Add UiThreadExecutor

This CL adds an executor which runs tasks on the Ui thread, using the existing
ThreadUtil class.

Bug: 67752611
Test: UiThreadExecutorTest
PiperOrigin-RevId: 175046280
Change-Id: Iff15e216be0e91891a9d63fddf1288ecbec41f83

1 files changed, 77 insertions, 0 deletions

diff --git a/java/com/android/dialer/common/concurrent/UiThreadExecutor.java b/java/com/android/dialer/common/concurrent/UiThreadExecutor.java
new file mode 100644
index 000000000..7b95d70ea
--- /dev/null
+++ b/java/com/android/dialer/common/concurrent/UiThreadExecutor.java
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2017 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 com.android.dialer.common.concurrent;
+
+import com.google.common.util.concurrent.AbstractListeningExecutorService;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.SettableFuture;
+import java.util.List;
+import java.util.concurrent.Callable;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * An ExecutorService that delegates to the UI thread. Rejects attempts to shut down, and all
+ * shutdown related APIs are unimplemented.
+ *
+ */
+public class UiThreadExecutor extends AbstractListeningExecutorService {
+
+  @Override
+  public void shutdown() {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public List<Runnable> shutdownNow() {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public boolean isShutdown() {
+    return false;
+  }
+
+  @Override
+  public boolean isTerminated() {
+    return false;
+  }
+
+  @Override
+  public boolean awaitTermination(long l, TimeUnit timeUnit) throws InterruptedException {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public <V> ListenableFuture<V> submit(final Callable<V> task) {
+    final SettableFuture<V> resultFuture = SettableFuture.create();
+    ThreadUtil.postOnUiThread(
+        () -> {
+          try {
+            resultFuture.set(task.call());
+          } catch (Exception e) {
+            // uncaught exceptions on the UI thread should crash the app
+            resultFuture.setException(e);
+            throw new RuntimeException(e);
+          }
+        });
+    return resultFuture;
+  }
+
+  @Override
+  public void execute(final Runnable runnable) {
+    ThreadUtil.postOnUiThread(runnable);
+  }
+}