/*
 * Copyright (c) 1998, 2004, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.swing.colorchooser;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import javax.swing.border.*;
import java.awt.image.*;

/**
 * Implements the default HSB Color chooser
 *
 *  @author Tom Santos
 *  @author Steve Wilson
 *  @author Mark Davidson
 *  @author Shannon Hickey
 */
class DefaultHSBChooserPanel extends AbstractColorChooserPanel implements ChangeListener, HierarchyListener {

    private transient HSBImage palette;
    private transient HSBImage sliderPalette;

    private transient Image paletteImage;
    private transient Image sliderPaletteImage;

    private JSlider slider;
    private JSpinner hField;
    private JSpinner sField;
    private JSpinner bField;

    private JTextField redField;
    private JTextField greenField;
    private JTextField blueField;

    private boolean isAdjusting = false; // Flag which indicates that values are set internally
    private Point paletteSelection = new Point();
    private JLabel paletteLabel;
    private JLabel sliderPaletteLabel;

    private JRadioButton hRadio;
    private JRadioButton sRadio;
    private JRadioButton bRadio;

    private static final int PALETTE_DIMENSION = 200;
    private static final int MAX_HUE_VALUE = 359;
    private static final int MAX_SATURATION_VALUE = 100;
    private static final int MAX_BRIGHTNESS_VALUE = 100;

    private int currentMode = HUE_MODE;

    private static final int HUE_MODE = 0;
    private static final int SATURATION_MODE = 1;
    private static final int BRIGHTNESS_MODE = 2;

    public DefaultHSBChooserPanel() {
    }

    private void addPaletteListeners() {
        paletteLabel.addMouseListener(new MouseAdapter() {
            public void mousePressed(MouseEvent e ) {
                float[] hsb = new float[3];
                palette.getHSBForLocation( e.getX(), e.getY(), hsb );
                updateHSB( hsb[0], hsb[1], hsb[2] );
            }
        });

        paletteLabel.addMouseMotionListener(new MouseMotionAdapter() {
            public void mouseDragged( MouseEvent e ){
                int labelWidth = paletteLabel.getWidth();

                int labelHeight = paletteLabel.getHeight();
                int x = e.getX();
                int y = e.getY();

                if ( x >= labelWidth ) {
                    x = labelWidth - 1;
                }

                if ( y >= labelHeight ) {
                    y = labelHeight - 1;
                }

                if ( x < 0 ) {
                    x = 0;
                }

                if ( y < 0 ) {
                    y = 0;
                }

                float[] hsb = new float[3];
                palette.getHSBForLocation( x, y, hsb );
                updateHSB( hsb[0], hsb[1], hsb[2] );
            }
        });
    }

    private void updatePalette( float h, float s, float b ) {
        int x = 0;
        int y = 0;

        switch ( currentMode ) {
        case HUE_MODE:
            if ( h != palette.getHue() ) {
                palette.setHue( h );
                palette.nextFrame();
            }
            x = PALETTE_DIMENSION - (int)(s * PALETTE_DIMENSION);
            y = PALETTE_DIMENSION - (int)(b * PALETTE_DIMENSION);
            break;
        case SATURATION_MODE:
            if ( s != palette.getSaturation() ) {
                palette.setSaturation( s );
                palette.nextFrame();
            }
            x = (int)(h * PALETTE_DIMENSION);
            y = PALETTE_DIMENSION - (int)(b * PALETTE_DIMENSION);
            break;
        case BRIGHTNESS_MODE:
            if ( b != palette.getBrightness() ) {
                palette.setBrightness( b );
                palette.nextFrame();
            }
            x = (int)(h * PALETTE_DIMENSION);
            y = PALETTE_DIMENSION - (int)(s * PALETTE_DIMENSION);
            break;
        }

        paletteSelection.setLocation( x, y );
        paletteLabel.repaint();
    }

    private void updateSlider( float h, float s, float b ) {
        // Update the slider palette if necessary.
        // When the slider is the hue slider or the hue hasn't changed,
        // the hue of the palette will not need to be updated.
        if (currentMode != HUE_MODE && h != sliderPalette.getHue() ) {
            sliderPalette.setHue( h );
            sliderPalette.nextFrame();
        }

