[libwnck] Window: emit class-changed signal when the instance or group class name changes

[Marco Trevisan <marcotrevi src gnome org>]

commit 90c5c63392369b04fad3bc07b08c15f80d13ac84
Author: Marco Trevisan (TreviÃo) <mail 3v1n0 net>
Date:   Wed Jan 9 15:20:32 2013 +0100

    Window: emit class-changed signal when the instance or group class name changes
    
    https://bugzilla.gnome.org/show_bug.cgi?id=691424

 libwnck/window.c |   62 +++++++++++++++++++++++++++++++++++++++++++++++-------
 libwnck/window.h |    8 ++++--
 2 files changed, 59 insertions(+), 11 deletions(-)
---
diff --git a/libwnck/window.c b/libwnck/window.c
index 28bbb37..b375aa1 100644
--- a/libwnck/window.c
+++ b/libwnck/window.c
@@ -162,6 +162,7 @@ struct _WnckWindowPrivate
 
   guint need_emit_name_changed : 1;
   guint need_emit_icon_changed : 1;
+  guint need_emit_class_changed : 1;
 };
 
 G_DEFINE_TYPE (WnckWindow, wnck_window, G_TYPE_OBJECT);
@@ -174,6 +175,7 @@ enum {
   ICON_CHANGED,
   ACTIONS_CHANGED,
   GEOMETRY_CHANGED,
+  CLASS_CHANGED,
   LAST_SIGNAL
 };
 
@@ -191,6 +193,7 @@ static void emit_actions_changed   (WnckWindow       *window,
                                     WnckWindowActions changed_mask,
                                     WnckWindowActions new_actions);
 static void emit_geometry_changed  (WnckWindow      *window);
+static void emit_class_changed  (WnckWindow      *window);
 
 static void update_name      (WnckWindow *window);
 static void update_state     (WnckWindow *window);
@@ -306,6 +309,7 @@ wnck_window_init (WnckWindow *window)
 
   window->priv->need_emit_name_changed = FALSE;
   window->priv->need_emit_icon_changed = FALSE;
+  window->priv->need_emit_class_changed = FALSE;
 }
 
 static void
@@ -419,6 +423,21 @@ wnck_window_class_init (WnckWindowClass *klass)
                   NULL, NULL,
                   g_cclosure_marshal_VOID__VOID,
                   G_TYPE_NONE, 0);
+
+  /**
+   * WnckWindow::class-changed:
+   * @window: the #WnckWindow which emitted the signal.
+   *
+   * Emitted when the class name or instance name of @window changes.
+   */
+  signals[CLASS_CHANGED] =
+    g_signal_new ("class_changed",
+                  G_OBJECT_CLASS_TYPE (object_class),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (WnckWindowClass, class_changed),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
 }
 
 static void
@@ -584,6 +603,7 @@ _wnck_window_create (Window      xwindow,
   window->priv->need_update_frame_extents = TRUE;
   window->priv->need_emit_name_changed = FALSE;
   window->priv->need_emit_icon_changed = FALSE;
+  window->priv->need_emit_class_changed = FALSE;
   force_update_now (window);
 
   return window;
@@ -3110,21 +3130,35 @@ update_startup_id (WnckWindow *window)
 static void
 update_wmclass (WnckWindow *window)
 {
+  char *new_res_class = NULL;
+  char *new_res_name = NULL;
+
   if (!window->priv->need_update_wmclass)
     return;
 
   window->priv->need_update_wmclass = FALSE;
 
-  g_free (window->priv->res_class);
-  g_free (window->priv->res_name);
-
-  window->priv->res_class = NULL;
-  window->priv->res_name = NULL;
-
   _wnck_get_wmclass (WNCK_SCREEN_XSCREEN (window->priv->screen),
                      window->priv->xwindow,
-                     &window->priv->res_class,
-                     &window->priv->res_name);
+                     &new_res_class,
+                     &new_res_name);
+
+  if (g_strcmp0 (window->priv->res_class, new_res_class) != 0 ||
+      g_strcmp0 (window->priv->res_name, new_res_name) != 0)
+    {
+      window->priv->need_emit_class_changed = TRUE;
+
+      g_free (window->priv->res_class);
+      g_free (window->priv->res_name);
+
+      window->priv->res_class = new_res_class;
+      window->priv->res_name = new_res_name;
+    }
+  else
+    {
+      g_free (new_res_class);
+      g_free (new_res_name);
+    }
 }
 
 static void
@@ -3251,6 +3285,9 @@ force_update_now (WnckWindow *window)
 
   if (window->priv->need_emit_icon_changed)
     emit_icon_changed (window);
+
+  if (window->priv->need_emit_class_changed)
+    emit_class_changed (window);
 }
 
 
@@ -3320,6 +3357,15 @@ emit_icon_changed (WnckWindow *window)
 }
 
 static void
+emit_class_changed (WnckWindow *window)
+{
+  window->priv->need_emit_class_changed = FALSE;
+  g_signal_emit (G_OBJECT (window),
+                 signals[CLASS_CHANGED],
+                 0);
+}
+
+static void
 emit_actions_changed   (WnckWindow       *window,
                         WnckWindowActions changed_mask,
                         WnckWindowActions new_actions)
diff --git a/libwnck/window.h b/libwnck/window.h
index dbdb529..dcc43cd 100644
--- a/libwnck/window.h
+++ b/libwnck/window.h
@@ -274,13 +274,15 @@ struct _WnckWindowClass
                               WnckWindowActions new_actions);
 
   /* Changed size/position */
-  void (* geometry_changed)      (WnckWindow       *window);
-  
+  void (* geometry_changed)  (WnckWindow       *window);
+
+  /* Changed class group/instance name */
+  void (* class_changed)     (WnckWindow       *window);
+
   /* Padding for future expansion */
   void (* pad1) (void);
   void (* pad2) (void);
   void (* pad3) (void);
-  void (* pad4) (void);
 };
 
 GType wnck_window_get_type (void) G_GNUC_CONST;