content: /*
   * Copyright (C) 2013 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.support.rastermill;
  
  import android.graphics.Bitmap;
  import java.nio.ByteBuffer;
  
  import java.io.InputStream;
  
  public class FrameSequence {
      static {
          System.loadLibrary("framesequence");
      }
  
      private final long mNativeFrameSequence;
      private final int mWidth;
      private final int mHeight;
      private final boolean mOpaque;
      private final int mFrameCount;
      private final int mDefaultLoopCount;
  
      public int getWidth() { return mWidth; }
      public int getHeight() { return mHeight; }
      public boolean isOpaque() { return mOpaque; }
      public int getFrameCount() { return mFrameCount; }
      public int getDefaultLoopCount() { return mDefaultLoopCount; }
  
      private static native FrameSequence nativeDecodeByteArray(byte[] data, int offset, int length);
      private static native FrameSequence nativeDecodeStream(InputStream is, byte[] tempStorage);
      private static native FrameSequence nativeDecodeByteBuffer(ByteBuffer buffer, int offset, int capacity);
      private static native void nativeDestroyFrameSequence(long nativeFrameSequence);
      private static native long nativeCreateState(long nativeFrameSequence);
      private static native void nativeDestroyState(long nativeState);
      private static native long nativeGetFrame(long nativeState, int frameNr,
              Bitmap output, int previousFrameNr);
  
      @SuppressWarnings("unused") // called by native
      private FrameSequence(long nativeFrameSequence, int width, int height,
                            boolean opaque, int frameCount, int defaultLoopCount) {
          mNativeFrameSequence = nativeFrameSequence;
          mWidth = width;
          mHeight = height;
          mOpaque = opaque;
          mFrameCount = frameCount;
          mDefaultLoopCount = defaultLoopCount;
      }
  
      public static FrameSequence decodeByteArray(byte[] data) {
          return decodeByteArray(data, 0, data.length);
      }
  
      public static FrameSequence decodeByteArray(byte[] data, int offset, int length) {
          if (data == null) throw new IllegalArgumentException();
          if (offset < 0 || length < 0 || (offset + length > data.length)) {
              throw new IllegalArgumentException("invalid offset/length parameters");
          }
          return nativeDecodeByteArray(data, offset, length);
      }
  
      public static FrameSequence decodeByteBuffer(ByteBuffer buffer) {
          if (buffer == null) throw new IllegalArgumentException();
          if (!buffer.isDirect()) {
              if (buffer.hasArray()) {
                  byte[] byteArray = buffer.array();
                  return decodeByteArray(byteArray, buffer.position(), buffer.remaining());
              } else {
                  throw new IllegalArgumentException("Cannot have non-direct ByteBuffer with no byte array");
              }
          }
          return nativeDecodeByteBuffer(buffer, buffer.position(), buffer.remaining());
      }
  
      public static FrameSequence decodeStream(InputStream stream) {
          if (stream == null) throw new IllegalArgumentException();
          byte[] tempStorage = new byte[16 * 1024]; // TODO: use buffer pool
          return nativeDecodeStream(stream, tempStorage);
      }
  
      State createState() {
          if (mNativeFrameSequence == 0) {
              throw new IllegalStateException("attempted to use incorrectly built FrameSequence");
          }
  
          long nativeState = nativeCreateState(mNativeFrameSequence);
          if (nativeState == 0) {
              return null;
          }
          return new State(nativeState);
      }
  
      @Override
      protected void finalize() throws Throwable {
          try {
              if (mNativeFrameSequence != 0) nativeDestroyFrameSequence(mNativeFrameSequence);
          } finally {
              super.finalize();
          }
      }
  
      /**
       * Playback state used when moving frames forward in a frame sequence.
       *
       * Note that this doesn't require contiguous frames to be rendered, it just stores
       * information (in the case of gif, a recall buffer) that will be used to construct
       * frames based upon data recorded before previousFrameNr.
       *
       * Note: {@link #destroy()} *must* be called before the object is GC'd to free native resources
       *
       * Note: State holds a native ref to its FrameSequence instance, so its FrameSequence should
       * remain ref'd while it is in use
       */
      static class State {
          private long mNativeState;
  
          public State(long nativeState) {
              mNativeState = nativeState;
          }
  
          public void destroy() {
              if (mNativeState != 0) {
                  nativeDestroyState(mNativeState);
                  mNativeState = 0;
              }
          }
  
          // TODO: consider adding alternate API for drawing into a SurfaceTexture
          public long getFrame(int frameNr, Bitmap output, int previousFrameNr) {
              if (output == null || output.getConfig() != Bitmap.Config.ARGB_8888) {
                  throw new IllegalArgumentException("Bitmap passed must be non-null and ARGB_8888");
              }
              if (mNativeState == 0) {
                  throw new IllegalStateException("attempted to draw destroyed FrameSequenceState");
              }
              return nativeGetFrame(mNativeState, frameNr, output, previousFrameNr);
          }
      }
  }
  