Modify the check units flow so that it asks the user to pick either

metric or imperial. Metric is the default. Thus no longer need to
send the user to the 'Display' settings page.

MyTracks/src/com/google/android/apps/mytracks/MyTracksApplication.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2008 Google Inc.
+ *
+ * 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.google.android.apps.mytracks;
+
+import com.google.android.apps.mytracks.content.TrackDataHub;
+
+import android.app.Application;
+
+/**
+ * MyTracksApplication for keeping global state.
+ *
+ * @author jshih@google.com (Jimmy Shih)
+ */
+public class MyTracksApplication extends Application {
+
+  private TrackDataHub trackDataHub;
+
+  /**
+   * Gets the application's TrackDataHub.
+   * 
+   * Note: use synchronized to make sure only one instance is created per application.
+   */
+  public synchronized TrackDataHub getTrackDataHub() {
+    if (trackDataHub == null) {
+      trackDataHub = TrackDataHub.newInstance(getApplicationContext());
+    }
+    return trackDataHub;
+  }
+}