Allow apps to be slow at loading children and thumbnails by making those... (69b07859) · Commits · e / os / android_frameworks_base

api/current.txt

+7 −2

Original line number	Diff line number	Diff line
		@@ -16235,8 +16235,8 @@ package android.media.browse {
		method public void notifyChildrenChanged(android.net.Uri);
		method public android.os.IBinder onBind(android.content.Intent);
		method public abstract android.media.browse.MediaBrowserService.BrowserRoot onGetRoot(java.lang.String, int, android.os.Bundle);
		method public abstract android.graphics.Bitmap onGetThumbnail(android.net.Uri, int, int);
		method public abstract java.util.List<android.media.browse.MediaBrowserItem> onLoadChildren(android.net.Uri);
		method protected abstract void onLoadChildren(android.net.Uri, android.media.browse.MediaBrowserService.Result<java.util.List<android.media.browse.MediaBrowserItem>>);
		method protected abstract void onLoadThumbnail(android.net.Uri, int, int, android.media.browse.MediaBrowserService.Result<android.graphics.Bitmap>);
		method public void setSessionToken(android.media.session.MediaSession.Token);
		field public static final java.lang.String SERVICE_ACTION = "android.media.browse.MediaBrowserService";
		}
		@@ -16247,6 +16247,11 @@ package android.media.browse {
		method public android.net.Uri getRootUri();
		}

		public class MediaBrowserService.Result {
		method public void detach();
		method public void sendResult(T);
		}

		}

		package android.media.effect {

media/java/android/media/browse/MediaBrowserService.java

+154 −24

Original line number	Diff line number	Diff line
		@@ -70,6 +70,13 @@ import java.util.Set;
		*/
		public abstract class MediaBrowserService extends Service {
		private static final String TAG = "MediaBrowserService";
		private static final boolean DBG = false;

		/**
		* The {@link Intent} that must be declared as handled by the service.
		*/
		@SdkConstant(SdkConstantType.SERVICE_ACTION)
		public static final String SERVICE_ACTION = "android.media.browse.MediaBrowserService";

		private final ArrayMap<IBinder, ConnectionRecord> mConnections = new ArrayMap();
		private final Handler mHandler = new Handler();
		@@ -88,10 +95,65 @@ public abstract class MediaBrowserService extends Service {
		}

		/**
		* The {@link Intent} that must be declared as handled by the service.
		* Completion handler for asynchronous callback methods in {@link MediaBrowserService}.
		* <p>
		* Each of the methods that takes one of these to send the result must call
		* {@link #sendResult} to respond to the caller with the given results. If those
		* functions return without calling {@link #sendResult}, they must instead call
		* {@link #detach} before returning, and then may call {@link #sendResult} when
		* they are done. If more than one of those methods is called, an exception will
		* be thrown.
		*
		* @see MediaBrowserService#onLoadChildren
		* @see MediaBrowserService#onLoadThumbnail
		*/
		@SdkConstant(SdkConstantType.SERVICE_ACTION)
		public static final String SERVICE_ACTION = "android.media.browse.MediaBrowserService";
		public class Result<T> {
		private Object mDebug;
		private boolean mDetachCalled;
		private boolean mSendResultCalled;

		Result(Object debug) {
		mDebug = debug;
		}

		/**
		* Send the result back to the caller.
		*/
		public void sendResult(T result) {
		if (mSendResultCalled) {
		throw new IllegalStateException("sendResult() called twice for: " + mDebug);
		}
		mSendResultCalled = true;
		onResultSent(result);
		}

		/**
		* Detach this message from the current thread and allow the {@link #sendResult}
		* call to happen later.
		*/
		public void detach() {
		if (mDetachCalled) {
		throw new IllegalStateException("detach() called when detach() had already"
		+ " been called for: " + mDebug);
		}
		if (mSendResultCalled) {
		throw new IllegalStateException("detach() called when sendResult() had already"
		+ " been called for: " + mDebug);
		}
		mDetachCalled = true;
		}

		boolean isDone() {
		return mDetachCalled \|\| mSendResultCalled;
		}

		/**
		* Called when the result is sent, after assertions about not being called twice
		* have happened.
		*/
		void onResultSent(T result) {
		}
		}

		private class ServiceBinder extends IMediaBrowserService.Stub {
		@Override
		@@ -206,14 +268,51 @@ public abstract class MediaBrowserService extends Service {
		@Override
		public void loadThumbnail(final Uri uri, final int width, final int height,
		final IMediaBrowserServiceCallbacks callbacks) {
		if (uri == null) {
		throw new IllegalStateException("loadThumbnail sent null list for uri " + uri);
		}
		mHandler.post(new Runnable() {
		@Override
		public void run() {
		Bitmap bitmap = onGetThumbnail(uri, width, height);
		// In theory we could return a result to a new connection, but in practice
		// the other side in MediaBrowser uses a new IMediaBrowserServiceCallbacks
		// object every time it calls connect(), so as long as it does that we won't
		// see results sent for the wrong connection.
		final ConnectionRecord connection = mConnections.get(callbacks.asBinder());
		if (connection == null) {
		if (DBG) {
		Log.d(TAG, "Not loading bitmap for invalid connection. uri=" + uri);
		}
		return;
		}

		final Result<Bitmap> result = new Result<Bitmap>(uri) {
		@Override
		void onResultSent(Bitmap bitmap) {
		if (mConnections.get(connection.callbacks.asBinder()) != connection) {
		if (DBG) {
		Log.d(TAG, "Not sending onLoadThumbnail result for connection"
		+ " that has been disconnected. pkg=" + connection.pkg
		+ " uri=" + uri);
		}
		return;
		}

		try {
		callbacks.onLoadThumbnail(uri, width, height, bitmap);
		} catch (RemoteException e) {
		Log.e(TAG, "RemoteException in calling onLoadThumbnail", e);
		// The other side is in the process of crashing.
		Log.w(TAG, "RemoteException in calling onLoadThumbnail", e);
		}
		}
		};

		onLoadThumbnail(uri, width, height, result);

		if (!result.isDone()) {
		throw new IllegalStateException("onLoadThumbnail must call detach() or"
		+ " sendResult() before returning for package=" + connection.pkg
		+ " uri=" + uri);
		}
		}
		});
		@@ -261,15 +360,28 @@ public abstract class MediaBrowserService extends Service {

