#NEWLINE# def addListener( self , listener , iface = None ) : #NEWLINE# #INDENT# 'Adds a color change listener\n\n        @param listener:\n                   The color change listener\n        ' #NEWLINE# if ( isinstance ( listener , IColorChangeListener ) and ( ( iface is None ) or issubclass ( iface , IColorChangeListener ) ) ) : #NEWLINE# #INDENT# self . registerListener ( ColorChangeEvent , listener , _COLOR_CHANGE_METHOD ) #NEWLINE# #UNINDENT# super ( ColorPickerHistory , self ) . addListener ( listener , listener )