1 files changed, 99 insertions, 0 deletions
diff --git a/src/com/google/android/libraries/backup/PreferenceBackupUtil.java b/src/com/google/android/libraries/backup/PreferenceBackupUtil.java
new file mode 100644
index 0000000..6cc4012
--- /dev/null
+++ b/src/com/google/android/libraries/backup/PreferenceBackupUtil.java
@@ -0,0 +1,99 @@
+package com.google.android.libraries.backup;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.database.Cursor;
+import android.media.Ringtone;
+import android.media.RingtoneManager;
+import android.net.Uri;
+import android.support.annotation.Nullable;
+import android.support.annotation.VisibleForTesting;
+
+/**
+ * Utility class of static methods to help process shared preferences for backup and restore.
+ */
+public class PreferenceBackupUtil {
+
+  @VisibleForTesting
+  @Nullable
+  static String getRingtoneTitleFromUri(Context context, @Nullable String uri) {
+    if (uri == null) {
+      return null;
+    }
+
+    Ringtone sound = RingtoneManager.getRingtone(context, Uri.parse(uri));
+    if (sound == null) {
+      return null;
+    }
+    return sound.getTitle(context);
+  }
+
+  /**
+   * Get ringtone uri from a preference key in a shared preferences file, retrieve the associated
+   * ringtone's title and, if possible, save the title to the target preference key.
+   *
+   * @param srcRingtoneUriPrefKey preference key of the ringtone uri.
+   * @param dstRingtoneTitlePrefKey preference key where the ringtone title should be put.
+   * @return whether the ringtoneTitleKey was set.
+   */
+  public static boolean encodeRingtonePreference(Context context, String prefsName,
+      String srcRingtoneUriPrefKey, String dstRingtoneTitlePrefKey) {
+    SharedPreferences preferences = context.getSharedPreferences(prefsName, Context.MODE_PRIVATE);
+
+    String uri = preferences.getString(srcRingtoneUriPrefKey, null);
+    String title = getRingtoneTitleFromUri(context, uri);
+    if (title == null) {
+      return false;
+    }
+
+    preferences.edit().putString(dstRingtoneTitlePrefKey, title).apply();
+    return true;
+  }
+
+  @VisibleForTesting
+  @Nullable
+  static String getRingtoneUriFromTitle(Context context, @Nullable String title, int ringtoneType) {
+    // Check whether the ringtoneType is a valid combination of the 3 ringtone types.
+    if ((ringtoneType == 0)
+        || ((RingtoneManager.TYPE_ALL & ringtoneType) != ringtoneType)) {
+      throw new IllegalStateException();
+    }
+    if (title == null) {
+      return null;
+    }
+
+    RingtoneManager manager = new RingtoneManager(context);
+    manager.setType(ringtoneType);
+    Cursor cur = manager.getCursor();
+    for (int i = 0; i < cur.getCount(); i++) {
+      Ringtone ringtone = manager.getRingtone(i);
+      if (ringtone.getTitle(context).equals(title)) {
+        return manager.getRingtoneUri(i).toString();
+      }
+    }
+
+    return null;
+  }
+
+  /**
+   * Get ringtone title from a preference key of a shared preferences file, find a ringtone with the
+   * same title and, if possible, save its uri to the target preference key.
+   *
+   * @param dstRingtoneUriPrefKey preference key where the ringtone uri should be put.
+   * @param srcRingtoneTitlePrefKey preference key of the ringtone title.
+   * @return whether the ringtoneUriKey was set.
+   */
+  public static boolean decodeRingtonePreference(Context context, String prefsName,
+      String dstRingtoneUriPrefKey, String srcRingtoneTitlePrefKey, int ringtoneType) {
+    SharedPreferences preferences = context.getSharedPreferences(prefsName, Context.MODE_PRIVATE);
+
+    String title = preferences.getString(srcRingtoneTitlePrefKey, null);
+    String uri = getRingtoneUriFromTitle(context, title, ringtoneType);
+    if (uri == null) {
+      return false;
+    }
+
+    preferences.edit().putString(dstRingtoneUriPrefKey, uri).apply();
+    return true;
+  }
+}
+\ No newline at end of file