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      1 /*
      2  * Copyright (C) 2013 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.support.rastermill;
     18 
     19 import android.graphics.Bitmap;
     20 
     21 import java.io.InputStream;
     22 
     23 public class FrameSequence {
     24     static {
     25         System.loadLibrary("framesequence");
     26     }
     27 
     28     private final long mNativeFrameSequence;
     29     private final int mWidth;
     30     private final int mHeight;
     31     private final boolean mOpaque;
     32     private final int mFrameCount;
     33     private final int mDefaultLoopCount;
     34 
     35     public int getWidth() { return mWidth; }
     36     public int getHeight() { return mHeight; }
     37     public boolean isOpaque() { return mOpaque; }
     38     public int getFrameCount() { return mFrameCount; }
     39     public int getDefaultLoopCount() { return mDefaultLoopCount; }
     40 
     41     private static native FrameSequence nativeDecodeByteArray(byte[] data, int offset, int length);
     42     private static native FrameSequence nativeDecodeStream(InputStream is, byte[] tempStorage);
     43     private static native void nativeDestroyFrameSequence(long nativeFrameSequence);
     44     private static native long nativeCreateState(long nativeFrameSequence);
     45     private static native void nativeDestroyState(long nativeState);
     46     private static native long nativeGetFrame(long nativeState, int frameNr,
     47             Bitmap output, int previousFrameNr);
     48 
     49     @SuppressWarnings("unused") // called by native
     50     private FrameSequence(long nativeFrameSequence, int width, int height,
     51                           boolean opaque, int frameCount, int defaultLoopCount) {
     52         mNativeFrameSequence = nativeFrameSequence;
     53         mWidth = width;
     54         mHeight = height;
     55         mOpaque = opaque;
     56         mFrameCount = frameCount;
     57         mDefaultLoopCount = defaultLoopCount;
     58     }
     59 
     60     public static FrameSequence decodeByteArray(byte[] data) {
     61         return decodeByteArray(data, 0, data.length);
     62     }
     63 
     64     public static FrameSequence decodeByteArray(byte[] data, int offset, int length) {
     65         if (data == null) throw new IllegalArgumentException();
     66         if (offset < 0 || length < 0 || (offset + length > data.length)) {
     67             throw new IllegalArgumentException("invalid offset/length parameters");
     68         }
     69         return nativeDecodeByteArray(data, offset, length);
     70     }
     71 
     72     public static FrameSequence decodeStream(InputStream stream) {
     73         if (stream == null) throw new IllegalArgumentException();
     74         byte[] tempStorage = new byte[16 * 1024]; // TODO: use buffer pool
     75         return nativeDecodeStream(stream, tempStorage);
     76     }
     77 
     78     State createState() {
     79         if (mNativeFrameSequence == 0) {
     80             throw new IllegalStateException("attempted to use incorrectly built FrameSequence");
     81         }
     82 
     83         long nativeState = nativeCreateState(mNativeFrameSequence);
     84         if (nativeState == 0) {
     85             return null;
     86         }
     87         return new State(nativeState);
     88     }
     89 
     90     @Override
     91     protected void finalize() throws Throwable {
     92         try {
     93             if (mNativeFrameSequence != 0) nativeDestroyFrameSequence(mNativeFrameSequence);
     94         } finally {
     95             super.finalize();
     96         }
     97     }
     98 
     99     /**
    100      * Playback state used when moving frames forward in a frame sequence.
    101      *
    102      * Note that this doesn't require contiguous frames to be rendered, it just stores
    103      * information (in the case of gif, a recall buffer) that will be used to construct
    104      * frames based upon data recorded before previousFrameNr.
    105      *
    106      * Note: {@link #destroy()} *must* be called before the object is GC'd to free native resources
    107      *
    108      * Note: State holds a native ref to its FrameSequence instance, so its FrameSequence should
    109      * remain ref'd while it is in use
    110      */
    111     static class State {
    112         private long mNativeState;
    113 
    114         public State(long nativeState) {
    115             mNativeState = nativeState;
    116         }
    117 
    118         public void destroy() {
    119             if (mNativeState != 0) {
    120                 nativeDestroyState(mNativeState);
    121                 mNativeState = 0;
    122             }
    123         }
    124 
    125         // TODO: consider adding alternate API for drawing into a SurfaceTexture
    126         public long getFrame(int frameNr, Bitmap output, int previousFrameNr) {
    127             if (output == null || output.getConfig() != Bitmap.Config.ARGB_8888) {
    128                 throw new IllegalArgumentException("Bitmap passed must be non-null and ARGB_8888");
    129             }
    130             if (mNativeState == 0) {
    131                 throw new IllegalStateException("attempted to draw destroyed FrameSequenceState");
    132             }
    133             return nativeGetFrame(mNativeState, frameNr, output, previousFrameNr);
    134         }
    135     }
    136 }
    137