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 * 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

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package javax.swing.plaf.synth;

import java.beans.*;

import javax.swing.*;

import javax.swing.plaf.*;

import java.awt.*;

/**

 * Provides the Synth L&F UI delegate for

 * {@link javax.swing.JViewport}.

 *

 * @since 1.7

 */

public class SynthViewportUI extends ViewportUI

                             implements PropertyChangeListener, SynthUI {

    private SynthStyle style;

    /**

     * Creates a new UI object for the given component.

     *

     * @param c component to create UI object for

     * @return the UI object

     */

    public static ComponentUI createUI(JComponent c) {

        return new SynthViewportUI();

    }

    /**

     * @inheritDoc

     */

    @Override

    public void installUI(JComponent c) {

        super.installUI(c);

        installDefaults(c);

        installListeners(c);

    }

    /**

     * @inheritDoc

     */

    @Override

    public void uninstallUI(JComponent c) {

        super.uninstallUI(c);

        uninstallListeners(c);

        uninstallDefaults(c);

    }

    /**

     * Installs defaults for a viewport.

     *

     * @param c a {@code JViewport} object

     */

    protected void installDefaults(JComponent c) {

        updateStyle(c);

    }

    private void updateStyle(JComponent c) {

        SynthContext context = getContext(c, ENABLED);

        // Note: JViewport is special cased as it does not allow for

        // a border to be set. JViewport.setBorder is overriden to throw

        // an IllegalArgumentException. Refer to SynthScrollPaneUI for

        // details of this.

        SynthStyle newStyle = SynthLookAndFeel.getStyle(context.getComponent(),

                                                        context.getRegion());

        SynthStyle oldStyle = context.getStyle();

        if (newStyle != oldStyle) {

            if (oldStyle != null) {

                oldStyle.uninstallDefaults(context);

            }

            context.setStyle(newStyle);

            newStyle.installDefaults(context);

        }

        this.style = newStyle;

        context.dispose();

    }

    /**

     * Installs listeners into the viewport.

     *

     * @param c a {@code JViewport} object

     */

    protected void installListeners(JComponent c) {

        c.addPropertyChangeListener(this);

    }

    /**

     * Uninstalls listeners from the viewport.

     *

     * @param c a {@code JViewport} object

     */

    protected void uninstallListeners(JComponent c) {

        c.removePropertyChangeListener(this);

    }

    /**

     * Uninstalls defaults from a viewport.

     *

     * @param c a {@code JViewport} object

     */

    protected void uninstallDefaults(JComponent c) {

        SynthContext context = getContext(c, ENABLED);

        style.uninstallDefaults(context);

        context.dispose();

        style = null;

    }

    /**

     * @inheritDoc

     */

    @Override

    public SynthContext getContext(JComponent c) {

        return getContext(c, SynthLookAndFeel.getComponentState(c));

    }

    private SynthContext getContext(JComponent c, int state) {

        return SynthContext.getContext(SynthContext.class, c,

                                       getRegion(c), style, state);

    }

    private Region getRegion(JComponent c) {

        return SynthLookAndFeel.getRegion(c);

    }

    /**

     * Notifies this UI delegate to repaint the specified component.

     * This method paints the component background, then calls

     * the {@link #paint(SynthContext,Graphics)} method.

     *

     * <p>In general, this method does not need to be overridden by subclasses.

     * All Look and Feel rendering code should reside in the {@code paint} method.

     *

     * @param g the {@code Graphics} object used for painting

     * @param c the component being painted

     * @see #paint(SynthContext,Graphics)

     */

    @Override

    public void update(Graphics g, JComponent c) {

        SynthContext context = getContext(c);

        SynthLookAndFeel.update(context, g);

        context.getPainter().paintViewportBackground(context,

                          g, 0, 0, c.getWidth(), c.getHeight());

        paint(context, g);

        context.dispose();

    }

    /**

     * Paints the border. The method is never called,

     * because the {@code JViewport} class does not support a border.

     * This implementation does nothing.

     *

     * @param context a component context

     * @param g the {@code Graphics} to paint on

     * @param x the X coordinate

     * @param y the Y coordinate

     * @param w width of the border

     * @param h height of the border

     */

    @Override

    public void paintBorder(SynthContext context, Graphics g, int x,

                            int y, int w, int h) {

    }

    /**

     * Paints the specified component according to the Look and Feel.

     * <p>This method is not used by Synth Look and Feel.

     * Painting is handled by the {@link #paint(SynthContext,Graphics)} method.

     *

     * @param g the {@code Graphics} object used for painting

     * @param c the component being painted

     * @see #paint(SynthContext,Graphics)

     */

    @Override

    public void paint(Graphics g, JComponent c) {

        SynthContext context = getContext(c);

        paint(context, g);

        context.dispose();

    }

    /**

     * Paints the specified component. This implementation does nothing.

     *

     * @param context context for the component being painted

     * @param g the {@code Graphics} object used for painting

     * @see #update(Graphics,JComponent)

     */

    protected void paint(SynthContext context, Graphics g) {

    }

    /**

     * @inheritDoc

     */

    @Override

    public void propertyChange(PropertyChangeEvent e) {

        if (SynthLookAndFeel.shouldUpdateStyle(e)) {

            updateStyle((JComponent)e.getSource());

        }

    }

}