Add a utility of isLowRamDevice

Bug: 8967766

Change-Id: Id7132d1155bb3489bdab72d613289335945808e8

java/src/com/android/inputmethod/compat/ActivityManagerCompatUtils.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2013 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.inputmethod.compat;
+
+import android.app.ActivityManager;
+import android.content.Context;
+
+import java.lang.reflect.Method;
+
+public class ActivityManagerCompatUtils {
+    private static final Object LOCK = new Object();
+    private static volatile Boolean sBoolean = null;
+    private static final Method METHOD_isLowRamDevice = CompatUtils.getMethod(
+            ActivityManager.class, "isLowRamDevice");
+
+    private ActivityManagerCompatUtils() {
+        // Do not instantiate this class.
+    }
+
+    public static boolean isLowRamDevice(Context context) {
+        if (sBoolean == null) {
+            synchronized(LOCK) {
+                if (sBoolean == null) {
+                    final ActivityManager am =
+                            (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
+                    sBoolean = (Boolean)CompatUtils.invoke(am, false, METHOD_isLowRamDevice);
+                }
+            }
+        }
+        return sBoolean;
+    }
+}