Core accessibility settings should not be cleared on restore.

1. The core accessibility settings required for a blind user to use
   the device should not be overwritten on restore. There could have
   been enabled via a global gesture from setup wizard, hence the
   user definitely needs them. Restoring disabled values for these
   settings render the device useless unless sighted help is sought.

bug:7138401

Change-Id: Idc593889aa61fada65b0407623720517c827df53

Author: sganov

packages/SettingsProvider/src/com/android/providers/settings/SettingsHelper.java

@@ -20,11 +20,8 @@
 
 import android.app.ActivityManagerNative;
 import android.app.IActivityManager;
-import android.app.backup.BackupDataInput;
 import android.app.backup.IBackupManager;
-import android.content.ContentResolver;
 import android.content.Context;
-import android.content.IContentService;
 import android.content.res.Configuration;
 import android.location.LocationManager;
 import android.media.AudioManager;
@@ -33,23 +30,15 @@
 import android.os.ServiceManager;
 import android.provider.Settings;
 import android.text.TextUtils;
-import android.util.Log;
 
 public class SettingsHelper {
-    private static final String TAG = "SettingsHelper";
-
     private Context mContext;
     private AudioManager mAudioManager;
-    private IContentService mContentService;
-    private IPowerManager mPowerManager;
 
     public SettingsHelper(Context context) {
         mContext = context;
         mAudioManager = (AudioManager) context
                 .getSystemService(Context.AUDIO_SERVICE);
-        mContentService = ContentResolver.getContentService();
-        mPowerManager = IPowerManager.Stub.asInterface(
-                ServiceManager.getService("power"));
     }
 
     /**
@@ -71,10 +60,31 @@ public boolean restoreValue(String name, String value) {
             return false;
         } else if (Settings.Secure.BACKUP_AUTO_RESTORE.equals(name)) {
             setAutoRestore(Integer.parseInt(value) == 1);
+        } else if (isAlreadyConfiguredCriticalAccessibilitySetting(name)) {
+            return false;
         }
         return true;
     }
 
+    private boolean isAlreadyConfiguredCriticalAccessibilitySetting(String name) {
+        // These are the critical accessibility settings that are required for a
+        // blind user to be able to interact with the device. If these settings are
+        // already configured, we will not overwrite them. If they are already set,
+        // it means that the user has performed a global gesture to enable accessibility
+        // and definitely needs these features working after the restore.
+        if (Settings.Secure.ACCESSIBILITY_ENABLED.equals(name)
+                || Settings.Secure.ACCESSIBILITY_SCRIPT_INJECTION.equals(name)
+                || Settings.Secure.ACCESSIBILITY_SPEAK_PASSWORD.equals(name)
+                || Settings.Secure.TOUCH_EXPLORATION_ENABLED.equals(name)) {
+            return Settings.Secure.getInt(mContext.getContentResolver(), name, 0) != 0;
+        } else if (Settings.Secure.TOUCH_EXPLORATION_GRANTED_ACCESSIBILITY_SERVICES.equals(name)
+                || Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES.equals(name)) {
+            return !TextUtils.isEmpty(Settings.Secure.getString(
+                    mContext.getContentResolver(), name));
+        }
+        return false;
+    }
+
     private void setAutoRestore(boolean enabled) {
         try {
             IBackupManager bm = IBackupManager.Stub.asInterface(