Exceptions - Java Software Solutions: Foundations of Program Design - page 568

LISTING 11.12 continued

playButton.addActionListener ( new ButtonListener());

current = null ;
}

//*****************************************************************
// Represents the action listener for the combo box.
//*****************************************************************
private class ComboListener implements ActionListener
{
//--------------------------------------------------------------
// Stops playing the current selection (if any) and resets
// the current selection to the one chosen.
//--------------------------------------------------------------
public void actionPerformed (ActionEvent event)
{
if (current != null )
current.stop();

current = music[musicCombo.getSelectedIndex()];
}
}

//*****************************************************************
// Represents the action listener for both control buttons.
//*****************************************************************
private class ButtonListener implements ActionListener
{
//--------------------------------------------------------------
// Stops the current selection (if any) in either case. If
// the play button was pressed, start playing it again.
//--------------------------------------------------------------
public void actionPerformed (ActionEvent event)
{
if (current != null )
current.stop();

if (event.getSource() == playButton)
if (current != null )
current.play();
}
}