001/*
002 * #%L
003 * GwtMaterial
004 * %%
005 * Copyright (C) 2015 - 2017 GwtMaterialDesign
006 * %%
007 * Licensed under the Apache License, Version 2.0 (the "License");
008 * you may not use this file except in compliance with the License.
009 * You may obtain a copy of the License at
010 * 
011 *      http://www.apache.org/licenses/LICENSE-2.0
012 * 
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 * #L%
019 */
020package gwt.material.design.client.base;
021
022import com.google.gwt.dom.client.Document;
023import com.google.gwt.text.shared.Parser;
024import com.google.gwt.text.shared.Renderer;
025import com.google.gwt.user.client.ui.ValueBox;
026import gwt.material.design.client.ui.MaterialNumberBox;
027
028import java.io.IOException;
029import java.text.ParseException;
030
031/**
032 * Base class to handle number values on {@code <input type="number">} elements.
033 * <p>
034 * The parsing and formatting is done by the browser, using the user specific i18n settings.
035 *
036 * @author gilberto-torrezan
037 * @see MaterialNumberBox
038 */
039@SuppressWarnings({"rawtypes", "unchecked"})
040public class NumberBox<T> extends ValueBox<T> {
041
042    public NumberBox(NumberHandler handler) {
043        // currently there's no way to create a <input type="number"> directly
044        super(Document.get().createTextInputElement(), handler, handler);
045    }
046
047    public static class NumberHandler<T> implements Renderer<T>, Parser<T> {
048
049        MaterialNumberBox<T> numberBox;
050
051        public NumberHandler(MaterialNumberBox<T> numberBox) {
052            this.numberBox = numberBox;
053        }
054
055        /*
056         * Note: This assumes that getValue() from the custom MaterialNumberBox was overridden to avoid using the parser.
057         */
058        @Override
059        public T parse(CharSequence text) throws ParseException {
060            return numberBox.getValue();
061        }
062
063        @Override
064        public String render(T object) {
065            if (object == null) {
066                return "";
067            }
068            return object.toString();
069        }
070
071        @Override
072        public void render(T object, Appendable appendable) throws IOException {
073            appendable.append(render(object));
074        }
075    }
076
077}