		/**
		* Called to get information about the children of a media item.
		* <p>
		* Implementations must call result.{@link Result#sendResult result.sendResult} with the list
		* of children. If loading the children will be an expensive operation that should be performed
		* on another thread, result.{@link Result#detach result.detach} may be called before returning
		* from this function, and then {@link Result#sendResult result.sendResult} called when
		* the loading is complete.
		*
		* @param parentUri The uri of the parent media item whose
		* children are to be queried.
		* @return The list of children, or null if the uri is invalid.
		*/
		public abstract @Nullable List<MediaBrowserItem> onLoadChildren(@NonNull Uri parentUri);
		protected abstract void onLoadChildren(@NonNull Uri parentUri,
		@NonNull Result<List<MediaBrowserItem>> result);

		/**
		* Called to get the thumbnail of a particular media item.
		* <p>
		* Implementations must call result.{@link Result#sendResult result.sendResult} with the bitmap.
		* If loading the bitmap will be an expensive operation that should be performed
		* on another thread, result.{@link Result#detach result.detach} may be called before returning
		* from this function, and then {@link Result#sendResult result.sendResult} called when
		* the loading is complete.
		*
		* @param uri The uri of the media item.
		* @param width The requested width of the icon in dp.
		@@ -278,7 +390,8 @@ public abstract class MediaBrowserService extends Service {
		* @return The file descriptor of the thumbnail, which may then be loaded
		* using a bitmap factory, or null if the item does not have a thumbnail.
		*/
		public abstract @Nullable Bitmap onGetThumbnail(@NonNull Uri uri, int width, int height);
		protected abstract void onLoadThumbnail(@NonNull Uri uri, int width, int height,
		@NonNull Result<Bitmap> result);

		/**
		* Call to set the media session.
		@@ -363,14 +476,22 @@ public abstract class MediaBrowserService extends Service {
		* Call onLoadChildren and then send the results back to the connection.
		* <p>
		* Callers must make sure that this connection is still connected.
		* <p>
		* TODO: Think about caching and combining these calls.
		*/
		private void performLoadChildren(Uri uri, ConnectionRecord connection) {
		final List<MediaBrowserItem> list = onLoadChildren(uri);
		private void performLoadChildren(final Uri uri, final ConnectionRecord connection) {
		final Result<List<MediaBrowserItem>> result = new Result<List<MediaBrowserItem>>(uri) {
		@Override
		void onResultSent(List<MediaBrowserItem> list) {
		if (list == null) {
		throw new IllegalStateException("onLoadChildren returned null for uri " + uri);
		throw new IllegalStateException("onLoadChildren sent null list for uri " + uri);
		}
		if (mConnections.get(connection.callbacks.asBinder()) != connection) {
		if (DBG) {
		Log.d(TAG, "Not sending onLoadChildren result for connection that has"
		+ " been disconnected. pkg=" + connection.pkg + " uri=" + uri);
		}
		return;
		}

		final ParceledListSlice<MediaBrowserItem> pls = new ParceledListSlice(list);
		try {
		connection.callbacks.onLoadChildren(uri, pls);
		@@ -380,6 +501,15 @@ public abstract class MediaBrowserService extends Service {
		+ " package=" + connection.pkg);
		}
		}
		};

		onLoadChildren(uri, result);

		if (!result.isDone()) {
		throw new IllegalStateException("onLoadChildren must call detach() or sendResult()"
		+ " before returning for package=" + connection.pkg + " uri=" + uri);
		}
		}

		/**
		* Contains information that the browser service needs to send to the client

tests/MusicServiceDemo/src/com/example/android/musicservicedemo/BrowserService.java

+20 −14

Original line number	Diff line number	Diff line
		@@ -121,23 +121,29 @@ public class BrowserService extends MediaBrowserService {
		}

		@Override
		protected List<MediaBrowserItem> onLoadChildren(Uri parentUri) {
		final ArrayList<MediaBrowserItem> results = new ArrayList();
		protected void onLoadChildren(final Uri parentUri,
		final Result<List<MediaBrowserItem>> result) {
		new Handler().postDelayed(new Runnable() {
		public void run() {
		final ArrayList<MediaBrowserItem> list = new ArrayList();

		for (int i=0; i<10; i++) {
		results.add(new MediaBrowserItem.Builder(
		list.add(new MediaBrowserItem.Builder(
		Uri.withAppendedPath(BASE_URI, Integer.toString(i)),
		MediaBrowserItem.FLAG_BROWSABLE, "Title " + i)
		.setSummary("Summary " + i)
		.build());
		}

		return results;
		result.sendResult(list);
		}
		}, 2000);
		result.detach();
		}

		@Override
		protected Bitmap onGetThumbnail(Uri uri, int width, int height) {
		return null;
		protected void onLoadThumbnail(Uri uri, int width, int height, Result<Bitmap> result) {
		result.sendResult(null);
		}

		/*