Mega Code Archive
Download manager
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**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
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#ifndef TEXTPROGRESSBAR_H
#define TEXTPROGRESSBAR_H
#include <QString>
class TextProgressBar
{
public:
TextProgressBar();
void clear();
void update();
void setMessage(const QString &message);
void setStatus(qint64 value, qint64 maximum);
private:
QString message;
qint64 value;
qint64 maximum;
int iteration;
};
#endif
#include "textprogressbar.h"
#include <QByteArray>
#include <stdio.h>
TextProgressBar::TextProgressBar()
: value(0), maximum(-1), iteration(0)
{
}
void TextProgressBar::clear()
{
printf("\n");
fflush(stdout);
iteration = 0;
value = 0;
maximum = -1;
}
void TextProgressBar::update()
{
++iteration;
if (maximum > 0) {
// we know the maximum
// draw a progress bar
int percent = value * 100 / maximum;
int hashes = percent / 2;
QByteArray progressbar(hashes, '#');
if (percent % 2)
progressbar += '>';
printf("\r[%-50s] %3d%% %s ",
progressbar.constData(),
percent,
qPrintable(message));
} else {
// we don't know the maximum, so we can't draw a progress bar
int center = (iteration % 48) + 1; // 50 spaces, minus 2
QByteArray before(qMax(center - 2, 0), ' ');
QByteArray after(qMin(center + 2, 50), ' ');
printf("\r[%s###%s] %s ",
before.constData(), after.constData(), qPrintable(message));
}
}
void TextProgressBar::setMessage(const QString &m)
{
message = m;
}
void TextProgressBar::setStatus(qint64 val, qint64 max)
{
value = val;
maximum = max;
}
#ifndef DOWNLOADMANAGER_H
#define DOWNLOADMANAGER_H
#include <QFile>
#include <QObject>
#include <QQueue>
#include <QTime>
#include <QUrl>
#include <QNetworkAccessManager>
#include "textprogressbar.h"
class DownloadManager: public QObject
{
Q_OBJECT
public:
DownloadManager(QObject *parent = 0);
void append(const QUrl &url);
void append(const QStringList &urlList);
QString saveFileName(const QUrl &url);
signals:
void finished();
private slots:
void startNextDownload();
void downloadProgress(qint64 bytesReceived, qint64 bytesTotal);
void downloadFinished();
void downloadReadyRead();
private:
QNetworkAccessManager manager;
QQueue<QUrl> downloadQueue;
QNetworkReply *currentDownload;
QFile output;
QTime downloadTime;
TextProgressBar progressBar;
int downloadedCount;
int totalCount;
};
#endif
#include "downloadmanager.h"
#include <QFileInfo>
#include <QNetworkRequest>
#include <QNetworkReply>
#include <QString>
#include <QStringList>
#include <QTimer>
#include <stdio.h>
DownloadManager::DownloadManager(QObject *parent)
: QObject(parent), downloadedCount(0), totalCount(0)
{
}
void DownloadManager::append(const QStringList &urlList)
{
foreach (QString url, urlList)
append(QUrl::fromEncoded(url.toLocal8Bit()));
if (downloadQueue.isEmpty())
QTimer::singleShot(0, this, SIGNAL(finished()));
}
void DownloadManager::append(const QUrl &url)
{
if (downloadQueue.isEmpty())
QTimer::singleShot(0, this, SLOT(startNextDownload()));
downloadQueue.enqueue(url);
++totalCount;
}
QString DownloadManager::saveFileName(const QUrl &url)
{
QString path = url.path();
QString basename = QFileInfo(path).fileName();
if (basename.isEmpty())
basename = "download";
if (QFile::exists(basename)) {
// already exists, don't overwrite
int i = 0;
basename += '.';
while (QFile::exists(basename + QString::number(i)))
++i;
basename += QString::number(i);
}
return basename;
}
void DownloadManager::startNextDownload()
{
if (downloadQueue.isEmpty()) {
printf("%d/%d files downloaded successfully\n", downloadedCount, totalCount);
emit finished();
return;
}
QUrl url = downloadQueue.dequeue();
QString filename = saveFileName(url);
output.setFileName(filename);
if (!output.open(QIODevice::WriteOnly)) {
fprintf(stderr, "Problem opening save file '%s' for download '%s': %s\n",
qPrintable(filename), url.toEncoded().constData(),
qPrintable(output.errorString()));
startNextDownload();
return; // skip this download
}
QNetworkRequest request(url);
currentDownload = manager.get(request);
connect(currentDownload, SIGNAL(downloadProgress(qint64,qint64)),
SLOT(downloadProgress(qint64,qint64)));
connect(currentDownload, SIGNAL(finished()),
SLOT(downloadFinished()));
connect(currentDownload, SIGNAL(readyRead()),
SLOT(downloadReadyRead()));
// prepare the output
printf("Downloading %s...\n", url.toEncoded().constData());
downloadTime.start();
}
void DownloadManager::downloadProgress(qint64 bytesReceived, qint64 bytesTotal)
{
progressBar.setStatus(bytesReceived, bytesTotal);
// calculate the download speed
double speed = bytesReceived * 1000.0 / downloadTime.elapsed();
QString unit;
if (speed < 1024) {
unit = "bytes/sec";
} else if (speed < 1024*1024) {
speed /= 1024;
unit = "kB/s";
} else {
speed /= 1024*1024;
unit = "MB/s";
}
progressBar.setMessage(QString::fromLatin1("%1 %2")
.arg(speed, 3, 'f', 1).arg(unit));
progressBar.update();
}
void DownloadManager::downloadFinished()
{
progressBar.clear();
output.close();
if (currentDownload->error()) {
// download failed
fprintf(stderr, "Failed: %s\n", qPrintable(currentDownload->errorString()));
} else {
printf("Succeeded.\n");
++downloadedCount;
}
currentDownload->deleteLater();
startNextDownload();
}
void DownloadManager::downloadReadyRead()
{
output.write(currentDownload->readAll());
}
#include <QCoreApplication>
#include <QStringList>
#include "downloadmanager.h"
#include <stdio.h>
int main(int argc, char **argv)
{
QCoreApplication app(argc, argv);
QStringList arguments = app.arguments();
arguments.takeFirst(); // remove the first argument, which is the program's name
if (arguments.isEmpty()) {
printf("Qt Download example\n"
"Usage: downloadmanager url1 [url2... urlN]\n"
"\n"
"Downloads the URLs passed in the command-line to the local directory\n"
"If the target file already exists, a .0, .1, .2, etc. is appended to\n"
"differentiate.\n");
return 0;
}
DownloadManager manager;
manager.append(arguments);
QObject::connect(&manager, SIGNAL(finished()), &app, SLOT(quit()));
app.exec();
}
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