Java tutorial
package org.gwtbootstrap3.client.ui.base.mixin; /* * #%L * GwtBootstrap3 * %% * Copyright (C) 2013 GwtBootstrap3 * %% * 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 java.util.List; import org.gwtbootstrap3.client.ui.base.HasDataTarget; import org.gwtbootstrap3.client.ui.constants.Attributes; import com.google.gwt.dom.client.Document; import com.google.gwt.dom.client.Element; import com.google.gwt.user.client.ui.UIObject; import com.google.gwt.user.client.ui.Widget; /** * @author Sven Jacobs */ public class DataTargetMixin<T extends UIObject & HasDataTarget> extends AbstractMixin implements HasDataTarget { /** * Ensures the given element has a non-empty id. * * @param element The element being examined. * @see Document#createUniqueId() */ private void ensureId(final Element element) { final String id = element.getId(); if (id == null || id.isEmpty()) { element.setId(Document.get().createUniqueId()); } } public DataTargetMixin(final T uiObject) { super(uiObject); } @Override public void setDataTargetWidget(final Widget widget) { final Element element = widget.getElement(); ensureId(element); this.setDataTarget("#" + element.getId()); } @Override public void setDataTargetWidgets(final List<Widget> widgets) { final String styleName = Document.get().createUniqueId(); for (final Widget widget : widgets) { widget.addStyleName(styleName); } this.setDataTarget("." + styleName); } @Override public void setDataTarget(final String dataTarget) { if (dataTarget != null) { uiObject.getElement().setAttribute(Attributes.DATA_TARGET, dataTarget); } else { uiObject.getElement().removeAttribute(Attributes.DATA_TARGET); } } @Override public String getDataTarget() { return uiObject.getElement().getAttribute(Attributes.DATA_TARGET); } }