ColorPicker3.java Source code

Introduction

Here is the source code for ColorPicker3.java

Source

/*
Java Swing, 2nd Edition
By Marc Loy, Robert Eckstein, Dave Wood, James Elliott, Brian Cole
ISBN: 0-596-00408-7
Publisher: O'Reilly 
*/
// ColorPicker3.java
//A quick test of the JColorChooser dialog. This example adds a custom
//preview pane.
//

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Icon;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import javax.swing.colorchooser.AbstractColorChooserPanel;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class ColorPicker3 extends JFrame {

    Color c;

    public ColorPicker3() {
        super("JColorChooser Test Frame");
        setSize(200, 100);
        final JButton go = new JButton("Show JColorChoser");
        final Container contentPane = getContentPane();
        go.addActionListener(new ActionListener() {
            final JColorChooser chooser = new JColorChooser();

            boolean first = true;

            public void actionPerformed(ActionEvent e) {
                if (first) {
                    first = false;
                    GrayScalePanel gsp = new GrayScalePanel();
                    chooser.addChooserPanel(gsp);
                    chooser.setPreviewPanel(new CustomPane());
                }
                JDialog dialog = JColorChooser.createDialog(ColorPicker3.this, "Demo 3", true, chooser,
                        new ActionListener() {
                            public void actionPerformed(ActionEvent e) {
                                c = chooser.getColor();
                            }
                        }, null);
                dialog.setVisible(true);
                contentPane.setBackground(c);
            }
        });
        contentPane.add(go, BorderLayout.SOUTH);
        // addWindowListener(new BasicWindowMonitor()); // 1.1 & 1.2
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    public class CustomPane extends JPanel {
        JLabel j1 = new JLabel("This is a custom preview pane", JLabel.CENTER);

        JLabel j2 = new JLabel("This label previews the background", JLabel.CENTER);

        public CustomPane() {
            super(new GridLayout(0, 1));
            j2.setOpaque(true);
            add(j1);
            add(j2);
        }

        public void setForeground(Color c) {
            super.setForeground(c);
            if (j1 != null) {
                j1.setForeground(c);
                j2.setBackground(c);
            }
        }
    }

    public static void main(String args[]) {
        ColorPicker3 cp3 = new ColorPicker3();
        cp3.setVisible(true);
    }
}

//GrayScalePanel.java
//A simple implementation of the AbstractColorChooserPanel class. This class
//provides a slider and a textfield for picking out a shade of gray.
//

class GrayScalePanel extends AbstractColorChooserPanel implements ChangeListener, ActionListener {

    JSlider scale;

    JTextField percentField;

    // Set up our list of grays. We'll assume we have all 256 possible shades,
    // and we'll do it when the class is loaded.
    static Color[] grays = new Color[256];
    static {
        for (int i = 0; i < 256; i++) {
            grays[i] = new Color(i, i, i);
        }
    }

    public GrayScalePanel() {
        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);
    }

    // We did this work in the constructor so we can skip it here.
    protected void buildChooser() {
    }

    // Make sure the slider is in sync with the other panels.
    public void updateChooser() {
        Color c = getColorSelectionModel().getSelectedColor();
        scale.setValue(toGray(c));
    }

    protected int toGray(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);
    }

    // Pick a name for our tab in the chooser
    public String getDisplayName() {
        return "Gray Scale";
    }

    // No need for an icon.
    public Icon getSmallDisplayIcon() {
        return null;
    }

    public Icon getLargeDisplayIcon() {
        return null;
    }

    // And lastly, update the selection model as our slider changes.
    public void stateChanged(ChangeEvent ce) {
        getColorSelectionModel().setSelectedColor(grays[scale.getValue()]);
        percentField.setText("" + (100 - (int) Math.round(scale.getValue() / 2.55)));
    }

    public void actionPerformed(ActionEvent ae) {
        int val = 100 - Integer.parseInt(ae.getActionCommand());
        getColorSelectionModel().setSelectedColor(grays[(int) (val * 2.55)]);
    }
}