DataSourceBitmapLoader.java
/*
* Copyright 2023 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 androidx.media3.datasource;
import static androidx.media3.common.util.Assertions.checkArgument;
import static androidx.media3.common.util.Assertions.checkStateNotNull;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import androidx.annotation.Nullable;
import androidx.media3.common.util.BitmapLoader;
import androidx.media3.common.util.UnstableApi;
import com.google.common.base.Supplier;
import com.google.common.base.Suppliers;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.common.util.concurrent.MoreExecutors;
import java.io.IOException;
import java.util.concurrent.Executors;
/**
* A {@link BitmapLoader} implementation that uses a {@link DataSource} to support fetching images
* from URIs.
*
* <p>Loading tasks are delegated to a {@link ListeningExecutorService} defined during construction.
* If no executor service is passed, all tasks are delegated to a single-thread executor service
* that is shared between instances of this class.
*/
@UnstableApi
public final class DataSourceBitmapLoader implements BitmapLoader {
public static final Supplier<ListeningExecutorService> DEFAULT_EXECUTOR_SERVICE =
Suppliers.memoize(
() -> MoreExecutors.listeningDecorator(Executors.newSingleThreadExecutor()));
private final ListeningExecutorService listeningExecutorService;
private final DataSource.Factory dataSourceFactory;
/**
* Creates an instance that uses a {@link DefaultHttpDataSource} for image loading and delegates
* loading tasks to a {@link Executors#newSingleThreadExecutor()}.
*/
public DataSourceBitmapLoader(Context context) {
this(checkStateNotNull(DEFAULT_EXECUTOR_SERVICE.get()), new DefaultDataSource.Factory(context));
}
/**
* Creates an instance that delegates loading tasks to the {@link ListeningExecutorService}.
*
* @param listeningExecutorService The {@link ListeningExecutorService}.
* @param dataSourceFactory The {@link DataSource.Factory} that creates the {@link DataSource}
* used to load the image.
*/
public DataSourceBitmapLoader(
ListeningExecutorService listeningExecutorService, DataSource.Factory dataSourceFactory) {
this.listeningExecutorService = listeningExecutorService;
this.dataSourceFactory = dataSourceFactory;
}
@Override
public ListenableFuture<Bitmap> decodeBitmap(byte[] data) {
return listeningExecutorService.submit(() -> decode(data));
}
/** Loads an image from a {@link Uri}. */
@Override
public ListenableFuture<Bitmap> loadBitmap(Uri uri) {
return listeningExecutorService.submit(() -> load(dataSourceFactory.createDataSource(), uri));
}
private static Bitmap decode(byte[] data) {
@Nullable Bitmap bitmap = BitmapFactory.decodeByteArray(data, /* offset= */ 0, data.length);
checkArgument(bitmap != null, "Could not decode image data");
return bitmap;
}
private static Bitmap load(DataSource dataSource, Uri uri) throws IOException {
DataSpec dataSpec = new DataSpec(uri);
dataSource.open(dataSpec);
byte[] readData = DataSourceUtil.readToEnd(dataSource);
return decode(readData);
}
}