/*

 * Copyright (c) 2005, 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

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 */

package java.awt;

import java.io.IOException;

import java.awt.image.*;

import java.net.URL;

import java.net.URLConnection;

import java.io.File;

import sun.util.logging.PlatformLogger;

import sun.awt.image.SunWritableRaster;

/**

 * The splash screen can be displayed at application startup, before the

 * Java Virtual Machine (JVM) starts. The splash screen is displayed as an

 * undecorated window containing an image. You can use GIF, JPEG, or PNG files

 * for the image. Animation is supported for the GIF format, while transparency

 * is supported both for GIF and PNG.  The window is positioned at the center

 * of the screen. The position on multi-monitor systems is not specified. It is

 * platform and implementation dependent.  The splash screen window is closed

 * automatically as soon as the first window is displayed by Swing/AWT (may be

 * also closed manually using the Java API, see below).

 * <P>

 * If your application is packaged in a jar file, you can use the

 * "SplashScreen-Image" option in a manifest file to show a splash screen.

 * Place the image in the jar archive and specify the path in the option.

 * The path should not have a leading slash.

 * <BR>

 * For example, in the <code>manifest.mf</code> file:

 * <PRE>

 * Manifest-Version: 1.0

 * Main-Class: Test

 * SplashScreen-Image: filename.gif

 * </PRE>

 * <P>

 * If the Java implementation provides the command-line interface and you run

 * your application by using the command line or a shortcut, use the Java

 * application launcher option to show a splash screen. The Oracle reference

 * implementation allows you to specify the splash screen image location with

 * the {@code -splash:} option.

 * <BR>

 * For example:

 * <PRE>

 * java -splash:filename.gif Test

 * </PRE>

 * The command line interface has higher precedence over the manifest

 * setting.

 * <p>

 * The splash screen will be displayed as faithfully as possible to present the

 * whole splash screen image given the limitations of the target platform and

 * display.

 * <p>

 * It is implied that the specified image is presented on the screen "as is",

 * i.e. preserving the exact color values as specified in the image file. Under

 * certain circumstances, though, the presented image may differ, e.g. when

 * applying color dithering to present a 32 bits per pixel (bpp) image on a 16

 * or 8 bpp screen. The native platform display configuration may also affect

 * the colors of the displayed image (e.g.  color profiles, etc.)

 * <p>

 * The {@code SplashScreen} class provides the API for controlling the splash

 * screen. This class may be used to close the splash screen, change the splash

 * screen image, get the splash screen native window position/size, and paint

 * in the splash screen. It cannot be used to create the splash screen. You

 * should use the options provided by the Java implementation for that.

 * <p>

 * This class cannot be instantiated. Only a single instance of this class

 * can exist, and it may be obtained by using the {@link #getSplashScreen()}

 * static method. In case the splash screen has not been created at

 * application startup via the command line or manifest file option,

 * the <code>getSplashScreen</code> method returns <code>null</code>.

 *

 * @author Oleg Semenov

 * @since 1.6

 */

public final class SplashScreen {

    SplashScreen(long ptr) { // non-public constructor

        splashPtr = ptr;

    }

    /**

     * Returns the {@code SplashScreen} object used for

     * Java startup splash screen control on systems that support display.

     *

     * @throws UnsupportedOperationException if the splash screen feature is not

     *         supported by the current toolkit

     * @throws HeadlessException if {@code GraphicsEnvironment.isHeadless()}

     *         returns true

     * @return the {@link SplashScreen} instance, or <code>null</code> if there is

     *         none or it has already been closed

     */

    public static  SplashScreen getSplashScreen() {

        synchronized (SplashScreen.class) {

            if (GraphicsEnvironment.isHeadless()) {

                throw new HeadlessException();

            }

            // SplashScreen class is now a singleton

            if (!wasClosed && theInstance == null) {

                java.security.AccessController.doPrivileged(

                    new java.security.PrivilegedAction<Void>() {

                        public Void run() {

                            System.loadLibrary("splashscreen");

                            return null;

                        }

                    });

                long ptr = _getInstance();

                if (ptr != 0 && _isVisible(ptr)) {

                    theInstance = new SplashScreen(ptr);

                }

            }

            return theInstance;

        }

    }

    /**

     * Changes the splash screen image. The new image is loaded from the

     * specified URL; GIF, JPEG and PNG image formats are supported.

     * The method returns after the image has finished loading and the window

     * has been updated.

