called on apply

def on_apply(self, event):
        '''called on apply'''
        for label in self.setting_map.keys():
            setting = self.setting_map[label]
            ctrl = self.controls[label]
            value = ctrl.GetValue()
            if str(value) != str(setting.value):
                oldvalue = setting.value
                if not setting.set(value):
                    print("Invalid value %s for %s" % (value, setting.name))
                    continue
                if str(oldvalue) != str(setting.value):
                    self.parent_pipe.send(setting)