Polymorphism - Java Software Solutions: Foundations of Program Design - page 530

LISTING 10.16 continued

SliderListener listener = new SliderListener();
rSlider.addChangeListener (listener);
gSlider.addChangeListener (listener);
bSlider.addChangeListener (listener);

rLabel = new JLabel ("Red: 0");
rLabel.setAlignmentX (Component.LEFT_ALIGNMENT);
gLabel = new JLabel ("Green: 0");
gLabel.setAlignmentX (Component.LEFT_ALIGNMENT);
bLabel = new JLabel ("Blue: 0");
bLabel.setAlignmentX (Component.LEFT_ALIGNMENT);

controls = new JPanel();
BoxLayout layout = new BoxLayout (controls, BoxLayout.Y_AXIS);
controls.setLayout (layout);
controls.add (rLabel);
controls.add (rSlider);
controls.add (Box.createRigidArea ( new Dimension (0, 20)));
controls.add (gLabel);
controls.add (gSlider);
controls.add (Box.createRigidArea ( new Dimension (0, 20)));
controls.add (bLabel);
controls.add (bSlider);

colorPanel = new JPanel();
colorPanel.setPreferredSize ( new Dimension (100, 100));
colorPanel.setBackground ( new Color (0, 0, 0));

add (controls);
add (colorPanel);
}

//*****************************************************************
// Represents the listener for all three sliders.
//*****************************************************************
private class SliderListener implements ChangeListener
{
private int red, green, blue;