/*

 * Copyright (c) 2013, 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 sun.awt.image;

import java.awt.Image;

import java.awt.image.ImageObserver;

import java.awt.image.MultiResolutionImage;

import java.util.Arrays;

import java.util.List;

public class MultiResolutionToolkitImage extends ToolkitImage implements MultiResolutionImage {

    Image resolutionVariant;

    public MultiResolutionToolkitImage(Image lowResolutionImage, Image resolutionVariant) {

        super(lowResolutionImage.getSource());

        this.resolutionVariant = resolutionVariant;

    }

    @Override

    public Image getResolutionVariant(double destWidth, double destHeight) {

        checkSize(destWidth, destHeight);

        return ((destWidth <= getWidth() && destHeight <= getHeight()))

                ? this : resolutionVariant;

    }

    private static void checkSize(double width, double height) {

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

            throw new IllegalArgumentException(String.format(

                    "Width (%s) or height (%s) cannot be <= 0", width, height));

        }

        if (!Double.isFinite(width) || !Double.isFinite(height)) {

            throw new IllegalArgumentException(String.format(

                    "Width (%s) or height (%s) is not finite", width, height));

        }

    }

    public Image getResolutionVariant() {

        return resolutionVariant;

    }

    @Override

    public List<Image> getResolutionVariants() {

        return Arrays.<Image>asList(this, resolutionVariant);

    }

    private static final int BITS_INFO = ImageObserver.SOMEBITS

            | ImageObserver.FRAMEBITS | ImageObserver.ALLBITS;

    private static class ObserverCache {

        @SuppressWarnings("deprecation")

        static final SoftCache INSTANCE = new SoftCache();

    }

    public static ImageObserver getResolutionVariantObserver(

            final Image image, final ImageObserver observer,

            final int imgWidth, final int imgHeight,

            final int rvWidth, final int rvHeight) {

        return getResolutionVariantObserver(image, observer,

                imgWidth, imgHeight, rvWidth, rvHeight, false);

    }

    public static ImageObserver getResolutionVariantObserver(

            final Image image, final ImageObserver observer,

            final int imgWidth, final int imgHeight,

            final int rvWidth, final int rvHeight, boolean concatenateInfo) {

        if (observer == null) {

            return null;

        }

        synchronized (ObserverCache.INSTANCE) {

            ImageObserver o = (ImageObserver) ObserverCache.INSTANCE.get(observer);

            if (o == null) {

                o = (Image resolutionVariant, int flags,

                        int x, int y, int width, int height) -> {

                            if ((flags & (ImageObserver.WIDTH | BITS_INFO)) != 0) {

                                width = (width + 1) / 2;

                            }

                            if ((flags & (ImageObserver.HEIGHT | BITS_INFO)) != 0) {

                                height = (height + 1) / 2;

                            }

                            if ((flags & BITS_INFO) != 0) {

                                x /= 2;

                                y /= 2;

                            }

                            if(concatenateInfo){

                                flags &= ((ToolkitImage) image).

                                        getImageRep().check(null);

                            }

                            return observer.imageUpdate(

                                    image, flags, x, y, width, height);

                        };

                ObserverCache.INSTANCE.put(observer, o);

            }

            return o;

        }

    }

}