window: Cache _NET_WM_ICON_GEOMETRY

Rather than doing a server round trip each time when retrieving the
icon geometry, use the existing property mechanism to cache it.

https://bugzilla.gnome.org/show_bug.cgi?id=692997

src/core/window-private.h

@@ -220,6 +220,9 @@ struct _MetaWindow
   
   /* whether net_wm_user_time has been set yet */
   guint net_wm_user_time_set : 1;
+
+  /* whether net_wm_icon_geometry has been set */
+  guint icon_geometry_set : 1;
   
   /* These are the flags from WM_PROTOCOLS */
   guint take_focus : 1;
@@ -391,6 +394,9 @@ struct _MetaWindow
    */
   MetaRectangle user_rect;
   
+  /* Cached net_wm_icon_geometry */
+  MetaRectangle icon_geometry;
+
   /* Requested geometry */
   int border_width;
   /* x/y/w/h here get filled with ConfigureRequest values */

src/core/window-props.c

@@ -245,6 +245,33 @@ reload_kwm_win_icon (MetaWindow    *window,
   reload_icon (window, window->display->atom__KWM_WIN_ICON);
 }
 
+static void
+reload_icon_geometry (MetaWindow    *window,
+                      MetaPropValue *value,
+                      gboolean       initial)
+{
+  if (value->type != META_PROP_VALUE_INVALID)
+    {
+      if (value->v.cardinal_list.n_cardinals != 4)
+        {
+          meta_verbose ("_NET_WM_ICON_GEOMETRY on %s has %d values instead of 4\n",
+                        window->desc, value->v.cardinal_list.n_cardinals);
+        }
+      else
+        {
+          window->icon_geometry.x = (int)value->v.cardinal_list.cardinals[0];
+          window->icon_geometry.y = (int)value->v.cardinal_list.cardinals[1];
+          window->icon_geometry.width = (int)value->v.cardinal_list.cardinals[2];
+          window->icon_geometry.height = (int)value->v.cardinal_list.cardinals[3];
+          window->icon_geometry_set = TRUE;
+        }
+    }
+  else
+    {
+      window->icon_geometry_set = FALSE;
+    }
+}
+
 static void
 reload_struts (MetaWindow    *window,
                MetaPropValue *value,
@@ -1728,7 +1755,7 @@ meta_display_init_window_prop_hooks (MetaDisplay *display)
     { display->atom_WM_STATE,          META_PROP_VALUE_INVALID,  NULL,                     FALSE, FALSE },
     { display->atom__NET_WM_ICON,      META_PROP_VALUE_INVALID,  reload_net_wm_icon,       FALSE, FALSE },
     { display->atom__KWM_WIN_ICON,     META_PROP_VALUE_INVALID,  reload_kwm_win_icon,      FALSE, FALSE },
-    { display->atom__NET_WM_ICON_GEOMETRY, META_PROP_VALUE_INVALID, NULL,                  FALSE, FALSE },
+    { display->atom__NET_WM_ICON_GEOMETRY, META_PROP_VALUE_CARDINAL_LIST, reload_icon_geometry,     FALSE, FALSE },
     { display->atom_WM_CLIENT_LEADER,  META_PROP_VALUE_INVALID, complain_about_broken_client, FALSE, FALSE },
     { display->atom_SM_CLIENT_ID,      META_PROP_VALUE_INVALID, complain_about_broken_client, FALSE, FALSE },
     { display->atom_WM_WINDOW_ROLE,    META_PROP_VALUE_INVALID, reload_wm_window_role,        FALSE, FALSE },

src/core/window.c

@@ -7151,9 +7151,7 @@ send_configure_notify (MetaWindow *window)
  *
  * Gets the location of the icon corresponding to the window. The location
  * will be provided set by the task bar or other user interface element
- * displaying the icon, and is relative to the root window. This currently
+ * displaying the icon, and is relative to the root window.
- * retrieves the icon geometry from the X server as a round trip on every
- * call.
  *
  * Return value: %TRUE if the icon geometry was succesfully retrieved.
  */
@@ -7161,33 +7159,12 @@ gboolean
 meta_window_get_icon_geometry (MetaWindow    *window,
                                MetaRectangle *rect)
 {
-  gulong *geometry = NULL;
-  int nitems;
-
   g_return_val_if_fail (!window->override_redirect, FALSE);
 
-  if (meta_prop_get_cardinal_list (window->display,
+  if (window->icon_geometry_set)
-                                   window->xwindow,
-                                   window->display->atom__NET_WM_ICON_GEOMETRY,
-                                   &geometry, &nitems))
     {
-      if (nitems != 4)
-        {
-          meta_verbose ("_NET_WM_ICON_GEOMETRY on %s has %d values instead of 4\n",
-                        window->desc, nitems);
-          meta_XFree (geometry);
-          return FALSE;
-        }
-
       if (rect)
-        {
+        *rect = window->icon_geometry;
-          rect->x = geometry[0];
-          rect->y = geometry[1];
-          rect->width = geometry[2];
-          rect->height = geometry[3];
-        }
-
-      meta_XFree (geometry);
 
       return TRUE;
     }