Do not merge.

Backport changes related to BitmapRegionDecoder from HoneyComb to
Gingerbread.

Bug: 3309014

////////////////////////////////////////////////////
This is a combination of 7 commits.
Revert "Do not merge."

This reverts commit f7681f84918c27f6a626681ce37ed2a236c44e82.

Change-Id: I46fd710600b1649773eaea2d9abc2b21a592f9a6

Fix a initialization bug in BitmapRegionDecoder.

Change-Id: I6c1151fd34970a84d4de52d664d9a5dc464892c5

Fix segfault when tring to throw IOException.

Change-Id: I530cc4409ba4ca17cec933afad077c5f60ba554f

Fix 3122139, where previewing an attachment for the second time will
fail.

Use AutoFDSeek to mark and restore the position before we read data from
the descriptor.

Change-Id: I3d4f012dce486e19b113bc90a98b94031cfa8195

Add inPreferQualityOverSpeed into BitmapFactory.Options.

The new field allows a developer to use a more accurate by
slightly slower IDCT method in JPEG decode. This in turns improves the
quality of the reconstructed image.

The field by default is not set and thus does not affect existing
applications.

Bug: 3238925
Change-Id: I93d55b7226e47a43e639325cd1a677694d6f2ee4

Unhide inPreferQualityOverSpeed in BitmapFactory.Options.

The new field allows a developer to use a more accurate by
slightly slower IDCT method in JPEG decode. This in turns improves the
quality of the reconstructed image.

The field by default is not set and thus does not affect existing
applications.

Bug: 3238925

Related changes: https://android-git.corp.google.com/g/#change,83291 and
                 https://android-git.corp.google.com/g/#change,83294

Change-Id: I969f5c413f9b2179454aeb90e18ae8222ee583b4

Correct the API comments.

BitmapRegionDecoder supports PNG as well.

2 files changed, 273 insertions, 0 deletions

diff --git a/graphics/java/android/graphics/BitmapFactory.java b/graphics/java/android/graphics/BitmapFactory.java
index 7b49bc5..3f1a566 100644
--- a/graphics/java/android/graphics/BitmapFactory.java
+++ b/graphics/java/android/graphics/BitmapFactory.java
@@ -206,10 +206,20 @@ public class BitmapFactory {
         public boolean inNativeAlloc;
 
         /**
+         * If inPreferQualityOverSpeed is set to true, the decoder will try to
+         * decode the reconstructed image to a higher quality even at the
+         * expense of the decoding speed. Currently the field only affects JPEG
+         * decode, in the case of which a more accurate, but slightly slower,
+         * IDCT method will be used instead.
+         */
+        public boolean inPreferQualityOverSpeed;
+
+        /**
          * The resulting width of the bitmap, set independent of the state of
          * inJustDecodeBounds. However, if there is an error trying to decode,
          * outWidth will be set to -1.
          */
+
         public int outWidth;
 
