Java tutorial
/* * Copyright 2000-2018 Vaadin Ltd. * * 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.vaadin.client.renderers; import com.google.gwt.core.client.GWT; import com.google.gwt.user.client.ui.Image; import com.vaadin.client.widget.grid.RendererCellReference; /** * A renderer that renders an image into a cell. Click handlers can be added to * the renderer, invoked every time any of the images rendered by that rendered * is clicked. * * @since 7.4 * @author Vaadin Ltd */ public class ImageRenderer extends ClickableRenderer<String, Image> { public static final String TRANSPARENT_GIF_1PX = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7"; @Override public Image createWidget() { Image image = GWT.create(Image.class); image.addClickHandler(this); return image; } @Override public void render(RendererCellReference cell, String url, Image image) { if (url == null) { image.setUrl(TRANSPARENT_GIF_1PX); } else { image.setUrl(url); } } }