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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package sun.swing;

import sun.awt.image.SurfaceManager;
import sun.java2d.SurfaceData;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.Image;
import java.awt.geom.AffineTransform;
import java.awt.image.AbstractMultiResolutionImage;
import java.awt.image.BufferedImage;
import java.awt.image.ImageObserver;
import java.awt.image.VolatileImage;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

A base class used for icons or images that are expensive to paint.
A subclass will do the following:

Invoke paint when you want to paint the image,
    if you are implementing Icon you'll invoke this from
    paintIcon.
    The args argument is useful when additional state is needed.
Override paintToImage to render the image.  The code that
    lives here is equivalent to what previously would go in
    paintIcon, for an Icon.

The two ways to use this class are:

Invoke paint to draw the cached reprensentation at
    the specified location.
Invoke getImage to get the cached reprensentation and
    draw the image yourself.  This is primarly useful when you are not
    using VolatileImage.

/**
 * A base class used for icons or images that are expensive to paint.
 * A subclass will do the following:
 * <ol>
 * <li>Invoke <code>paint</code> when you want to paint the image,
 *     if you are implementing <code>Icon</code> you'll invoke this from
 *     <code>paintIcon</code>.
 *     The args argument is useful when additional state is needed.
 * <li>Override <code>paintToImage</code> to render the image.  The code that
 *     lives here is equivalent to what previously would go in
 *     <code>paintIcon</code>, for an <code>Icon</code>.
 * </ol>
 * The two ways to use this class are:
 * <ol>
 * <li>Invoke <code>paint</code> to draw the cached reprensentation at
 *     the specified location.
 * <li>Invoke <code>getImage</code> to get the cached reprensentation and
 *     draw the image yourself.  This is primarly useful when you are not
 *     using <code>VolatileImage</code>.
 * </ol>
 *
 *
 */
public abstract class CachedPainter {
    // CacheMap maps from class to ImageCache.
    private static final Map<Object,ImageCache> cacheMap = new HashMap<>();

    private static ImageCache getCache(Object key) {
        synchronized(CachedPainter.class) {
            ImageCache cache = cacheMap.get(key);
            if (cache == null) {
                if (key == PainterMultiResolutionCachedImage.class) {
                    cache = new ImageCache(32);
                } else {
                    cache = new ImageCache(1);
                }
                cacheMap.put(key, cache);
            }
            return cache;
        }
    }

    
Creates an instance of CachedPainter that will cache up
to cacheCount images of this class.
Params:
cacheCount – Max number of images to cache/**
     * Creates an instance of <code>CachedPainter</code> that will cache up
     * to <code>cacheCount</code> images of this class.
     *
     * @param cacheCount Max number of images to cache
     */
    public CachedPainter(int cacheCount) {
        getCache(getClass()).setMaxCount(cacheCount);
    }

    
Renders the cached image to the passed in Graphic.
If there is no cached image paintToImage will be invoked.
paintImage is invoked to paint the cached image.
Params:
c – Component rendering to, this may be null.
g – Graphics to paint to
x – X-coordinate to render to
y – Y-coordinate to render to
w – Width to render in
h – Height to render in
args – Variable arguments that will be passed to paintToImage/**
     * Renders the cached image to the passed in <code>Graphic</code>.
     * If there is no cached image <code>paintToImage</code> will be invoked.
     * <code>paintImage</code> is invoked to paint the cached image.
     *
     * @param c Component rendering to, this may be null.
     * @param g Graphics to paint to
     * @param x X-coordinate to render to
     * @param y Y-coordinate to render to
     * @param w Width to render in
     * @param h Height to render in
     * @param args Variable arguments that will be passed to paintToImage
     */
    public void paint(Component c, Graphics g, int x,
                         int y, int w, int h, Object... args) {
        if (w <= 0 || h <= 0) {
            return;
        }
        synchronized (CachedPainter.class) {
            paint0(c, g, x, y, w, h, args);
        }
    }

    private Image getImage(Object key, Component c,
                           int baseWidth, int baseHeight,
                           int w, int h, Object... args) {
        GraphicsConfiguration config = getGraphicsConfiguration(c);
        ImageCache cache = getCache(key);
        Image image = cache.getImage(key, config, w, h, args);
        int attempts = 0;
        VolatileImage volatileImage = (image instanceof VolatileImage)
                ? (VolatileImage) image
                : null;
        do {
            boolean draw = false;
            if (volatileImage != null) {
                // See if we need to recreate the image
                switch (volatileImage.validate(config)) {
                case VolatileImage.IMAGE_INCOMPATIBLE:
                    volatileImage.flush();
                    image = null;
                    break;
                case VolatileImage.IMAGE_RESTORED:
                    draw = true;
                    break;
                }
            }
            if (image == null) {
                // Recreate the image
                if( config != null && (w != baseHeight || h != baseWidth)) {
                    AffineTransform tx = config.getDefaultTransform();
                    double sx = tx.getScaleX();
                    double sy = tx.getScaleY();
                    if ( Double.compare(sx, 1) != 0 ||
                                                   Double.compare(sy, 1) != 0) {
                        if (Math.abs(sx * baseWidth - w) < 1 &&
                            Math.abs(sy * baseHeight - h) < 1) {
                            w = baseWidth;
                            h = baseHeight;
                        } else {
                            w = (int)Math.ceil(w / sx);
                            h = (int)Math.ceil(w / sy);
                        }
                    }
                }
                image = createImage(c, w, h, config, args);
                cache.setImage(key, config, w, h, args, image);
                draw = true;
                volatileImage = (image instanceof VolatileImage)
                        ? (VolatileImage) image
                        : null;
            }
            if (draw) {
                // Render to the Image
                Graphics2D g2 = (Graphics2D) image.getGraphics();
                if (volatileImage == null) {
                    if ((w != baseWidth || h != baseHeight)) {
                        g2.scale((double) w / baseWidth,
                                (double) h / baseHeight);
                    }
                    paintToImage(c, image, g2, baseWidth, baseHeight, args);
                } else {
                    SurfaceData sd = SurfaceManager.getManager(volatileImage)
                            .getPrimarySurfaceData();
                    double sx = sd.getDefaultScaleX();
                    double sy = sd.getDefaultScaleY();
                    if ( Double.compare(sx, 1) != 0 ||
                                                   Double.compare(sy, 1) != 0) {
                        g2.scale(1 / sx, 1 / sy);
                    }
                    paintToImage(c, image, g2, (int)Math.ceil(w * sx),
                                               (int)Math.ceil(h * sy), args);
                }
                g2.dispose();
            }

