Don't restore device specific preferences

There are two categories of preferences:
1. That are part of the default shared preference
   They were all getting backed up and restored.
   Added a blacklist to not restore some of these.
   e.g. current account

2. That are in a non-default shared preference file.
   These are not getting backed up currently, but added a specific
   local preference file for all such preferences.

Bug: 17288591
Change-Id: I2f748be971a2337543e5014434aa39313fd1e1d8

1 files changed, 29 insertions, 2 deletions

diff --git a/java/src/com/android/inputmethod/latin/BackupAgent.java b/java/src/com/android/inputmethod/latin/BackupAgent.java
index 1f044618a..fb672e14b 100644
--- a/java/src/com/android/inputmethod/latin/BackupAgent.java
+++ b/java/src/com/android/inputmethod/latin/BackupAgent.java
@@ -17,15 +17,42 @@
 package com.android.inputmethod.latin;
 
 import android.app.backup.BackupAgentHelper;
+import android.app.backup.BackupDataInput;
 import android.app.backup.SharedPreferencesBackupHelper;
+import android.content.SharedPreferences;
+import android.os.ParcelFileDescriptor;
+
+import com.android.inputmethod.latin.settings.LocalSettingsConstants;
+
+import java.io.IOException;
 
 /**
- * Backs up the Latin IME shared preferences.
+ * Backup/restore agent for LatinIME.
+ * Currently it backs up the default shared preferences.
  */
 public final class BackupAgent extends BackupAgentHelper {
+    private static final String PREF_SUFFIX = "_preferences";
+
     @Override
     public void onCreate() {
         addHelper("shared_pref", new SharedPreferencesBackupHelper(this,
-                getPackageName() + "_preferences"));
+                getPackageName() + PREF_SUFFIX));
+    }
+
+    @Override
+    public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState)
+            throws IOException {
+        // Let the restore operation go through
+        super.onRestore(data, appVersionCode, newState);
+
+        // Remove the preferences that we don't want restored.
+        final SharedPreferences.Editor prefEditor = getSharedPreferences(
+                getPackageName() + PREF_SUFFIX, MODE_PRIVATE).edit();
+        final String[] prefsToRemove = LocalSettingsConstants.PREFS_TO_SKIP_RESTORING;
+        for (final String key : prefsToRemove) {
+            prefEditor.remove(key);
+        }
+        // Flush the changes to disk.
+        prefEditor.commit();
     }
 }