Allow enabled accessibility service to toggle tocuh exploration after an upgrade to JellyBean.

1. Before JellyBean touch exploration was a global setting controlled by the user via
   the UI. However, if the enabled accessibility services do not handle touch exploration
   mode, enabling it makes no sense. Therefore, in JellyBean the services request touch
   exploration mode and the user is presented with a dialog to allow that and if she
   does we store that in the database.

   As a result of the above change a user that has enabled  accessibility, touch
   exploration, and some accessibility services running a pre-JellyBean system
   version may lose touch exploration state, thus rendering the device useless unless
   sighted help is provided, since the enabled service(s) are not in the list of
   services to which the user granted a permission to put the device in touch explore
   mode.

   The fix is during a database upgrade to allow allow all enabled accessibility
   services to toggle touch exploration provided accessibility and touch exploration
   are enabled and no services can toggle touch exploration. Note that the user has
   already manually enabled the services and touch exploration which means the she
   has given consent to have these services work in touch exploration mode

bug:6996354

Change-Id: I0af2dc578cc4fbcc90043341035163b876978ab2

Author: sganov

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

@@ -63,7 +63,7 @@ public class DatabaseHelper extends SQLiteOpenHelper {
     // database gets upgraded properly. At a minimum, please confirm that 'upgradeVersion'
     // is properly propagated through your change.  Not doing so will result in a loss of user
     // settings.
-    private static final int DATABASE_VERSION = 79;
+    private static final int DATABASE_VERSION = 80;
 
     private Context mContext;
 
@@ -1071,6 +1071,52 @@ public void onUpgrade(SQLiteDatabase db, int oldVersion, int currentVersion) {
             upgradeVersion = 79;
         }
 
+        if (upgradeVersion == 79) {
+            // Before touch exploration was a global setting controlled by the user
+            // via the UI. However, if the enabled accessibility services do not
+            // handle touch exploration mode, enabling it makes no sense. Therefore,
+            // now the services request touch exploration mode and the user is
+            // presented with a dialog to allow that and if she does we store that
+            // in the database. As a result of this change a user that has enabled
+            // accessibility, touch exploration, and some accessibility services
+            // may lose touch exploration state, thus rendering the device useless
+            // unless sighted help is provided, since the enabled service(s) are
+            // not in the list of services to which the user granted a permission
+            // to put the device in touch explore mode. Here we are allowing all
+            // enabled accessibility services to toggle touch exploration provided
+            // accessibility and touch exploration are enabled and no services can
+            // toggle touch exploration. Note that the user has already manually
+            // enabled the services and touch exploration which means the she has
+            // given consent to have these services work in touch exploration mode.
+            final boolean accessibilityEnabled = getIntValueFromTable(db, "secure",
+                    Settings.Secure.ACCESSIBILITY_ENABLED, 0) == 1;
+            final boolean touchExplorationEnabled = getIntValueFromTable(db, "secure",
+                    Settings.Secure.TOUCH_EXPLORATION_ENABLED, 0) == 1;
+            if (accessibilityEnabled && touchExplorationEnabled) {
+                String enabledServices = getStringValueFromTable(db, "secure",
+                        Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES, "");
+                String touchExplorationGrantedServices = getStringValueFromTable(db, "secure",
+                        Settings.Secure.TOUCH_EXPLORATION_GRANTED_ACCESSIBILITY_SERVICES, "");
+                if (TextUtils.isEmpty(touchExplorationGrantedServices)
+                        && !TextUtils.isEmpty(enabledServices)) {
+                    SQLiteStatement stmt = null;
+                    try {
+                        db.beginTransaction();
+                        stmt = db.compileStatement("INSERT OR REPLACE INTO secure(name,value)"
+                                + " VALUES(?,?);");
+                        loadSetting(stmt,
+                                Settings.Secure.TOUCH_EXPLORATION_GRANTED_ACCESSIBILITY_SERVICES,
+                                enabledServices);
+                        db.setTransactionSuccessful();
+                    } finally {
+                        db.endTransaction();
+                        if (stmt != null) stmt.close();
+                    }
+                }
+            }
+            upgradeVersion = 80;
+        }
+
         // *** Remember to update DATABASE_VERSION above!
 
         if (upgradeVersion != currentVersion) {
@@ -1700,18 +1746,28 @@ private void loadFractionSetting(SQLiteStatement stmt, String key, int resid, in
     }
 
     private int getIntValueFromSystem(SQLiteDatabase db, String name, int defaultValue) {
-        int value = defaultValue;
+        return getIntValueFromTable(db, "system", name, defaultValue);
+    }
+
+    private int getIntValueFromTable(SQLiteDatabase db, String table, String name,
+            int defaultValue) {
+        String value = getStringValueFromTable(db, table, name, null);
+        return (value != null) ? Integer.parseInt(value) : defaultValue;
+    }
+
+    private String getStringValueFromTable(SQLiteDatabase db, String table, String name,
+            String defaultValue) {
         Cursor c = null;
         try {
-            c = db.query("system", new String[] { Settings.System.VALUE }, "name='" + name + "'",
+            c = db.query(table, new String[] { Settings.System.VALUE }, "name='" + name + "'",
                     null, null, null, null);
             if (c != null && c.moveToFirst()) {
                 String val = c.getString(0);
-                value = val == null ? defaultValue : Integer.parseInt(val);
+                return val == null ? defaultValue : val;
             }
         } finally {
             if (c != null) c.close();
         }
-        return value;
+        return defaultValue;
     }
 }