A lot of cleanup:

* Splitting ExternalFileBackup into UI and non-UI parts
* Disabling backups while recording
* Triggering cloud backups when preferences are changed

MyTracks/AndroidManifest.xml

@@ -65,6 +65,9 @@
     <activity android:name="com.google.android.apps.mytracks.WelcomeActivity"
               android:label="@string/welcome"/>
 
+    <activity android:name="com.google.android.apps.mytracks.io.backup.BackupActivity"
+              android:label="@string/settings_backup" />
+
     <service android:name="com.google.android.apps.mytracks.services.TrackRecordingService"
              android:process=":trackrecord"
              android:label="Track Recording Service"

MyTracks/res/values/keys.xml

@@ -15,7 +15,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 -->
 <resources>
-  <!-- These are constants used internally for preferences - DO NOT TRANSLATE -->
+  <!-- Keys for application preferences - DO NOT TRANSLATE -->
   <string name="announcement_frequency_key">announcementFrequency</string>
   <string name="bluetooth_device_key">bluetoothDevice</string>
   <string name="bluetooth_pairing_key">bluetoothPairing</string>
@@ -28,9 +28,7 @@ limitations under the License.
   <string name="min_required_accuracy_key">minRequiredAccuracy</string>
   <string name="modular_stats_display_key">modularStatsDisplay</string>
   <string name="pick_existing_map_key">pickExistingMap</string>
-  <string name="recording_track_key">recordingTrack</string>
   <string name="report_speed_key">reportSpeed</string>
-  <string name="selected_track_key">selectedTrack</string>
   <string name="send_stats_and_points_key">sendStatsAndPoints</string>
   <string name="send_to_docs_key">sendToDocs</string>
   <string name="send_to_my_maps_key">sendToMyMaps</string>
@@ -39,6 +37,12 @@ limitations under the License.
   <string name="share_url_only_key">shareUrlOnly</string>
   <string name="signal_sampling_frequency_key">signalSamplingFrequency</string>
   <string name="split_frequency_key">splitFrequency</string>
+
+  <!-- Preference keys which keep transient state (not user preferences) - DO NOT TRANSLATE -->
+  <string name="recording_track_key">recordingTrack</string>
+  <string name="selected_track_key">selectedTrack</string>
+
+  <!-- Keys for non-persisted preferences - DO NOT TRANSLATE -->
   <string name="backup_to_sd_key">backupToSd</string>
   <string name="restore_from_sd_key">restoreFromSd</string>
 </resources>

MyTracks/res/values/strings.xml

@@ -222,16 +222,17 @@ limitations under the License.
   <string name="settings_backup">Backup</string>
   <string name="settings_sd_backup">SD Card Backup</string>
   <string name="settings_backup_to_sd">Backup now</string>
-  <string name="settings_backup_to_sd_summary">Write a full backup of all your tracks to the SD card</string>
+  <string name="settings_backup_to_sd_summary">Write a full copy of all your tracks and settings to the SD card</string>
   <string name="settings_restore_from_sd">Restore now</string>
-  <string name="settings_restore_from_sd_summary">Restore a backup from the SD card</string>
+  <string name="settings_restore_from_sd_summary">Restore all tracks and settings from the SD card</string>
+  <string name="settings_no_backup_while_recording">Cannot manipulate backups while recording a track.</string>
 
   <!-- Backups -->
-  <string name="restore_overwrites_warning">Restoring a backup from the SD card will OVERWRITE all your current tracks. Are you sure?</string>
+  <string name="restore_overwrites_warning">Restoring a backup from the SD card will OVERWRITE all your current tracks and settings. Are you sure?</string>
   <string name="select_backup_to_restore">Select the backup to restore</string>
   <string name="no_backups">No backups found.</string>
-  <string name="backup_write_progress_message">Writing all tracks to the SD card. This may take a while...</string>
-  <string name="backup_import_progress_message">Reading all tracks from the SD card. This may take a while...</string>
+  <string name="backup_write_progress_message">Writing all tracks and settings to the SD card. This may take a while...</string>
+  <string name="backup_import_progress_message">Reading all tracks and settings from the SD card. This may take a while...</string>
 
