/*
* Copyright 2010 Google Inc.
*
* 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.google.gwt.i18n.shared;
import com.google.gwt.i18n.client.HasDirection.Direction;
/**
* Direction estimator that uses the "first strong" heuristic.
*/
public class FirstStrongDirectionEstimator extends DirectionEstimator {
/**
* An instance of FirstStrongDirectionEstimator, to be returned by
* {@link #get}.
*/
private static final FirstStrongDirectionEstimator instance =
new FirstStrongDirectionEstimator();
/**
* Get an instance of FirstStrongDirectionEstimator.
*
* @return An instance of FirstStrongDirectionEstimator.
*/
public static FirstStrongDirectionEstimator get() {
return instance;
}
/**
* Estimates the direction of a given string using the "first strong"
* heuristic: The return value is determined by the first character in the
* string with strong directionality. If there is no such character, the
* return value is DEFAULT.
*
* @param str Input string.
* @return Direction The estimated direction of {@code str}.
*/
@Override
public Direction estimateDirection(String str) {
return BidiUtils.get().startsWithRtl(str) ? Direction.RTL :
BidiUtils.get().startsWithLtr(str) ? Direction.LTR : Direction.DEFAULT;
}
}