android/graphics/Bitmap_Delegate.java

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.graphics;

import com.android.ide.common.rendering.api.LayoutLog;
import com.android.ide.common.rendering.api.ResourceDensity;
import com.android.layoutlib.bridge.Bridge;
import com.android.layoutlib.bridge.impl.DelegateManager;

import android.graphics.Bitmap.Config;
import android.os.Parcel;

import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.Buffer;
import java.util.Arrays;

import javax.imageio.ImageIO;

/**
 * Delegate implementing the native methods of android.graphics.Bitmap
 *
 * Through the layoutlib_create tool, the original native methods of Bitmap have been replaced
 * by calls to methods of the same name in this delegate class.
 *
 * This class behaves like the original native implementation, but in Java, keeping previously
 * native data into its own objects and mapping them to int that are sent back and forth between
 * it and the original Bitmap class.
 *
 * @see DelegateManager
 *
 */
public final class Bitmap_Delegate {

    // ---- delegate manager ----
    private static final DelegateManager<Bitmap_Delegate> sManager =
            new DelegateManager<Bitmap_Delegate>();

    // ---- delegate helper data ----

    // ---- delegate data ----
    private final Config mConfig;
    private BufferedImage mImage;
    private boolean mHasAlpha = true;
    private int mGenerationId = 0;


    // ---- Public Helper methods ----

    /**
     * Returns the native delegate associated to a given {@link Bitmap_Delegate} object.
     */
    public static Bitmap_Delegate getDelegate(Bitmap bitmap) {
        return sManager.getDelegate(bitmap.mNativeBitmap);
    }

    /**
     * Returns the native delegate associated to a given an int referencing a {@link Bitmap} object.
     */
    public static Bitmap_Delegate getDelegate(int native_bitmap) {
        return sManager.getDelegate(native_bitmap);
    }

    /**
     * Creates and returns a {@link Bitmap} initialized with the given file content.
     *
     * @param input the file from which to read the bitmap content
     * @param isMutable whether the bitmap is mutable
     * @param density the density associated with the bitmap
     *
     * @see Bitmap#isMutable()
     * @see Bitmap#getDensity()
     */
    public static Bitmap createBitmap(File input, boolean isMutable, ResourceDensity density)
            throws IOException {
        // create a delegate with the content of the file.
        Bitmap_Delegate delegate = new Bitmap_Delegate(ImageIO.read(input), Config.ARGB_8888);

        return createBitmap(delegate, isMutable, density.getDpi());
    }

    /**
     * Creates and returns a {@link Bitmap} initialized with the given stream content.
     *
     * @param input the stream from which to read the bitmap content
     * @param isMutable whether the bitmap is mutable
     * @param density the density associated with the bitmap
     *
     * @see Bitmap#isMutable()
     * @see Bitmap#getDensity()
     */
    public static Bitmap createBitmap(InputStream input, boolean isMutable, ResourceDensity density)
            throws IOException {
        // create a delegate with the content of the stream.
        Bitmap_Delegate delegate = new Bitmap_Delegate(ImageIO.read(input), Config.ARGB_8888);

        return createBitmap(delegate, isMutable, density.getDpi());
    }

    /**
     * Creates and returns a {@link Bitmap} initialized with the given {@link BufferedImage}
     *
     * @param image the bitmap content
     * @param isMutable whether the bitmap is mutable
     * @param density the density associated with the bitmap
     *
     * @see Bitmap#isMutable()
     * @see Bitmap#getDensity()
     */
    public static Bitmap createBitmap(BufferedImage image, boolean isMutable,
            ResourceDensity density) throws IOException {
        // create a delegate with the given image.
        Bitmap_Delegate delegate = new Bitmap_Delegate(image, Config.ARGB_8888);

        return createBitmap(delegate, isMutable, density.getDpi());
    }

    /**
     * Returns the {@link BufferedImage} used by the delegate of the given {@link Bitmap}.
     */
    public static BufferedImage getImage(Bitmap bitmap) {
        // get the delegate from the native int.
        Bitmap_Delegate delegate = sManager.getDelegate(bitmap.mNativeBitmap);
        if (delegate == null) {
            return null;
        }

