diff options
Diffstat (limited to 'src/com/android/launcher3/widget/CachingWidgetPreviewLoader.java')
| -rw-r--r-- | src/com/android/launcher3/widget/CachingWidgetPreviewLoader.java | 289 |
1 files changed, 0 insertions, 289 deletions
diff --git a/src/com/android/launcher3/widget/CachingWidgetPreviewLoader.java b/src/com/android/launcher3/widget/CachingWidgetPreviewLoader.java deleted file mode 100644 index afceadd9a3..0000000000 --- a/src/com/android/launcher3/widget/CachingWidgetPreviewLoader.java +++ /dev/null @@ -1,289 +0,0 @@ -/* - * Copyright (C) 2021 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.launcher3.widget; - -import android.graphics.Bitmap; -import android.os.CancellationSignal; -import android.util.Size; - -import androidx.annotation.NonNull; -import androidx.annotation.Nullable; -import androidx.annotation.UiThread; -import androidx.collection.ArrayMap; -import androidx.collection.ArraySet; - -import com.android.launcher3.BaseActivity; -import com.android.launcher3.model.WidgetItem; -import com.android.launcher3.util.ComponentKey; - -import java.util.ArrayList; -import java.util.List; -import java.util.Map; -import java.util.Set; -import java.util.stream.Collectors; - -/** Wrapper around {@link DatabaseWidgetPreviewLoader} that contains caching logic. */ -public class CachingWidgetPreviewLoader implements WidgetPreviewLoader { - - @NonNull private final WidgetPreviewLoader mDelegate; - @NonNull private final Map<ComponentKey, Map<Size, CacheResult>> mCache = new ArrayMap<>(); - - public CachingWidgetPreviewLoader(@NonNull WidgetPreviewLoader delegate) { - mDelegate = delegate; - } - - /** Returns whether the preview is loaded for the item and size. */ - public boolean isPreviewLoaded(@NonNull WidgetItem item, @NonNull Size previewSize) { - return getPreview(item, previewSize) != null; - } - - /** Returns the cached preview for the item and size, or null if there is none. */ - @Nullable - public Bitmap getPreview(@NonNull WidgetItem item, @NonNull Size previewSize) { - CacheResult cacheResult = getCacheResult(item, previewSize); - if (cacheResult instanceof CacheResult.Loaded) { - return ((CacheResult.Loaded) cacheResult).mBitmap; - } else { - return null; - } - } - - @NonNull - private CacheResult getCacheResult(@NonNull WidgetItem item, @NonNull Size previewSize) { - synchronized (mCache) { - Map<Size, CacheResult> cacheResults = mCache.get(toComponentKey(item)); - if (cacheResults == null) { - return CacheResult.MISS; - } - - return cacheResults.getOrDefault(previewSize, CacheResult.MISS); - } - } - - /** - * Puts the result in the cache for the item and size. Returns the value previously in the - * cache, or null if there was none. - */ - @Nullable - private CacheResult putCacheResult( - @NonNull WidgetItem item, - @NonNull Size previewSize, - @Nullable CacheResult cacheResult) { - ComponentKey key = toComponentKey(item); - synchronized (mCache) { - Map<Size, CacheResult> cacheResults = mCache.getOrDefault(key, new ArrayMap<>()); - CacheResult previous; - if (cacheResult == null) { - previous = cacheResults.remove(previewSize); - if (cacheResults.isEmpty()) { - mCache.remove(key); - } else { - previous = cacheResults.put(previewSize, cacheResult); - mCache.put(key, cacheResults); - } - } else { - previous = cacheResults.put(previewSize, cacheResult); - mCache.put(key, cacheResults); - } - return previous; - } - } - - private void removeCacheResult(@NonNull WidgetItem item, @NonNull Size previewSize) { - ComponentKey key = toComponentKey(item); - synchronized (mCache) { - Map<Size, CacheResult> cacheResults = mCache.getOrDefault(key, new ArrayMap<>()); - cacheResults.remove(previewSize); - mCache.put(key, cacheResults); - } - } - - /** - * Gets the preview for the widget item and size, using the value in the cache if stored. - * - * @return a {@link CancellationSignal}, which can cancel the request before it loads - */ - @Override - @UiThread - @NonNull - public CancellationSignal loadPreview( - @NonNull BaseActivity activity, @NonNull WidgetItem item, @NonNull Size previewSize, - @NonNull WidgetPreviewLoadedCallback callback) { - CancellationSignal signal = new CancellationSignal(); - signal.setOnCancelListener(() -> { - synchronized (mCache) { - CacheResult cacheResult = getCacheResult(item, previewSize); - if (!