org.onesocialweb.gwt.client.ui.widget.SingleUploader.java Source code

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Here is the source code for org.onesocialweb.gwt.client.ui.widget.SingleUploader.java

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/*
 *  Copyright 2010 Vodafone Group Services 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 org.onesocialweb.gwt.client.ui.widget;

import org.onesocialweb.gwt.client.OswClient;
import org.onesocialweb.gwt.client.ui.dialog.AlertDialog;
import org.onesocialweb.gwt.service.OswServiceFactory;
import org.onesocialweb.gwt.service.UpdateCallback;
import org.onesocialweb.gwt.service.UploadStatus;

import com.google.gwt.event.dom.client.ChangeEvent;
import com.google.gwt.event.dom.client.ChangeHandler;
import com.google.gwt.http.client.URL;
import com.google.gwt.user.client.ui.FileUpload;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.FormPanel;
import com.google.gwt.user.client.ui.Hidden;
import com.google.gwt.user.client.ui.FormPanel.SubmitCompleteEvent;

public class SingleUploader extends FlowPanel {

    private final FileUpload upload = new FileUpload();
    private final FormPanel form = new FormPanel();
    private final ProgressBar progress = new ProgressBar();
    private final StyledLabel fileLabel = new StyledLabel("filelabel", "");
    private FlowPanel contents = new FlowPanel();
    private Hidden jid = new Hidden();
    private Hidden signature = new Hidden();
    private Hidden requestId = new Hidden();
    private String filename;
    private String fileurl;

    private Boolean isUploading = false;

    public SingleUploader() {

        addStyleName("uploader");

        // Because we're going to add a FileUpload widget, we'll need to set the
        // form to use the POST method, and multipart MIME encoding.
        form.setEncoding(FormPanel.ENCODING_MULTIPART);
        form.setMethod(FormPanel.METHOD_POST);

        // add the form
        form.setWidget(contents);
        add(form);

        // add the fileupload and hidden fields
        contents.add(upload);
        add(fileLabel);
        add(progress);
        fileLabel.setVisible(false);
        progress.setVisible(true);

        upload.setName("fileId");

        upload.addChangeHandler(new ChangeHandler() {

            @Override
            public void onChange(ChangeEvent event) {

                // check if we have a file
                if (upload.getFilename() != null && upload.getFilename().length() > 0) {

                    // TODO check for valid extensions

                    // change state to is uploading
                    setIsUploading(true);

                    // prepare for posting
                    String token = getToken();
                    signature.setName("signature");
                    signature.setValue(token);

                    jid.setName("jid");
                    jid.setValue(OswServiceFactory.getService().getUserFullJID());

                    requestId.setName("requestId");
                    requestId.setValue("123456");

                    form.setAction(OswClient.getInstance().getPreference("upload_endpoint") + "?"
                            + "requestId=123456&jid=" + URL.encode(OswServiceFactory.getService().getUserFullJID())
                            + "&signature=" + token);

                    // and fire in the hole
                    form.submit();

                    // get basic file information
                    filename = upload.getFilename();
                    fileLabel.setText(filename);

                    // hide upload selector and show progressbar
                    upload.setVisible(false);
                    progress.setVisible(true);
                    fileLabel.setVisible(true);
                }
            }
        });

        form.addSubmitCompleteHandler(new FormPanel.SubmitCompleteHandler() {
            public void onSubmitComplete(SubmitCompleteEvent event) {
                // we are going to use the xmpp channel to monitor progress
                // instead

            }
        });
    }

    public String getFileUrl() {
        return fileurl;
    }

    public void reset() {
        upload.setVisible(true);
        progress.setVisible(false);
        fileLabel.setText("");
        fileLabel.setVisible(false);
        form.reset();
    }

    private String getToken() {

        // get a token from the server
        String token = OswServiceFactory.getService().startUpload("123456", new UpdateCallback<UploadStatus>() {

            @Override
            public void onError() {
                AlertDialog.getInstance().showDialog(
                        "Oops, something went wrong with the upload. Please try again.", "Upload failed");
            }

            @Override
            public void onUpdate(UploadStatus update) {

                System.out.println(update.getBytesRead());

                // display progress
                if (update.getStatus().equals("progress")) {

                    progress.setProgress(update.getBytesRead());

                    return;
                }

                // if the file is complete
                if (update.getStatus().equals("completed")) {

                    // hide the progressbar
                    progress.setVisible(false);

                    // get the file size
                    fileLabel.setText(fileLabel.getText() + " (" + Math.round(update.getSize() / 1024) + " kB)");

                    // process the result
                    fileurl = OswClient.getInstance().getPreference("file_retrieval_endpoint") + "?" + "fileId="
                            + update.getFileId();
                    processResult(fileurl);

                    // we're no longer uploading
                    setIsUploading(false);

                    return;
                }

                if (update.getStatus().equals("error")) {

                    AlertDialog.getInstance().showDialog(
                            "Oops, something went wrong with the upload. Please try again.", "Upload failed");

                    // we're no longer uploading
                    setIsUploading(false);

                    return;
                }
            }

        });

        return token;
    }

    private void processResult(String filename) {

    }

    public void setIsUploading(Boolean isUploading) {
        this.isUploading = isUploading;
    }

    public Boolean getIsUploading() {
        return isUploading;
    }

}