Java tutorial
package gwt.material.design.client.base.helper; /* * #%L * GwtMaterial * %% * Copyright (C) 2015 GwtMaterialDesign * %% * Licensed 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. * #L% */ import com.google.gwt.dom.client.Element; import com.google.gwt.dom.client.Node; import com.google.gwt.dom.client.NodeList; import com.google.gwt.user.client.ui.HasWidgets; import com.google.gwt.user.client.ui.RootPanel; import com.google.gwt.user.client.ui.Widget; // TODO: Replace with jQuery JSInterop public class DOMHelper { public static Element getChildElementById(Element parent, String id) { if (parent != null) { for (int i = 0; i < parent.getChildCount(); i++) { Node childNode = parent.getChild(i); if (Element.is(childNode)) { Element child = Element.as(childNode); if (child.getId().equals(id)) { return child; } if (child.getChildCount() > 0) { return getChildElementById(child, id); } } } } return null; } public static Widget getChildWidgetById(HasWidgets parent, String id) { if (parent != null) { for (Widget child : parent) { if (child.getElement().getId().equals(id)) { return child; } } } return null; } public static Element getElementByAttribute(String attr, String value) { return getElementByAttribute(RootPanel.getBodyElement().getElementsByTagName("*"), attr, value); } public static Element getElementByAttribute(NodeList<Element> elems, String attr, String value) { if (elems != null) { for (int i = 0; i < elems.getLength(); i++) { Element child = elems.getItem(i); if (child.getAttribute(attr).equals(value)) { return child; } } } return null; } }