* Update plugins to not wait for realize signal, because plugin construction is now delayed until after this signal

* Add API to allow extra check before plugin creation and update systray to use it (bug #1482). Not sure if it will work properly for external plugins.

(Old svn revision: 20349)

libxfce4panel/xfce-panel-plugin-iface.h

@@ -51,6 +51,18 @@ typedef struct _XfcePanelPluginInterface XfcePanelPluginInterface;
  **/
 typedef void (*XfcePanelPluginFunc) (XfcePanelPlugin *plugin);
 
+/**
+ * XfcePanelPluginCheck:
+ *
+ * Callback function that is run before creating a plugin. It should return
+ * if the plugin is not available for whatever reason. It should be given as 
+ * the argument to the registration macros.
+ *
+ * See also: XFCE_PANEL_PLUGIN_REGISTER_EXTERNAL_WITH_CHECK() and
+ *           XFCE_PANEL_PLUGIN_REGISTER_INTERNAL_WITH_CHECK()
+ **/
+typedef gboolean (*XfcePanelPluginCheck) (GdkScreen *screen);
+
 
 GType xfce_panel_plugin_get_type (void) G_GNUC_CONST;
 

libxfce4panel/xfce-panel-plugin.h

@@ -53,6 +53,38 @@
         return 0; \
     }
 
+/**
+ * XFCE_PANEL_PLUGIN_REGISTER_EXTERNAL_WITH_CHECK
+ * @construct : name of a function that can be cast to an 
+ *              #XfcePanelPluginFunc
+ * @check     : name of a function that can be cast to an
+ *              #XfcePanelPluginCheck
+ *
+ * Registers and initializes the plugin. This is the only thing that is 
+ * required to create a panel plugin. The @check functions is run before
+ * creating the plugin, and should return FALSE if plugin creation is not
+ * possible.
+ *
+ * See also: <link linkend="XfcePanelPlugin">Panel Plugin interface</link>
+ **/
+#define XFCE_PANEL_PLUGIN_REGISTER_EXTERNAL_WITH_CHECK(construct,check) \
+    int \
+    main (int argc, char **argv) \
+    { \
+        GtkWidget *plugin; \
+        XfcePanelPluginCheck test = (XfcePanelPluginCheck)check; \
+        gtk_init (&argc, &argv); \
+        if (!test(gdk_screen_get_default())) return 2; \
+        plugin = xfce_external_panel_plugin_new (argc, argv, \
+                     (XfcePanelPluginFunc)construct); \
+        if (!plugin) return 1; \
+        g_signal_connect_after (plugin, "destroy", \
+                                G_CALLBACK (exit), NULL); \
+        gtk_widget_show (plugin); \
+        gtk_main (); \
+        return 0; \
+    }
+
 /**
  * XFCE_PANEL_PLUGIN_REGISTER_INTERNAL
  * @construct : name of a function that can be cast to an #XfcePanelPluginFunc
@@ -73,4 +105,33 @@
         return (XfcePanelPluginFunc)construct; \
     }
 
+/**
+ * XFCE_PANEL_PLUGIN_REGISTER_INTERNAL_WITH_CHECK
+ * @construct : name of a function that can be cast to an #XfcePanelPluginFunc
+ * @check     : name of a function that can be cast to an
+ *              #XfcePanelPluginCheck
+ *
+ * Registers and initializes the plugin. This is the only thing that is 
+ * required to create a panel plugin. The @check function is run before
+ * creating the plugin, and should return FALSE if plugin creation is not
+ * possible.
+ *
+ * This macro is for plugins implemented as a loadable module. Generally it is
+ * preferred to create an external plugin, for which you have to use
+ * XFCE_PANEL_PLUGIN_REGISTER_EXTERNAL() .
+ *
+ * See also: <link linkend="XfcePanelPlugin">Panel Plugin interface</link>
+ **/
+#define XFCE_PANEL_PLUGIN_REGISTER_INTERNAL_WITH_CHECK(construct,check) \
+    XfcePanelPluginFunc \
+    xfce_panel_plugin_get_construct (void) \
+    { \
+        return (XfcePanelPluginFunc)construct; \
+    } \
+    XfcePanelPluginCheck \
+    xfce_panel_plugin_get_check (void) \
+    { \
+        return (XfcePanelPluginCheck)check; \
+    }
+
 #endif /* _XFCE_PANEL_PLUGIN_H */

panel/panel-item-manager.c

@@ -63,6 +63,7 @@ struct _XfcePanelItemClass
     /* for loadable modules only */
     GModule *gmodule;
     XfcePanelPluginFunc construct;
+    XfcePanelPluginCheck check;
 };
 
 static GHashTable *plugin_classes = NULL;
@@ -330,8 +331,9 @@ _decrease_use_count (GtkWidget *item, XfcePanelItemClass *class)
 }
 
