_handler(&globalconf.prophs, WM_NORMAL_HINTS, UINT_MAX,
                              property_handle_wm_normal_hints, NULL);
     xcb_property_set_handler(&globalconf.prophs, WM_HINTS, UINT_MAX,

property.h

@@ -25,6 +25,7 @@
 #include "structs.h"
 
 void property_update_wm_transient_for(client_t *, xcb_get_property_reply_t *);
+void property_update_wm_client_leader(client_t *c, xcb_get_property_reply_t *reply);
 void property_update_wm_normal_hints(client_t *, xcb_get_property_reply_t *);
 void property_update_wm_hints(client_t *, xcb_get_property_reply_t *);
 void property_update_wm_name(client_t *);

structs.h

@@ -205,6 +205,8 @@ struct client_t
     xcb_window_t win;
     /** Window of the group leader */
     xcb_window_t group_win;
+    /** Window holding command needed to start it (session management related) */
+    xcb_window_t leader_win;
     /** Client logical screen */
     int screen;
     /** Client physical screen */