org.apache.myfaces.custom.dynamicResources.ResourceRenderer Maven / Gradle / Ivy

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.myfaces.custom.dynamicResources;

import java.io.IOException;

import javax.faces.context.FacesContext;
import javax.faces.context.ResponseStream;

/**
 * The ImageRenderer is used to render the binary data for a html img tag
 * Implementions must have a default constructor
 * 
 * @author Mathias Broekelmann
 * @version $Revision: 472727 $ $Date: 2006-11-09 02:08:46 +0100 (Do, 09 Nov 2006) $
 */
public interface ResourceRenderer
{
	/**
	 * This method will be called first, to set the contexts.
	 * 
     * @param facesContext the faces context
     * @param imageContext the image context width aditional image parameters
	 */
	void setContext(FacesContext facesContext, ResourceContext resourceContext) throws Exception;
	
    /**
     * The content length of the image to render.
     * Set to a negative value if you don't want to set the response content length.
     * 
     * @return the content length of the rendered image
     */
    int getContentLength();
    
    /**
     * The MimeType of the image. This is usally a value of 
     * image/jpeg, image/gif, image/png or anything else which can be 
     * used as an image for html
     *  
     * @return the Mime-Type, not null
     */
    String getContentType();

    /**
     * Called to render the image to the given outputstream.
     * 
     * @param out the outputstream which is used to write the binary data of the image
     *  
     * @throws IOException
     */
    void renderResource(ResponseStream out) throws IOException;
}