 GtkWidget *
-xfce_panel_item_manager_create_item (const char *name, const char *id,
-                                int size, XfceScreenPosition position)
+xfce_panel_item_manager_create_item (GdkScreen *screen, const char *name, 
+                                     const char *id, int size, 
+                                     XfceScreenPosition position)
 {
     XfcePanelItemClass *class;
     GtkWidget *item = NULL;
@@ -351,6 +353,7 @@ xfce_panel_item_manager_create_item (const char *name, const char *id,
         {
             gpointer symbol;
             XfcePanelPluginFunc (*get_construct) (void);
+            XfcePanelPluginCheck (*get_check) (void);
             
             if (!(class->gmodule = g_module_open (class->file, 0)))
             {
@@ -372,11 +375,29 @@ xfce_panel_item_manager_create_item (const char *name, const char *id,
             get_construct = symbol;
             
             class->construct = get_construct ();
+            
+            if (g_module_symbol (class->gmodule, 
+                                  "xfce_panel_plugin_get_check", &symbol))
+            {
+                get_check = symbol;
+                
+                class->check = get_check ();
+            }
+            else
+            {
+                class->check = NULL;
+            }
         }
 
-        item = xfce_internal_panel_plugin_new (class->plugin_name, id, 
-                                               class->name, size, position, 
-                                               class->construct);
+        if (!class->check || class->check(screen) == TRUE )
+        {
+            item = xfce_internal_panel_plugin_new (class->plugin_name, 
+                                                   id, 
+                                                   class->name, 
+                                                   size, 
+                                                   position, 
+                                                   class->construct);
+        }
     }
 
     if (item)

panel/panel-item-manager.h

@@ -41,10 +41,11 @@ void xfce_panel_item_manager_init (void);
 
 void xfce_panel_item_manager_cleanup (void);
 
-GtkWidget *xfce_panel_item_manager_create_item (const char *name, 
-                                           const char *id,
-                                           int size, 
-                                           XfceScreenPosition position);
+GtkWidget *xfce_panel_item_manager_create_item (GdkScreen *screen,
+                                                const char *name, 
+                                                const char *id,
+                                                int size, 
+                                                XfceScreenPosition position);
 
 /* for 'Add Item' dialog */
 GPtrArray *xfce_panel_item_manager_get_item_info_list (void);

panel/panel.c

@@ -810,11 +810,13 @@ panel_create_item (Panel *panel, const char *name, const char *id)
 {
     PanelPrivate *priv;
     GtkWidget *item = NULL;
+    XfceMonitor *xmon;
 
     priv = panel->priv;
+    xmon = panel_app_get_monitor (priv->monitor);
 
-    if ((item = xfce_panel_item_manager_create_item (name, id, 
-                    priv->size, priv->screen_position)) != NULL)
+    if ((item = xfce_panel_item_manager_create_item (xmon->screen,
+                    name, id, priv->size, priv->screen_position)) != NULL)
     {
         g_signal_connect (item, "menu-deactivated", 
                           G_CALLBACK (panel_menu_deactivated), panel);

plugins/iconbox/iconbox.c

@@ -670,13 +670,6 @@ iconbox_screen_changed (GtkWidget *plugin, GdkScreen *screen, Iconbox *ib)
     iconbox_init_icons (ib);
 }
 
-static void
-iconbox_realize (GtkWidget *plugin, Iconbox *ib)
-{
-  iconbox_screen_changed (GTK_WIDGET (plugin), 
-                          gtk_widget_get_screen (plugin), ib);
-}
-
 static void
 iconbox_construct (XfcePanelPlugin *plugin)
 {
@@ -748,7 +741,9 @@ iconbox_construct (XfcePanelPlugin *plugin)
         g_signal_connect (plugin, "screen-changed", 
                           G_CALLBACK (iconbox_screen_changed), iconbox);
     
-    g_signal_connect (plugin, "realize", G_CALLBACK (iconbox_realize), iconbox);
+    iconbox_screen_changed (GTK_WIDGET (plugin),
+                            gtk_widget_get_screen (GTK_WIDGET (plugin)), 
+                            iconbox);
 }
 
 /* -------------------------------------------------------------------- *

plugins/launcher/launcher.c

@@ -153,6 +153,9 @@ launcher_construct (XfcePanelPlugin *plugin)
     xfce_panel_plugin_menu_show_configure (plugin);
     g_signal_connect (plugin, "configure-plugin", 
                       G_CALLBACK (launcher_configure), launcher);
+
+    launcher_set_screen_position (launcher, 
+            xfce_panel_plugin_get_screen_position (plugin));
 }
 
