/*
 * Copyright 2006 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.util.tools;

import com.google.gwt.dev.util.Empty;

/**
 * Argument handler for flags that have no parameters.
 */
public abstract class ArgHandlerFlag extends ArgHandler {

  @Override
  public String[] getTagArgs() {
    return Empty.STRINGS;
  }

  @Override
  public int handle(String[] args, int startIndex) {
    if (setFlag()) {
      return 0;
    } else {
      return -1;
    }
  }

  @Override
  public boolean isRequired() {
    return false;
  }

  public abstract boolean setFlag();
}