        return delegate.mImage;
    }

    public static int getBufferedImageType(int nativeBitmapConfig) {
        switch (Config.sConfigs[nativeBitmapConfig]) {
            case ALPHA_8:
                return BufferedImage.TYPE_INT_ARGB;
            case RGB_565:
                return BufferedImage.TYPE_INT_ARGB;
            case ARGB_4444:
                return BufferedImage.TYPE_INT_ARGB;
            case ARGB_8888:
                return BufferedImage.TYPE_INT_ARGB;
        }

        return BufferedImage.TYPE_INT_ARGB;
    }

    /**
     * Returns the {@link BufferedImage} used by the delegate of the given {@link Bitmap}.
     */
    public BufferedImage getImage() {
        return mImage;
    }

    /**
     * Returns the Android bitmap config. Note that this not the config of the underlying
     * Java2D bitmap.
     */
    public Config getConfig() {
        return mConfig;
    }

    /**
     * Returns the hasAlpha rendering hint
     * @return true if the bitmap alpha should be used at render time
     */
    public boolean hasAlpha() {
        return mHasAlpha && mConfig != Config.RGB_565;
    }

    /**
     * Update the generationId.
     *
     * @see Bitmap#getGenerationId()
     */
    public void change() {
        mGenerationId++;
    }

    // ---- native methods ----

    /*package*/ static Bitmap nativeCreate(int[] colors, int offset, int stride, int width,
            int height, int nativeConfig, boolean mutable) {
        int imageType = getBufferedImageType(nativeConfig);

        // create the image
        BufferedImage image = new BufferedImage(width, height, imageType);

        if (colors != null) {
            image.setRGB(0, 0, width, height, colors, offset, stride);
        }

        // create a delegate with the content of the stream.
        Bitmap_Delegate delegate = new Bitmap_Delegate(image, Config.sConfigs[nativeConfig]);

        return createBitmap(delegate, mutable, Bitmap.getDefaultDensity());
    }

    /*package*/ static Bitmap nativeCopy(int srcBitmap, int nativeConfig, boolean isMutable) {
        Bitmap_Delegate srcBmpDelegate = sManager.getDelegate(srcBitmap);
        if (srcBmpDelegate == null) {
            return null;
        }

        BufferedImage srcImage = srcBmpDelegate.getImage();

        int width = srcImage.getWidth();
        int height = srcImage.getHeight();

        int imageType = getBufferedImageType(nativeConfig);

        // create the image
        BufferedImage image = new BufferedImage(width, height, imageType);

        // copy the source image into the image.
        int[] argb = new int[width * height];
        srcImage.getRGB(0, 0, width, height, argb, 0, width);
        image.setRGB(0, 0, width, height, argb, 0, width);

        // create a delegate with the content of the stream.
        Bitmap_Delegate delegate = new Bitmap_Delegate(image, Config.sConfigs[nativeConfig]);

        return createBitmap(delegate, isMutable, Bitmap.getDefaultDensity());
    }

    /*package*/ static void nativeDestructor(int nativeBitmap) {
        sManager.removeDelegate(nativeBitmap);
    }

    /*package*/ static void nativeRecycle(int nativeBitmap) {
        sManager.removeDelegate(nativeBitmap);
    }

    /*package*/ static boolean nativeCompress(int nativeBitmap, int format, int quality,
            OutputStream stream, byte[] tempStorage) {
        Bridge.getLog().error(LayoutLog.TAG_UNSUPPORTED,
                "Bitmap.compress() is not supported");
        return true;
    }

    /*package*/ static void nativeErase(int nativeBitmap, int color) {
        // get the delegate from the native int.
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return;
        }

        BufferedImage image = delegate.mImage;