         /**
diff --git a/graphics/java/android/graphics/BitmapRegionDecoder.java b/graphics/java/android/graphics/BitmapRegionDecoder.java
new file mode 100644
index 0000000..496e0c7
--- /dev/null
+++ b/graphics/java/android/graphics/BitmapRegionDecoder.java
@@ -0,0 +1,263 @@
+/* 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 android.content.res.AssetManager;
+
+import java.io.BufferedInputStream;
+import java.io.FileDescriptor;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * BitmapRegionDecoder can be used to decode a rectangle region from an image.
+ * BitmapRegionDecoder is particularly useful when an original image is large and
+ * you only need parts of the image.
+ *
+ * <p>To create a BitmapRegionDecoder, call newInstance(...).
+ * Given a BitmapRegionDecoder, users can call decodeRegion() repeatedly
+ * to get a decoded Bitmap of the specified region.
+ *
+ */
+public final class BitmapRegionDecoder {
+    private int mNativeBitmapRegionDecoder;
+    private boolean mRecycled;
+
+    /**
+     * Create a BitmapRegionDecoder from the specified byte array.
+     * Currently only the JPEG and PNG formats are supported.
+     *
+     * @param data byte array of compressed image data.
+     * @param offset offset into data for where the decoder should begin
+     *               parsing.
+     * @param length the number of bytes, beginning at offset, to parse
+     * @param isShareable If this is true, then the BitmapRegionDecoder may keep a
+     *                    shallow reference to the input. If this is false,
+     *                    then the BitmapRegionDecoder will explicitly make a copy of the
+     *                    input data, and keep that. Even if sharing is allowed,
+     *                    the implementation may still decide to make a deep
+     *                    copy of the input data. If an image is progressively encoded,
+     *                    allowing sharing may degrade the decoding speed.
+     * @return BitmapRegionDecoder, or null if the image data could not be decoded.
+     * @throws IOException if the image format is not supported or can not be decoded.
+     */
+    public static BitmapRegionDecoder newInstance(byte[] data,
+            int offset, int length, boolean isShareable) throws IOException {
+        if ((offset | length) < 0 || data.length < offset + length) {
+            throw new ArrayIndexOutOfBoundsException();
+        }
+        return nativeNewInstance(data, offset, length, isShareable);
+    }
+
+    /**
+     * Create a BitmapRegionDecoder from the file descriptor.
+     * The position within the descriptor will not be changed when
+     * this returns, so the descriptor can be used again as is.
+     * Currently only the JPEG and PNG formats are supported.
+     *
+     * @param fd The file descriptor containing the data to decode
+     * @param isShareable If this is true, then the BitmapRegionDecoder may keep a
+     *                    shallow reference to the input. If this is false,
+     *                    then the BitmapRegionDecoder will explicitly make a copy of the
+     *                    input data, and keep that. Even if sharing is allowed,
+     *                    the implementation may still decide to make a deep
+     *                    copy of the input data. If an image is progressively encoded,
+     *                    allowing sharing may degrade the decoding speed.
+     * @return BitmapRegionDecoder, or null if the image data could not be decoded.
+     * @throws IOException if the image format is not supported or can not be decoded.
+     */
+    public static BitmapRegionDecoder newInstance(
+            FileDescriptor fd, boolean isShareable) throws IOException {
+        return nativeNewInstance(fd, isShareable);
+    }
+
+    /**
+     * Create a BitmapRegionDecoder from an input stream.
+     * The stream's position will be where ever it was after the encoded data
+     * was read.
+     * Currently only the JPEG and PNG formats are supported.
+     *
+     * @param is The input stream that holds the raw data to be decoded into a
+     *           BitmapRegionDecoder.
+     * @param isShareable If this is true, then the BitmapRegionDecoder may keep a
+     *                    shallow reference to the input. If this is false,
+     *                    then the BitmapRegionDecoder will explicitly make a copy of the
+     *                    input data, and keep that. Even if sharing is allowed,
+     *                    the implementation may still decide to make a deep
+     *                    copy of the input data. If an image is progressively encoded,
+     *                    allowing sharing may degrade the decoding speed.
+     * @return BitmapRegionDecoder, or null if the image data could not be decoded.
+     * @throws IOException if the image format is not supported or can not be decoded.
+     */
+    public static BitmapRegionDecoder newInstance(InputStream is,
+            boolean isShareable) throws IOException {
+        // we need mark/reset to work properly in JNI
+
+        if (!is.markSupported()) {
+            is = new BufferedInputStream(is, 16 * 1024);
+        }
+
+        if (is instanceof AssetManager.AssetInputStream) {
+            return nativeNewInstance(
+                    ((AssetManager.AssetInputStream) is).getAssetInt(),
+                    isShareable);
+        } else {
+            // pass some temp storage down to the native code. 1024 is made up,
+            // but should be large enough to avoid too many small calls back
+            // into is.read(...).
+            byte [] tempStorage = new byte[16 * 1024];
