Moving some calls off the UI thread

This saves ~5ms in onNewIntent

Bug: 67305604
Change-Id: Ic97727b1c526e50bd3c8a1d8f511e1d7fd5e05e7

src/com/android/launcher3/util/UiThreadHelper.java

@@ -0,0 +1,76 @@
+/*
+ * 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.launcher3.util;
+
+import android.content.Context;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.IBinder;
+import android.os.Looper;
+import android.os.Message;
+import android.os.Process;
+import android.view.inputmethod.InputMethodManager;
+
+/**
+ * Utility class for offloading some class from UI thread
+ */
+public class UiThreadHelper {
+
+    private static HandlerThread sHandlerThread;
+    private static Handler sHandler;
+
+    private static final int MSG_HIDE_KEYBOARD = 1;
+
+    public static Looper getBackgroundLooper() {
+        if (sHandlerThread == null) {
+            sHandlerThread =
+                    new HandlerThread("UiThreadHelper", Process.THREAD_PRIORITY_FOREGROUND);
+            sHandlerThread.start();
+        }
+        return sHandlerThread.getLooper();
+    }
+
+    private static Handler getHandler(Context context) {
+        if (sHandler == null) {
+            sHandler = new Handler(getBackgroundLooper(),
+                    new UiCallbacks(context.getApplicationContext()));
+        }
+        return sHandler;
+    }
+
+    public static void hideKeyboardAsync(Context context, IBinder token) {
+        Message.obtain(getHandler(context), MSG_HIDE_KEYBOARD, token).sendToTarget();
+    }
+
+    private static class UiCallbacks implements Handler.Callback {
+
+        private final InputMethodManager mIMM;
+
+        UiCallbacks(Context context) {
+            mIMM = (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE);
+        }
+
+        @Override
+        public boolean handleMessage(Message message) {
+            switch (message.what) {
+                case MSG_HIDE_KEYBOARD:
+                    mIMM.hideSoftInputFromWindow((IBinder) message.obj, 0);
+                    return true;
+            }
+            return false;
+        }
+    }
+}