Java tutorial
/* * Copyright 2008 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.dingziran.effective.client.content.widgets; import com.google.gwt.core.client.GWT; import com.google.gwt.core.client.RunAsyncCallback; import com.google.gwt.i18n.client.Constants; import com.dingziran.effective.client.ContentWidget; import com.dingziran.effective.client.ContentWidgetView; import com.google.gwt.user.client.Window; import com.google.gwt.user.client.rpc.AsyncCallback; import com.google.gwt.user.client.ui.Button; import com.google.gwt.event.dom.client.ClickHandler; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.user.client.ui.FileUpload; import com.google.gwt.user.client.ui.HTML; import com.google.gwt.user.client.ui.VerticalPanel; import com.google.gwt.user.client.ui.Widget; /** * Example file. */ public class CwFileUpload extends ContentWidget { /** * The constants used in this Content Widget. */ public static interface CwConstants extends Constants { String cwFileUploadButton(); String cwFileUploadDescription(); String cwFileUploadName(); String cwFileUploadNoFileError(); String cwFileUploadSelectFile(); String cwFileUploadSuccessful(); } /** * An instance of the constants. */ private final CwConstants constants; /** * Constructor. * * @param constants the constants */ public CwFileUpload(CwConstants constants) { super(constants.cwFileUploadName(), constants.cwFileUploadDescription()); this.constants = constants; view = new ContentWidgetView(hasMargins(), hasScrollableContent()); view.setName(getName()); view.setDescription(getDescription()); setWidget(view); // Create a vertical panel to align the content VerticalPanel vPanel = new VerticalPanel(); // Add a label vPanel.add(new HTML(constants.cwFileUploadSelectFile())); // Add a file upload widget final FileUpload fileUpload = new FileUpload(); fileUpload.ensureDebugId("cwFileUpload"); vPanel.add(fileUpload); final String msg1 = constants.cwFileUploadNoFileError(); final String msg2 = constants.cwFileUploadSuccessful(); // Add a button to upload the file Button uploadButton = new Button(constants.cwFileUploadButton()); uploadButton.addClickHandler(new ClickHandler() { public void onClick(ClickEvent event) { String filename = fileUpload.getFilename(); if (filename.length() == 0) { Window.alert(msg1); } else { Window.alert(msg2); } } }); vPanel.add(new HTML("<br>")); vPanel.add(uploadButton); view.setExample(vPanel); } }