   <!-- MyTracksSky -->
   <string name="mytracks_sky">GPS Satellites</string>

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

@@ -15,10 +15,13 @@
  */
 package com.google.android.apps.mytracks;
 
-import com.google.android.apps.mytracks.io.backup.ExternalFileBackup;
+import com.google.android.apps.mytracks.io.backup.BackupActivity;
+import com.google.android.apps.mytracks.io.backup.BackupPreferencesListener;
 import com.google.android.apps.mytracks.services.SafeStatusAnnouncerTask;
 import com.google.android.maps.mytracks.R;
 
+import android.content.Intent;
+import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.preference.CheckBoxPreference;
 import android.preference.ListPreference;
@@ -50,6 +53,9 @@ public class MyTracksSettings extends PreferenceActivity {
   public static final int DEFAULT_SPLIT_FREQUENCY = 0;
 
   private static boolean mTTSAvailable;
+  private BackupPreferencesListener backupListener;
+
+  private SharedPreferences preferences;
 
   /* establish whether the tts class is available to us */
   static {
@@ -72,6 +78,11 @@ public class MyTracksSettings extends PreferenceActivity {
     preferenceManager.setSharedPreferencesName(SETTINGS_NAME);
     preferenceManager.setSharedPreferencesMode(0);
 
+    // Set up automatic preferences backup
+    backupListener = BackupPreferencesListener.create(this);
+    preferences = preferenceManager.getSharedPreferences();
+    preferences.registerOnSharedPreferenceChangeListener(backupListener);
+
     // Load the preferences to be displayed
     addPreferencesFromResource(R.xml.preferences);
 
@@ -101,28 +112,55 @@ public class MyTracksSettings extends PreferenceActivity {
       announcementFrequency.setSummary(
           R.string.settings_announcement_not_available_summary);
     }
+  }
+
+  @Override
+  protected void onResume() {
+    super.onResume();
 
-    // Add actions to the backup preferences
     Preference backupNowPreference = findPreference(getString(R.string.backup_to_sd_key));
     Preference restoreNowPreference = findPreference(getString(R.string.restore_from_sd_key));
+
+    // If recording, disable backup/restore (we don't want to get to inconsistent states)
+    boolean recording = preferences.getLong(getString(R.string.recording_track_key), -1) != -1;
+    backupNowPreference.setEnabled(!recording);
+    restoreNowPreference.setEnabled(!recording);
+    backupNowPreference.setSummary(
+        recording ? R.string.settings_no_backup_while_recording
+                  : R.string.settings_backup_to_sd_summary);
+    restoreNowPreference.setSummary(
+        recording ? R.string.settings_no_backup_while_recording
+                  : R.string.settings_restore_from_sd_summary);
+
+    // Add actions to the backup preferences
     backupNowPreference.setOnPreferenceClickListener(new OnPreferenceClickListener() {
       @Override
       public boolean onPreferenceClick(Preference preference) {
-        ExternalFileBackup helper = new ExternalFileBackup(MyTracksSettings.this);
-        helper.writeToDefaultFile();
+        Intent intent = new Intent(MyTracksSettings.this, BackupActivity.class);
+        intent.setAction(BackupActivity.BACKUP_ACTION);
+        startActivity(intent);
         return true;
       }
     });
     restoreNowPreference.setOnPreferenceClickListener(new OnPreferenceClickListener() {
       @Override
       public boolean onPreferenceClick(Preference preference) {
-        ExternalFileBackup helper = new ExternalFileBackup(MyTracksSettings.this);
-        helper.restoreFromFileList();
+        Intent intent = new Intent(MyTracksSettings.this, BackupActivity.class);
+        intent.setAction(BackupActivity.RESTORE_ACTION);
+        startActivity(intent);
         return true;
       }
     });
   }
 
+  @Override
+  protected void onDestroy() {
+    getPreferenceManager().getSharedPreferences()
+        .unregisterOnSharedPreferenceChangeListener(backupListener);
+
+    super.onPause();
+  }
+
   /**
    * Updates all the preferences which give options with distance units to use
    * the proper unit the user has selected.

