A few fixes.

- use fill_parent since we are still supporting api level 7.
- on the TrackListActivity, hide the empty view content
  until the check unit dialog has been showned.
- fix the ChartView height. ChartView is no longer displayed
  on the full canvas. The new design has a tab bar and a
  zoom control.
- In TrackDetailActivity, only call methods of a tab fragment
  if it is the current tab.

MyTracks/src/com/google/android/apps/mytracks/fragments/CheckUnitsDialogFragment.java

@@ -17,6 +17,7 @@
 package com.google.android.apps.mytracks.fragments;
 
 import com.google.android.apps.mytracks.Constants;
+import com.google.android.apps.mytracks.TrackListActivity;
 import com.google.android.apps.mytracks.util.ApiAdapterFactory;
 import com.google.android.apps.mytracks.util.CheckUnitsUtils;
 import com.google.android.maps.mytracks.R;
@@ -31,13 +32,13 @@ import android.support.v4.app.DialogFragment;
 
 /**
  * A DialogFragment to check preferred units.
- * 
+ *
  * @author Jimmy Shih
  */
 public class CheckUnitsDialogFragment extends DialogFragment {
 
   public static final String CHECK_UNITS_DIALOG_TAG = "checkUnitsDialog";
-  
+
   @Override
   public Dialog onCreateDialog(Bundle savedInstanceState) {
 
@@ -46,19 +47,18 @@ public class CheckUnitsDialogFragment extends DialogFragment {
         .setOnCancelListener(new DialogInterface.OnCancelListener() {
           @Override
           public void onCancel(DialogInterface dialog) {
-            CheckUnitsUtils.setCheckUnitsValue(getActivity());
+            handleButtonClicked();
           }
         })
         .setPositiveButton(R.string.generic_ok, new DialogInterface.OnClickListener() {
           @Override
           public void onClick(DialogInterface dialog, int which) {
-            CheckUnitsUtils.setCheckUnitsValue(getActivity());
-
             int position = ((AlertDialog) dialog).getListView().getSelectedItemPosition();
             SharedPreferences sharedPreferences = getActivity()
                 .getSharedPreferences(Constants.SETTINGS_NAME, Context.MODE_PRIVATE);
             ApiAdapterFactory.getApiAdapter().applyPreferenceChanges(sharedPreferences.edit()
                 .putBoolean(getString(R.string.metric_units_key), position == 0));
+            handleButtonClicked();
           }
         })
         .setSingleChoiceItems(new CharSequence[] { getString(R.string.preferred_units_metric),
@@ -66,4 +66,13 @@ public class CheckUnitsDialogFragment extends DialogFragment {
         .setTitle(R.string.preferred_units_title)
         .create();
   }
+
+  /**
+   * Handles a button click.
+   */
+  private void handleButtonClicked() {
+    CheckUnitsUtils.setCheckUnitsValue(getActivity());
+    TrackListActivity trackListActivity = (TrackListActivity) getActivity();
+    trackListActivity.enableEmptyView();
+  }
 }