        float value = 0f;

        switch ( currentMode ) {
        case HUE_MODE:
            value = h;
            break;
        case SATURATION_MODE:
            value = s;
            break;
        case BRIGHTNESS_MODE:
            value = b;
            break;
        }

        slider.setValue( Math.round(value * (slider.getMaximum())) );
    }

    private void updateHSBTextFields( float hue, float saturation, float brightness ) {
        int h =  Math.round(hue * 359);
        int s =  Math.round(saturation * 100);
        int b =  Math.round(brightness * 100);

        if (((Integer)hField.getValue()).intValue() != h) {
            hField.setValue(new Integer(h));
        }
        if (((Integer)sField.getValue()).intValue() != s) {
            sField.setValue(new Integer(s));
        }
        if (((Integer)bField.getValue()).intValue() != b) {
            bField.setValue(new Integer(b));
        }
    }

    /**
     * Updates the values of the RGB fields to reflect the new color change
     */
    private void updateRGBTextFields( Color color ) {
        redField.setText(String.valueOf(color.getRed()));
        greenField.setText(String.valueOf(color.getGreen()));
        blueField.setText(String.valueOf(color.getBlue()));
    }

    /**
     * Main internal method of updating the ui controls and the color model.
     */
    private void updateHSB( float h, float s, float b ) {
        if ( !isAdjusting ) {
            isAdjusting = true;

            updatePalette( h, s, b );
            updateSlider( h, s, b );
            updateHSBTextFields( h, s, b );

            Color color = Color.getHSBColor(h, s, b);
            updateRGBTextFields( color );

            getColorSelectionModel().setSelectedColor( color );

            isAdjusting = false;
        }
    }

    /**
      * Invoked automatically when the model's state changes.
      * It is also called by <code>installChooserPanel</code> to allow
      * you to set up the initial state of your chooser.
      * Override this method to update your <code>ChooserPanel</code>.
      */
    public void updateChooser() {
        if ( !isAdjusting ) {
            float[] hsb = getHSBColorFromModel();
            updateHSB( hsb[0], hsb[1], hsb[2] );
        }
    }

    public void installChooserPanel(JColorChooser enclosingChooser) {
        super.installChooserPanel(enclosingChooser);
        setInheritsPopupMenu(true);
        addHierarchyListener(this);
    }

    /**
     * Invoked when the panel is removed from the chooser.
     */
    public void uninstallChooserPanel(JColorChooser enclosingChooser) {
        super.uninstallChooserPanel(enclosingChooser);
        cleanupPalettesIfNecessary();
        removeAll();
        removeHierarchyListener(this);
    }

    /**
     * Returns an float array containing the HSB values of the selected color from
     * the ColorSelectionModel
     */
    private float[] getHSBColorFromModel()  {
        Color color = getColorFromModel();
        float[] hsb = new float[3];
        Color.RGBtoHSB( color.getRed(), color.getGreen(), color.getBlue(), hsb );

        return hsb;
    }

    /**
     * Builds a new chooser panel.
     */
    protected void buildChooser() {
        setLayout(new BorderLayout());
        JComponent spp = buildSliderPalettePanel();
        spp.setInheritsPopupMenu(true);
        add(spp, BorderLayout.BEFORE_LINE_BEGINS);

        JPanel controlHolder = new JPanel(new SmartGridLayout(1,3));
        JComponent hsbControls = buildHSBControls();
        hsbControls.setInheritsPopupMenu(true);
        controlHolder.add(hsbControls);

        controlHolder.add(new JLabel(" ")); // spacer

        JComponent rgbControls = buildRGBControls();
        rgbControls.setInheritsPopupMenu(true);
        controlHolder.add(rgbControls);
        controlHolder.setInheritsPopupMenu(true);

        controlHolder.setBorder(new EmptyBorder( 10, 5, 10, 5));
        add( controlHolder, BorderLayout.CENTER);
    }

    /**
     * Creates the panel with the uneditable RGB field
     */
    private JComponent buildRGBControls() {
        JPanel panel = new JPanel(new SmartGridLayout(2,3));
        panel.setInheritsPopupMenu(true);

