001// Copyright 2005 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.tapestry; 016 017/** 018 * Extends {@link org.apache.tapestry.IScriptProcessor} with a handful of additional methods 019 * needed when rendering a page response. 020 * 021 * @author Howard M. Lewis Ship 022 * @since 4.0 023 * @see org.apache.tapestry.html.Body 024 * @see org.apache.tapestry.TapestryUtils#getPageRenderSupport(IRequestCycle, Object) 025 */ 026public interface PageRenderSupport extends IScriptProcessor 027{ 028 /** 029 * Sets up the given URL to preload, and returns a reference to the loaded image, in the form of 030 * a snippet of JavaScript expression that can be inserted into some larger block of JavaScript 031 * as a function parameter, or as a property assignment. A typical return value might be 032 * <code>tapestry_preload[7].src</code>. 033 */ 034 035 public String getPreloadedImageReference(String url); 036}