 /* -------------------------------------------------------------------- *
@@ -1172,19 +1175,6 @@ plugin_icon_theme_changed (GtkWidget *w, gpointer ignored,
 
 /* Create Launcher Plugin Contents */
 
-static void
-plugin_realized (XfcePanelPlugin *plugin, LauncherPlugin *launcher)
-{
-    if (!GTK_WIDGET_REALIZED (launcher->iconbutton))
-    {
-        gtk_widget_realize (launcher->box);
-        gtk_widget_realize (launcher->iconbutton);
-    }
-
-    launcher_set_screen_position (launcher, 
-            xfce_panel_plugin_get_screen_position (plugin));
-}
-
 static LauncherPlugin *
 launcher_new (XfcePanelPlugin *plugin)
 {
@@ -1270,9 +1260,6 @@ launcher_new (XfcePanelPlugin *plugin)
     
     g_signal_connect (launcher->arrowbutton, "drag-leave", 
                       G_CALLBACK (launcher_menu_drag_leave), launcher);
-
-    g_signal_connect (plugin, "realize", G_CALLBACK (plugin_realized), 
-                      launcher);
     
     /* configuration */
     launcher_read_rc_file (plugin, launcher);

plugins/pager/pager.c

@@ -155,19 +155,6 @@ pager_write_rc_file (XfcePanelPlugin *plugin, Pager *pager)
     xfce_rc_close (rc);
 }
 
-static void 
-pager_realize (XfcePanelPlugin *plugin, Pager *pager)
-{
-    GdkScreen *screen;
-    int screen_idx;
-
-    screen = gtk_widget_get_screen (GTK_WIDGET (plugin));
-    screen_idx = gdk_screen_get_number (screen);
-    
-    pager->screen = netk_screen_get (screen_idx);
-    netk_pager_set_screen (NETK_PAGER (pager->pager), pager->screen);
-}
-
 /* create widgets and connect to signals */
 static void
 pager_n_workspaces_changed (NetkScreen * screen, NetkWorkspace * ws, 
@@ -211,6 +198,8 @@ pager_screen_changed (GtkWidget *plugin, GdkScreen *screen, Pager *pager)
 static void 
 pager_construct (XfcePanelPlugin *plugin)
 {
+    GdkScreen *screen;
+    int screen_idx;
     Pager *pager = g_new0 (Pager, 1);
 
     g_signal_connect (plugin, "orientation-changed", 
@@ -225,16 +214,15 @@ pager_construct (XfcePanelPlugin *plugin)
     g_signal_connect (plugin, "save", 
                       G_CALLBACK (pager_write_rc_file), pager);
 
-    g_signal_connect (plugin, "realize",
-		      G_CALLBACK (pager_realize), pager);
-    
     xfce_panel_plugin_menu_show_configure (plugin);
     g_signal_connect (plugin, "configure-plugin", 
                       G_CALLBACK (pager_properties_dialog), pager);
 
     pager->plugin = plugin;
 
-    pager->screen = netk_screen_get_default ();
+    screen = gtk_widget_get_screen (GTK_WIDGET (plugin));
+    screen_idx = gdk_screen_get_number (screen);
+    pager->screen = netk_screen_get (screen_idx);
     
     pager_read_rc_file (plugin, pager);
 

plugins/systray/systray.c

@@ -48,20 +48,38 @@ Systray;
 static void systray_properties_dialog (XfcePanelPlugin *plugin, 
                                        Systray *systray);
 
+static void systray_free_data (XfcePanelPlugin *plugin, Systray *systray);
+
 static void systray_construct (XfcePanelPlugin *plugin);
 
+static gboolean systray_check (GdkScreen *screen);
+
 
 /* -------------------------------------------------------------------- *
  *                             Systray                                  *
  * -------------------------------------------------------------------- */
 
+static gboolean 
+systray_check (GdkScreen *screen)
+{
+    Screen *scr = GDK_SCREEN_XSCREEN (screen);
+
+    if (xfce_system_tray_check_running (scr))
+    {
+        xfce_info (_("There is already a system tray running on this "
+                     "screen"));
+        return FALSE;
+    }
+    return TRUE;
+}
+
 static gboolean
 register_tray (Systray * systray)
 {
     GError *error = NULL;
     Screen *scr = GDK_SCREEN_XSCREEN (gtk_widget_get_screen (systray->frame));
 
