MediaBrowserService: Make SubscriptionCallback.onError be called
Bug: 26733259
Change-Id: I8324e1c56e87071e781550ac0701e632a4122e73
diff --git a/media/java/android/media/browse/MediaBrowser.java b/media/java/android/media/browse/MediaBrowser.java
index 9e67c15..ada0e2c 100644
--- a/media/java/android/media/browse/MediaBrowser.java
+++ b/media/java/android/media/browse/MediaBrowser.java
@@ -633,7 +633,6 @@
return;
}
- List<MediaItem> data = list == null ? null : list.getList();
if (DBG) {
Log.d(TAG, "onLoadChildren for " + mServiceComponent + " id=" + parentId);
}
@@ -644,10 +643,19 @@
// Tell the app.
SubscriptionCallback subscriptionCallback = subscription.getCallback(options);
if (subscriptionCallback != null) {
+ List<MediaItem> data = list == null ? null : list.getList();
if (options == null) {
- subscriptionCallback.onChildrenLoaded(parentId, data);
+ if (data == null) {
+ subscriptionCallback.onError(parentId);
+ } else {
+ subscriptionCallback.onChildrenLoaded(parentId, data);
+ }
} else {
- subscriptionCallback.onChildrenLoaded(parentId, data, options);
+ if (data == null) {
+ subscriptionCallback.onError(parentId, options);
+ } else {
+ subscriptionCallback.onChildrenLoaded(parentId, data, options);
+ }
}
return;
}
@@ -848,21 +856,21 @@
* Called when the list of children is loaded or updated.
*
* @param parentId The media id of the parent media item.
- * @param children The children which were loaded, or null if the id is invalid.
+ * @param children The children which were loaded.
*/
- public void onChildrenLoaded(@NonNull String parentId, List<MediaItem> children) {
+ public void onChildrenLoaded(@NonNull String parentId, @NonNull List<MediaItem> children) {
}
/**
* Called when the list of children is loaded or updated.
*
* @param parentId The media id of the parent media item.
- * @param children The children which were loaded, or null if the id is invalid.
+ * @param children The children which were loaded.
* @param options A bundle of service-specific arguments sent to the media
* browse service. The contents of this bundle may affect the
* information returned when browsing.
*/
- public void onChildrenLoaded(@NonNull String parentId, List<MediaItem> children,
+ public void onChildrenLoaded(@NonNull String parentId, @NonNull List<MediaItem> children,
@NonNull Bundle options) {
}
diff --git a/media/java/android/service/media/MediaBrowserService.java b/media/java/android/service/media/MediaBrowserService.java
index 480acd9..b5ea2a0 100644
--- a/media/java/android/service/media/MediaBrowserService.java
+++ b/media/java/android/service/media/MediaBrowserService.java
@@ -45,6 +45,7 @@
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.ArrayList;
+import java.util.Collections;
import java.util.HashMap;
import java.util.List;
@@ -120,8 +121,8 @@
* they are done. If more than one of those methods is called, an exception will
* be thrown.
*
- * @see MediaBrowserService#onLoadChildren
- * @see MediaBrowserService#onLoadItem
+ * @see #onLoadChildren
+ * @see #onLoadItem
*/
public class Result<T> {
private Object mDebug;
@@ -367,10 +368,16 @@
* {@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.
+ * </p><p>
+ * In case the media item does not have any children, call {@link Result#sendResult}
+ * with an empty list which is not {@code null}. If {@code null} is sent that means
+ * the given {@code parentId} is invalid and {@link MediaBrowser.SubscriptionCallback#onError}
+ * will be called.
+ * </p>
*
* @param parentId The id of the parent media item whose children are to be
* queried.
- * @param result The Result to send the list of children to, or null if the
+ * @param result The Result to send the list of children to. Send null if the
* id is invalid.
*/
public abstract void onLoadChildren(@NonNull String parentId,
@@ -385,10 +392,16 @@
* {@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.
+ * </p><p>
+ * In case the media item does not have any children, call {@link Result#sendResult}
+ * with an empty list which is not {@code null}. If {@code null} is sent that means
+ * the given {@code parentId} is invalid and {@link MediaBrowser.SubscriptionCallback#onError}
+ * will be called.
+ * </p>
*
* @param parentId The id of the parent media item whose children are to be
* queried.
- * @param result The Result to send the list of children to, or null if the
+ * @param result The Result to send the list of children to. Send null if the
* id is invalid.
* @param options A bundle of service-specific arguments sent from the media
* browse. The information returned through the result should be
@@ -416,7 +429,7 @@
*
* @param itemId The id for the specific
* {@link android.media.browse.MediaBrowser.MediaItem}.
- * @param result The Result to send the item to, or null if the id is
+ * @param result The Result to send the item to. Send null if the id is
* invalid.
*/
public void onLoadItem(String itemId, Result<MediaBrowser.MediaItem> result) {
@@ -630,6 +643,9 @@
private List<MediaBrowser.MediaItem> applyOptions(List<MediaBrowser.MediaItem> list,
final Bundle options) {
+ if (list == null) {
+ return null;
+ }
int page = options.getInt(MediaBrowser.EXTRA_PAGE, -1);
int pageSize = options.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1);
if (page == -1 && pageSize == -1) {
@@ -638,7 +654,7 @@
int fromIndex = pageSize * (page - 1);
int toIndex = fromIndex + pageSize;
if (page < 1 || pageSize < 1 || fromIndex >= list.size()) {
- return null;
+ return Collections.EMPTY_LIST;
}
if (toIndex > list.size()) {
toIndex = list.size();