Java tutorial
/* * This is part of Geomajas, a GIS framework, http://www.geomajas.org/. * * Copyright 2008-2013 Geosparc nv, http://www.geosparc.com/, Belgium. * * The program is available in open source according to the GNU Affero * General Public License. All contributions in this program are covered * by the Geomajas Contributors License Agreement. For full licensing * details, see LICENSE.txt in the project root. */ package org.geomajas.gwt.client.util.impl; import org.geomajas.global.GeomajasConstant; import org.geomajas.gwt.client.util.Dom; import org.geomajas.gwt.client.util.Log; import com.google.gwt.core.client.GWT; import com.google.gwt.dom.client.Document; import com.google.gwt.user.client.DOM; import com.google.gwt.user.client.Element; /** * <p> * Default implementation of {@link Dom} delegate. * </p> * * @author Jan De Moerloose */ public class DomImpl { /** * Initialization of the VML name-spaces. In order to be able to use VML in a page, this function has to be called * first! */ public void initVMLNamespace() { throw new RuntimeException("VML unsupported"); } /** * Assemble an DOM id. * * @param id base id * @param suffixes suffixes to add * @return id */ public String assembleId(String id, String... suffixes) { StringBuilder sb = new StringBuilder(); if (null != id) { sb.append(id); } for (String s : suffixes) { sb.append(Dom.ID_SEPARATOR); sb.append(s); } return sb.toString(); } /** * Disassemble an DOM id, removing suffixes. * * @param id base id * @param suffixes suffixes to remove * @return id */ public String disAssembleId(String id, String... suffixes) { int count = 0; for (String s : suffixes) { count += s.length() + Dom.ID_SEPARATOR.length(); } return id.substring(0, id.length() - count); } /** * <p> * Creates a new DOM element in the given name-space. If the name-space is HTML, a normal element will be created. * </p> * <p> * There is an exception when using Internet Explorer! For Internet Explorer a new element will be created of type * "namespace:tag". * </p> * * @param ns The name-space to be used in the element creation. * @param tag The tag-name to be used in the element creation. * @return Returns a newly created DOM element in the given name-space. */ public Element createElementNS(String ns, String tag, String id) { Element element; if (Dom.NS_HTML.equals(ns)) { element = DOM.createElement(tag); } else { element = createNameSpaceElement(ns, tag); } if (id != null) { DOM.setElementAttribute(element, "id", id); } Log.logDebug("Creating element " + id); return element; } /** * <p> * Creates a new DOM element in the given name-space. If the name-space is HTML, a normal element will be created. * </p> * <p> * There is an exception when using Internet Explorer! For Internet Explorer a new element will be created of type * "namespace:tag". * </p> * * @param ns The name-space to be used in the element creation. * @param tag The tag-name to be used in the element creation. * @return Returns a newly created DOM element in the given name-space. */ public Element createElementNS(String ns, String tag) { return createElementNS(ns, tag, null); } /** * Creates an HTML element with the given id. * * @param tagName the HTML tag of the element to be created * @return the newly-created element */ public Element createElement(String tagName, String id) { Log.logDebug("Creating element " + id); Element element = DOM.createElement(tagName).cast(); DOM.setElementAttribute(element, "id", id); return element; } private native Element createNameSpaceElement(String ns, String tag) /*-{ return $doc.createElementNS(ns, tag); }-*/; /** * <p> * Adds a new attribute in the given name-space to an element. * </p> * <p> * There is an exception when using Internet Explorer! For Internet Explorer the attribute of type "namespace:attr" * will be set. * </p> * * @param ns The name-space to be used in the element creation. * @param element The element to which the attribute is to be set. * @param attr The name of the attribute. * @param value The new value for the attribute. */ public void setElementAttributeNS(String ns, Element element, String attr, String value) { setNameSpaceAttribute(ns, element, attr, value); } private native void setNameSpaceAttribute(String ns, Element element, String attr, String value) /*-{ element.setAttributeNS(ns, attr, value); }-*/; /** * Is currently using Internet Explorer ? Consider using deferred binding instead of this flag to minimize your * download and support future browser versions. * * @return true or false - yes or no. */ public boolean isIE() { return false; } /** * Is the browser supporting SVG? Consider using deferred binding instead of this flag to minimize your download and * support future browser versions. * * @return true or false - yes or no. */ public boolean isSvg() { return true; } /** * Is the user currently using Firefox ? Consider using deferred binding instead