-    if (xfce_system_tray_check_running (scr))
+    if (!systray_check (gtk_widget_get_screen (systray->frame)))
     {
         xfce_info (_("There is already a system tray running on this "
                      "screen"));
@@ -108,12 +126,28 @@ message_new (XfceSystemTray * tray, GtkWidget * icon, glong id,
     g_print ("++ notification: %s\n", text);
 }
 
+static gboolean
+systray_remove (Systray *systray)
+{
+    GtkWidget *widget = GTK_WIDGET (systray->plugin);
+
+    systray_free_data (systray->plugin, systray);
+    gtk_widget_destroy (widget);
+
+    return FALSE;
+}
+
 static void
 systray_start (Systray *systray)
 {
     if (!systray->tray_registered)
     {
         systray->tray_registered = register_tray (systray);
+        
+        if (!systray->tray_registered)
+        {
+            g_idle_add ((GSourceFunc)systray_remove, systray);
+        }
     }
 }
 
@@ -133,7 +167,8 @@ systray_stop (Systray *systray)
 
 /* Register with the panel */
 
-XFCE_PANEL_PLUGIN_REGISTER_INTERNAL (systray_construct);
+XFCE_PANEL_PLUGIN_REGISTER_INTERNAL_WITH_CHECK (systray_construct, 
+                                                systray_check);
 
 
 /* Interface Implementation */
@@ -235,12 +270,6 @@ systray_write_rc_file (XfcePanelPlugin *plugin, Systray *systray)
     xfce_rc_close (rc);
 }
 
-static void
-frame_realize (GtkWidget *frame, Systray *systray)
-{
-  systray_start (systray);
-}
-
 /* create widgets and connect to signals */
 static void 
 systray_construct (XfcePanelPlugin *plugin)
@@ -312,8 +341,7 @@ systray_construct (XfcePanelPlugin *plugin)
     g_signal_connect (systray->tray, "message_new", G_CALLBACK (message_new),
                       systray);
 
-    g_signal_connect (systray->frame, "realize", G_CALLBACK (frame_realize),
-		      systray);
+    systray_start (systray);
 }
 
 /* -------------------------------------------------------------------- *

plugins/tasklist/tasklist.c

@@ -198,19 +198,6 @@ tasklist_write_rc_file (XfcePanelPlugin *plugin, Tasklist *tasklist)
     xfce_rc_close (rc);
 }
 
-static void 
-tasklist_realize (XfcePanelPlugin *plugin, Tasklist *tasklist)
-{
-    GdkScreen *screen;
-    int screen_idx;
-
-    screen = gtk_widget_get_screen (GTK_WIDGET (plugin));
-    screen_idx = gdk_screen_get_number (screen);
-    
-    netk_tasklist_set_screen (NETK_TASKLIST (tasklist->list), 
-                              netk_screen_get (screen_idx));
-}
-
 /* create widgets and connect to signals */
 static gboolean
 handle_expose (GtkWidget *widget, GdkEventExpose *ev, Tasklist *tasklist)
@@ -251,6 +238,8 @@ tasklist_screen_changed (GtkWidget *plugin, GdkScreen *screen,
 static void 
 tasklist_construct (XfcePanelPlugin *plugin)
 {
+    GdkScreen *screen;
+    int screen_idx;
     Tasklist *tasklist = g_new0 (Tasklist, 1);
 
     tasklist->plugin = plugin;
@@ -267,9 +256,6 @@ tasklist_construct (XfcePanelPlugin *plugin)
     g_signal_connect (plugin, "save", 
                       G_CALLBACK (tasklist_write_rc_file), tasklist);
 
-    g_signal_connect (plugin, "realize",
-		      G_CALLBACK (tasklist_realize), tasklist);
-
     xfce_panel_plugin_menu_show_configure (plugin);
     g_signal_connect (plugin, "configure-plugin", 
                       G_CALLBACK (tasklist_properties_dialog), tasklist);
@@ -296,7 +282,9 @@ tasklist_construct (XfcePanelPlugin *plugin)
     g_signal_connect (tasklist->handle, "expose-event", 
                       G_CALLBACK (handle_expose), tasklist);
 
-    tasklist->list = netk_tasklist_new (netk_screen_get_default ());
+    screen = gtk_widget_get_screen (GTK_WIDGET (plugin));
+    screen_idx = gdk_screen_get_number (screen);
+    tasklist->list = netk_tasklist_new (netk_screen_get (screen_idx));
     gtk_widget_show (tasklist->list);
     gtk_box_pack_start (GTK_BOX (tasklist->box), tasklist->list, 
                         TRUE, TRUE, 0);