Add a hook 'on_show_prefs' for plugins to setup their pref options prior

to the preferences dialog showing

deluge/ui/gtkui/pluginmanager.py

@@ -46,7 +46,8 @@ class PluginManager(deluge.pluginmanagerbase.PluginManagerBase,
             self, "gtkui.conf", "deluge.plugin.gtkui")
 
         self.hooks = {
-            "on_apply_prefs": []
+            "on_apply_prefs": [],
+            "on_show_prefs": []
         }
 
     def register_hook(self, hook, function):
@@ -80,6 +81,14 @@ class PluginManager(deluge.pluginmanagerbase.PluginManagerBase,
         self.enable_plugins()
 
     ## Hook functions
+    def run_on_show_prefs(self):
+        """This hook is run before the user is shown the preferences dialog.
+        It is designed so that plugins can update their preference page with
+        the config."""
+        log.debug("run_on_show_prefs")
+        for function in self.hooks["on_show_prefs"]:
+            function()
+            
     def run_on_apply_prefs(self):
         """This hook is run after the user clicks Apply or OK in the preferences
         dialog.

deluge/ui/gtkui/preferences.py

@@ -411,6 +411,7 @@ class Preferences(component.Component):
             self.plugin_liststore.set_value(row, 0, plugin)
             self.plugin_liststore.set_value(row, 1, enabled)
         
+        component.get("PluginManager").run_on_show_prefs()
         # Now show the dialog
         self.pref_dialog.show()