1 files changed, 49 insertions, 0 deletions
diff --git a/src/io/appium/droiddriver/helpers/DroidDriversInitializer.java b/src/io/appium/droiddriver/helpers/DroidDriversInitializer.java
new file mode 100644
index 0000000..727c97b
--- /dev/null
+++ b/src/io/appium/droiddriver/helpers/DroidDriversInitializer.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2015 DroidDriver committers
+ *
+ * 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 io.appium.droiddriver.helpers;
+
+import io.appium.droiddriver.DroidDriver;
+import io.appium.droiddriver.exceptions.UnrecoverableException;
+
+/**
+ * Calls {@link DroidDrivers#setSingleton} once and only once.
+ */
+public class DroidDriversInitializer extends SingleRun {
+  private static DroidDriversInitializer instance;
+  private final DroidDriver driver;
+
+  private DroidDriversInitializer(DroidDriver driver) {
+    this.driver = driver;
+  }
+
+  @Override
+  protected void run() {
+    DroidDrivers.setSingleton(driver);
+  }
+
+  public static synchronized DroidDriversInitializer get(DroidDriver driver) {
+    if (instance == null) {
+      instance = new DroidDriversInitializer(driver);
+    }
+
+    if (instance.driver != driver) {
+      throw new UnrecoverableException("The singleton DroidDriversInitializer has already been" +
+          " created with a different driver");
+    }
+    return instance;
+  }
+}