// Copyright 2006, 2008 The Apache Software Foundation

 //

 // 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.apache.tapestry5.runtime;

 import org.apache.tapestry5.ComponentResources;

 /**

  * A stateful object that manages the process of rendering a page. Rending a page in Tapestry is based on a command

  * queue.

  */

 public interface RenderQueue

 {

     /**

      * Adds the new command to the front of the queue.

      */

     void push(RenderCommand command);

     /**

      * Indicates that a component is starting its render. A stack of active components is used for exception reporting.

      *

      * @param resources identifies the component that is rendering

      */

     void startComponent(ComponentResources resources);

     /**

      * Corresponds to {@link #startComponent(String)}, used to denote when the most recently started component finishes

      * rendering.

      */

     void endComponent();

 }