httpwindow.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

/****************************************************************************
**
** Copyright (C) 2004-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the example classes 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 [e-mail].
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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****************************************************************************/

#include <QtGui>
#include <QtNetwork>

#include "httpwindow.h"

HttpWindow::HttpWindow(QWidget *parent)
    : QDialog(parent)
{
    urlLineEdit = new QLineEdit("http://www.ietf.org/iesg/1rfc_index.txt");

    urlLabel = new QLabel(tr("&URL:"));
    urlLabel->setBuddy(urlLineEdit);
    statusLabel = new QLabel(tr("Please enter the URL of a file you want to "
                                "download."));

    quitButton = new QPushButton(tr("Quit"));
    downloadButton = new QPushButton(tr("Download"));
    downloadButton->setDefault(true);

    progressDialog = new QProgressDialog(this);

    http = new QHttp(this);

    connect(urlLineEdit, SIGNAL(textChanged(const QString &)),
            this, SLOT(enableDownloadButton()));
    connect(http, SIGNAL(requestFinished(int, bool)),
            this, SLOT(httpRequestFinished(int, bool)));
    connect(http, SIGNAL(dataReadProgress(int, int)),
            this, SLOT(updateDataReadProgress(int, int)));
    connect(http, SIGNAL(responseHeaderReceived(const QHttpResponseHeader &)),
            this, SLOT(readResponseHeader(const QHttpResponseHeader &)));
    connect(progressDialog, SIGNAL(canceled()), this, SLOT(cancelDownload()));
    connect(downloadButton, SIGNAL(clicked()), this, SLOT(downloadFile()));
    connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));

    QHBoxLayout *topLayout = new QHBoxLayout;
    topLayout->addWidget(urlLabel);
    topLayout->addWidget(urlLineEdit);

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

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

    setWindowTitle(tr("HTTP"));
    urlLineEdit->setFocus();
}

void HttpWindow::downloadFile()
{
    QUrl url(urlLineEdit->text());
    QFileInfo fileInfo(url.path());
    QString fileName = fileInfo.fileName();

    if (QFile::exists(fileName)) {
        QMessageBox::information(this, tr("HTTP"),
                                 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("HTTP"),
                                 tr("Unable to save the file %1: %2.")
                                 .arg(fileName).arg(file->errorString()));
        delete file;
        file = 0;
        return;
    }

    http->setHost(url.host(), url.port() != -1 ? url.port() : 80);
    if (!url.userName().isEmpty())
        http->setUser(url.userName(), url.password());

    httpRequestAborted = false;
    httpGetId = http->get(url.path(), file);

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

void HttpWindow::cancelDownload()
{
    statusLabel->setText(tr("Download canceled."));
    httpRequestAborted = true;
    http->abort();
    downloadButton->setEnabled(true);
}

void HttpWindow::httpRequestFinished(int requestId, bool error)
{
    if (httpRequestAborted) {
        if (file) {
            file->close();
            file->remove();
            delete file;
            file = 0;
        }

        progressDialog->hide();
        return;
    }

    if (requestId != httpGetId)
        return;

    progressDialog->hide();
    file->close();

    if (error) {
        file->remove();
        QMessageBox::information(this, tr("HTTP"),
                                 tr("Download failed: %1.")
                                 .arg(http->errorString()));
    } else {
        QString fileName = QFileInfo(QUrl(urlLineEdit->text()).path()).fileName();
        statusLabel->setText(tr("Downloaded %1 to current directory.").arg(fileName));
    }

    downloadButton->setEnabled(true);
    delete file;
    file = 0;
}

void HttpWindow::readResponseHeader(const QHttpResponseHeader &responseHeader)
{
    if (responseHeader.statusCode() != 200) {
        QMessageBox::information(this, tr("HTTP"),
                                 tr("Download failed: %1.")
                                 .arg(responseHeader.reasonPhrase()));
        httpRequestAborted = true;
        progressDialog->hide();
        http->abort();
        return;
    }
}

void HttpWindow::updateDataReadProgress(int bytesRead, int totalBytes)
{
    if (httpRequestAborted)
        return;

    progressDialog->setMaximum(totalBytes);
    progressDialog->setValue(bytesRead);
}

void HttpWindow::enableDownloadButton()
{
    downloadButton->setEnabled(!urlLineEdit->text().isEmpty());
}