/*

 * Copyright (c) 2013, 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 sun.swing;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.Component;

import java.awt.Container;

import java.awt.EventQueue;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.Rectangle;

import java.awt.image.BufferedImage;

import java.awt.image.DataBufferInt;

import java.security.AccessController;

import javax.swing.JLayeredPane;

import javax.swing.JPanel;

import javax.swing.JRootPane;

import javax.swing.LayoutFocusTraversalPolicy;

import javax.swing.RootPaneContainer;

import sun.awt.LightweightFrame;

import sun.security.action.GetPropertyAction;

/**

 * The frame serves as a lightweight container which paints its content

 * to an offscreen image and provides access to the image's data via the

 * {@link LightweightContent} interface. Note, that it may not be shown

 * as a standalone toplevel frame. Its purpose is to provide functionality

 * for lightweight embedding.

 *

 * @author Artem Ananiev

 * @author Anton Tarasov

 */

public final class JLightweightFrame extends LightweightFrame implements RootPaneContainer {

    private final JRootPane rootPane = new JRootPane();

    private LightweightContent content;

    private Component component;

    private JPanel contentPane;

    private BufferedImage bbImage;

    /**

     * {@code copyBufferEnabled}, true by default, defines the following strategy.

     * A duplicating (copy) buffer is created for the original pixel buffer.

     * The copy buffer is synchronized with the original buffer every time the

     * latter changes. {@code JLightweightFrame} passes the copy buffer array

     * to the {@link LightweightContent#imageBufferReset} method. The code spot

     * which synchronizes two buffers becomes the only critical section guarded

     * by the lock (managed with the {@link LightweightContent#paintLock()},

     * {@link LightweightContent#paintUnlock()} methods).

     */

    private boolean copyBufferEnabled;

    private int[] copyBuffer;

    /**

     * Constructs a new, initially invisible {@code JLightweightFrame}

     * instance.

     */

    public JLightweightFrame() {

        super();

        copyBufferEnabled = "true".equals(AccessController.

            doPrivileged(new GetPropertyAction("jlf.copyBufferEnabled", "true")));

        add(rootPane, BorderLayout.CENTER);

        setFocusTraversalPolicy(new LayoutFocusTraversalPolicy());

        if (getGraphicsConfiguration().isTranslucencyCapable()) {

            setBackground(new Color(0, 0, 0, 0));

        }

    }

    /**

     * Sets the {@link LightweightContent} instance for this frame.

     * The {@code JComponent} object returned by the

     * {@link LightweightContent#getComponent()} method is immediately

     * added to the frame's content pane.

     *

     * @param content the {@link LightweightContent} instance

     */

        this.content = content;

        this.component = content.getComponent();

        initInterior();

    }

    @Override

    public Graphics getGraphics() {

        if (bbImage == null) return null;

        Graphics2D g = bbImage.createGraphics();

        g.setBackground(getBackground());

        g.setColor(getForeground());

        g.setFont(getFont());

        return g;

    }

    /**

     * {@inheritDoc}

     *

     * @see LightweightContent#focusGrabbed()

     */

    @Override

    public void grabFocus() {

        if (content != null) content.focusGrabbed();

    }

    /**

     * {@inheritDoc}

     *

     * @see LightweightContent#focusUngrabbed()

     */

    @Override

    public void ungrabFocus() {

        if (content != null) content.focusUngrabbed();

    }

    private void syncCopyBuffer(boolean reset, int x, int y, int w, int h) {

        content.paintLock();

        try {

            int[] srcBuffer = ((DataBufferInt)bbImage.getRaster().getDataBuffer()).getData();

            if (reset) {

                copyBuffer = new int[srcBuffer.length];

            }

            int linestride = bbImage.getWidth();

            for (int i=0; i<h; i++) {

                int from = (y + i) * linestride + x;

                System.arraycopy(srcBuffer, from, copyBuffer, from, w);

            }

        } finally {

            content.paintUnlock();

        }

    }

    private void initInterior() {

        contentPane = new JPanel() {

            @Override

            public void paint(Graphics g) {

                if (!copyBufferEnabled) {

                    content.paintLock();

                }

                try {

                    super.paint(g);

                    final Rectangle clip = g.getClipBounds() != null ?

