/*
 * Copyright (C) 2013 DroidDriver committers
 *
 * 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.android.droiddriver.finders;

import com.google.android.droiddriver.UiElement;
import com.google.common.base.Preconditions;

/**
 * Find UiElement by using the UiElement returned by parent Finder as context
 * for the child Finder.
 */
public class ChainFinder implements Finder {
  private final Finder parent;
  private final Finder child;

  protected ChainFinder(Finder parent, Finder child) {
    this.parent = Preconditions.checkNotNull(parent);
    this.child = Preconditions.checkNotNull(child);
  }

  @Override
  public String toString() {
    return String.format("ChainFinder{%s, %s}", parent, child);
  }

  @Override
  public UiElement find(UiElement context) {
    return child.find(parent.find(context));
  }
}