Java tutorial
/* * Smart GWT (GWT for SmartClient) * Copyright 2008 and beyond, Isomorphic Software, Inc. * * Smart GWT is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License version 3 * as published by the Free Software Foundation. Smart GWT is also * available under typical commercial license terms - see * http://smartclient.com/license * * This software is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. */ package com.smartgwt.client.widgets; import com.smartgwt.client.event.*; import com.smartgwt.client.core.*; import com.smartgwt.client.types.*; import com.smartgwt.client.data.*; import com.smartgwt.client.data.events.*; import com.smartgwt.client.rpc.*; import com.smartgwt.client.widgets.*; import com.smartgwt.client.widgets.events.*; import com.smartgwt.client.widgets.form.*; import com.smartgwt.client.widgets.form.validator.*; import com.smartgwt.client.widgets.form.fields.*; import com.smartgwt.client.widgets.tile.*; import com.smartgwt.client.widgets.tile.events.*; import com.smartgwt.client.widgets.grid.*; import com.smartgwt.client.widgets.grid.events.*; import com.smartgwt.client.widgets.chart.*; import com.smartgwt.client.widgets.layout.*; import com.smartgwt.client.widgets.layout.events.*; import com.smartgwt.client.widgets.menu.*; import com.smartgwt.client.widgets.tab.*; import com.smartgwt.client.widgets.toolbar.*; import com.smartgwt.client.widgets.tree.*; import com.smartgwt.client.widgets.tree.events.*; import com.smartgwt.client.widgets.viewer.*; import com.smartgwt.client.widgets.calendar.*; import com.smartgwt.client.widgets.calendar.events.*; import com.smartgwt.client.widgets.cube.*; import java.util.Date; import java.util.List; import java.util.Map; import java.util.HashMap; import com.google.gwt.user.client.ui.Widget; import com.google.gwt.core.client.JavaScriptObject; import com.google.gwt.user.client.Element; import com.smartgwt.client.util.*; import com.google.gwt.event.shared.*; import com.google.gwt.event.shared.HasHandlers; /** * The ViewLoader component can be used to load new Smart GWT-based user interfaces into a running application. <P> * <b>NOTE:</b> before using a ViewLoader, be sure that you have read about and understood the {@link * com.smartgwt.client.docs.SmartArchitecture Smart GWT Architecture}. The most responsive and scalable application * architecture preloads views rather than using ViewLoaders. <P> A ViewLoader is a Canvas, and can be provided anywhere a * Canvas can be provided: as a Tab pane, and Layout member, etc. When a ViewLoader draws, it shows a {@link * com.smartgwt.client.widgets.ViewLoader#getLoadingMessage loading message}, then performs an RPC to the {@link * com.smartgwt.client.widgets.ViewLoader#getViewURL viewURL} to load components. <P> The response from the viewURL should * be Smart GWT components defined in JavaScript, with no surrounding <SCRIPT> tags or other HTML framing. The * returned script can be dynamically generated, for example, it may be the result of a JSP containing an XML view * description enclosed in {@link com.smartgwt.client.docs.XmlTag <isomorphicXML>} tags. <P> In the returned script, * the special variable "viewLoader" is available to refer to the ViewLoader instance that is loading components. The * intended usage is that the returned script creates a view consisting of Smart GWT components, then calls * <code>viewLoader.setView(myView)</code> to place the loaded view into the ViewLoader. If the view does not call * setView() explicitly, the viewLoader will find the last top-level UI component (Canvas subclass) created by the view and * set that as the current view. Top-level in this case means that the UI component is not contained in another UI * component as a member or child. <p> The ViewLoader relies on the XMLHttpRequest object which can be disabled by * end-users in some supported browsers. See {@link com.smartgwt.client.docs.PlatformDependencies} for more information. * @see com.smartgwt.client.rpc.RPCRequest#getEvalResult */ public class ViewLoader extends Label { public static ViewLoader getOrCreateRef(JavaScriptObject jsObj) { if (jsObj == null) return null; BaseWidget obj = BaseWidget.getRef(jsObj); if (obj != null) { return (ViewLoader) obj; } else { return new ViewLoader(jsObj); } } public ViewLoader() { scClassName = "ViewLoader"; } public ViewLoader(JavaScriptObject jsObj) { super(jsObj); } protected native JavaScriptObject create()/*-{ var config = this.@com.smartgwt.client.widgets.BaseWidget::getConfig()(); var scClassName = this.@com.smartgwt.client.widgets.BaseWidget::scClassName; var widget = $wnd.isc[scClassName].create(config); this.