MyTracks/src/com/google/android/apps/mytracks/io/backup/BackupActivity.java

@@ -0,0 +1,278 @@
+/*
+ * Copyright 2010 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.io.backup;
+
+import com.google.android.apps.mytracks.MyTracks;
+import com.google.android.apps.mytracks.util.FileUtils;
+import com.google.android.maps.mytracks.R;
+
+import android.app.Activity;
+import android.app.AlertDialog;
+import android.app.AlertDialog.Builder;
+import android.app.Dialog;
+import android.app.ProgressDialog;
+import android.content.DialogInterface;
+import android.content.DialogInterface.OnCancelListener;
+import android.content.DialogInterface.OnClickListener;
+import android.content.Intent;
+import android.os.Bundle;
+import android.widget.Toast;
+
+import java.io.IOException;
+import java.text.SimpleDateFormat;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.Date;
+
+/**
+ * Activity which shows a UI for writing or restoring a backup,
+ * and calls the approriate handler for actually executing those
+ * operations.
+ *
+ * @author Rodrigo Damazio
+ */
+public class BackupActivity extends Activity {
+
+  // Since the user sees this format, we use the local timezone
+  private static final SimpleDateFormat DISPLAY_BACKUP_FORMAT =
+      new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
+
+  private static final Comparator<Date> REVERSE_DATE_ORDER =
+      new Comparator<Date>() {
+        @Override
+        public int compare(Date s1, Date s2) {
+          return s2.compareTo(s1);
+        }
+      };
+
+  public static final String BACKUP_ACTION = "backup";
+  public static final String RESTORE_ACTION = "restore";
+
+  private final FileUtils fileUtils = new FileUtils();
+  private final ExternalFileBackup backup = new ExternalFileBackup(this, fileUtils);
+
+  @Override
+  protected void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+
+    Intent intent = getIntent();
+    if (intent != null) {
+      String action = intent.getAction();
+      if (action != null) {
+        if (action.equals(BACKUP_ACTION)) {
+          writeBackup();
+        } else if (action.equals(RESTORE_ACTION)) {
+          restoreBackup();
+        } else {
+          throw new IllegalArgumentException("Unknown action: " + action);
+        }
+      }
+    }
+  }
+
+  /**
+   * Writes a full backup to the default file.
+   * This shows the results to the user.
+   */
+  private void writeBackup() {
+    if (!fileUtils.isSdCardAvailable()) {
+      showToast(R.string.io_no_external_storage_found);
+      finish();
+      return;
+    }
+
+    if (!backup.isBackupsDirectoryAvailable(true)) {
+      showToast(R.string.io_create_dir_failed);
+      finish();
+      return;
+    }
+
+    final ProgressDialog progressDialog = ProgressDialog.show(
+        this,
+        getString(R.string.progress_title),
+        getString(R.string.backup_write_progress_message),
+        true);
+
+    // Do the writing in another thread
+    new Thread() {
+      @Override
+      public void run() {
+        try {
+          backup.writeToDefaultFile();
+          showToast(R.string.io_write_finished);
+        } catch (IOException e) {
+          showToast(R.string.io_write_failed);
+          return;
+        } finally {
+          dismissDialog(progressDialog);
+          finish();
+        }
+      }
+    }.start();
+  }
+
+  /**
+   * Restores a full backup from the SD card.
+   * The user will be given a choice of which backup to restore as well as a
+   * confirmation dialog.
+   */
+  private void restoreBackup() {
+    // Get the list of existing backups
+    if (!fileUtils.isSdCardAvailable()) {
+      showToast(R.string.io_no_external_storage_found);
+      finish();
+      return;
+    }
+
+    if (!backup.isBackupsDirectoryAvailable(false)) {
+      showToast(R.string.no_backups);
+      finish();
+      return;
+    }
+
+    final Date[] backupDates = backup.getAvailableBackups();
+    if (backupDates == null || backupDates.length == 0) {
+      showToast(R.string.no_backups);
+      finish();
