Categories: S60 | Python | Code Examples | How To

From Forum Nokia Wiki

The code below shows a method that can be used to change your menu dynamically in PyS60, depending on some preconditions that may change in your application in the course of its execution:

Class Application:
 
    def UpdateMenu(self):
 
        def HasWaypoints():
            return len(self.waypoints) > 0
 
        def HasTracks():
            return len(self.tracks) > 0
 
        def HasOpenTracks():
            return len(self.opentracks) > 0
 
        def HasMaps():
            return len(self.maps) > 0
 
        def CreateMenu(items):
            menu = []
            for i in items:
                if i[0]():
                    menu.append((i[1],i[2]))
            if len(menu) > 0:
                return tuple(menu)
            else:
                return None
 
        items = [
                ( HasMaps,            u'Open Map',               self.OpenMap ),
                ( HasWaypoints,       u'Monitor Waypoint',       self.MonitorWaypoint ),
                ( HasTracks,          u'Open Track',             self.OpenTrack ),
                ( HasOpenTracks,      u'Close Track',            self.CloseTrack ),
            ]
 
        menu = [
            (u'About',                          self.About),
            ) ]
 
        dyn_menu = CreateMenu(items)
        if dyn_menu != None:
            menu.append( (u'GPS', dyn_menu) )
 
        appuifw.app.menu = menu
 
    def CloseOpenTracks():
        self.opentracks = []
        self.UpdateMenu()

Now whenever the precondition changes in the application, you can call UpdateMenu, and the menu is changed accordingly, as is demonstrated in the CloseOpenTracks method.