diff options
Diffstat (limited to 'src/com/android/gallery3d/app/SlideshowDataAdapter.java')
-rw-r--r-- | src/com/android/gallery3d/app/SlideshowDataAdapter.java | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/src/com/android/gallery3d/app/SlideshowDataAdapter.java b/src/com/android/gallery3d/app/SlideshowDataAdapter.java new file mode 100644 index 000000000..6f9b98e8e --- /dev/null +++ b/src/com/android/gallery3d/app/SlideshowDataAdapter.java @@ -0,0 +1,187 @@ +/* + * 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 com.android.gallery3d.app; + +import com.android.gallery3d.app.SlideshowPage.Slide; +import com.android.gallery3d.data.ContentListener; +import com.android.gallery3d.data.MediaItem; +import com.android.gallery3d.data.MediaObject; +import com.android.gallery3d.util.Future; +import com.android.gallery3d.util.FutureListener; +import com.android.gallery3d.util.ThreadPool; +import com.android.gallery3d.util.ThreadPool.Job; +import com.android.gallery3d.util.ThreadPool.JobContext; + +import android.graphics.Bitmap; + +import java.util.LinkedList; +import java.util.concurrent.atomic.AtomicBoolean; + +public class SlideshowDataAdapter implements SlideshowPage.Model { + @SuppressWarnings("unused") + private static final String TAG = "SlideshowDataAdapter"; + + private static final int IMAGE_QUEUE_CAPACITY = 3; + + public interface SlideshowSource { + public void addContentListener(ContentListener listener); + public void removeContentListener(ContentListener listener); + public long reload(); + public MediaItem getMediaItem(int index); + } + + private final SlideshowSource mSource; + + private int mLoadIndex = 0; + private int mNextOutput = 0; + private boolean mIsActive = false; + private boolean mNeedReset; + private boolean mDataReady; + + private final LinkedList<Slide> mImageQueue = new LinkedList<Slide>(); + + private Future<Void> mReloadTask; + private final ThreadPool mThreadPool; + + private long mDataVersion = MediaObject.INVALID_DATA_VERSION; + private final AtomicBoolean mNeedReload = new AtomicBoolean(false); + private final SourceListener mSourceListener = new SourceListener(); + + public SlideshowDataAdapter(GalleryContext context, SlideshowSource source, int index) { + mSource = source; + mLoadIndex = index; + mNextOutput = index; + mThreadPool = context.getThreadPool(); + } + + public MediaItem loadItem() { + if (mNeedReload.compareAndSet(true, false)) { + long v = mSource.reload(); + if (v != mDataVersion) { + mDataVersion = v; + mNeedReset = true; + return null; + } + } + return mSource.getMediaItem(mLoadIndex); + } + + private class ReloadTask implements Job<Void> { + public Void run(JobContext jc) { + while (true) { + synchronized (SlideshowDataAdapter.this) { + while (mIsActive && (!mDataReady + || mImageQueue.size() >= IMAGE_QUEUE_CAPACITY)) { + try { + SlideshowDataAdapter.this.wait(); + } catch (InterruptedException ex) { + // ignored. + } + continue; + } + } + if (!mIsActive) return null; + mNeedReset = false; + + MediaItem item = loadItem(); + + if (mNeedReset) { + synchronized (SlideshowDataAdapter.this) { + mImageQueue.clear(); + mLoadIndex = mNextOutput; + } + continue; + } + + if (item == null) { + synchronized (SlideshowDataAdapter.this) { + if (!mNeedReload.get()) mDataReady = false; + SlideshowDataAdapter.this.notifyAll(); + } + continue; + } + + Bitmap bitmap = item + .requestImage(MediaItem.TYPE_THUMBNAIL) + .run(jc); + + if (bitmap != null) { + synchronized (SlideshowDataAdapter.this) { + mImageQueue.addLast( + new Slide(item, mLoadIndex, bitmap)); + if (mImageQueue.size() == 1) { + SlideshowDataAdapter.this.notifyAll(); + } + } + } + ++mLoadIndex; + } + } + } + + private class SourceListener implements ContentListener { + public void onContentDirty() { + synchronized (SlideshowDataAdapter.this) { + mNeedReload.set(true); + mDataReady = true; + SlideshowDataAdapter.this.notifyAll(); + } + } + } + + private synchronized Slide innerNextBitmap() { + while (mIsActive && mDataReady && mImageQueue.isEmpty()) { + try { + wait(); + } catch (InterruptedException t) { + throw new AssertionError(); + } + } + if (mImageQueue.isEmpty()) return null; + mNextOutput++; + this.notifyAll(); + return mImageQueue.removeFirst(); + } + + public Future<Slide> nextSlide(FutureListener<Slide> listener) { + return mThreadPool.submit(new Job<Slide>() { + public Slide run(JobContext jc) { + jc.setMode(ThreadPool.MODE_NONE); + return innerNextBitmap(); + } + }, listener); + } + + public void pause() { + synchronized (this) { + mIsActive = false; + notifyAll(); + } + mSource.removeContentListener(mSourceListener); + mReloadTask.cancel(); + mReloadTask.waitDone(); + mReloadTask = null; + } + + public synchronized void resume() { + mIsActive = true; + mSource.addContentListener(mSourceListener); + mNeedReload.set(true); + mDataReady = true; + mReloadTask = mThreadPool.submit(new ReloadTask()); + } +} |