How to get the Color pane from JColorChooser and use it in my own window?

Question

I am new to Java and Java swing.

I need to extract only the color pane and get the color from that pane in my own window.

Basically, I want to remove other unnecessary components in the default ColorPanel. I am successful in removing the other panels and sliders. But not further.

JColorChooser

Answer 1

It's difficult and requires some AWT/Swing hacks (like Robot class), but possible. I would not advise you to use this code, but if it's required...

import java.awt.AWTException;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.Robot;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import java.util.function.Predicate;

import javax.swing.JColorChooser;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;

/**
 * <code>ChooserTryout</code>.
 */
public class ChooserTryout {

    public static void main(String[] args) {
        try {
            Robot robot = new Robot();
            SwingUtilities.invokeLater(() -> new ChooserTryout().startUI(robot));
        } catch (AWTException e) {
            e.printStackTrace();
        }
    }

    public void startUI(Robot robot) {
        JFrame frm = new JFrame("Color test");
        JColorChooser chooser = new JColorChooser();
        JLabel label = new JLabel("Here is your actual color");
        label.setOpaque(true);
        List<JComponent> comps =
                getAllChildrenOfClass(chooser, JComponent.class, c -> c.getClass().getName().contains("DiagramComponent"));
        JComponent c = comps.get(3);
        c.setPreferredSize(new Dimension(300, 300));
        c.addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                Point p = c.getLocationOnScreen();
                p.translate(e.getX(), e.getY());
                Color color = robot.getPixelColor(p.x, p.y);
                System.out.println("You've clicked color: " + color);
                label.setForeground(color);
            };
        });
        frm.add(c);
        frm.add(label, BorderLayout.SOUTH);
        frm.pack();
        frm.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frm.setLocationRelativeTo(null);
        frm.setVisible(true);
    }

    /**
     * Searches for all children of the given component which are instances of the given class and satisfies the given condition.
     *
     * @param aRoot start object for search. May not be null.
     * @param aClass class to search. May not be null.
     * @param condition condition to be satisfied. May not be null.
     * @param <E> class of component.
     * @return list of all children of the given component which are instances of the given class. Never null.
     */
    public static <E> List<E> getAllChildrenOfClass(Container aRoot, Class<E> aClass, Predicate<E> condition) {
        final List<E> result = new ArrayList<>();
        final Component[] children = aRoot.getComponents();
        for (final Component c : children) {
            if (aClass.isInstance(c) && condition.test(aClass.cast(c))) {
                result.add(aClass.cast(c));
            }
            if (c instanceof Container) {
                result.addAll(getAllChildrenOfClass((Container) c, aClass, condition));
            }
        }
        return result;
    }

}