+            return nativeNewInstance(is, tempStorage, isShareable);
+        }
+    }
+
+    /**
+     * Create a BitmapRegionDecoder from a file path.
+     * Currently only the JPEG and PNG formats are supported.
+     *
+     * @param pathName complete path name for the file to be decoded.
+     * @param isShareable If this is true, then the BitmapRegionDecoder may keep a
+     *                    shallow reference to the input. If this is false,
+     *                    then the BitmapRegionDecoder will explicitly make a copy of the
+     *                    input data, and keep that. Even if sharing is allowed,
+     *                    the implementation may still decide to make a deep
+     *                    copy of the input data. If an image is progressively encoded,
+     *                    allowing sharing may degrade the decoding speed.
+     * @return BitmapRegionDecoder, or null if the image data could not be decoded.
+     * @throws IOException if the image format is not supported or can not be decoded.
+     */
+    public static BitmapRegionDecoder newInstance(String pathName,
+            boolean isShareable) throws IOException {
+        BitmapRegionDecoder decoder = null;
+        InputStream stream = null;
+
+        try {
+            stream = new FileInputStream(pathName);
+            decoder = newInstance(stream, isShareable);
+        } finally {
+            if (stream != null) {
+                try {
+                    stream.close();
+                } catch (IOException e) {
+                    // do nothing here
+                }
+            }
+        }
+        return decoder;
+    }
+
+    /*  Private constructor that must receive an already allocated native
+        region decoder int (pointer).
+
+        This can be called from JNI code.
+    */
+    private BitmapRegionDecoder(int decoder) {
+        mNativeBitmapRegionDecoder = decoder;
+        mRecycled = false;
+    }
+
+    /**
+     * Decodes a rectangle region in the image specified by rect.
+     *
+     * @param rect The rectangle that specified the region to be decode.
+     * @param options null-ok; Options that control downsampling.
+     *             inPurgeable is not supported.
+     * @return The decoded bitmap, or null if the image data could not be
+     *         decoded.
+     */
+    public Bitmap decodeRegion(Rect rect, BitmapFactory.Options options) {
+        checkRecycled("decodeRegion called on recycled region decoder");
+        if (rect.left < 0 || rect.top < 0 || rect.right > getWidth()
+                || rect.bottom > getHeight())
+            throw new IllegalArgumentException("rectangle is not inside the image");
+        return nativeDecodeRegion(mNativeBitmapRegionDecoder, rect.left, rect.top,
+                rect.right - rect.left, rect.bottom - rect.top, options);
+    }
+
+    /** Returns the original image's width */
+    public int getWidth() {
+        checkRecycled("getWidth called on recycled region decoder");
+        return nativeGetWidth(mNativeBitmapRegionDecoder);
+    }
+
+    /** Returns the original image's height */
+    public int getHeight() {
+        checkRecycled("getHeight called on recycled region decoder");
+        return nativeGetHeight(mNativeBitmapRegionDecoder);
+    }
+
+    /**
+     * Frees up the memory associated with this region decoder, and mark the
+     * region decoder as "dead", meaning it will throw an exception if decodeRegion(),
+     * getWidth() or getHeight() is called.
+     *
+     * <p>This operation cannot be reversed, so it should only be called if you are
+     * sure there are no further uses for the region decoder. This is an advanced call,
+     * and normally need not be called, since the normal GC process will free up this
+     * memory when there are no more references to this region decoder.
+     */
+    public void recycle() {
+        if (!mRecycled) {
+            nativeClean(mNativeBitmapRegionDecoder);
+            mRecycled = true;
+        }
+    }
+
+    /**
+     * Returns true if this region decoder has been recycled.
+     * If so, then it is an error to try use its method.
+     *
+     * @return true if the region decoder has been recycled
+     */
+    public final boolean isRecycled() {
+        return mRecycled;
+    }
+
+    /**
+     * Called by methods that want to throw an exception if the region decoder
+     * has already been recycled.
+     */
+    private void checkRecycled(String errorMessage) {
+        if (mRecycled) {
+            throw new IllegalStateException(errorMessage);
+        }
+    }
+
+    @Override
+    protected void finalize() throws Throwable {
+        try {
+            recycle();
+        } finally {
+            super.finalize();
+        }
+    }
+
+    private static native Bitmap nativeDecodeRegion(int lbm,
+            int start_x, int start_y, int width, int height,
+            BitmapFactory.Options options);
+    private static native int nativeGetWidth(int lbm);
+    private static native int nativeGetHeight(int lbm);
+    private static native void nativeClean(int lbm);
+
+    private static native BitmapRegionDecoder nativeNewInstance(
+            byte[] data, int offset, int length, boolean isShareable);
+    private static native BitmapRegionDecoder nativeNewInstance(
+            FileDescriptor fd, boolean isShareable);
+    private static native BitmapRegionDecoder nativeNewInstance(
+            InputStream is, byte[] storage, boolean isShareable);
+    private static native BitmapRegionDecoder nativeNewInstance(
+            int asset, boolean isShareable);
+}