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

4 files changed, 44 insertions, 9 deletions

diff --git a/java/src/com/android/inputmethod/latin/settings/AccountsSettingsFragment.java b/java/src/com/android/inputmethod/latin/settings/AccountsSettingsFragment.java
index 45792fe0e..fa716457c 100644
--- a/java/src/com/android/inputmethod/latin/settings/AccountsSettingsFragment.java
+++ b/java/src/com/android/inputmethod/latin/settings/AccountsSettingsFragment.java
@@ -167,7 +167,7 @@ public final class AccountsSettingsFragment extends SubScreenFragment {
 
     @Nullable
     private String getCurrentlySelectedAccount() {
-        return getSharedPreferences().getString(Settings.PREF_ACCOUNT_NAME, null);
+        return getSharedPreferences().getString(LocalSettingsConstants.PREF_ACCOUNT_NAME, null);
     }
 
     /**
@@ -219,7 +219,7 @@ public final class AccountsSettingsFragment extends SubScreenFragment {
             final Object selectedItem = lv.getItemAtPosition(lv.getCheckedItemPosition());
             getSharedPreferences()
                     .edit()
-                    .putString(Settings.PREF_ACCOUNT_NAME, (String) selectedItem)
+                    .putString(LocalSettingsConstants.PREF_ACCOUNT_NAME, (String) selectedItem)
                     .apply();
         }
     }
@@ -233,7 +233,7 @@ public final class AccountsSettingsFragment extends SubScreenFragment {
         public void onClick(DialogInterface dialog, int which) {
             getSharedPreferences()
                     .edit()
-                    .remove(Settings.PREF_ACCOUNT_NAME)
+                    .remove(LocalSettingsConstants.PREF_ACCOUNT_NAME)
                     .apply();
         }
     }
diff --git a/java/src/com/android/inputmethod/latin/settings/LocalSettingsConstants.java b/java/src/com/android/inputmethod/latin/settings/LocalSettingsConstants.java
new file mode 100644
index 000000000..71d6065e0
--- /dev/null
+++ b/java/src/com/android/inputmethod/latin/settings/LocalSettingsConstants.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * 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.android.inputmethod.latin.settings;
+
+/**
+ * Collection of device specific preference constants.
+ */
+public class LocalSettingsConstants {
+    // Preference file for storing preferences that are tied to a device
+    // and are not backed up.
+    public static final String PREFS_FILE = "local_prefs";
+
+    // Preference key for the current account.
+    // Do not restore.
+    public static final String PREF_ACCOUNT_NAME = "pref_account_name";
+
+    // List of preference keys to skip from being restored by backup agent.
+    // These preferences are tied to a device and hence should not be restored.
+    // e.g. account name.
+    // Ideally they could have been kept in a separate file that wasn't backed up
+    // however the preference UI currently only deals with the default
+    // shared preferences which makes it non-trivial to move these out to
+    // a different shared preferences file.
+    public static final String[] PREFS_TO_SKIP_RESTORING = new String[] {
+        PREF_ACCOUNT_NAME
+    };
+}
diff --git a/java/src/com/android/inputmethod/latin/settings/Settings.java b/java/src/com/android/inputmethod/latin/settings/Settings.java
index 84596b4ad..103033c16 100644
--- a/java/src/com/android/inputmethod/latin/settings/Settings.java
+++ b/java/src/com/android/inputmethod/latin/settings/Settings.java
@@ -106,8 +106,6 @@ public final class Settings implements SharedPreferences.OnSharedPreferenceChang
     public static final String PREF_KEY_IS_INTERNAL = "pref_key_is_internal";
 
     public static final String PREF_ENABLE_METRICS_LOGGING = "pref_enable_metrics_logging";
-    public static final String PREF_ACCOUNT_NAME = "pref_account_name";
-
     // This preference key is deprecated. Use {@link #PREF_SHOW_LANGUAGE_SWITCH_KEY} instead.
     // This is being used only for the backward compatibility.
     private static final String PREF_SUPPRESS_LANGUAGE_SWITCH_KEY =
diff --git a/java/src/com/android/inputmethod/latin/settings/SettingsValues.java b/java/src/com/android/inputmethod/latin/settings/SettingsValues.java
index ce8a0ab9c..660b4e095 100644
--- a/java/src/com/android/inputmethod/latin/settings/SettingsValues.java
+++ b/java/src/com/android/inputmethod/latin/settings/SettingsValues.java
@@ -64,7 +64,6 @@ public class SettingsValues {
     public final boolean mSoundOn;
     public final boolean mKeyPreviewPopupOn;
     public final boolean mShowsVoiceInputKey;
-    public final String mAccountName;
     public final boolean mIncludesOtherImesInLanguageSwitchList;
     public final boolean mShowsLanguageSwitchKey;
     public final boolean mUseContactsDict;
@@ -141,7 +140,6 @@ public class SettingsValues {
         mShowsVoiceInputKey = needsToShowVoiceInputKey(prefs, res)
                 && mInputAttributes.mShouldShowVoiceInputKey
                 && SubtypeSwitcher.getInstance().isShortcutImeEnabled();
-        mAccountName = prefs.getString(Settings.PREF_ACCOUNT_NAME, null);
         final String autoCorrectionThresholdRawValue = prefs.getString(
                 Settings.PREF_AUTO_CORRECTION_THRESHOLD,
                 res.getString(R.string.auto_correction_threshold_mode_index_modest));
@@ -385,8 +383,6 @@ public class SettingsValues {
         sb.append("" + mKeyPreviewPopupOn);
         sb.append("\n   mShowsVoiceInputKey = ");
         sb.append("" + mShowsVoiceInputKey);
-        sb.append("\n   mAccountName = ");
-        sb.append("" + mAccountName);
         sb.append("\n   mIncludesOtherImesInLanguageSwitchList = ");
         sb.append("" + mIncludesOtherImesInLanguageSwitchList);
         sb.append("\n   mShowsLanguageSwitchKey = ");