of this flag to minimize your * download and support future browser versions. * * @return true or false - yes or no. */ public boolean isFireFox() { return false; } /** * Is the user currently using Chrome? Consider using deferred binding instead of this flag to minimize your * download and support future browser versions. * * @return true or false - yes or no. */ public boolean isChrome() { return false; } /** * Is the user currently using Safari? Consider using deferred binding instead of this flag to minimize your * download and support future browser versions. * * @return true or false - yes or no. */ public boolean isSafari() { return false; } /** * Is the user currently using a Webkit based browser (such as Chrome or Safari)? Consider using deferred binding * instead of this flag to minimize your download and support future browser versions. * * @return true or false - yes or no. */ public boolean isWebkit() { return false; } protected native String getUserAgent() /*-{ return navigator.userAgent.toLowerCase(); }-*/; /** * Similar method to the "setInnerHTML", but specified for setting SVG. Using the regular setInnerHTML, it is not * possible to set a string of SVG on an object. This method can do that. On the other hand, this method is better * not used for setting normal HTML as an element's innerHTML. * * @param element The element onto which to set the SVG string. * @param svg The string of SVG to set on the element. */ public void setInnerSvg(Element element, String svg) { svg = "<g xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\">" + svg + "</g>"; setInnerHTML(element, svg); } private native void setInnerHTML(Element element, String svg) /*-{ var fragment = new DOMParser().parseFromString(svg,"text/xml"); if(fragment) { var children = fragment.childNodes; for(var i=0; i < children.length; i++) { var node = @org.geomajas.gwt.client.util.Dom::cloneSvgElement(Lcom/google/gwt/user/client/Element;) (children[i]); element.appendChild (node); } } }-*/; /** * Clone a single SVG element. * * @param source The source SVG element. * @return Returns the clone. */ public Element cloneSvgElement(Element source) { if (source == null || source.getNodeName() == null) { return null; } if ("#text".equals(source.getNodeName())) { return Document.get().createTextNode(source.getNodeValue()).cast(); } Element clone = createElementNS(Dom.NS_SVG, source.getNodeName(), Dom.createUniqueId()); cloneAttributes(source, clone); for (int i = 0; i < source.getChildCount(); i++) { Element child = source.getChild(i).cast(); clone.appendChild(cloneSvgElement(child)); } return clone; } private native void cloneAttributes(Element source, Element target) /*-{ if (source != null && target != null) { for (var i=0; i<source.attributes.length; i++) { var attribute = source.attributes.item(i); if (attribute.value != null && attribute.value.length > 0) { var atClone = null; try { atClone = $doc.createAttributeNS(attribute.namespaceURI, attribute.name); } catch (e) { atClone = $doc.createAttribute(attribute.name); } atClone.value = attribute.value; target.setAttributeNode(atClone); } } } }-*/; /** * Convert a URL to an absolute URL. This assumes the page is at the application root. * <p/> * It converts relative URLs by prepending the HostPageBaseURL and converts classpath resources to use the resource * dispatcher. * * @param url URL to convert * @return converted URL */ public String makeUrlAbsolute(String url) { String href = url; if (href.indexOf(':') <= 0) { // SVG in Chrome can't handle relative paths (the xml:base attribute has not yet been tested): href = GWT.getHostPageBaseURL() + href; } else if (href.startsWith(GeomajasConstant.CLASSPATH_URL_PREFIX)) { href = GWT.getHostPageBaseURL() + "d/resource/" + href.substring(GeomajasConstant.CLASSPATH_URL_PREFIX.length()); } return href; } /** * Determine whether one element is equal to, or the child of, another. * * @param parent the potential parent element * @param child the potential child element * @return <code>true</code> if the relationship holds */ public boolean isOrHasChild(Element parent, Element child) { return DOM.isOrHasChild(parent, child); } /** * Is the browser supporting transformations? Not all browsers support alternatives, so this check can be necessary. * * @return true or false - yes or no. * @since 1.3.0 */ public boolean isTransformationSupported() { return false; } /** * Set the CSS3 transform property (e.g. 'scale(2)'). * * @param element * @param transform * @since 1.3.0 */ public void setTransform(Element element, String transform) { throw new RuntimeException("Transformation unsupported"); } /** * Set the CSS3 transform-origin property (defaults to center, e.g. '10 px 20 px'). * * @param element * @param origin * @since 1.3.0 */ public void setTransformOrigin(Element element, String origin) { throw new RuntimeException("Transformation origin unsupported"); } }