001/*
002 *  Copyright 2012 GWT-Bootstrap
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package com.github.gwtbootstrap.client.ui.base;
017
018import com.github.gwtbootstrap.client.ui.constants.Constants;
019import com.google.gwt.user.client.Element;
020
021
022/**
023 * The helper class for {@link HasPlaceholder} interface.
024 * 
025 * @since 2.0.4.0
026 * @author ohashi keisuke
027 *
028 */
029public class PlaceholderHelper {
030
031        //TODO 2012/05/04 ohashi keisuke. Support for non HTML5 Browser.
032        //I designed this class as non static class.
033        //Maybe we can use deffered binding for non HTML5 Browser support.
034        
035        /**
036         * Set a placeholder attribute (HTML5) to the element.
037         * 
038         * @param element the element be set 
039         * @param placeholder
040         *            the String to show. Use a empty string or null to remove the attribute.
041         */
042        public void setPlaceholer(Element element , String placeholder) {
043                if (placeholder == null || placeholder.trim().isEmpty()) {
044                        element.removeAttribute(Constants.PLACEHOLDER);
045                        return;
046                }
047                element.setAttribute(Constants.PLACEHOLDER, placeholder);
048        }
049        
050        /**
051         * Get a placeholder attribute (HTML5) from the element.
052         * <p>
053         * If the element don't have placeholder attribute,This return empty string.
054         * </p>
055         * @param element the element
056         * @return placeholder attribute.
057         */
058        public String getPlaceholder(Element element) {
059                return element.hasAttribute(Constants.PLACEHOLDER) 
060                                ? element.getAttribute(Constants.PLACEHOLDER)
061                                : "";
062        }
063}