            // If we did this 3 times and the contents are still lost
            // assume we're painting to a VolatileImage that is bogus and
            // give up.  Presumably we'll be called again to paint.
        } while ((volatileImage != null) &&
                 volatileImage.contentsLost() && ++attempts < 3);

        return image;
    }

    private void paint0(Component c, Graphics g, int x,
                        int y, int w, int h, Object... args) {
        Object key = getClass();
        GraphicsConfiguration config = getGraphicsConfiguration(c);
        ImageCache cache = getCache(key);
        Image image = cache.getImage(key, config, w, h, args);

        if (image == null) {
            image = new PainterMultiResolutionCachedImage(w, h);
            cache.setImage(key, config, w, h, args, image);
        }

        if (image instanceof PainterMultiResolutionCachedImage) {
            ((PainterMultiResolutionCachedImage) image).setParams(c, args);
        }

        // Render to the passed in Graphics
        paintImage(c, g, x, y, w, h, image, args);
    }

    
Paints the representation to cache to the supplied Graphics.
Params:
c – Component painting to, may be null.
image – Image to paint to
g – Graphics to paint to, obtained from the passed in Image.
w – Width to paint to
h – Height to paint to
args – Arguments supplied to paint/**
     * Paints the representation to cache to the supplied Graphics.
     *
     * @param c Component painting to, may be null.
     * @param image Image to paint to
     * @param g Graphics to paint to, obtained from the passed in Image.
     * @param w Width to paint to
     * @param h Height to paint to
     * @param args Arguments supplied to <code>paint</code>
     */
    protected abstract void paintToImage(Component c, Image image, Graphics g,
                                         int w, int h, Object[] args);


    
Paints the image to the specified location.
Params:
c – Component painting to
g – Graphics to paint to
x – X coordinate to paint to
y – Y coordinate to paint to
w – Width to paint to
h – Height to paint to
image – Image to paint
args – Arguments supplied to paint/**
     * Paints the image to the specified location.
     *
     * @param c Component painting to
     * @param g Graphics to paint to
     * @param x X coordinate to paint to
     * @param y Y coordinate to paint to
     * @param w Width to paint to
     * @param h Height to paint to
     * @param image Image to paint
     * @param args Arguments supplied to <code>paint</code>
     */
    protected void paintImage(Component c, Graphics g,
                              int x, int y, int w, int h, Image image,
                              Object[] args) {
        g.drawImage(image, x, y, null);
    }

    
Creates the image to cache.  This returns an opaque image, subclasses
that require translucency or transparency will need to override this
method.
Params:
c – Component painting to
w – Width of image to create
h – Height to image to create
config – GraphicsConfiguration that will be
       rendered to, this may be null.
args – Arguments passed to paint/**
     * Creates the image to cache.  This returns an opaque image, subclasses
     * that require translucency or transparency will need to override this
     * method.
     *
     * @param c Component painting to
     * @param w Width of image to create
     * @param h Height to image to create
     * @param config GraphicsConfiguration that will be
     *        rendered to, this may be null.
     * @param args Arguments passed to paint
     */
    protected Image createImage(Component c, int w, int h,
                                GraphicsConfiguration config, Object[] args) {
        if (config == null) {
            return new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        }
        return config.createCompatibleVolatileImage(w, h);
    }

    
Clear the image cache
/**
     * Clear the image cache
     */
    protected void flush() {
        synchronized(CachedPainter.class) {
            getCache(getClass()).flush();
        }
    }

    private GraphicsConfiguration getGraphicsConfiguration(Component c) {
        if (c == null) {
            return null;
        }
        return c.getGraphicsConfiguration();
    }

    class PainterMultiResolutionCachedImage extends AbstractMultiResolutionImage {

        private final int baseWidth;
        private final int baseHeight;
        private Component c;
        private Object[] args;

        public PainterMultiResolutionCachedImage(int baseWidth, int baseHeight) {
            this.baseWidth = baseWidth;
            this.baseHeight = baseHeight;
        }

        public void setParams(Component c, Object[] args) {
            this.c = c;
            this.args = args;
        }

        @Override
        public int getWidth(ImageObserver observer) {
            return baseWidth;
        }

        @Override
        public int getHeight(ImageObserver observer) {
            return baseHeight;
        }

        @Override
        public Image getResolutionVariant(double destWidth, double destHeight) {
            int w = (int) Math.ceil(destWidth);
            int h = (int) Math.ceil(destHeight);
            return getImage(PainterMultiResolutionCachedImage.class,
                    c, baseWidth, baseHeight, w, h, args);
        }

        @Override
        protected Image getBaseImage() {
            return getResolutionVariant(baseWidth, baseHeight);
        }

        @Override
        public java.util.List<Image> getResolutionVariants() {
            return Arrays.asList(getResolutionVariant(baseWidth, baseHeight));
        }
    }
}