Sets the editable state for this instance.
        
        :param      state | <bool>

def setEditable( self, state ):
        """
        Sets the editable state for this instance.
        
        :param      state | <bool>
        """
        self._editable = state
        
        if not state:
            self.setEditTriggers(QtGui.QTreeWidget.NoEditTriggers)
        else:
            triggers  = QtGui.QTreeWidget.DoubleClicked
            triggers |= QtGui.QTreeWidget.AnyKeyPressed
            triggers |= QtGui.QTreeWidget.EditKeyPressed
            triggers |= QtGui.QTreeWidget.SelectedClicked
            
            self.setEditTriggers(triggers)