Start accepting Executors instead of Handlers.

After discussion in API council, our new best-practices are to have
developers provide an Executor to dispatch callbacks/listeners on,
instead of the previous guidance of using a Handler.

Define Context.getMainExecutor() to easily obtain an Executor
associated with the main thread of application.  This allows new
APIs to require a @NonNull Executor.  Also define a new
@CallbackExecutor auto-doc annotation that explains background and
points developers at new Context method above.

Test: cts-tradefed run commandAndExit cts-dev -m CtsContentTestCases -t android.content.cts.ContextTest#testMainLooper
Test: cts-tradefed run commandAndExit cts-dev -m CtsContentTestCases -t android.content.cts.ContextTest#testMainExecutor
Bug: 70348426
Change-Id: I536892bcd80fcfba1bb1ddf67648c08a26d7ddd2

1 files changed, 8 insertions, 3 deletions

diff --git a/test-mock/src/android/test/mock/MockContext.java b/test-mock/src/android/test/mock/MockContext.java
index 5e5ba462cfca..4dfd0507f351 100644
--- a/test-mock/src/android/test/mock/MockContext.java
+++ b/test-mock/src/android/test/mock/MockContext.java
@@ -19,13 +19,12 @@ package android.test.mock;
 import android.annotation.SystemApi;
 import android.app.IApplicationThread;
 import android.app.IServiceConnection;
-import android.app.Notification;
+import android.content.BroadcastReceiver;
 import android.content.ComponentName;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
-import android.content.BroadcastReceiver;
 import android.content.IntentSender;
 import android.content.ServiceConnection;
 import android.content.SharedPreferences;
@@ -44,8 +43,8 @@ import android.os.Handler;
 import android.os.IBinder;
 import android.os.Looper;
 import android.os.UserHandle;
-import android.view.DisplayAdjustments;
 import android.view.Display;
+import android.view.DisplayAdjustments;
 
 import java.io.File;
 import java.io.FileInputStream;
@@ -53,6 +52,7 @@ import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.concurrent.Executor;
 
 /**
  * A mock {@link android.content.Context} class.  All methods are non-functional and throw
@@ -87,6 +87,11 @@ public class MockContext extends Context {
     }
 
     @Override
+    public Executor getMainExecutor() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
     public Context getApplicationContext() {
         throw new UnsupportedOperationException();
     }