        Color color = getColorFromModel();
        redField = new JTextField( String.valueOf(color.getRed()), 3 );
        redField.setEditable(false);
        redField.setHorizontalAlignment( JTextField.RIGHT );
        redField.setInheritsPopupMenu(true);

        greenField = new JTextField(String.valueOf(color.getGreen()), 3 );
        greenField.setEditable(false);
        greenField.setHorizontalAlignment( JTextField.RIGHT );
        greenField.setInheritsPopupMenu(true);

        blueField = new JTextField( String.valueOf(color.getBlue()), 3 );
        blueField.setEditable(false);
        blueField.setHorizontalAlignment( JTextField.RIGHT );
        blueField.setInheritsPopupMenu(true);

        String redString = UIManager.getString("ColorChooser.hsbRedText");
        String greenString = UIManager.getString("ColorChooser.hsbGreenText");
        String blueString = UIManager.getString("ColorChooser.hsbBlueText");

        panel.add( new JLabel(redString) );
        panel.add( redField );
        panel.add( new JLabel(greenString) );
        panel.add( greenField );
        panel.add( new JLabel(blueString) );
        panel.add( blueField );

        return panel;
    }

    /**
     * Creates the panel with the editable HSB fields and the radio buttons.
     */
    private JComponent buildHSBControls() {

        String hueString = UIManager.getString("ColorChooser.hsbHueText");
        String saturationString = UIManager.getString("ColorChooser.hsbSaturationText");
        String brightnessString = UIManager.getString("ColorChooser.hsbBrightnessText");

        RadioButtonHandler handler = new RadioButtonHandler();

        hRadio = new JRadioButton(hueString);
        hRadio.addActionListener(handler);
        hRadio.setSelected(true);
        hRadio.setInheritsPopupMenu(true);

        sRadio = new JRadioButton(saturationString);
        sRadio.addActionListener(handler);
        sRadio.setInheritsPopupMenu(true);

        bRadio = new JRadioButton(brightnessString);
        bRadio.addActionListener(handler);
        bRadio.setInheritsPopupMenu(true);

        ButtonGroup group = new ButtonGroup();
        group.add(hRadio);
        group.add(sRadio);
        group.add(bRadio);

        float[] hsb = getHSBColorFromModel();

        hField = new JSpinner(new SpinnerNumberModel((int)(hsb[0] * 359), 0, 359, 1));
        sField = new JSpinner(new SpinnerNumberModel((int)(hsb[1] * 100), 0, 100, 1));
        bField = new JSpinner(new SpinnerNumberModel((int)(hsb[2] * 100), 0, 100, 1));

        hField.addChangeListener(this);
        sField.addChangeListener(this);
        bField.addChangeListener(this);

        hField.setInheritsPopupMenu(true);
        sField.setInheritsPopupMenu(true);
        bField.setInheritsPopupMenu(true);

        JPanel panel = new JPanel( new SmartGridLayout(2, 3) );

        panel.add(hRadio);
        panel.add(hField);
        panel.add(sRadio);
        panel.add(sField);
        panel.add(bRadio);
        panel.add(bField);
        panel.setInheritsPopupMenu(true);

        return panel;
    }

    /**
     * Handler for the radio button classes.
     */
    private class RadioButtonHandler implements ActionListener  {
        public void actionPerformed(ActionEvent evt)  {
            Object obj = evt.getSource();

            if (obj instanceof JRadioButton)  {
                JRadioButton button = (JRadioButton)obj;
                if (button == hRadio) {
                    setMode(HUE_MODE);
                } else if (button == sRadio) {
                    setMode(SATURATION_MODE);
                } else if (button == bRadio) {
                    setMode(BRIGHTNESS_MODE);
                }
            }
        }
    }

    private void setMode(int mode) {
        if (currentMode == mode) {
            return;
        }

        isAdjusting = true;  // Ensure no events propagate from changing slider value.
        currentMode = mode;

        float[] hsb = getHSBColorFromModel();