@com.smartgwt.client.widgets.BaseWidget::doInit()(); return widget; }-*/; // ********************* Properties / Attributes *********************** /** * By default a ViewLoader will explicitly prevent browser caching. <P> Set to true to allow browser caching <b>if the * browser would normally do so</b>, in other words, if the HTTP headers returned with the response indicate that the * response can be cached. * * @param allowCaching allowCaching Default value is false * @throws IllegalStateException this property cannot be changed after the component has been created */ public void setAllowCaching(Boolean allowCaching) throws IllegalStateException { setAttribute("allowCaching", allowCaching, false); } /** * By default a ViewLoader will explicitly prevent browser caching. <P> Set to true to allow browser caching <b>if the * browser would normally do so</b>, in other words, if the HTTP headers returned with the response indicate that the * response can be cached. * * * @return Boolean */ public Boolean getAllowCaching() { return getAttributeAsBoolean("allowCaching"); } /** * Selects the HTTP method that will be used when fetching content. Valid values are "POST" and "GET". * * @param httpMethod httpMethod Default value is "GET" */ public void setHttpMethod(String httpMethod) { setAttribute("httpMethod", httpMethod, true); } /** * Selects the HTTP method that will be used when fetching content. Valid values are "POST" and "GET". * * * @return String */ public String getHttpMethod() { return getAttributeAsString("httpMethod"); } /** * Message to show while the view is loading. Use <code>"\${loadingImage}"</code> to include {@link * com.smartgwt.client.widgets.Canvas#loadingImageSrc a loading image}. * * @param loadingMessage loadingMessage Default value is "Loading View...&nbsp;\${loadingImage}" * @throws IllegalStateException this property cannot be changed after the component has been created */ public void setLoadingMessage(String loadingMessage) throws IllegalStateException { setAttribute("loadingMessage", loadingMessage, false); } /** * Message to show while the view is loading. Use <code>"\${loadingImage}"</code> to include {@link * com.smartgwt.client.widgets.Canvas#loadingImageSrc a loading image}. * * * @return String */ public String getLoadingMessage() { return getAttributeAsString("loadingMessage"); } /** * URL to load components from. * * <br><br>If this method is called after the component has been drawn/initialized: * Change the URL this component loads a view from. Triggers a fetch from the new URL. <P> Can also be called with no arguments to reload the view from the existing {@link com.smartgwt.client.widgets.ViewLoader#getViewURL viewURL}. * * @param viewURL URL to retrieve view from. Default value is null * @throws IllegalStateException this property cannot be changed after the component has been created * */ public void setViewURL(String viewURL) throws IllegalStateException { setAttribute("viewURL", viewURL, false); } /** * URL to load components from. * * * @return String * */ public String getViewURL() { return getAttributeAsString("viewURL"); } // ********************* Methods *********************** /** * Retrieve the current view. May be null if the view has not yet been loaded, or has been explicitly set to null. * * @return the current view */ public native Canvas getView() /*-{ var self = this.@com.smartgwt.client.widgets.BaseWidget::getOrCreateJsObj()(); var ret = self.getView(); if(ret == null || ret === undefined) return null; var retVal = @com.smartgwt.client.widgets.BaseWidget::getRef(Lcom/google/gwt/core/client/JavaScriptObject;)(ret); if(retVal == null) { retVal = @com.smartgwt.client.widgets.Canvas::new(Lcom/google/gwt/core/client/JavaScriptObject;)(ret); } return retVal; }-*/; /** * StringMethod fired when the view has been loaded. Has no default implementation. May be observed or overridden to fire * custom logic when loading completes. * @param view the view that was loaded */ public native void viewLoaded(Canvas view) /*-{ var self = this.@com.smartgwt.client.widgets.BaseWidget::getOrCreateJsObj()(); self.viewLoaded(view.@com.smartgwt.client.widgets.BaseWidget::getOrCreateJsObj()()); }-*/; // ********************* Static Methods *********************** /** * Class level method to set the default properties of this class. If set, then all subsequent instances of this * class will automatically have the default properties that were set when this method was called. This is a powerful * feature that eliminates the need for users to create a separate hierarchy of subclasses that only alter the default * properties of this class. Can also be used for skinning / styling purposes. * <P> * <b>Note:</b> This method is intended for setting default attributes only and will effect all instances of the * underlying class (including those automatically generated in JavaScript). * This method should not be used to apply standard EventHandlers or override methods for * a class - use a custom subclass instead. * * @param viewLoaderProperties properties that should be used as new defaults when instances of this class are created */ public static native void setDefaultProperties(ViewLoader viewLoaderProperties) /*-{ var properties = $wnd.isc.addProperties({},viewLoaderProperties.@com.smartgwt.client.widgets.BaseWidget::getConfig()()); delete properties.ID; $wnd.isc.ViewLoader.addProperties(properties); }-*/; // *********************************************************** }