ftpwindow.cpp Example File
^{network/ftp/ftpwindow.cpp}

    /****************************************************************************
    **
    ** Copyright (C) 2004-2005 Trolltech AS. All rights reserved.
    **
    ** This file is part of the documentation of the Qt Toolkit.
    **
    ** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at sales@trolltech.com.
    **
    ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
    ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
    **
    ****************************************************************************/

    #include <QtGui>
    #include <QtNetwork>

    #include "ftpwindow.h"

    FtpWindow::FtpWindow(QWidget *parent)
        : QDialog(parent)
    {
        ftpServerLabel = new QLabel(tr("Ftp &server:"));
        ftpServerLineEdit = new QLineEdit("ftp.trolltech.com");
        ftpServerLabel->setBuddy(ftpServerLineEdit);

        statusLabel = new QLabel(tr("Please enter the name of an FTP server."));

        fileList = new QListWidget;

        connectButton = new QPushButton(tr("Connect"));
        connectButton->setDefault(true);

        downloadButton = new QPushButton(tr("Download"));
        downloadButton->setEnabled(false);

        cdToParentButton = new QPushButton;
        cdToParentButton->setIcon(QPixmap(":/images/cdtoparent.png"));
        cdToParentButton->setEnabled(false);

        quitButton = new QPushButton(tr("Quit"));

        ftp = new QFtp(this);

        progressDialog = new QProgressDialog(this);

        connect(ftpServerLineEdit, SIGNAL(textChanged(const QString &)),
                this, SLOT(enableConnectButton()));
        connect(fileList, SIGNAL(itemDoubleClicked(QListWidgetItem *)),
                this, SLOT(processItem(QListWidgetItem *)));
        connect(fileList, SIGNAL(itemEntered(QListWidgetItem *)),
                this, SLOT(processItem(QListWidgetItem *)));
        connect(fileList, SIGNAL(itemSelectionChanged()),
                this, SLOT(enableDownloadButton()));
        connect(ftp, SIGNAL(commandFinished(int, bool)),
                this, SLOT(ftpCommandFinished(int, bool)));
        connect(ftp, SIGNAL(listInfo(const QUrlInfo &)),
                this, SLOT(addToList(const QUrlInfo &)));
        connect(ftp, SIGNAL(dataTransferProgress(qint64, qint64)),
                this, SLOT(updateDataTransferProgress(qint64, qint64)));
        connect(progressDialog, SIGNAL(canceled()), this, SLOT(cancelDownload()));
        connect(connectButton, SIGNAL(clicked()), this, SLOT(connectToFtpServer()));
        connect(cdToParentButton, SIGNAL(clicked()), this, SLOT(cdToParent()));
        connect(downloadButton, SIGNAL(clicked()), this, SLOT(downloadFile()));
        connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));

        QHBoxLayout *topLayout = new QHBoxLayout;
        topLayout->addWidget(ftpServerLabel);
        topLayout->addWidget(ftpServerLineEdit);
        topLayout->addWidget(cdToParentButton);

        QHBoxLayout *buttonLayout = new QHBoxLayout;
        buttonLayout->addStretch(1);
        buttonLayout->addWidget(downloadButton);
        buttonLayout->addWidget(connectButton);
        buttonLayout->addWidget(quitButton);

        QVBoxLayout *mainLayout = new QVBoxLayout;
        mainLayout->addLayout(topLayout);
        mainLayout->addWidget(fileList);
        mainLayout->addWidget(statusLabel);
        mainLayout->addLayout(buttonLayout);
        setLayout(mainLayout);

        setWindowTitle(tr("FTP"));
    }

    void FtpWindow::connectToFtpServer()
    {
        QApplication::setOverrideCursor(Qt::WaitCursor);
        ftp->connectToHost(ftpServerLineEdit->text());
        ftp->login();
        ftp->list();
        statusLabel->setText(tr("Connecting to FTP server %1...")
                             .arg(ftpServerLineEdit->text()));
    }

    void FtpWindow::downloadFile()
    {
        QString fileName = fileList->currentItem()->text();