        switch (currentMode) {
            case HUE_MODE:
                slider.setInverted(true);
                slider.setMaximum(MAX_HUE_VALUE);
                palette.setValues(HSBImage.HSQUARE, hsb[0], 1.0f, 1.0f);
                sliderPalette.setValues(HSBImage.HSLIDER, 0f, 1.0f, 1.0f);
                break;
            case SATURATION_MODE:
                slider.setInverted(false);
                slider.setMaximum(MAX_SATURATION_VALUE);
                palette.setValues(HSBImage.SSQUARE, hsb[0], hsb[1], 1.0f);
                sliderPalette.setValues(HSBImage.SSLIDER, hsb[0], 1.0f, 1.0f);
                break;
            case BRIGHTNESS_MODE:
                slider.setInverted(false);
                slider.setMaximum(MAX_BRIGHTNESS_VALUE);
                palette.setValues(HSBImage.BSQUARE, hsb[0], 1.0f, hsb[2]);
                sliderPalette.setValues(HSBImage.BSLIDER, hsb[0], 1.0f, 1.0f);
                break;
        }

        isAdjusting = false;

        palette.nextFrame();
        sliderPalette.nextFrame();

        updateChooser();
    }

    protected JComponent buildSliderPalettePanel() {

        // This slider has to have a minimum of 0.  A lot of math in this file is simplified due to this.
        slider = new JSlider(JSlider.VERTICAL, 0, MAX_HUE_VALUE, 0);
        slider.setInverted(true);
        slider.setPaintTrack(false);
        slider.setPreferredSize(new Dimension(slider.getPreferredSize().width, PALETTE_DIMENSION + 15));
        slider.addChangeListener(this);
        slider.setInheritsPopupMenu(true);
        // We're not painting ticks, but need to ask UI classes to
        // paint arrow shape anyway, if possible.
        slider.putClientProperty("Slider.paintThumbArrowShape", Boolean.TRUE);
        paletteLabel = createPaletteLabel();
        addPaletteListeners();
        sliderPaletteLabel = new JLabel();

        JPanel panel = new JPanel();
        panel.add( paletteLabel );
        panel.add( slider );
        panel.add( sliderPaletteLabel );

        initializePalettesIfNecessary();

        return panel;
    }

    private void initializePalettesIfNecessary() {
        if (palette != null) {
            return;
        }

        float[] hsb = getHSBColorFromModel();

        switch(currentMode){
            case HUE_MODE:
                palette = new HSBImage(HSBImage.HSQUARE, PALETTE_DIMENSION, PALETTE_DIMENSION, hsb[0], 1.0f, 1.0f);
                sliderPalette = new HSBImage(HSBImage.HSLIDER, 16, PALETTE_DIMENSION, 0f, 1.0f, 1.0f);
                break;
            case SATURATION_MODE:
                palette = new HSBImage(HSBImage.SSQUARE, PALETTE_DIMENSION, PALETTE_DIMENSION, 1.0f, hsb[1], 1.0f);
                sliderPalette = new HSBImage(HSBImage.SSLIDER, 16, PALETTE_DIMENSION, 1.0f, 0f, 1.0f);
                break;
            case BRIGHTNESS_MODE:
                palette = new HSBImage(HSBImage.BSQUARE, PALETTE_DIMENSION, PALETTE_DIMENSION, 1.0f, 1.0f, hsb[2]);
                sliderPalette = new HSBImage(HSBImage.BSLIDER, 16, PALETTE_DIMENSION, 1.0f, 1.0f, 0f);
                break;
        }
        paletteImage = Toolkit.getDefaultToolkit().createImage(palette);
        sliderPaletteImage = Toolkit.getDefaultToolkit().createImage(sliderPalette);

        paletteLabel.setIcon(new ImageIcon(paletteImage));
        sliderPaletteLabel.setIcon(new ImageIcon(sliderPaletteImage));
    }

    private void cleanupPalettesIfNecessary() {
        if (palette == null) {
            return;
        }

        palette.aborted = true;
        sliderPalette.aborted = true;

        palette.nextFrame();
        sliderPalette.nextFrame();

        palette = null;
        sliderPalette = null;

        paletteImage = null;
        sliderPaletteImage = null;

        paletteLabel.setIcon(null);
        sliderPaletteLabel.setIcon(null);
    }

    protected JLabel createPaletteLabel() {
        return new JLabel() {
            protected void paintComponent( Graphics g ) {
                super.paintComponent( g );
                g.setColor( Color.white );
                g.drawOval( paletteSelection.x - 4, paletteSelection.y - 4, 8, 8 );
            }
        };
    }

    public String getDisplayName() {
        return UIManager.getString("ColorChooser.hsbNameText");
    }