                            g.getClipBounds() :

                            new Rectangle(0, 0, contentPane.getWidth(), contentPane.getHeight());

                    clip.x = Math.max(0, clip.x);

                    clip.y = Math.max(0, clip.y);

                    clip.width = Math.min(contentPane.getWidth(), clip.width);

                    clip.height = Math.min(contentPane.getHeight(), clip.height);

                    EventQueue.invokeLater(new Runnable() {

                        @Override

                        public void run() {

                            if (copyBufferEnabled) {

                                syncCopyBuffer(false, clip.x, clip.y, clip.width, clip.height);

                            }

                            content.imageUpdated(clip.x, clip.y, clip.width, clip.height);

                        }

                    });

                } finally {

                    if (!copyBufferEnabled) {

                        content.paintUnlock();

                    }

                }

            }

            @Override

            protected boolean isPaintingOrigin() {

                return true;

            }

        };

        contentPane.setLayout(new BorderLayout());

        contentPane.add(component);

        setContentPane(contentPane);

    }

    @SuppressWarnings("deprecation")

    @Override public void reshape(int x, int y, int width, int height) {

        super.reshape(x, y, width, height);

        if (width == 0 || height == 0) {

            return;

        }

        if (!copyBufferEnabled) {

            content.paintLock();

        }

        try {

            if ((bbImage == null) || (width != bbImage.getWidth()) || (height != bbImage.getHeight())) {

                boolean createBB = true;

                int newW = width;

                int newH = height;

                if (bbImage != null) {

                    int oldW = bbImage.getWidth();

                    int oldH = bbImage.getHeight();

                    if ((oldW >= newW) && (oldH >= newH)) {

                        createBB = false;

                    } else {

                        if (oldW >= newW) {

                            newW = oldW;

                        } else {

                            newW = Math.max((int)(oldW * 1.2), width);

                        }

                        if (oldH >= newH) {

                            newH = oldH;

                        } else {

                            newH = Math.max((int)(oldH * 1.2), height);

                        }

                    }

                }

                if (createBB) {

                    BufferedImage oldBB = bbImage;

                    bbImage = new BufferedImage(newW, newH, BufferedImage.TYPE_INT_ARGB_PRE);

                    if (oldBB != null) {

                        Graphics g = bbImage.getGraphics();

                        try {

                            g.drawImage(oldBB, 0, 0, newW, newH, null);

                        } finally {

                            g.dispose();

                            oldBB.flush();

                        }

                    }

                    int[] pixels = ((DataBufferInt)bbImage.getRaster().getDataBuffer()).getData();

                    if (copyBufferEnabled) {

                        syncCopyBuffer(true, 0, 0, width, height);

                        pixels = copyBuffer;

                    }

                    content.imageBufferReset(pixels, 0, 0, width, height, bbImage.getWidth());

                    return;

                }

            }

            content.imageReshaped(0, 0, width, height);

        } finally {

            if (!copyBufferEnabled) {

                content.paintUnlock();

            }

        }

    }

    @Override

    public JRootPane getRootPane() {

        return rootPane;

    }

    @Override

    public void setContentPane(Container contentPane) {

        getRootPane().setContentPane(contentPane);

    }

    @Override

    public Container getContentPane() {

        return getRootPane().getContentPane();

    }

    @Override

    public void setLayeredPane(JLayeredPane layeredPane) {

        getRootPane().setLayeredPane(layeredPane);

    }

    @Override

    public JLayeredPane getLayeredPane() {

        return getRootPane().getLayeredPane();

    }

    @Override

    public void setGlassPane(Component glassPane) {

        getRootPane().setGlassPane(glassPane);

    }

    @Override

    public Component getGlassPane() {

        return getRootPane().getGlassPane();

    }

}