        Graphics2D g = image.createGraphics();
        try {
            g.setColor(new java.awt.Color(color, true));

            g.fillRect(0, 0, image.getWidth(), image.getHeight());
        } finally {
            g.dispose();
        }
    }

    /*package*/ static int nativeWidth(int nativeBitmap) {
        // get the delegate from the native int.
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return 0;
        }

        return delegate.mImage.getWidth();
    }

    /*package*/ static int nativeHeight(int nativeBitmap) {
        // get the delegate from the native int.
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return 0;
        }

        return delegate.mImage.getHeight();
    }

    /*package*/ static int nativeRowBytes(int nativeBitmap) {
        // get the delegate from the native int.
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return 0;
        }

        return delegate.mImage.getWidth();
    }

    /*package*/ static int nativeConfig(int nativeBitmap) {
        // get the delegate from the native int.
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return 0;
        }

        return delegate.mConfig.nativeInt;
    }

    /*package*/ static boolean nativeHasAlpha(int nativeBitmap) {
        // get the delegate from the native int.
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return true;
        }

        return delegate.mHasAlpha;
    }

    /*package*/ static int nativeGetPixel(int nativeBitmap, int x, int y) {
        // get the delegate from the native int.
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return 0;
        }

        return delegate.mImage.getRGB(x, y);
    }

    /*package*/ static void nativeGetPixels(int nativeBitmap, int[] pixels, int offset,
            int stride, int x, int y, int width, int height) {
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return;
        }

        delegate.getImage().getRGB(x, y, width, height, pixels, offset, stride);
    }


    /*package*/ static void nativeSetPixel(int nativeBitmap, int x, int y, int color) {
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return;
        }

        delegate.getImage().setRGB(x, y, color);
    }

    /*package*/ static void nativeSetPixels(int nativeBitmap, int[] colors, int offset,
            int stride, int x, int y, int width, int height) {
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return;
        }

        delegate.getImage().setRGB(x, y, width, height, colors, offset, stride);
    }

    /*package*/ static void nativeCopyPixelsToBuffer(int nativeBitmap, Buffer dst) {
        // FIXME implement native delegate
        throw new UnsupportedOperationException("Native delegate needed for Bitmap.nativeCopyPixelsToBuffer");
    }

    /*package*/ static void nativeCopyPixelsFromBuffer(int nb, Buffer src) {
        // FIXME implement native delegate
        throw new UnsupportedOperationException("Native delegate needed for Bitmap.nativeCopyPixelsFromBuffer");
    }

    /*package*/ static int nativeGenerationId(int nativeBitmap) {
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return 0;
        }

        return delegate.mGenerationId;
    }

    /*package*/ static Bitmap nativeCreateFromParcel(Parcel p) {
        // This is only called by Bitmap.CREATOR (Parcelable.Creator<Bitmap>), which is only
        // used during aidl call so really this should not be called.
        Bridge.getLog().error(LayoutLog.TAG_UNSUPPORTED,
                "AIDL is not suppored, and therefore Bitmaps cannot be created from parcels.");
        return null;
    }

    /*package*/ static boolean nativeWriteToParcel(int nativeBitmap, boolean isMutable,
            int density, Parcel p) {
        // This is only called when sending a bitmap through aidl, so really this should not
        // be called.
        Bridge.getLog().error(LayoutLog.TAG_UNSUPPORTED,
                "AIDL is not suppored, and therefore Bitmaps cannot be written to parcels.");
        return false;
    }

    /*package*/ static Bitmap nativeExtractAlpha(int nativeBitmap, int nativePaint,
            int[] offsetXY) {
        Bitmap_Delegate bitmap = sManager.getDelegate(nativeBitmap);
        if (bitmap == null) {
            return null;
        }

        // get the paint which can be null if nativePaint is 0.
        Paint_Delegate paint = Paint_Delegate.getDelegate(nativePaint);

        if (paint != null && paint.getMaskFilter() != null) {
            Bridge.getLog().fidelityWarning(LayoutLog.TAG_MASKFILTER,
                    "MaskFilter not supported in Bitmap.extractAlpha",
                    null);
        }

        int alpha = paint != null ? paint.getAlpha() : 0xFF;
        BufferedImage image = createCopy(bitmap.getImage(), BufferedImage.TYPE_INT_ARGB, alpha);

