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 * Copyright (c) 2002, 2014, 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

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package javax.swing.plaf.synth;

import javax.swing.*;

import javax.swing.text.JTextComponent;

import javax.swing.border.*;

import javax.swing.plaf.*;

import javax.swing.plaf.basic.*;

import java.beans.PropertyChangeListener;

import java.beans.PropertyChangeEvent;

import java.awt.*;

import java.awt.event.ContainerListener;

import java.awt.event.ContainerEvent;

import java.awt.event.FocusListener;

import java.awt.event.FocusEvent;

/**

 * Provides the Synth L&F UI delegate for

 * {@link javax.swing.JScrollPane}.

 *

 * @author Scott Violet

 * @since 1.7

 */

public class SynthScrollPaneUI extends BasicScrollPaneUI

                               implements PropertyChangeListener, SynthUI {

    private SynthStyle style;

    private boolean viewportViewHasFocus = false;

    private ViewportViewFocusHandler viewportViewFocusHandler;

    /**

     * Creates a new UI object for the given component.

     *

     * @param x component to create UI object for

     * @return the UI object

     */

    public static ComponentUI createUI(JComponent x) {

        return new SynthScrollPaneUI();

    }

    /**

     * 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().paintScrollPaneBackground(context,

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

        paint(context, g);

    }

    /**

     * 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);

    }

    /**

     * Paints the specified component.

     *

     * @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) {

        Border vpBorder = scrollpane.getViewportBorder();

        if (vpBorder != null) {

            Rectangle r = scrollpane.getViewportBorderBounds();

            vpBorder.paintBorder(scrollpane, g, r.x, r.y, r.width, r.height);

        }

    }

    /**

     * {@inheritDoc}

     */

    @Override

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

                            int y, int w, int h) {

        context.getPainter().paintScrollPaneBorder(context, g, x, y, w, h);

    }

    /**

     * {@inheritDoc}

     */

    @Override

    protected void installDefaults(JScrollPane scrollpane) {

        updateStyle(scrollpane);

    }

    private void updateStyle(JScrollPane c) {

        SynthContext context = getContext(c, ENABLED);

        SynthStyle oldStyle = style;

        style = SynthLookAndFeel.updateStyle(context, this);

        if (style != oldStyle) {

            Border vpBorder = scrollpane.getViewportBorder();

            if ((vpBorder == null) ||( vpBorder instanceof UIResource)) {

                scrollpane.setViewportBorder(new ViewportBorder(context));

            }

            if (oldStyle != null) {

                uninstallKeyboardActions(c);

                installKeyboardActions(c);

            }

        }

    }

    /**

     * {@inheritDoc}

     */

    @Override

    protected void installListeners(JScrollPane c) {

        super.installListeners(c);

        c.addPropertyChangeListener(this);

        if (UIManager.getBoolean("ScrollPane.useChildTextComponentFocus")){

            viewportViewFocusHandler = new ViewportViewFocusHandler();

            c.getViewport().addContainerListener(viewportViewFocusHandler);

            Component view = c.getViewport().getView();

            if (view instanceof JTextComponent) {

                view.addFocusListener(viewportViewFocusHandler);

            }

        }

    }

    /**

     * {@inheritDoc}

     */

    @Override

    protected void uninstallDefaults(JScrollPane c) {

        SynthContext context = getContext(c, ENABLED);

        style.uninstallDefaults(context);

        if (scrollpane.getViewportBorder() instanceof UIResource) {

            scrollpane.setViewportBorder(null);

        }

    }

    /**

     * {@inheritDoc}

     */

    @Override

    protected void uninstallListeners(JComponent c) {

        super.uninstallListeners(c);

        c.removePropertyChangeListener(this);

        if (viewportViewFocusHandler != null) {

            JViewport viewport = ((JScrollPane) c).getViewport();

            viewport.removeContainerListener(viewportViewFocusHandler);

            if (viewport.getView()!= null) {

                viewport.getView().removeFocusListener(viewportViewFocusHandler);

            }

            viewportViewFocusHandler = null;

        }

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public SynthContext getContext(JComponent c) {

        return getContext(c, getComponentState(c));

    }

    private SynthContext getContext(JComponent c, int state) {

        return SynthContext.getContext(c, style, state);

    }

    private int getComponentState(JComponent c) {

        int baseState = SynthLookAndFeel.getComponentState(c);

        if (viewportViewFocusHandler!=null && viewportViewHasFocus){

            baseState = baseState | FOCUSED;

        }

        return baseState;

    }

    public void propertyChange(PropertyChangeEvent e) {

        if (SynthLookAndFeel.shouldUpdateStyle(e)) {

            updateStyle(scrollpane);

        }

    }

    @SuppressWarnings("serial") // Superclass is not serializable across versions

    private class ViewportBorder extends AbstractBorder implements UIResource {

        private Insets insets;

        ViewportBorder(SynthContext context) {

            this.insets = (Insets)context.getStyle().get(context,

                                            "ScrollPane.viewportBorderInsets");

            if (this.insets == null) {

                this.insets = SynthLookAndFeel.EMPTY_UIRESOURCE_INSETS;

            }

        }

        @Override

        public void paintBorder(Component c, Graphics g, int x, int y,

                            int width, int height) {

            JComponent jc = (JComponent)c;

            SynthContext context = getContext(jc);

            SynthStyle style = context.getStyle();

            if (style == null) {

                assert false: "SynthBorder is being used outside after the " +

                              " UI has been uninstalled";

                return;

            }

            context.getPainter().paintViewportBorder(context, g, x, y, width,

                                                     height);

        }

        @Override

        public Insets getBorderInsets(Component c, Insets insets) {

            if (insets == null) {

                return new Insets(this.insets.top, this.insets.left,

                                  this.insets.bottom, this.insets.right);

            }

            insets.top = this.insets.top;

            insets.bottom = this.insets.bottom;

            insets.left = this.insets.left;

            insets.right = this.insets.left;

            return insets;

        }

        @Override

        public boolean isBorderOpaque() {

            return false;

        }

    }

    /**

     * Handle keeping track of the viewport's view's focus

     */

    private class ViewportViewFocusHandler implements ContainerListener,

            FocusListener{

        public void componentAdded(ContainerEvent e) {

            if (e.getChild() instanceof JTextComponent) {

                e.getChild().addFocusListener(this);

                viewportViewHasFocus = e.getChild().isFocusOwner();

                scrollpane.repaint();

            }

        }

        public void componentRemoved(ContainerEvent e) {

            if (e.getChild() instanceof JTextComponent) {

                e.getChild().removeFocusListener(this);

            }

        }

        public void focusGained(FocusEvent e) {

            viewportViewHasFocus = true;

            scrollpane.repaint();

        }

        public void focusLost(FocusEvent e) {

            viewportViewHasFocus = false;

            scrollpane.repaint();

        }

    }

}