AlbumSlidingWindow.java revision f9a0a4306d589b4a4e20554fed512a603426bfa1 
1/*
2 * Copyright (C) 2010 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 com.android.gallery3d.ui;
18
19import com.android.gallery3d.app.GalleryActivity;
20import com.android.gallery3d.common.BitmapUtils;
21import com.android.gallery3d.common.LruCache;
22import com.android.gallery3d.common.Utils;
23import com.android.gallery3d.data.MediaItem;
24import com.android.gallery3d.data.Path;
25import com.android.gallery3d.util.Future;
26import com.android.gallery3d.util.FutureListener;
27import com.android.gallery3d.util.ThreadPool;
28import com.android.gallery3d.util.ThreadPool.Job;
29import com.android.gallery3d.util.ThreadPool.JobContext;
30
31import android.graphics.Bitmap;
32import android.graphics.Color;
33import android.os.Message;
34
35public class AlbumSlidingWindow implements AlbumView.ModelListener {
36    @SuppressWarnings("unused")
37    private static final String TAG = "AlbumSlidingWindow";
38
39    private static final int MSG_LOAD_BITMAP_DONE = 0;
40    private static final int MSG_UPDATE_SLOT = 1;
41    private static final int MIN_THUMB_SIZE = 100;
42
43    public static interface Listener {
44        public void onSizeChanged(int size);
45        public void onContentInvalidated();
46        public void onWindowContentChanged(
47                int slot, DisplayItem old, DisplayItem update);
48    }
49
50    private final AlbumView.Model mSource;
51    private int mSize;
52
53    private int mContentStart = 0;
54    private int mContentEnd = 0;
55
56    private int mActiveStart = 0;
57    private int mActiveEnd = 0;
58
59    private Listener mListener;
60    private int mFocusIndex = -1;
61
62    private final AlbumDisplayItem mData[];
63    private final ColorTexture mWaitLoadingTexture;
64    private SelectionDrawer mSelectionDrawer;
65
66    private SynchronizedHandler mHandler;
67    private ThreadPool mThreadPool;
68    private int mSlotWidth, mSlotHeight;
69
70    private int mActiveRequestCount = 0;
71    private boolean mIsActive = false;
72
73    private int mDisplayItemSize;  // 0: disabled
74    private LruCache<Path, Bitmap> mImageCache = new LruCache<Path, Bitmap>(1000);
75
76    public AlbumSlidingWindow(GalleryActivity activity,
77            AlbumView.Model source, int cacheSize,
78            int slotWidth, int slotHeight, int displayItemSize) {
79        source.setModelListener(this);
80        mSource = source;
81        mData = new AlbumDisplayItem[cacheSize];
82        mSize = source.size();
83        mSlotWidth = slotWidth;
84        mSlotHeight = slotHeight;
85        mDisplayItemSize = displayItemSize;
86
87        mWaitLoadingTexture = new ColorTexture(Color.TRANSPARENT);
88        mWaitLoadingTexture.setSize(1, 1);
89
90        mHandler = new SynchronizedHandler(activity.getGLRoot()) {
91            @Override
92            public void handleMessage(Message message) {
93                switch (message.what) {
94                    case MSG_LOAD_BITMAP_DONE: {
95                        ((AlbumDisplayItem) message.obj).onLoadBitmapDone();
96                        break;
97                    }
98                    case MSG_UPDATE_SLOT: {
99                        updateSlotContent(message.arg1);
100                        break;
101                    }
102                }
103            }
104        };
105
106        mThreadPool = activity.getThreadPool();
107    }
108
109    public void setSelectionDrawer(SelectionDrawer drawer) {
110        mSelectionDrawer = drawer;
111    }
112
113    public void setListener(Listener listener) {
114        mListener = listener;
115    }
116
117    public void setFocusIndex(int slotIndex) {
118        mFocusIndex = slotIndex;
119    }
120
121    public DisplayItem get(int slotIndex) {
122        Utils.assertTrue(isActiveSlot(slotIndex),
123                "invalid slot: %s outsides (%s, %s)",
124                slotIndex, mActiveStart, mActiveEnd);
125        return mData[slotIndex % mData.length];
126    }
127
128    public int size() {
129        return mSize;
130    }
131
132    public boolean isActiveSlot(int slotIndex) {
133        return slotIndex >= mActiveStart && slotIndex < mActiveEnd;
134    }
135
136    private void setContentWindow(int contentStart, int contentEnd) {
137        if (contentStart == mContentStart && contentEnd == mContentEnd) return;
138
139        if (!mIsActive) {
140            mContentStart = contentStart;
141            mContentEnd = contentEnd;
142            mSource.setActiveWindow(contentStart, contentEnd);
143            return;
144        }
145
146        if (contentStart >= mContentEnd || mContentStart >= contentEnd) {
147            for (int i = mContentStart, n = mContentEnd; i < n; ++i) {
148                freeSlotContent(i);
149            }
150            mSource.setActiveWindow(contentStart, contentEnd);
151            for (int i = contentStart; i < contentEnd; ++i) {
152                prepareSlotContent(i);
153            }
154        } else {
155            for (int i = mContentStart; i < contentStart; ++i) {
156                freeSlotContent(i);
157            }
158            for (int i = contentEnd, n = mContentEnd; i < n; ++i) {
