RGBAColourChooser.java Source code

Introduction

Here is the source code for RGBAColourChooser.java

Source

//package com.ryanm.util.swing;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.util.LinkedList;
import java.util.List;

import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

/**
 * A widget to manipulate an RGBA colour.
 * 
 * @author ryanm
 */
public class RGBAColourChooser extends Box implements ChangeListener {
    private JLabel redLabel = new JLabel("R");

    private JSlider redSlider = new JSlider(0, 255);

    private JLabel greenLabel = new JLabel("G");

    private JSlider greenSlider = new JSlider(0, 255);

    private JLabel blueLabel = new JLabel("B");

    private JSlider blueSlider = new JSlider(0, 255);

    private JLabel alphaLabel = new JLabel("A");

    private JSlider alphaSlider = new JSlider(0, 255);

    private Box sliderBox;

    private Color oldValue = Color.WHITE;

    private List<ChangeListener> listeners = new LinkedList<ChangeListener>();

    private JPanel previewer = new JPanel() {
        @Override
        public void paint(Graphics g) {
            int width = getWidth();
            int height = getHeight();

            g.setColor(Color.white);
            g.fillRect(0, 0, width, height);

            g.setColor(Color.black);
            g.fillRect(0, height / 2, width / 2, height / 2);
            g.fillRect(width / 2, 0, width / 2, height / 2);

            g.setColor(oldValue);
            g.fillRect(width / 4, height / 4, width / 2, height / 2);
        }

        @Override
        public Dimension getPreferredSize() {
            int size = sliderBox.getHeight();

            size = size == 0 ? 64 : size;

            return new Dimension(size, size);
        }

        @Override
        public Dimension getMaximumSize() {
            return getPreferredSize();
        }
    };

    /**
     * Constructs a new RGBAColourChooser
     */
    public RGBAColourChooser() {
        super(BoxLayout.X_AXIS);

        Box rb = new Box(BoxLayout.X_AXIS);
        rb.add(redLabel);
        rb.add(redSlider);
        Box gb = new Box(BoxLayout.X_AXIS);
        gb.add(greenLabel);
        gb.add(greenSlider);
        Box bb = new Box(BoxLayout.X_AXIS);
        bb.add(blueLabel);
        bb.add(blueSlider);
        Box ab = new Box(BoxLayout.X_AXIS);
        ab.add(alphaLabel);
        ab.add(alphaSlider);

        redSlider.setValue(oldValue.getRed());
        greenSlider.setValue(oldValue.getGreen());
        blueSlider.setValue(oldValue.getBlue());
        alphaSlider.setValue(oldValue.getAlpha());

        redSlider.addChangeListener(this);
        greenSlider.addChangeListener(this);
        blueSlider.addChangeListener(this);
        alphaSlider.addChangeListener(this);

        redSlider.setToolTipText(String.valueOf(redSlider.getValue()));
        greenSlider.setToolTipText(String.valueOf(greenSlider.getValue()));
        blueSlider.setToolTipText(String.valueOf(blueSlider.getValue()));
        alphaSlider.setToolTipText(String.valueOf(alphaSlider.getValue()));

        sliderBox = new Box(BoxLayout.Y_AXIS);
        sliderBox.add(rb);
        sliderBox.add(gb);
        sliderBox.add(bb);
        sliderBox.add(ab);

        add(previewer);
        add(Box.createHorizontalStrut(5));
        add(sliderBox);

    }

    /**
     * Sets the widget's selected colour
     * 
     * @param color
     *           The new colour
     */
    public void setColour(Color color) {
        if (!oldValue.equals(color)) {
            // copy the values
            oldValue = color;

            redSlider.removeChangeListener(this);
            greenSlider.removeChangeListener(this);
            blueSlider.removeChangeListener(this);
            alphaSlider.removeChangeListener(this);

            redSlider.setValue(oldValue.getRed());
            greenSlider.setValue(oldValue.getGreen());
            blueSlider.setValue(oldValue.getBlue());
            alphaSlider.setValue(oldValue.getAlpha());

            redSlider.setToolTipText(String.valueOf(redSlider.getValue()));
            greenSlider.setToolTipText(String.valueOf(greenSlider.getValue()));
            blueSlider.setToolTipText(String.valueOf(blueSlider.getValue()));
            alphaSlider.setToolTipText(String.valueOf(alphaSlider.getValue()));

            redSlider.addChangeListener(this);
            greenSlider.addChangeListener(this);
            blueSlider.addChangeListener(this);
            alphaSlider.addChangeListener(this);

            previewer.repaint();

            ChangeEvent ce = new ChangeEvent(this);
            for (ChangeListener listener : listeners) {
                listener.stateChanged(ce);
            }
        }
    }

    /**
     * Gets the widget's currently selected colour
     * 
     * @return The current colour
     */
    public Color getColour() {
        return oldValue;
    }

    @Override
    public void stateChanged(ChangeEvent e) {
        int red = redSlider.getValue();
        int green = greenSlider.getValue();
        int blue = blueSlider.getValue();
        int alpha = alphaSlider.getValue();

        setColour(new Color(red, green, blue, alpha));
    }

    @Override
    public void setEnabled(boolean b) {
        alphaLabel.setEnabled(b);
        alphaSlider.setEnabled(b);
        blueLabel.setEnabled(b);
        blueSlider.setEnabled(b);
        greenLabel.setEnabled(b);
        greenSlider.setEnabled(b);
        redLabel.setEnabled(b);
        redSlider.setEnabled(b);
    }

    @Override
    public boolean isEnabled() {
        return alphaSlider.isEnabled();
    }

    /**
     * Adds a change listener to this widget. The ChangeListener will
     * be appraised of any changes to the selected colour
     * 
     * @param listener
     *           The listener to add
     */
    public void addChangeListener(ChangeListener listener) {
        listeners.add(listener);
    }

    /**
     * Removes a ChangeListener from this widget. The ChangeListener
     * will no longer be appraised of changes to the selected colour
     * 
     * @param listener
     *           The listener to remove
     */
    public void removeChangeListener(ChangeListener listener) {
        listeners.remove(listener);
    }
}