| /* |
| * Copyright 2010 Google Inc. |
| * |
| * 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. |
| */ |
| package com.google.gwt.user.client.ui; |
| |
| import com.google.gwt.dom.client.Document; |
| import com.google.gwt.dom.client.Element; |
| import com.google.gwt.editor.client.IsEditor; |
| import com.google.gwt.editor.client.LeafValueEditor; |
| import com.google.gwt.editor.client.adapters.TakesValueEditor; |
| import com.google.gwt.text.shared.Parser; |
| import com.google.gwt.text.shared.Renderer; |
| import com.google.gwt.text.shared.ToStringRenderer; |
| import com.google.gwt.uibinder.client.UiConstructor; |
| import com.google.gwt.user.client.TakesValue; |
| |
| import java.text.ParseException; |
| |
| /** |
| * A label displaying its value through a renderer. |
| * |
| * @param <T> the value type. |
| */ |
| public class ValueLabel<T> extends LabelBase<T> implements TakesValue<T>, |
| IsEditor<LeafValueEditor<T>> { |
| |
| /** |
| * Creates a ValueLabel widget that wraps an existing <span> element. |
| * <p> |
| * The ValueLabel's value will be <code>null</code>, whether the element being |
| * wrapped has content or not. Use {@link #wrap(Element, Renderer, Parser)} to |
| * parse the initial element's content to initialize the ValueLabel's value. |
| * <p> |
| * This element must already be attached to the document. If the element is |
| * removed from the document, you must call |
| * {@link RootPanel#detachNow(Widget)}. |
| * |
| * @param element the element to be wrapped |
| * @param renderer the renderer used to render values into the element |
| */ |
| public static <T> ValueLabel<T> wrap(Element element, |
| Renderer<? super T> renderer) { |
| // Assert that the element is attached. |
| assert Document.get().getBody().isOrHasChild(element); |
| |
| ValueLabel<T> label = new ValueLabel<T>(element, renderer); |
| |
| // Mark it attached and remember it for cleanup. |
| label.onAttach(); |
| RootPanel.detachOnWindowClose(label); |
| |
| return label; |
| } |
| |
| /** |
| * Creates a ValueLabel widget that wraps an existing <span> element. |
| * <p> |
| * The ValueLabel's value will be initialized with the element's content, |
| * passed through the <code>parser</code>. |
| * <p> |
| * This element must already be attached to the document. If the element is |
| * removed from the document, you must call |
| * {@link RootPanel#detachNow(Widget)}. |
| * |
| * @param element the element to be wrapped |
| * @param renderer the renderer used to render values into the element |
| * @param parser the parser used to initialize the ValueLabel's value from the |
| * element's content |
| */ |
| public static <T> ValueLabel<T> wrap(Element element, |
| Renderer<? super T> renderer, Parser<? extends T> parser) |
| throws ParseException { |
| ValueLabel<T> label = wrap(element, renderer); |
| |
| label.setValue(parser.parse(element.getInnerText())); |
| |
| // Mark it attached and remember it for cleanup. |
| label.onAttach(); |
| RootPanel.detachOnWindowClose(label); |
| |
| return label; |
| } |
| |
| private final Renderer<? super T> renderer; |
| private T value; |
| private LeafValueEditor<T> editor; |
| |
| public ValueLabel() { |
| this(ToStringRenderer.instance()); |
| } |
| |
| /** |
| * Creates an empty value label. |
| * |
| * @param renderer |
| */ |
| @UiConstructor |
| public ValueLabel(Renderer<? super T> renderer) { |
| super(true); |
| this.renderer = renderer; |
| } |
| |
| /** |
| * This constructor may be used by subclasses to explicitly use an existing |
| * element. This element must be either a <span> or a <div> |
| * element. |
| * |
| * @param element the element to be used |
| */ |
| protected ValueLabel(Element element, Renderer<? super T> renderer) { |
| super(element); |
| this.renderer = renderer; |
| } |
| |
| public LeafValueEditor<T> asEditor() { |
| if (editor == null) { |
| editor = TakesValueEditor.of(this); |
| } |
| return editor; |
| } |
| |
| public T getValue() { |
| return value; |
| } |
| |
| public void setValue(T value) { |
| this.value = value; |
| directionalTextHelper.setText(renderer.render(value)); |
| updateHorizontalAlignment(); |
| } |
| } |