159                freeSlotContent(i);
160            }
161            mSource.setActiveWindow(contentStart, contentEnd);
162            for (int i = contentStart, n = mContentStart; i < n; ++i) {
163                prepareSlotContent(i);
164            }
165            for (int i = mContentEnd; i < contentEnd; ++i) {
166                prepareSlotContent(i);
167            }
168        }
169
170        mContentStart = contentStart;
171        mContentEnd = contentEnd;
172    }
173
174    public void setActiveWindow(int start, int end) {
175        Utils.assertTrue(start <= end
176                && end - start <= mData.length && end <= mSize,
177                "%s, %s, %s, %s", start, end, mData.length, mSize);
178        DisplayItem data[] = mData;
179
180        mActiveStart = start;
181        mActiveEnd = end;
182
183        // If no data is visible, keep the cache content
184        if (start == end) return;
185
186        int contentStart = Utils.clamp((start + end) / 2 - data.length / 2,
187                0, Math.max(0, mSize - data.length));
188        int contentEnd = Math.min(contentStart + data.length, mSize);
189        setContentWindow(contentStart, contentEnd);
190        if (mIsActive) updateAllImageRequests();
191    }
192
193    // We would like to request non active slots in the following order:
194    // Order:    8 6 4 2                   1 3 5 7
195    //         |---------|---------------|---------|
196    //                   |<-  active  ->|
197    //         |<-------- cached range ----------->|
198    private void requestNonactiveImages() {
199        int range = Math.max(
200                (mContentEnd - mActiveEnd), (mActiveStart - mContentStart));
201        for (int i = 0 ;i < range; ++i) {
202            requestSlotImage(mActiveEnd + i, false);
203            requestSlotImage(mActiveStart - 1 - i, false);
204        }
205    }
206
207    private void requestSlotImage(int slotIndex, boolean isActive) {
208        if (slotIndex < mContentStart || slotIndex >= mContentEnd) return;
209        AlbumDisplayItem item = mData[slotIndex % mData.length];
210        item.requestImage();
211    }
212
213    private void cancelNonactiveImages() {
214        int range = Math.max(
215                (mContentEnd - mActiveEnd), (mActiveStart - mContentStart));
216        for (int i = 0 ;i < range; ++i) {
217            cancelSlotImage(mActiveEnd + i, false);
218            cancelSlotImage(mActiveStart - 1 - i, false);
219        }
220    }
221
222    private void cancelSlotImage(int slotIndex, boolean isActive) {
223        if (slotIndex < mContentStart || slotIndex >= mContentEnd) return;
224        AlbumDisplayItem item = mData[slotIndex % mData.length];
225        item.cancelImageRequest();
226    }
227
228    private void freeSlotContent(int slotIndex) {
229        AlbumDisplayItem data[] = mData;
230        int index = slotIndex % data.length;
231        AlbumDisplayItem original = data[index];
232        if (original != null) {
233            original.recycle();
234            data[index] = null;
235        }
236    }
237
238    private void prepareSlotContent(final int slotIndex) {
239        mData[slotIndex % mData.length] = new AlbumDisplayItem(
240                slotIndex, mSource.get(slotIndex));
241    }
242
243    private void updateSlotContent(final int slotIndex) {
244        MediaItem item = mSource.get(slotIndex);
245        AlbumDisplayItem data[] = mData;
246        int index = slotIndex % data.length;
247        AlbumDisplayItem original = data[index];
248        AlbumDisplayItem update = new AlbumDisplayItem(slotIndex, item);
249        data[index] = update;
250        boolean isActive = isActiveSlot(slotIndex);
251        if (mListener != null && isActive) {
252            mListener.onWindowContentChanged(slotIndex, original, update);
253        }
254        if (original != null) {
255            if (isActive && original.isRequestInProgress()) {
256                --mActiveRequestCount;
257            }
258            original.recycle();
259        }
260        if (isActive) {
261            if (mActiveRequestCount == 0) cancelNonactiveImages();
262            ++mActiveRequestCount;
263            update.requestImage();
264        } else {
265            if (mActiveRequestCount == 0) update.requestImage();
266        }
267    }
268
269    private void updateAllImageRequests() {
270        mActiveRequestCount = 0;
271        AlbumDisplayItem data[] = mData;
272        for (int i = mActiveStart, n = mActiveEnd; i < n; ++i) {
273            AlbumDisplayItem item = data[i % data.length];
274            item.requestImage();
275            if (item.isRequestInProgress()) ++mActiveRequestCount;
276        }
277        if (mActiveRequestCount == 0) {
278            requestNonactiveImages();
279        } else {
280            cancelNonactiveImages();
281        }
282    }
283
284    private class AlbumDisplayItem extends AbstractDisplayItem
285            implements FutureListener<Bitmap>, Job<Bitmap> {
286        private Future<Bitmap> mFuture;
287        private final int mSlotIndex;
288        private final int mMediaType;
289        private Texture mContent;
