001/* 002 * This library is part of OpenCms - 003 * the Open Source Content Management System 004 * 005 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com) 006 * 007 * This library is free software; you can redistribute it and/or 008 * modify it under the terms of the GNU Lesser General Public 009 * License as published by the Free Software Foundation; either 010 * version 2.1 of the License, or (at your option) any later version. 011 * 012 * This library is distributed in the hope that it will be useful, 013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 015 * Lesser General Public License for more details. 016 * 017 * For further information about Alkacon Software, please see the 018 * company website: http://www.alkacon.com 019 * 020 * For further information about OpenCms, please see the 021 * project website: http://www.opencms.org 022 * 023 * You should have received a copy of the GNU Lesser General Public 024 * License along with this library; if not, write to the Free Software 025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 026 */ 027 028package org.opencms.gwt.client.util; 029 030import com.google.gwt.core.client.JavaScriptObject; 031 032/** 033 * Helper class used to create a native Javascript function to call into GWT code.<p> 034 */ 035public class CmsScriptCallbackHelper { 036 037 /** The stored arguments. */ 038 protected JavaScriptObject m_arguments; 039 040 /** 041 * Creates a native JS function which, when executed, calls this object's run() method.<p> 042 * 043 * @return the JS function 044 */ 045 public native JavaScriptObject createCallback() /*-{ 046 var self = this; 047 return function() { 048 self.@org.opencms.gwt.client.util.CmsScriptCallbackHelper::setArguments(Lcom/google/gwt/core/client/JavaScriptObject;)(arguments); 049 self.@org.opencms.gwt.client.util.CmsScriptCallbackHelper::run()(); 050 } 051 }-*/; 052 053 /** 054 * Installs the Javascript function generated by this helper as a global function, i.e. an attribute on 'window'.<p> 055 * 056 * @param name the function name 057 */ 058 public void installCallbackOnWindow(String name) { 059 060 CmsJsUtil.setAttribute(CmsJsUtil.getWindow(), name, createCallback()); 061 } 062 063 /** 064 * This method is called by the callback created by createCallback().<p> 065 */ 066 public void run() { 067 // override this method to put actual logic here 068 } 069 070 /** 071 * Sets the function arguments so they can be accessed later in the run() method.<p> 072 * 073 * @param arguments the function arguments 074 */ 075 public void setArguments(JavaScriptObject arguments) { 076 077 m_arguments = arguments; 078 } 079 080}