    /**
     * Provides a hint to the look and feel as to the
     * <code>KeyEvent.VK</code> constant that can be used as a mnemonic to
     * access the panel. A return value <= 0 indicates there is no mnemonic.
     * <p>
     * The return value here is a hint, it is ultimately up to the look
     * and feel to honor the return value in some meaningful way.
     * <p>
     * This implementation looks up the value from the default
     * <code>ColorChooser.hsbMnemonic</code>, or if it
     * isn't available (or not an <code>Integer</code>) returns -1.
     * The lookup for the default is done through the <code>UIManager</code>:
     * <code>UIManager.get("ColorChooser.rgbMnemonic");</code>.
     *
     * @return KeyEvent.VK constant identifying the mnemonic; <= 0 for no
     *         mnemonic
     * @see #getDisplayedMnemonicIndex
     * @since 1.4
     */
    public int getMnemonic() {
        return getInt("ColorChooser.hsbMnemonic", -1);
    }

    /**
     * Provides a hint to the look and feel as to the index of the character in
     * <code>getDisplayName</code> that should be visually identified as the
     * mnemonic. The look and feel should only use this if
     * <code>getMnemonic</code> returns a value > 0.
     * <p>
     * The return value here is a hint, it is ultimately up to the look
     * and feel to honor the return value in some meaningful way. For example,
     * a look and feel may wish to render each
     * <code>AbstractColorChooserPanel</code> in a <code>JTabbedPane</code>,
     * and further use this return value to underline a character in
     * the <code>getDisplayName</code>.
     * <p>
     * This implementation looks up the value from the default
     * <code>ColorChooser.rgbDisplayedMnemonicIndex</code>, or if it
     * isn't available (or not an <code>Integer</code>) returns -1.
     * The lookup for the default is done through the <code>UIManager</code>:
     * <code>UIManager.get("ColorChooser.hsbDisplayedMnemonicIndex");</code>.
     *
     * @return Character index to render mnemonic for; -1 to provide no
     *                   visual identifier for this panel.
     * @see #getMnemonic
     * @since 1.4
     */
    public int getDisplayedMnemonicIndex() {
        return getInt("ColorChooser.hsbDisplayedMnemonicIndex", -1);
    }

    public Icon getSmallDisplayIcon() {
        return null;
    }

    public Icon getLargeDisplayIcon() {
        return null;
    }

    /**
     * Class for the slider and palette images.
     */
    class HSBImage extends SyntheticImage {
        protected float h = .0f;
        protected float s = .0f;
        protected float b = .0f;
        protected float[] hsb = new float[3];

        protected boolean isDirty = true;
        protected int cachedY;
        protected int cachedColor;
        protected int type;

        private static final int HSQUARE = 0;
        private static final int SSQUARE = 1;
        private static final int BSQUARE = 2;
        private static final int HSLIDER = 3;
        private static final int SSLIDER = 4;
        private static final int BSLIDER = 5;

        protected HSBImage(int type, int width, int height, float h, float s, float b) {
            super(width, height);
            setValues(type, h, s, b);
        }

        public void setValues(int type, float h, float s, float b) {
            this.type = type;
            cachedY = -1;
            cachedColor = 0;
            setHue( h );
            setSaturation( s );
            setBrightness( b );
        }

        public final void setHue( float hue ) {
            h = hue;
        }

        public final void setSaturation( float saturation ) {
            s = saturation;
        }

        public final void setBrightness( float brightness ) {
            b = brightness;
        }

        public final float getHue() {
            return h;
        }

        public final float getSaturation() {
            return s;
        }

        public final float getBrightness() {
            return b;
        }

        protected boolean isStatic() {
            return false;
        }

        public synchronized void nextFrame() {
            isDirty = true;
            notifyAll();
        }

