/* * #%L * GwtMaterial * %% * Copyright (C) 2015 - 2017 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% */ package gwt.material.design.client.ui; import com.google.gwt.dom.client.OptionElement; import gwt.material.design.client.base.AllowBlankKeyFactory; import gwt.material.design.client.ui.html.Option; //@formatter:off /** * <p>Material ListBox is another dropdown component that will set / get the value depends on the selected index * <h3>UiBinder Usage:</h3> * <p> * <pre> * {@code * <m:MaterialListBox ui:field="lstBox" /> * } * </pre> * <h3>Java Usage:</h3> * <p> * <pre> * {@code * // functions * lstBox.setSelectedIndex(2); * lstBox.getSelectedIndex(); * lstBox.addValueChangeHandler(handler); * } * </pre> * </p> * * @author kevzlou7979 * @author Ben Dol * @see <a href="http://gwtmaterialdesign.github.io/gwt-material-demo/#listbox">Material ListBox</a> * @see <a href="https://material.io/guidelines/components/menus.html">Material Design Specification</a> */ //@formatter:on public class MaterialListBox extends MaterialListValueBox<String> { public void add(Option option) { getSelectElement().add(OptionElement.as(option.getElement()), null); values.add(option.getValue()); } @Override public String getValue() { String value = super.getValue(); if (value == null) { return AllowBlankKeyFactory.BLANK_VALUE_TEXT; } else { return value; } } @Override public void setValue(String value) { if (AllowBlankKeyFactory.BLANK_VALUE_TEXT.equals(value)) { super.setValue(null); } else { super.setValue(value); } } }