+      return;
+    }
+    Arrays.sort(backupDates, REVERSE_DATE_ORDER);
+
+    // Show a confirmation dialog
+    Builder confirmationDialogBuilder = new AlertDialog.Builder(this);
+    confirmationDialogBuilder.setMessage(R.string.restore_overwrites_warning);
+    confirmationDialogBuilder.setCancelable(false);
+    confirmationDialogBuilder.setNegativeButton(android.R.string.no, new OnClickListener() {
+      @Override
+      public void onClick(DialogInterface dialog, int which) {
+        BackupActivity.this.finish();
+      }
+    });
+    confirmationDialogBuilder.setPositiveButton(android.R.string.yes, new OnClickListener() {
+      @Override
+      public void onClick(DialogInterface dialog, int which) {
+        pickBackupForRestore(backupDates);
+      }
+    });
+    confirmationDialogBuilder.create().show();
+  }
+
+  /**
+   * Shows a backup list for the user to pick, then restores it.
+   *
+   * @param backupDir the backup directory
+   * @param backupDates the list of available backup files
+   */
+  private void pickBackupForRestore(final Date[] backupDates) {
+    if (backupDates.length == 1) {
+      // Only one choice, don't bother showing the list
+      restoreFromDateAsync(backupDates[0]);
+      finish();
+      return;
+    }
+
+    // Make a user-visible version of the backup filenames
+    final String backupDateStrs[] = new String[backupDates.length];
+    for (int i = 0; i < backupDates.length; i++) {
+      backupDateStrs[i] = DISPLAY_BACKUP_FORMAT.format(backupDates[i]);
+    }
+
+    // Show a dialog for the user to pick which backup to restore
+    Builder dialogBuilder = new AlertDialog.Builder(this);
+    dialogBuilder.setCancelable(true);
+    dialogBuilder.setTitle(R.string.select_backup_to_restore);
+    dialogBuilder.setItems(backupDateStrs, new OnClickListener() {
+      @Override
+      public void onClick(DialogInterface dialog, int which) {
+        // User picked to restore this one
+        restoreFromDateAsync(backupDates[which]);
+      }
+    });
+    dialogBuilder.setOnCancelListener(new OnCancelListener() {
+      @Override
+      public void onCancel(DialogInterface dialog) {
+        BackupActivity.this.finish();
+      }
+    });
+    dialogBuilder.create().show();
+  }
+
+  /**
+   * Shows a progress dialog, then starts restoring the backup osynchronously.
+   *
+   * @param inputFile the file to restore from
+   */
+  private void restoreFromDateAsync(final Date date) {
+    // Show a progress dialog
+    final ProgressDialog progressDialog = ProgressDialog.show(
+        this,
+        getString(R.string.progress_title),
+        getString(R.string.backup_import_progress_message),
+        true);
+
+    // Do the actual importing in another thread (don't block the UI)
+    new Thread() {
+      @Override
+      public void run() {
+        try {
+          backup.restoreFromDate(date);
+          showToast(R.string.io_read_finished);
+        } catch (IOException e) {
+          showToast(R.string.io_read_failed);
+        } finally {
+          dismissDialog(progressDialog);
+
+          // Data may have been restored, "reboot" the app to catch it
+          restartApplication();
+        }
+      }
+    }.start();
+  }
+
+  /**
+   * Restarts My Tracks completely.
+   * This forces any modified data to be re-read.
+   */
+  private void restartApplication() {
+    Intent intent = new Intent(this, MyTracks.class);
+    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+    startActivity(intent);
+  }
+
+  /**
+   * Shows a toast with the given contents.
+   */
+  private void showToast(final int resId) {
+    runOnUiThread(new Runnable() {
+      @Override
+      public void run() {
+        Toast.makeText(BackupActivity.this, resId, Toast.LENGTH_LONG).show();
+      }
+    });
+  }
+
+  /**
+   * Safely dismisses the given dialog.
+   */
+  private void dismissDialog(final Dialog dialog) {
+    runOnUiThread(new Runnable() {
+      @Override
+      public void run() {
+        dialog.dismiss();
+      }
+    });
+  }
+}

