HtmlClosureCollection.java

/**
 * 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 org.waveprotocol.wave.client.uibuilder;

import org.waveprotocol.wave.client.common.safehtml.SafeHtmlBuilder;
import org.waveprotocol.wave.model.util.CollectionUtils;

import java.util.Collection;

/**
 * An HtmlClosure composed of a list of HtmlClosures.
 *
 */
public final class HtmlClosureCollection implements HtmlClosure {

  /** Collection of closures, lazily created. */
  private Collection<HtmlClosure> children;

  /**
   * Creates a closures collection.
   */
  public HtmlClosureCollection() {
  }

  /**
   * Adds a closure to this collection.
   *
   * @param child closure to add
   */
  public void add(HtmlClosure child) {
    if (children == null) {
      children = CollectionUtils.createQueue();
    }
    children.add(child);
  }

  @Override
  public void outputHtml(SafeHtmlBuilder out) {
    if (children != null) {
      for (HtmlClosure builder : children) {
        builder.outputHtml(out);
      }
    }
  }
}