        // create the delegate. The actual Bitmap config is only an alpha channel
        Bitmap_Delegate delegate = new Bitmap_Delegate(image, Config.ALPHA_8);

        // the density doesn't matter, it's set by the Java method.
        return createBitmap(delegate, false /*isMutable*/,
                ResourceDensity.DEFAULT_DENSITY /*density*/);
    }

    /*package*/ static void nativePrepareToDraw(int nativeBitmap) {
        // nothing to be done here.
    }

    /*package*/ static void nativeSetHasAlpha(int nativeBitmap, boolean hasAlpha) {
        // get the delegate from the native int.
        Bitmap_Delegate delegate = sManager.getDelegate(nativeBitmap);
        if (delegate == null) {
            return;
        }

        delegate.mHasAlpha = hasAlpha;
    }

    /*package*/ static boolean nativeSameAs(int nb0, int nb1) {
        Bitmap_Delegate delegate1 = sManager.getDelegate(nb0);
        if (delegate1 == null) {
            return false;
        }

        Bitmap_Delegate delegate2 = sManager.getDelegate(nb1);
        if (delegate2 == null) {
            return false;
        }

        BufferedImage image1 = delegate1.getImage();
        BufferedImage image2 = delegate2.getImage();
        if (delegate1.mConfig != delegate2.mConfig ||
                image1.getWidth() != image2.getWidth() ||
                image1.getHeight() != image2.getHeight()) {
            return false;
        }

        // get the internal data
        int w = image1.getWidth();
        int h = image2.getHeight();
        int[] argb1 = new int[w*h];
        int[] argb2 = new int[w*h];

        image1.getRGB(0, 0, w, h, argb1, 0, w);
        image2.getRGB(0, 0, w, h, argb2, 0, w);

        // compares
        if (delegate1.mConfig == Config.ALPHA_8) {
            // in this case we have to manually compare the alpha channel as the rest is garbage.
            final int length = w*h;
            for (int i = 0 ; i < length ; i++) {
                if ((argb1[i] & 0xFF000000) != (argb2[i] & 0xFF000000)) {
                    return false;
                }
            }
            return true;
        }

        return Arrays.equals(argb1, argb2);
    }

    // ---- Private delegate/helper methods ----

    private Bitmap_Delegate(BufferedImage image, Config config) {
        mImage = image;
        mConfig = config;
    }

    private static Bitmap createBitmap(Bitmap_Delegate delegate, boolean isMutable, int density) {
        // get its native_int
        int nativeInt = sManager.addDelegate(delegate);

        // and create/return a new Bitmap with it
        return new Bitmap(nativeInt, null /* buffer */, isMutable, null /*ninePatchChunk*/, density);
    }

    /**
     * Creates and returns a copy of a given BufferedImage.
     * <p/>
     * if alpha is different than 255, then it is applied to the alpha channel of each pixel.
     *
     * @param image the image to copy
     * @param imageType the type of the new image
     * @param alpha an optional alpha modifier
     * @return a new BufferedImage
     */
    /*package*/ static BufferedImage createCopy(BufferedImage image, int imageType, int alpha) {
        int w = image.getWidth();
        int h = image.getHeight();

        BufferedImage result = new BufferedImage(w, h, imageType);

        int[] argb = new int[w * h];
        image.getRGB(0, 0, image.getWidth(), image.getHeight(), argb, 0, image.getWidth());

        if (alpha != 255) {
            final int length = argb.length;
            for (int i = 0 ; i < length; i++) {
                int a = (argb[i] >>> 24 * alpha) / 255;
                argb[i] = (a << 24) | (argb[i] & 0x00FFFFFF);
            }
        }

        result.setRGB(0, 0, w, h, argb, 0, w);

        return result;
    }

}