MyTracks/src/com/google/android/apps/mytracks/io/backup/BackupPreferencesListener.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2010 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.io.backup;
+
+import com.google.android.apps.mytracks.MyTracksConstants;
+
+import android.app.backup.BackupManager;
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
+
+/**
+ * Shared preferences listener which notifies the backup system about new data
+ * being available for backup.
+ * This class is API-version-safe and will provide a dummy implementation if
+ * the device doesn't support backup services.
+ *
+ * @author Rodrigo Damazio
+ */
+public abstract class BackupPreferencesListener implements OnSharedPreferenceChangeListener {
+
+  /**
+   * Real implementation of the listener, which calls the {@link BackupManager}.
+   */
+  private static class BackupPreferencesListenerImpl extends BackupPreferencesListener {
+    private final BackupManager backupManager;
+
+    public BackupPreferencesListenerImpl(Context context) {
+      this.backupManager = new BackupManager(context);
+    }
+
+    @Override
+    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
+      backupManager.dataChanged();
+    }
+  }
+
+  /**
+   * Dummy implementation of the listener which does nothing.
+   */
+  private static class DummyBackupPreferencesListener extends BackupPreferencesListener {
+    @Override
+    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
+      // Do nothing
+    }
+  }
+
+  /**
+   * Creates and returns a proper instance of the listener for this device.
+   */
+  public static BackupPreferencesListener create(Context context) {
+    if (MyTracksConstants.ANDROID_API_LEVEL >= 8) {
+      return new BackupPreferencesListenerImpl(context);
+    } else {
+      return new DummyBackupPreferencesListener();
+    }
+  }
+}

MyTracks/src/com/google/android/apps/mytracks/io/backup/ExternalFileBackup.java

@@ -21,34 +21,24 @@ import com.google.android.apps.mytracks.content.TrackPointsColumns;
 import com.google.android.apps.mytracks.content.TracksColumns;
 import com.google.android.apps.mytracks.content.WaypointsColumns;
 import com.google.android.apps.mytracks.util.FileUtils;
-import com.google.android.maps.mytracks.R;
 
-import android.app.AlertDialog;
-import android.app.AlertDialog.Builder;
-import android.app.Dialog;
-import android.app.ProgressDialog;
 import android.content.ContentResolver;
 import android.content.Context;
-import android.content.DialogInterface;
-import android.content.DialogInterface.OnClickListener;
 import android.content.SharedPreferences;
 import android.database.Cursor;
-import android.os.Handler;
 import android.util.Log;
-import android.widget.Toast;
 
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
-import java.io.FilenameFilter;
 import java.io.IOException;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
-import java.util.Arrays;
-import java.util.Comparator;
+import java.util.ArrayList;
 import java.util.Date;
+import java.util.List;
 import java.util.TimeZone;
 
 /**
@@ -56,7 +46,7 @@ import java.util.TimeZone;
  *
  * @author Rodrigo Damazio
  */
-public class ExternalFileBackup {
+class ExternalFileBackup {
   // Filename format - in UTC
   private static final SimpleDateFormat BACKUP_FILENAME_FORMAT =
       new SimpleDateFormat("'backup-'yyyy-MM-dd_HH-mm-ss");
@@ -64,232 +54,95 @@ public class ExternalFileBackup {
     BACKUP_FILENAME_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
   }
 
-  // Since the user sees this format, we use the local timezone
-  private static final SimpleDateFormat DISPLAY_BACKUP_FORMAT =
-      new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
-
   private static final String BACKUPS_SUBDIR = "backups";
   private static final int BACKUP_FILE_VERSION = 1;
-  
-  private static final Comparator<String> REVERSE_STRING_COMPARATOR =
-      new Comparator<String>() {
-        @Override
-        public int compare(String s1, String s2) {
-          return s2.compareTo(s1);
-        }
-      };
 
   private final Context context;
   private final FileUtils fileUtils;
-  private final Handler uiThreadHandler = new Handler();
 
