Add ExecutorContentObserver.
This allows creating a ContentObserver with an Executor instead of a Handler.
This is currently done by creating an awkward constructor on ContentObserver that takes an Executor and an unused int to avoid breaking source compatibility. It is marked with @hide because it is really awkward.
ExecutorContentObserver, which is less weird, is also marked @hide. This could theoretically be unhidden, but will be valuable to platform source even as-is.
Change-Id: Ie3a0f200abcf1834cbf969186dc3a5aa11efb8a4
Fixes: 232409779
diff --git a/core/java/android/database/ContentObserver.java b/core/java/android/database/ContentObserver.java
index 39c9400..4322bed 100644
--- a/core/java/android/database/ContentObserver.java
+++ b/core/java/android/database/ContentObserver.java
@@ -31,6 +31,7 @@
import java.util.Arrays;
import java.util.Collection;
+import java.util.concurrent.Executor;
/**
* Receives call backs for changes to content.
@@ -54,6 +55,7 @@
private Transport mTransport; // guarded by mLock
Handler mHandler;
+ private final Executor mExecutor;
/**
* Creates a content observer.
@@ -62,6 +64,18 @@
*/
public ContentObserver(Handler handler) {
mHandler = handler;
+ mExecutor = null;
+ }
+
+ /**
+ * @hide
+ * Creates a content observer with an executor.
+ *
+ * @param executor The executor to run {@link #onChange} on, or null if none.
+ * @param unused a second argument to avoid source incompatibility.
+ */
+ public ContentObserver(@Nullable Executor executor, int unused) {
+ mExecutor = executor;
}
/**
@@ -306,12 +320,19 @@
/** @hide */
public final void dispatchChange(boolean selfChange, @NonNull Collection<Uri> uris,
@NotifyFlags int flags, @UserIdInt int userId) {
- if (mHandler == null) {
- onChange(selfChange, uris, flags, userId);
- } else {
+ if (mExecutor != null) {
+ mExecutor.execute(() -> {
+ onChange(selfChange, uris, flags, userId);
+ });
+ } else if (mHandler != null) {
+ // Supporting Handler directly rather than wrapping in a HandlerExecutor
+ // avoids introducing a RejectedExecutionException for legacy code when
+ // the post fails.
mHandler.post(() -> {
onChange(selfChange, uris, flags, userId);
});
+ } else {
+ onChange(selfChange, uris, flags, userId);
}
}
diff --git a/core/java/android/database/ExecutorContentObserver.java b/core/java/android/database/ExecutorContentObserver.java
new file mode 100644
index 0000000..3ea807d
--- /dev/null
+++ b/core/java/android/database/ExecutorContentObserver.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 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 android.database;
+
+import android.annotation.Nullable;
+
+import java.util.concurrent.Executor;
+
+/**
+ * @hide
+ *
+ * Receives callbacks for changes to content.
+ * Must be implemented by objects which are added to a {@link ContentObservable}.
+ */
+public abstract class ExecutorContentObserver extends ContentObserver {
+ /**
+ * Creates a content observer that uses an executor for change handling.
+ *
+ * @param executor The executor to run {@link #onChange} on, or null if none.
+ */
+ public ExecutorContentObserver(@Nullable Executor executor) {
+ super(executor, 0);
+ }
+}