/*

  * Copyright 2004-2008 the Seasar Foundation and the Others.

  *

  * 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.seasar.uruma.component.base;

 import java.util.ArrayList;

 import java.util.List;

 import org.seasar.uruma.component.UIComponent;

 import org.seasar.uruma.component.UIComponentContainer;

 import org.seasar.uruma.component.UIElement;

 import org.seasar.uruma.context.PartContext;

 import org.seasar.uruma.context.WidgetHandle;

 /**

  * {@link UIComponentContainer} の子要素を表す基底クラスです。<br />

  * 

  * @author bskuroneko

  */

 public abstract class AbstractUIContainerItemComponent extends

         AbstractItemComponent implements UIComponentContainer {

     private List<UIElement> children = new ArrayList<UIElement>();

     /*

      * @see org.seasar.uruma.component.UIElementContainer#addChild(org.seasar.uruma.component.UIElement)

      */

     public void addChild(final UIElement child) {

         children.add(child);

         if (child instanceof UIComponent) {

             ((UIComponent) child).setParent(getParent());

         }

     }

     /*

      * @see org.seasar.uruma.component.UIElementContainer#getChildren()

      */

     public List<UIElement> getChildren() {

         return children;

     }

     /**

      * 子コンポーネントを取得します。<br />

      * 子コンポーネントが複数存在する場合、最初の一個を返します。

      * 

      * @return 子コンポーネント。存在しない場合は <code>null</code>。

      */

     public UIElement getChild() {

         if (children.size() > 0) {

             return children.get(0);

         } else {

             return null;

         }

     }

     /*

      * @see org.seasar.uruma.component.jface.AbstractUIComponent#doRender(org.seasar.uruma.context.WidgetHandle,

      *      org.seasar.uruma.context.PartContext)

      */

     @Override

     protected void doRender(final WidgetHandle parent, final PartContext context) {

         UIElement content = getChild();

         if ((content != null) && (content instanceof UIComponent)) {

             WidgetHandle parentHandle = context.getWidgetHandle(getParent()

                     .getId());

             ((UIComponent) content).render(parentHandle, context);

         }

     }

 }