        if (QFile::exists(fileName)) {
            QMessageBox::information(this, tr("FTP"),
                                     tr("There already exists a file called %1 in "
                                        "the current directory.")
                                     .arg(fileName));
            return;
        }

        file = new QFile(fileName);
        if (!file->open(QIODevice::WriteOnly)) {
            QMessageBox::information(this, tr("FTP"),
                                     tr("Unable to save the file %1: %2.")
                                     .arg(fileName).arg(file->errorString()));
            delete file;
            return;
        }

        ftp->get(fileList->currentItem()->text(), file);

        progressDialog->setLabelText(tr("Downloading %1...").arg(fileName));
        progressDialog->show();
        downloadButton->setEnabled(false);
    }

    void FtpWindow::cancelDownload()
    {
        ftp->abort();
    }

    void FtpWindow::ftpCommandFinished(int, bool error)
    {
        if (ftp->currentCommand() == QFtp::ConnectToHost) {
            if (error) {
                QApplication::restoreOverrideCursor();
                QMessageBox::information(this, tr("FTP"),
                                         tr("Unable to connect to the FTP server "
                                            "at %1. Please check that the host "
                                            "name is correct.")
                                         .arg(ftpServerLineEdit->text()));
                return;
            }

            statusLabel->setText(tr("Logged onto %1.")
                                 .arg(ftpServerLineEdit->text()));
            fileList->setFocus();
            connectButton->setEnabled(false);
            downloadButton->setDefault(true);
            return;
        }

        if (ftp->currentCommand() == QFtp::Get) {
            QApplication::restoreOverrideCursor();
            if (error) {
                statusLabel->setText(tr("Canceled download of %1.")
                                     .arg(file->fileName()));
                file->close();
                file->remove();
            } else {
                statusLabel->setText(tr("Downloaded %1 to current directory.")
                                     .arg(file->fileName()));
                file->close();
            }
            delete file;
            enableDownloadButton();
        } else if (ftp->currentCommand() == QFtp::List) {
            QApplication::restoreOverrideCursor();
            if (isDirectory.isEmpty()) {
                fileList->addItem(tr("<empty>"));
                fileList->setEnabled(false);
            }
        }
    }

    void FtpWindow::addToList(const QUrlInfo &urlInfo)
    {
        QListWidgetItem *item = new QListWidgetItem;
        item->setText(urlInfo.name());
        QPixmap pixmap(urlInfo.isDir() ? ":/images/dir.png" : ":/images/file.png");
        item->setIcon(pixmap);

        isDirectory[urlInfo.name()] = urlInfo.isDir();
        fileList->addItem(item);
        if (!fileList->currentItem()) {
            fileList->setCurrentItem(fileList->item(0));
            fileList->setEnabled(true);
        }
    }

    void FtpWindow::processItem(QListWidgetItem *item)
    {
        QString name = item->text();
        if (isDirectory.value(name)) {
            fileList->clear();
            isDirectory.clear();
            currentPath += "/" + name;
            ftp->cd(name);
            ftp->list();
            cdToParentButton->setEnabled(true);
            QApplication::setOverrideCursor(Qt::WaitCursor);
            return;
        }
    }

    void FtpWindow::cdToParent()
    {
        QApplication::setOverrideCursor(Qt::WaitCursor);
        fileList->clear();
        isDirectory.clear();
        currentPath = currentPath.left(currentPath.lastIndexOf('/'));
        if (currentPath.isEmpty()) {
            cdToParentButton->setEnabled(false);
            ftp->cd("/");
        } else {
            ftp->cd(currentPath);
        }
        ftp->list();
    }

    void FtpWindow::updateDataTransferProgress(qint64 readBytes,
                                               qint64 totalBytes)
    {
        progressDialog->setMaximum(totalBytes);
        progressDialog->setValue(readBytes);
    }

    void FtpWindow::enableConnectButton()
    {
        connectButton->setEnabled(!ftpServerLineEdit->text().isEmpty());
    }

    void FtpWindow::enableDownloadButton()
    {
        QListWidgetItem *current = fileList->currentItem();
        if (current) {
            QString currentFile = current->text();
            downloadButton->setEnabled(!isDirectory.value(currentFile));
        } else {
            downloadButton->setEnabled(false);
        }
    }