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diff --git a/trunk/dimbola/gtkapp.py b/trunk/dimbola/gtkapp.py
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+# Copyright (C) 2009  Lars Wirzenius <liw@liw.fi>
+# 
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+'''Helper class for writing PyGTK applications.'''
+
+
+import gobject
+import gtk
+
+
+class GtkApplication(object):
+
+    '''Base class for GTK+ applications.
+    
+    This class provides some convenience functions for GTK+ applications.
+    It makes some assumptions to simplify things:
+    
+    * The UI will be made with Glade and described with a .ui file, 
+      using GtkBuilder.
+    * A dictionary of all widgets is created as the widgets attribute.
+      It is indexed by the name of the widget, as defined in the .ui file.
+    * Callbacks will be named on_widgetname_signalname. They will be connected
+      automatically if this naming convention is followed.
+    * Methods named widgetname_is_sensitive control the sensitivity of
+      widgets that need to become sensitive or not based on the state of
+      the program.
+    * signal callbacks and *_is_sensitive are methods of "controllers",
+      which are provided to setup_widgets as an argument, and which it
+      stores into the controllers attribute.
+    
+    '''
+
+    def setup_widgets(self, glade_filename, controllers):
+        '''Find all widgets and connect them to signal handlers.
+        
+        The list of controllers will be stored in the controllers 
+        attribute.
+        
+        '''
+
+        self.controllers = controllers
+
+        if not hasattr(self, 'widgets'):
+            self.widgets = {}
+        builder = gtk.Builder()
+        if builder.add_from_file(glade_filename) == 0:
+            raise Exception('GtkBuilder.add_from_file failed for %s' % 
+                            glade_filename)
+        for widget in builder.get_objects():
+            if isinstance(widget, gtk.Widget):
+                self.setup_a_widget(widget)
+
+    def setup_a_widget(self, widget):
+        name = widget.get_property('name')
+        self.widgets[name] = widget
+        for controller in self.controllers:
+            for attr in dir(controller):
+                prefix = 'on_%s_' % name
+                if attr.startswith(prefix):
+                    signal_name = attr[len(prefix):]
+                    method = getattr(controller, attr)
+                    widget.connect(signal_name, method)
+
+    def set_sensitive(self):
+        '''Set all widgets to be sensitive or not.
+        
+        The sensitivity of each widget is tested with a method called
+        widgetname_is_sensitive. The method must be in one of the controllers
+        given to setup_widgets.
+        
+        You should call this whenever one of the conditions for sensitivity
+        changes.
+        
+        '''
+        
+        suffix = '_is_sensitive'
+        for controller in self.controllers:
+            for attrname in dir(controller):
+                if attrname.endswith(suffix):
+                    widgetname = attrname[:-len(suffix)]
+                    if widgetname in self.widgets:
+                        widget = self.widgets[widgetname]
+                        method = getattr(controller, attrname)
+                        widget.set_sensitive(bool(method()))
+