I need ToolWindow to trigger show/hide events

I need to get componentShown and componentHidden event

for some reason it doesn't work. It only works actually the first time it is created.

this.toolWindow.getComponent().addComponentListener ( new ComponentAdapter ()
{
    public void componentShown ( ComponentEvent e )
    {
        System.out.println ( "Component shown" );
    }

    public void componentHidden ( ComponentEvent e )
    {
        System.out.println ( "Component hidden" );
    }
} );