     * The splash screen window is resized according to the size of

     * the image and is centered on the screen.

     *

     * @param imageURL the non-<code>null</code> URL for the new

     *        splash screen image

     * @throws NullPointerException if {@code imageURL} is <code>null</code>

     * @throws IOException if there was an error while loading the image

     * @throws IllegalStateException if the splash screen has already been

     *         closed

     */

    public void setImageURL(URL imageURL) throws NullPointerException, IOException, IllegalStateException {

        checkVisible();

        URLConnection connection = imageURL.openConnection();

        connection.connect();

        int length = connection.getContentLength();

        java.io.InputStream stream = connection.getInputStream();

        byte[] buf = new byte[length];

        int off = 0;

        while(true) {

            // check for available data

            int available = stream.available();

            if (available <= 0) {

                // no data available... well, let's try reading one byte

                // we'll see what happens then

                available = 1;

            }

            // check for enough room in buffer, realloc if needed

            // the buffer always grows in size 2x minimum

            if (off + available > length) {

                length = off*2;

                if (off + available > length) {

                    length = available+off;

                }

                byte[] oldBuf = buf;

                buf = new byte[length];

                System.arraycopy(oldBuf, 0, buf, 0, off);

            }

            // now read the data

            int result = stream.read(buf, off, available);

            if (result < 0) {

                break;

            }

            off += result;

        }

        synchronized(SplashScreen.class) {

            checkVisible();

            if (!_setImageData(splashPtr, buf)) {

                throw new IOException("Bad image format or i/o error when loading image");

            }

            this.imageURL = imageURL;

        }

    }

    private void checkVisible() {

        if (!isVisible()) {

            throw new IllegalStateException("no splash screen available");

        }

    }

    /**

     * Returns the current splash screen image.

     *

     * @return URL for the current splash screen image file

     * @throws IllegalStateException if the splash screen has already been closed

     */

    public URL getImageURL() throws IllegalStateException {

        synchronized (SplashScreen.class) {

            checkVisible();

            if (imageURL == null) {

                try {

                    String fileName = _getImageFileName(splashPtr);

                    String jarName = _getImageJarName(splashPtr);

                    if (fileName != null) {

                        if (jarName != null) {

                            imageURL = new URL("jar:"+(new File(jarName).toURL().toString())+"!/"+fileName);

                        } else {

                            imageURL = new File(fileName).toURL();

                        }

                    }

                }

                catch(java.net.MalformedURLException e) {

                    if (log.isLoggable(PlatformLogger.Level.FINE)) {

                        log.fine("MalformedURLException caught in the getImageURL() method", e);

                    }

                }

            }

            return imageURL;

        }

    }

    /**

     * Returns the bounds of the splash screen window as a {@link Rectangle}.

     * This may be useful if, for example, you want to replace the splash

     * screen with your window at the same location.

     * <p>

     * You cannot control the size or position of the splash screen.

     * The splash screen size is adjusted automatically when the image changes.

     * <p>

     * The image may contain transparent areas, and thus the reported bounds may

     * be larger than the visible splash screen image on the screen.

     *

     * @return a {@code Rectangle} containing the splash screen bounds

     * @throws IllegalStateException if the splash screen has already been closed

     */

    public Rectangle getBounds() throws IllegalStateException {

        synchronized (SplashScreen.class) {

            checkVisible();

            return _getBounds(splashPtr);

        }

    }

    /**

     * Returns the size of the splash screen window as a {@link Dimension}.

     * This may be useful if, for example,

     * you want to draw on the splash screen overlay surface.

     * <p>

     * You cannot control the size or position of the splash screen.

     * The splash screen size is adjusted automatically when the image changes.

     * <p>

     * The image may contain transparent areas, and thus the reported size may

     * be larger than the visible splash screen image on the screen.

     *

     * @return a {@link Dimension} object indicating the splash screen size

     * @throws IllegalStateException if the splash screen has already been closed

     */

    public Dimension getSize() throws IllegalStateException {

        return getBounds().getSize();

    }

    /**

     * Creates a graphics context (as a {@link Graphics2D} object) for the splash

     * screen overlay image, which allows you to draw over the splash screen.

     * Note that you do not draw on the main image but on the image that is

     * displayed over the main image using alpha blending. Also note that drawing

     * on the overlay image does not necessarily update the contents of splash

     * screen window. You should call {@code update()} on the

     * <code>SplashScreen</code> when you want the splash screen to be

     * updated immediately.