(cacheResult instanceof CacheResult.Loading)) { - // If the key isn't actively loading, then this is a no-op. Cancelling loading - // shouldn't clear the cache if we've already loaded. - return; - } - - CacheResult.Loading prev = (CacheResult.Loading) cacheResult; - CacheResult.Loading updated = prev.withoutCallback(callback); - - if (updated.mCallbacks.isEmpty()) { - // If the last callback was removed, then cancel the underlying request in the - // delegate. - prev.mCancellationSignal.cancel(); - removeCacheResult(item, previewSize); - } else { - // If there are other callbacks still active, then don't cancel the delegate's - // request, just remove this callback from the set. - putCacheResult(item, previewSize, updated); - } - } - }); - - synchronized (mCache) { - CacheResult cacheResult = getCacheResult(item, previewSize); - if (cacheResult instanceof CacheResult.Loaded) { - // If the bitmap is already present in the cache, invoke the callback immediately. - callback.onPreviewLoaded(((CacheResult.Loaded) cacheResult).mBitmap); - return signal; - } - - if (cacheResult instanceof CacheResult.Loading) { - // If we're already loading the preview for this key, then just add the callback - // to the set we'll call after it loads. - CacheResult.Loading prev = (CacheResult.Loading) cacheResult; - putCacheResult(item, previewSize, prev.withCallback(callback)); - return signal; - } - - CancellationSignal delegateCancellationSignal = - mDelegate.loadPreview( - activity, - item, - previewSize, - preview -> { - CacheResult prev; - synchronized (mCache) { - prev = putCacheResult( - item, previewSize, new CacheResult.Loaded(preview)); - } - if (prev instanceof CacheResult.Loading) { - // Notify each stored callback that the preview has loaded. - ((CacheResult.Loading) prev).mCallbacks - .forEach(c -> c.onPreviewLoaded(preview)); - } else { - // If there isn't a loading object in the cache, then we were - // notified before adding this signal to the cache. Just - // call back to the provided callback, there can't be others. - callback.onPreviewLoaded(preview); - } - }); - ArraySet<WidgetPreviewLoadedCallback> callbacks = new ArraySet<>(); - callbacks.add(callback); - putCacheResult( - item, - previewSize, - new CacheResult.Loading(delegateCancellationSignal, callbacks)); - } - - return signal; - } - - /** Clears all cached previews for {@code items}, cancelling any in-progress preview loading. */ - public void clearPreviews(Iterable<WidgetItem> items) { - List<CacheResult> previousCacheResults = new ArrayList<>(); - synchronized (mCache) { - for (WidgetItem item : items) { - Map<Size, CacheResult> previousMap = mCache.remove(toComponentKey(item)); - if (previousMap != null) { - previousCacheResults.addAll(previousMap.values()); - } - } - } - - for (CacheResult previousCacheResult : previousCacheResults) { - if (previousCacheResult instanceof CacheResult.Loading) { - ((CacheResult.Loading) previousCacheResult).mCancellationSignal.cancel(); - } - } - } - - /** Clears all cached previews, cancelling any in-progress preview loading. */ - public void clearAll() { - List<CacheResult> previousCacheResults; - synchronized (mCache) { - previousCacheResults = - mCache - .values() - .stream() - .flatMap(sizeToResult -> sizeToResult.values().stream()) - .collect(Collectors.toList()); - mCache.clear(); - } - - for (CacheResult previousCacheResult : previousCacheResults) { - if (previousCacheResult instanceof CacheResult.Loading) { - ((CacheResult.Loading) previousCacheResult).mCancellationSignal.cancel(); - } - } - } - - private abstract static class CacheResult { - static final CacheResult MISS = new CacheResult() {}; - - static final class Loading extends CacheResult { - @NonNull final CancellationSignal mCancellationSignal; - @NonNull final Set<WidgetPreviewLoadedCallback> mCallbacks; - - Loading(@NonNull CancellationSignal cancellationSignal, - @NonNull Set<WidgetPreviewLoadedCallback> callbacks) { - mCancellationSignal = cancellationSignal; - mCallbacks = callbacks; - } - - @NonNull - Loading withCallback(@NonNull WidgetPreviewLoadedCallback callback) { - if (mCallbacks.contains(callback)) return this; - Set<WidgetPreviewLoadedCallback> newCallbacks = - new ArraySet<>(mCallbacks.size() + 1); - newCallbacks.addAll(mCallbacks); - newCallbacks.add(callback); - return new Loading(mCancellationSignal, newCallbacks); - } - - @NonNull - Loading withoutCallback(@NonNull WidgetPreviewLoadedCallback callback) { - if (!mCallbacks.contains(callback)) return this; - Set<WidgetPreviewLoadedCallback> newCallbacks = - new ArraySet<>(mCallbacks.size() - 1); - for (WidgetPreviewLoadedCallback existingCallback : mCallbacks) { - if (!existingCallback.equals(callback)) { - newCallbacks.add(existingCallback); - } - } - return new Loading(mCancellationSignal, newCallbacks); - } - } - - static final class Loaded extends CacheResult { - @NonNull final Bitmap mBitmap; - - Loaded(@NonNull Bitmap bitmap) { - mBitmap = bitmap; - } - } - } - - @NonNull - private static ComponentKey toComponentKey(@NonNull WidgetItem item) { - return new ComponentKey(item.componentName, item.user); - } -} |