290
291        public AlbumDisplayItem(int slotIndex, MediaItem item) {
292            super(item);
293            mMediaType = (item == null)
294                    ? MediaItem.MEDIA_TYPE_UNKNOWN
295                    : item.getMediaType();
296            mSlotIndex = slotIndex;
297            updateContent(mWaitLoadingTexture);
298        }
299
300        @Override
301        protected void onBitmapAvailable(Bitmap bitmap) {
302            boolean isActiveSlot = isActiveSlot(mSlotIndex);
303            if (isActiveSlot) {
304                --mActiveRequestCount;
305                if (mActiveRequestCount == 0) requestNonactiveImages();
306            }
307            if (bitmap != null) {
308                BitmapTexture texture = new BitmapTexture(bitmap);
309                texture.setThrottled(true);
310                updateContent(texture);
311                if (mListener != null && isActiveSlot) {
312                    mListener.onContentInvalidated();
313                }
314            }
315        }
316
317        private void updateContent(Texture content) {
318            mContent = content;
319
320            int width = mContent.getWidth();
321            int height = mContent.getHeight();
322
323            float scalex = mDisplayItemSize / (float) width;
324            float scaley = mDisplayItemSize / (float) height;
325            float scale = Math.min(scalex, scaley);
326
327            width = (int) Math.floor(width * scale);
328            height = (int) Math.floor(height * scale);
329
330            setSize(width, height);
331        }
332
333        @Override
334        public boolean render(GLCanvas canvas, int pass) {
335            if (pass == 0) {
336                Path path = null;
337                if (mMediaItem != null) path = mMediaItem.getPath();
338                mSelectionDrawer.draw(canvas, mContent, mWidth, mHeight,
339                        getRotation(), path, mMediaType);
340                return (mFocusIndex == mSlotIndex);
341            } else if (pass == 1) {
342                mSelectionDrawer.drawFocus(canvas, mWidth, mHeight);
343            }
344            return false;
345        }
346
347        @Override
348        public void startLoadBitmap() {
349            if (mDisplayItemSize < MIN_THUMB_SIZE) {
350                Path path = mMediaItem.getPath();
351                if (mImageCache.containsKey(path)) {
352                    Bitmap bitmap = mImageCache.get(path);
353                    updateImage(bitmap, false);
354                    return;
355                }
356                mFuture = mThreadPool.submit(this, this);
357            } else {
358                mFuture = mThreadPool.submit(mMediaItem.requestImage(
359                        MediaItem.TYPE_MICROTHUMBNAIL), this);
360            }
361        }
362
363        // This gets the bitmap and scale it down.
364        public Bitmap run(JobContext jc) {
365            Job<Bitmap> job = mMediaItem.requestImage(
366                    MediaItem.TYPE_MICROTHUMBNAIL);
367            Bitmap bitmap = job.run(jc);
368            if (bitmap != null) {
369                bitmap = BitmapUtils.resizeDownBySideLength(
370                        bitmap, mDisplayItemSize, true);
371            }
372            return bitmap;
373        }
374
375        @Override
376        public void cancelLoadBitmap() {
377            if (mFuture != null) {
378                mFuture.cancel();
379            }
380        }
381
382        @Override
383        public void onFutureDone(Future<Bitmap> bitmap) {
384            mHandler.sendMessage(mHandler.obtainMessage(MSG_LOAD_BITMAP_DONE, this));
385        }
386
387        private void onLoadBitmapDone() {
388            Future<Bitmap> future = mFuture;
389            mFuture = null;
390            Bitmap bitmap = future.get();
391            boolean isCancelled = future.isCancelled();
392            if (mDisplayItemSize < MIN_THUMB_SIZE && (bitmap != null || !isCancelled)) {
393                Path path = mMediaItem.getPath();
394                mImageCache.put(path, bitmap);
395            }
396            updateImage(bitmap, isCancelled);
397        }
398
399        @Override
400        public String toString() {
401            return String.format("AlbumDisplayItem[%s]", mSlotIndex);
402        }
403    }
404
405    public void onSizeChanged(int size) {
406        if (mSize != size) {
407            mSize = size;
408            if (mListener != null) mListener.onSizeChanged(mSize);
409        }
410    }
411
412    public void onWindowContentChanged(int index) {
413        if (index >= mContentStart && index < mContentEnd && mIsActive) {
414            updateSlotContent(index);
415        }
416    }
417
418    public void resume() {
419        mIsActive = true;
420        for (int i = mContentStart, n = mContentEnd; i < n; ++i) {
421            prepareSlotContent(i);
422        }
423        updateAllImageRequests();
424    }
425
426    public void pause() {
427        mIsActive = false;
428        for (int i = mContentStart, n = mContentEnd; i < n; ++i) {
429            freeSlotContent(i);
430        }
431        mImageCache.clear();
432    }
433}
434