File	Doc	Category	Size	Date	Package
GrayScalePanel.java	API Doc	Example	2636	Thu Oct 24 20:14:24 BST 2002	None

GrayScalePanel

• java.lang.Object
  • java.awt.Component
    • java.awt.Container
      • javax.swing.JComponent
        • javax.swing.JPanel
          • javax.swing.colorchooser.AbstractColorChooserPanel

Fields Summary
JSlider	scale
JTextField	percentField
static Color[]	grays

Constructors Summary

public GrayScalePanel() for (int i=0; i<256; i++) { grays[i] = new Color(i, i, i); } setLayout(new GridLayout(0, 1)); // create the slider and attach us as a listener scale = new JSlider(JSlider.HORIZONTAL, 0, 255, 128); scale.addChangeListener(this); // Set up our display for the chooser add(new JLabel("Pick your shade of gray:", JLabel.CENTER)); JPanel jp = new JPanel(); jp.add(new JLabel("Black")); jp.add(scale); jp.add(new JLabel("White")); add(jp); JPanel jp2 = new JPanel(); percentField = new JTextField(3); percentField.setHorizontalAlignment(SwingConstants.RIGHT); percentField.addActionListener(this); jp2.add(percentField); jp2.add(new JLabel("%")); add(jp2);

Methods Summary
public void	actionPerformed(java.awt.event.ActionEvent ae) int val = 100 - Integer.parseInt(ae.getActionCommand()); getColorSelectionModel().setSelectedColor(grays[(int)(val * 2.55)]);
protected void	buildChooser()
public java.lang.String	getDisplayName() return "Gray Scale";
public javax.swing.Icon	getLargeDisplayIcon() return null;
public javax.swing.Icon	getSmallDisplayIcon() return null;
public void	stateChanged(javax.swing.event.ChangeEvent ce) getColorSelectionModel().setSelectedColor(grays[scale.getValue()]); percentField.setText("" + (100-(int)Math.round(scale.getValue() / 2.55)));
protected int	toGray(java.awt.Color c) int r = c.getRed(); int g = c.getGreen(); int b = c.getBlue(); // Grab the luminance the same way GIMP does... return (int)Math.round(0.3 * r + 0.59 * g + 0.11 * b );
public void	updateChooser() Color c = getColorSelectionModel().getSelectedColor(); scale.setValue(toGray(c));