1 files changed, 246 insertions, 0 deletions
diff --git a/framesequence/src/android/support/rastermill/FrameSequenceDrawable.java b/framesequence/src/android/support/rastermill/FrameSequenceDrawable.java
new file mode 100644
index 0000000..94f4da0
--- /dev/null
+++ b/framesequence/src/android/support/rastermill/FrameSequenceDrawable.java
@@ -0,0 +1,246 @@
+/*
+ * 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 android.graphics.Canvas;
+import android.graphics.ColorFilter;
+import android.graphics.Paint;
+import android.graphics.PixelFormat;
+import android.graphics.Rect;
+import android.graphics.drawable.Animatable;
+import android.graphics.drawable.Drawable;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.SystemClock;
+
+public class FrameSequenceDrawable extends Drawable implements Animatable, Runnable {
+    private static final Object sLock = new Object();
+    private static HandlerThread sDecodingThread;
+    private static Handler sDecodingThreadHandler;
+    private static void initializeDecodingThread() {
+        synchronized (sLock) {
+            if (sDecodingThread != null) return;
+
+            sDecodingThread = new HandlerThread("FrameSequence decoding thread");
+            sDecodingThread.start();
+            sDecodingThreadHandler = new Handler(sDecodingThread.getLooper());
+        }
+    }
+
+    private final FrameSequence mFrameSequence;
+    private final FrameSequence.State mFrameSequenceState;
+
+    private final Paint mPaint;
+    private final Rect mSrcRect;
+
+    //Protects the fields below
+    private final Object mLock = new Object();
+
+    private Bitmap mFrontBitmap;
+    private Bitmap mBackBitmap;
+
+    private static final int STATE_SCHEDULED = 1;
+    private static final int STATE_DECODING = 2;
+    private static final int STATE_WAITING_TO_SWAP = 3;
+    private static final int STATE_READY_TO_SWAP = 4;
+
+    private int mState;
+
+    private long mLastSwap;
+    private int mNextFrameToDecode;
+
+    /**
+     * Runs on decoding thread, only modifies mBackBitmap's pixels
+     */
+    private Runnable mDecodeRunnable = new Runnable() {
+        @Override
+        public void run() {
+            int nextFrame;
+            Bitmap bitmap;
+            synchronized (mLock) {
+                nextFrame = mNextFrameToDecode;
+                if (nextFrame < 0) {
+                    return;
+                }
+                bitmap = mBackBitmap;
+                mState = STATE_DECODING;
+            }
+            int lastFrame = nextFrame - 2;
+            long invalidateTimeMs = mFrameSequenceState.getFrame(nextFrame, bitmap, lastFrame);
+
+            synchronized (mLock) {
+                if (mNextFrameToDecode < 0 || mState != STATE_DECODING) return;
+                invalidateTimeMs += mLastSwap;
+
+                mState = STATE_WAITING_TO_SWAP;
+            }
+            scheduleSelf(FrameSequenceDrawable.this, invalidateTimeMs);
+        }
+    };
+
+
+    public FrameSequenceDrawable(FrameSequence frameSequence) {
+        if (frameSequence == null) throw new IllegalArgumentException();
+
+        mFrameSequence = frameSequence;
+        mFrameSequenceState = frameSequence.createState();
+        // TODO: add callback for requesting bitmaps, to allow for reuse
+        final int width = frameSequence.getWidth();
+        final int height = frameSequence.getHeight();
+
+        mFrontBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+        mBackBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+        mSrcRect = new Rect(0, 0, width, height);
+        mPaint = new Paint();
+        mPaint.setFilterBitmap(true);
+
+        mLastSwap = 0;
+
+        mNextFrameToDecode = -1;
+        mFrameSequenceState.getFrame(0, mFrontBitmap, -1);
+        initializeDecodingThread();
+    }
+
+    @Override
+    protected void finalize() throws Throwable {
+        try {
+            mFrontBitmap.recycle();
+            mBackBitmap.recycle();
+            mFrameSequenceState.recycle();
+        } finally {
+            super.finalize();
+        }
+    }
+
+    @Override
+    public void draw(Canvas canvas) {
+        synchronized (mLock) {
+            if (isRunning() && mState == STATE_READY_TO_SWAP) {
+                // Because draw has occurred, the view system is guaranteed to no longer hold a
+                // reference to the old mFrontBitmap, so we now use it to produce the next frame
+                Bitmap tmp = mBackBitmap;
+                mBackBitmap = mFrontBitmap;
+                mFrontBitmap = tmp;
+
+                mLastSwap = SystemClock.uptimeMillis();
+                scheduleDecodeLocked();
+            }
+        }
+
+        canvas.drawBitmap(mFrontBitmap, mSrcRect, getBounds(), mPaint);
+    }
+
+    private void scheduleDecodeLocked() {
+        mState = STATE_SCHEDULED;
+        mNextFrameToDecode = (mNextFrameToDecode + 1) % mFrameSequence.getFrameCount();
+        sDecodingThreadHandler.post(mDecodeRunnable);
+    }
+
+    @Override
+    public void run() {
+        // set ready to swap
+        synchronized (mLock) {
+            if (mState != STATE_WAITING_TO_SWAP || mNextFrameToDecode < 0) return;
+            mState = STATE_READY_TO_SWAP;
+        }
+        invalidateSelf();
+    }
+
+    @Override
+    public void start() {
+        if (!isRunning()) {
+            synchronized (mLock) {
+                if (mState == STATE_SCHEDULED) return; // already scheduled
+                scheduleDecodeLocked();
+            }
+        }
+    }
+
+    @Override
+    public void stop() {
+        if (isRunning()) {
+            unscheduleSelf(this);
+        }
+    }
+
+    @Override
+    public boolean isRunning() {
+        synchronized (mLock) {
+            return mNextFrameToDecode > -1;
+        }
+    }
+
+    @Override
+    public void scheduleSelf(Runnable what, long when) {
+        super.scheduleSelf(what, when);
+    }
+
+    @Override
+    public void unscheduleSelf(Runnable what) {
+        synchronized (mLock) {
+            mNextFrameToDecode = -1;
+        }
+        super.unscheduleSelf(what);
+    }
+
+    @Override
+    public boolean setVisible(boolean visible, boolean restart) {
+        boolean changed = super.setVisible(visible, restart);
+
+        if (!visible) {
+            stop();
+        } else if (restart || changed) {
+            stop();
+            start();
+        }
+
+        return changed;
+    }
+
+    // drawing properties
+
+    @Override
+    public void setFilterBitmap(boolean filter) {
+        mPaint.setFilterBitmap(filter);
+    }
+
+    @Override
+    public void setAlpha(int alpha) {
+        mPaint.setAlpha(alpha);
+    }
+
+    @Override
+    public void setColorFilter(ColorFilter colorFilter) {
+        mPaint.setColorFilter(colorFilter);
+    }
+
+    @Override
+    public int getIntrinsicWidth() {
+        return mFrameSequence.getWidth();
+    }
+
+    @Override
+    public int getIntrinsicHeight() {
+        return mFrameSequence.getHeight();
+    }
+
+    @Override
+    public int getOpacity() {
+        return mFrameSequence.isOpaque() ? PixelFormat.OPAQUE : PixelFormat.TRANSPARENT;
+    }
+}