-  public ExternalFileBackup(Context context) {
+  public ExternalFileBackup(Context context, FileUtils fileUtils) {
     this.context = context;
-    this.fileUtils = new FileUtils();
+    this.fileUtils = fileUtils;
   }
 
   /**
-   * Writes a full backup to the default file.
-   * This shows the results to the user.
+   * Returns whether the backups directory is (or can be made) available.
+   *
+   * @param create whether to try creating the directory if it doesn't exist
    */
-  public void writeToDefaultFile() {
-    if (!fileUtils.isSdCardAvailable()) {
-      showToast(R.string.io_no_external_storage_found);
-      return;
-    }
+  public boolean isBackupsDirectoryAvailable(boolean create) {
+    return getBackupsDirectory(create) != null;
+  }
 
+  /**
+   * Returns the backup directory, or null if not available.
+   *
+   * @param create whether to try creating the directory if it doesn't exist
+   */
+  private File getBackupsDirectory(boolean create) {
     String dirName = fileUtils.buildExternalDirectoryPath(BACKUPS_SUBDIR);
     final File dir = new File(dirName);
-    if (!fileUtils.ensureDirectoryExists(dir)) {
-      showToast(R.string.io_create_dir_failed);
-      return;
+    Log.d(MyTracksConstants.TAG, "Dir: " + dir.getAbsolutePath());
+    if (create) {
+      // Try to create - if that fails, return null
+      return fileUtils.ensureDirectoryExists(dir) ? dir : null;
+    } else {
+      // Return it if it already exists, otherwise return null
+      return dir.isDirectory() ? dir : null;
     }
-
-    final ProgressDialog progressDialog = ProgressDialog.show(
-        context,
-        context.getString(R.string.progress_title),
-        context.getString(R.string.backup_write_progress_message),
-        true);
-
-    // Do the writing in another thread
-    new Thread() {
-      @Override
-      public void run() {
-        try {
-          final String filename = BACKUP_FILENAME_FORMAT.format(new Date());
-          final File outputFile = new File(dir, filename);
-
-          Log.d(MyTracksConstants.TAG, "Writing backup to file " + filename);
-          writeToFile(outputFile);
-          showToast(R.string.io_write_finished);
-        } catch (IOException e) {
-          showToast(R.string.io_write_failed);
-          return;
-        } finally {
-          dismissDialog(progressDialog);
-        }
-      }
-    }.start();
-  }
-
-  /**
-   * Restores a full backup from the SD card.
-   * The user will be given a choice of which backup to restore as well as a
-   * confirmation dialog.
-   */
-  public void restoreFromFileList() {
-    // Get the list of existing backups
-    if (!fileUtils.isSdCardAvailable()) {
-      showToast(R.string.io_no_external_storage_found);
-      return;
-    }
-
-    String dirName = fileUtils.buildExternalDirectoryPath(BACKUPS_SUBDIR);
-    final File backupDir = new File(dirName);
-    if (!backupDir.isDirectory()) {
-      showToast(R.string.no_backups);
-      return;
-    }
-
-    final String[] backupFiles = getAvailableBackups(backupDir);
-
-    if (backupFiles == null || backupFiles.length == 0) {
-      showToast(R.string.no_backups);
-      return;
-    }
-
-    // Show a confirmation dialog
-    Builder confirmationDialogBuilder = new AlertDialog.Builder(context);
-    confirmationDialogBuilder.setMessage(R.string.restore_overwrites_warning);
-    confirmationDialogBuilder.setCancelable(false);
-    confirmationDialogBuilder.setNegativeButton(android.R.string.no, null);
-    confirmationDialogBuilder.setPositiveButton(android.R.string.yes, new OnClickListener() {
-      @Override
-      public void onClick(DialogInterface dialog, int which) {
-        restoreFromFileListConfirmed(backupDir, backupFiles);
-      }
-    });
-    confirmationDialogBuilder.create().show();
-  }
-
-  /**
-   * Shows a backup list for the user to pick, then restores it.
-   *
-   * @param backupDir the backup directory
-   * @param backupFiles the list of available backup files
-   */
-  private void restoreFromFileListConfirmed(final File backupDir, final String[] backupFiles) {
-    if (backupFiles.length == 1) {
-      // Only one choice, don't bother showing the list
-      File inputFile = new File(backupDir, backupFiles[0]);
-      restoreFromFileAsync(inputFile);
-      return;
-    }
-
-    // Make a user-visible version of the backup filenames
-    final String backupFileDates[] = new String[backupFiles.length];
-    for (int i = 0; i < backupFiles.length; i++) {
-      try {
-        Date backupDate = BACKUP_FILENAME_FORMAT.parse(backupFiles[i]);
-        backupFileDates[i] = DISPLAY_BACKUP_FORMAT.format(backupDate);
-      } catch (ParseException e) {
-        throw new IllegalStateException("All filenames should be good here");
-      }
-    }
-    Arrays.sort(backupFileDates, REVERSE_STRING_COMPARATOR);
-
-    // Show a dialog for the user to pick which backup to restore
-    Builder dialogBuilder = new AlertDialog.Builder(context);
-    dialogBuilder.setCancelable(true);
-    dialogBuilder.setTitle(R.string.select_backup_to_restore);
-    dialogBuilder.setItems(backupFileDates, new OnClickListener() {
-      @Override
-      public void onClick(DialogInterface dialog, int which) {
-        // User picked to restore this one
-        final String fileName = backupFiles[which];
-        final File inputFile = new File(backupDir, fileName);
-
-        restoreFromFileAsync(inputFile);
-      }
-    });
-    dialogBuilder.create().show();
-  }
-
-  /**
-   * Shows a progress dialog, then starts restoring the backup osynchronously.
-   *
-   * @param inputFile the file to restore from
-   */
-  private void restoreFromFileAsync(final File inputFile) {
-    // Show a progress dialog
-    final ProgressDialog progressDialog = ProgressDialog.show(
-        context,
-        context.getString(R.string.progress_title),
-        context.getString(R.string.backup_import_progress_message),
-        true);
-
-    // Do the actual importing in another thread (don't block the UI)
-    new Thread() {
-      @Override
-      public void run() {
-        try {
-          Log.d(MyTracksConstants.TAG, "Restoring from file " + inputFile.getAbsolutePath());
-          restoreFromFile(inputFile);
-          showToast(R.string.io_read_finished);
-        } catch (IOException e) {
-          showToast(R.string.io_read_failed);
-        } finally {
-          dismissDialog(progressDialog);
-        }
-      }
-    }.start();
   }
 
