FrameSequence.java revision e36c5d675c8c2f900ef186a55edf71ce36ca9fa0 
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
17package android.support.rastermill;
18
19import android.graphics.Bitmap;
20
21import java.io.InputStream;
22
23public 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 #recycle()} *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 recycle() {
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 recycled FrameSequenceState");
132            }
133            return nativeGetFrame(mNativeState, frameNr, output, previousFrameNr);
134        }
135    }
136
137    // TODO: add recycle() cleanup method
138}
139