        public synchronized void addConsumer(ImageConsumer ic) {
            isDirty = true;
            super.addConsumer(ic);
        }

        private int getRGBForLocation( int x, int y ) {
            if (type >= HSLIDER && y == cachedY) {
                return cachedColor;
            }

            getHSBForLocation( x, y, hsb );
            cachedY = y;
            cachedColor = Color.HSBtoRGB( hsb[0], hsb[1], hsb[2] );

            return cachedColor;
        }

        public void getHSBForLocation( int x, int y, float[] hsbArray ) {
            switch (type) {
                case HSQUARE: {
                    float saturationStep = ((float)x) / width;
                    float brightnessStep = ((float)y) / height;
                    hsbArray[0] = h;
                    hsbArray[1] = s - saturationStep;
                    hsbArray[2] = b - brightnessStep;
                    break;
                }
                case SSQUARE: {
                    float brightnessStep = ((float)y) / height;
                    float step = 1.0f / ((float)width);
                    hsbArray[0] = x * step;
                    hsbArray[1] = s;
                    hsbArray[2] = 1.0f - brightnessStep;
                    break;
                }
                case BSQUARE: {
                    float saturationStep = ((float)y) / height;
                    float step = 1.0f / ((float)width);
                    hsbArray[0] = x * step;
                    hsbArray[1] = 1.0f - saturationStep;
                    hsbArray[2] = b;
                    break;
                }
                case HSLIDER: {
                    float step = 1.0f / ((float)height);
                    hsbArray[0] = y * step;
                    hsbArray[1] = s;
                    hsbArray[2] = b;
                    break;
                }
                case SSLIDER: {
                    float saturationStep = ((float)y) / height;
                    hsbArray[0] = h;
                    hsbArray[1] = s - saturationStep;
                    hsbArray[2] = b;
                    break;
                }
                case BSLIDER: {
                    float brightnessStep = ((float)y) / height;
                    hsbArray[0] = h;
                    hsbArray[1] = s;
                    hsbArray[2] = b - brightnessStep;
                    break;
                }
            }
        }

        /**
         * Overriden method from SyntheticImage
         */
        protected void computeRow( int y, int[] row ) {
            if ( y == 0 ) {
                synchronized ( this ) {
                    try {
                        while ( !isDirty ) {
                            wait();
                        }
                    } catch (InterruptedException ie) {
                    }
                    isDirty = false;
                }
            }

            if (aborted) {
                return;
            }

            for ( int i = 0; i < row.length; ++i ) {
                row[i] = getRGBForLocation( i, y );
            }
        }
    }

    public void stateChanged(ChangeEvent e) {
        if (e.getSource() == slider) {
            boolean modelIsAdjusting = slider.getModel().getValueIsAdjusting();

            if (!modelIsAdjusting && !isAdjusting) {
                int sliderValue = slider.getValue();
                int sliderRange = slider.getMaximum();
                float value = (float)sliderValue / (float)sliderRange;

                float[] hsb = getHSBColorFromModel();

                switch ( currentMode ){
                    case HUE_MODE:
                        updateHSB(value, hsb[1], hsb[2]);
                        break;
                    case SATURATION_MODE:
                        updateHSB(hsb[0], value, hsb[2]);
                        break;
                    case BRIGHTNESS_MODE:
                        updateHSB(hsb[0], hsb[1], value);
                        break;
                }
            }
        } else if (e.getSource() instanceof JSpinner) {
            float hue = ((Integer)hField.getValue()).floatValue() / 359f;
            float saturation = ((Integer)sField.getValue()).floatValue() / 100f;
            float brightness = ((Integer)bField.getValue()).floatValue() / 100f;

            updateHSB(hue, saturation, brightness);
        }
    }

    public void hierarchyChanged(HierarchyEvent he) {
        if ((he.getChangeFlags() & HierarchyEvent.DISPLAYABILITY_CHANGED) != 0) {
            if (isDisplayable()) {
                initializePalettesIfNecessary();
            } else {
                cleanupPalettesIfNecessary();
            }
        }
    }

}