   /**
    * Returns a list of available backups to be restored.
    */
-  public String[] getAvailableBackups(File dir) {
-    return dir.list(new FilenameFilter() {
-      @Override
-      public boolean accept(File dir, String filename) {
-        try {
-          BACKUP_FILENAME_FORMAT.parse(filename);
-          return true;
-        } catch (ParseException e) {
-          return false;
-        }
+  public Date[] getAvailableBackups() {
+    File dir = getBackupsDirectory(false);
+    if (dir == null) { return null; }
+    String[] fileNames = dir.list();
+
+    List<Date> backupDates = new ArrayList<Date>(fileNames.length);
+    for (int i = 0; i < fileNames.length; i++) {
+      String fileName = fileNames[i];
+      try {
+        backupDates.add(BACKUP_FILENAME_FORMAT.parse(fileName));
+      } catch (ParseException e) {
+        // Not a backup file, ignore
       }
-    });
+    }
+
+    return backupDates.toArray(new Date[backupDates.size()]);
   }
 
   /**
-   * Shows a toast with the given contents.
+   * Writes the backup to the default file.
    */
-  private void showToast(final int resId) {
-    uiThreadHandler.post(new Runnable() {
-      @Override
-      public void run() {
-        Toast.makeText(context, resId, Toast.LENGTH_LONG).show();
-      }
-    });
+  public void writeToDefaultFile() throws IOException {
+    writeToFile(getFileForDate(new Date()));
   }
 
