com.google.gwt.gears.sample.uploaddemo.client.UploadDemo.java Source code

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Here is the source code for com.google.gwt.gears.sample.uploaddemo.client.UploadDemo.java

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/*
 * 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.google.gwt.gears.sample.uploaddemo.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.gears.client.Factory;
import com.google.gwt.gears.client.blob.Blob;
import com.google.gwt.gears.client.desktop.Desktop;
import com.google.gwt.gears.client.desktop.File;
import com.google.gwt.gears.client.desktop.OpenFilesHandler;
import com.google.gwt.gears.client.httprequest.HttpRequest;
import com.google.gwt.gears.client.httprequest.ProgressEvent;
import com.google.gwt.gears.client.httprequest.ProgressHandler;
import com.google.gwt.gears.client.httprequest.RequestCallback;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.SimplePanel;
import com.google.gwt.user.client.ui.TextBox;

/**
 * Roughly replicates a FORM upload using Gears.
 * <p>
 * When the user clicks the Browse button, the Desktop.openFiles method is
 * invoked allowing the user to select a file. The selection is saved as a Blob
 * reference and upload as the body of the POST request when the Upload button
 * is clicked.
 */
public class UploadDemo implements EntryPoint {
    final Factory factory = Factory.getInstance();
    RootPanel root;
    Blob selectedFile;

    /**
     * This is the entry point method.
     */
    public void onModuleLoad() {
        root = RootPanel.get();

        final Button browse = new Button("Browse");

        final Button upload = new Button("Upload");
        upload.setEnabled(false);

        final TextBox selected = new TextBox();
        selected.setEnabled(false);

        final SimplePanel progressInner = new SimplePanel();
        progressInner.addStyleName("progressInner");

        final SimplePanel progressGauge = new SimplePanel();
        progressGauge.addStyleName("progressGauge");
        progressGauge.add(progressInner);

        final HTML result = new HTML();

        browse.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent event) {
                Desktop desktop = factory.createDesktop();
                desktop.openFiles(new OpenFilesHandler() {

                    public void onOpenFiles(OpenFilesEvent event) {
                        File[] files = event.getFiles();
                        selected.setText(files[0].getName());
                        selectedFile = files[0].getBlob();
                        upload.setEnabled(true);
                    }
                }, true);
            }
        });

        upload.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent event) {
                HttpRequest request = factory.createHttpRequest();
                request.open("POST", GWT.getModuleBaseURL() + "upload");
                request.setRequestHeader("X-Filename", selected.getText());

                request.setCallback(new RequestCallback() {
                    public void onResponseReceived(HttpRequest request) {
                        String msg = request.getStatus() + " " + request.getResponseText();
                        if (request.getStatus() != 200) {
                            result.setHTML("<p style=\"color:red\">" + msg + "</p>");
                        } else {
                            result.setHTML("<p style=\"color:green\">" + msg + "</p>");
                        }
                    }
                });

                request.getUpload().setProgressHandler(new ProgressHandler() {
                    public void onProgress(ProgressEvent event) {
                        double pcnt = ((double) event.getLoaded() / event.getTotal());
                        progressInner.setWidth((int) Math.floor(pcnt * 100) + "%");
                    }
                });
                request.send(selectedFile);
            }
        });

        HorizontalPanel inputPanel = new HorizontalPanel();
        inputPanel.add(selected);
        inputPanel.add(browse);
        inputPanel.add(upload);

        root.add(inputPanel);
        root.add(new HTML("Progress:"));
        root.add(progressGauge);
        root.add(result);
    }
}