     * <p>

     * The pixel (0, 0) in the coordinate space of the graphics context

     * corresponds to the origin of the splash screen native window bounds (see

     * {@link #getBounds()}).

     *

     * @return graphics context for the splash screen overlay surface

     * @throws IllegalStateException if the splash screen has already been closed

     */

    public Graphics2D createGraphics() throws IllegalStateException {

        synchronized (SplashScreen.class) {

            if (image==null) {

                Dimension dim = getSize();

                image = new BufferedImage(dim.width, dim.height, BufferedImage.TYPE_INT_ARGB);

            }

            return image.createGraphics();

        }

    }

    /**

     * Updates the splash window with current contents of the overlay image.

     *

     * @throws IllegalStateException if the overlay image does not exist;

     *         for example, if {@code createGraphics} has never been called,

     *         or if the splash screen has already been closed

     */

    public void update() throws IllegalStateException {

        BufferedImage image;

        synchronized (SplashScreen.class) {

            checkVisible();

            image = this.image;

        }

        if (image == null) {

            throw new IllegalStateException("no overlay image available");

        }

        DataBuffer buf = image.getRaster().getDataBuffer();

        if (!(buf instanceof DataBufferInt)) {

            throw new AssertionError("Overlay image DataBuffer is of invalid type == "+buf.getClass().getName());

        }

        int numBanks = buf.getNumBanks();

        if (numBanks!=1) {

            throw new AssertionError("Invalid number of banks =="+numBanks+" in overlay image DataBuffer");

        }

        if (!(image.getSampleModel() instanceof SinglePixelPackedSampleModel)) {

            throw new AssertionError("Overlay image has invalid sample model == "+image.getSampleModel().getClass().getName());

        }

        SinglePixelPackedSampleModel sm = (SinglePixelPackedSampleModel)image.getSampleModel();

        int scanlineStride = sm.getScanlineStride();

        Rectangle rect = image.getRaster().getBounds();

        // Note that we steal the data array here, but just for reading

        // so we do not need to mark the DataBuffer dirty...

        int[] data = SunWritableRaster.stealData((DataBufferInt)buf, 0);

        synchronized(SplashScreen.class) {

            checkVisible();

            _update(splashPtr, data, rect.x, rect.y, rect.width, rect.height, scanlineStride);

        }

    }

    /**

     * Hides the splash screen, closes the window, and releases all associated

     * resources.

     *

     * @throws IllegalStateException if the splash screen has already been closed

     */

    public void close() throws IllegalStateException {

        synchronized (SplashScreen.class) {

            checkVisible();

            _close(splashPtr);

            image = null;

            SplashScreen.markClosed();

        }

    }

    static void markClosed() {

        synchronized (SplashScreen.class) {

            wasClosed = true;

            theInstance = null;

        }

    }

    /**

     * Determines whether the splash screen is visible. The splash screen may

     * be hidden using {@link #close()}, it is also hidden automatically when

     * the first AWT/Swing window is made visible.

     * <p>

     * Note that the native platform may delay presenting the splash screen

     * native window on the screen. The return value of {@code true} for this

     * method only guarantees that the conditions to hide the splash screen

     * window have not occurred yet.

     *

     * @return true if the splash screen is visible (has not been closed yet),

     *         false otherwise

     */

    public boolean isVisible() {

        synchronized (SplashScreen.class) {

            return !wasClosed && _isVisible(splashPtr);

        }

    }

    private BufferedImage image; // overlay image

    private final long splashPtr; // pointer to native Splash structure

    private static boolean wasClosed = false;

    private URL imageURL;

    /**

     * The instance reference for the singleton.

     * (<code>null</code> if no instance exists yet.)

     *

     * @see #getSplashScreen

     * @see #close

     */

    private static SplashScreen theInstance = null;

    private static final PlatformLogger log = PlatformLogger.getLogger("java.awt.SplashScreen");

    private native static void _update(long splashPtr, int[] data, int x, int y, int width, int height, int scanlineStride);

    private native static boolean _isVisible(long splashPtr);

    private native static Rectangle _getBounds(long splashPtr);

    private native static long _getInstance();

    private native static void _close(long splashPtr);

    private native static String _getImageFileName(long splashPtr);

    private native static String _getImageJarName(long SplashPtr);

    private native static boolean _setImageData(long SplashPtr, byte[] data);

};