   /**
-   * Safely dismisses the given dialog.
+   * Restores the backup from the given date.
    */
-  private void dismissDialog(final Dialog dialog) {
-    uiThreadHandler.post(new Runnable() {
-      @Override
-      public void run() {
-        dialog.dismiss();
-      }
-    });
+  public void restoreFromDate(Date when) throws IOException {
+    restoreFromFile(getFileForDate(when));
+  }
+
+  /**
+   * Produces the proper file descriptor for the given backup date.
+   */
+  private File getFileForDate(Date when) {
+    File dir = getBackupsDirectory(false);
+    String fileName = BACKUP_FILENAME_FORMAT.format(when);
+    File file = new File(dir, fileName);
+    return file;
   }
 
   /**
    * Synchronously writes a backup to the given file.
    */
   private void writeToFile(File outputFile) throws IOException {
+    Log.d(MyTracksConstants.TAG, "Writing backup to file " + outputFile.getAbsolutePath());
+
     // Create all the auxiliary classes that will do the writing
     PreferenceBackupHelper preferencesHelper = new PreferenceBackupHelper();
     DatabaseDumper trackDumper = new DatabaseDumper(
@@ -313,11 +166,6 @@ public class ExternalFileBackup {
       // Output a version header
       outWriter.writeInt(BACKUP_FILE_VERSION);
 
-      // Dump preferences
-      SharedPreferences preferences =
-          context.getSharedPreferences(MyTracksSettings.SETTINGS_NAME, 0);
-      preferencesHelper.exportPreferences(preferences, outWriter);
-
       // Dump the entire contents of each table
       ContentResolver contentResolver = context.getContentResolver();
       Cursor tracksCursor = contentResolver.query(
@@ -343,6 +191,17 @@ public class ExternalFileBackup {
       } finally {
         pointsCursor.close();
       }
+
+      // Dump preferences
+      SharedPreferences preferences =
+          context.getSharedPreferences(MyTracksSettings.SETTINGS_NAME, 0);
+      preferencesHelper.exportPreferences(preferences, outWriter);
+    } catch (IOException e) {
+      // We tried to delete the partially created file, but do nothing
+      // if that also fails.
+      outputFile.delete();
+
+      throw e;
     } finally {
       outputStream.flush();
       outputStream.close();
@@ -353,7 +212,7 @@ public class ExternalFileBackup {
    * Synchronously restores the backup from the given file.
    */
   private void restoreFromFile(File inputFile) throws IOException {
-    // TODO: At this point we should stop recording if we were
+    Log.d(MyTracksConstants.TAG, "Restoring from file " + inputFile.getAbsolutePath());
 
     PreferenceBackupHelper preferencesHelper = new PreferenceBackupHelper();
     ContentResolver resolver = context.getContentResolver();
@@ -370,12 +229,7 @@ public class ExternalFileBackup {
         throw new IOException("Unknown backup file version " + backupVersion);
       }
 
-      // Restore preferences
-      SharedPreferences preferences =
-          context.getSharedPreferences(MyTracksSettings.SETTINGS_NAME, 0);
-      preferencesHelper.importPreferences(reader, preferences);
-
-      // Delete all previous contents of the tables.
+      // Delete all previous contents of the tables and preferences.
       resolver.delete(TracksColumns.CONTENT_URI, null, null);
       resolver.delete(TrackPointsColumns.CONTENT_URI, null, null);
       resolver.delete(WaypointsColumns.CONTENT_URI, null, null);
@@ -384,6 +238,11 @@ public class ExternalFileBackup {
       trackImporter.importAllRows(reader);
       waypointImporter.importAllRows(reader);
       pointImporter.importAllRows(reader);
+
+      // Restore preferences
+      SharedPreferences preferences =
+          context.getSharedPreferences(MyTracksSettings.SETTINGS_NAME, 0);
+      preferencesHelper.importPreferences(reader, preferences);
     } finally {
       inputStream.close();
     }

MyTracks/src/com/google/android/apps/mytracks/io/backup/PreferenceBackupHelper.java

@@ -25,7 +25,6 @@ import java.io.ByteArrayOutputStream;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
-import java.io.OutputStream;
 import java.util.Map;
 
 /**