httpdownload.cpp

#include "httpdownload.h"
#include "ui_httpdownload.h"
#include "mainwindow.h"
//#include "inputdialog.h"

HttpDownload::HttpDownload(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::HttpDownload)
{
    QString content;
    ui->setupUi(this);
    //ui->urlEdit->setText("https://nchc.dl.sourceforge.net/project/hplip/hplip/3.20.3/hplip-3.20.3.run");
    QFile sources;
    sources.setFileName("newssources.txt");
    if (sources.open(QIODevice::ReadOnly)) {
        while(!sources.atEnd()) {
            QString line = sources.readLine();
            //QStringList fields = line.split(",");
            line = line.trimmed();
            int pos1 = line.indexOf("|");
            if (pos1 != -1) ui->urlList->addItem(line.mid(0,pos1));
            else ui->urlList->addItem(line);
        }
        sources.close();
        ui->urlList->addItem("");
            //qDebug() << infile.size() << in.readAll();
    }


    ui->urlList->itemData(ui->urlList->currentIndex());
    ui->statusLabel->setWordWrap(true);
    ui->downloadButton->setDefault(true);
    ui->quitButton->setAutoDefault(false);


    //connect(ui->urlList, SIGNAL(textChanged(QString)),
    //            this, SLOT(enableDownloadButton()));

}

HttpDownload::~HttpDownload()
{
    delete ui;
}

void HttpDownload::on_downloadButton_clicked()
{
    QString data = ui->urlList->itemText(ui->urlList->currentIndex());
    if (data == "") {
        tmpstring = "";
        labeltext = "Enter URL :";
        inputDialog addurl;
        addurl.setModal(true); // if nomodal is needed then create pointer inputdialog *datesearch; in mainwindow.h private section, then here use inputdialog = new datesearch(this); datesearch.show();
        addurl.exec();
        data = tmpstring;
    }
    if (data != "") {
    manager = new QNetworkAccessManager(this);
    progressDialog = new QProgressDialog(this);

    connect(progressDialog, SIGNAL(canceled()), this, SLOT(cancelDownload()));
    // get url
    //url = (ui->urlEdit->text());

    tmpstring = data;
    data.remove(QRegularExpression("[\\n\\t\\r]"));
    //qDebug() << data;
    //url = (ui->urlList->itemText(ui->urlList->currentIndex()));
    url = (data);
    //qDebug() << url;
    QFileInfo fileInfo(url.path());
    QString fileName = fileInfo.fileName();
    fileName.remove(QRegularExpression("[\\n\\t\\r]"));
    if (fileName.isEmpty())
        fileName = "headnews.html";
    filesource = fileName;
    if (QFile::exists(fileName)) {
        //if (QMessageBox::question(this, tr("HTTP"),
          //      tr("There already exists a file called %1 in "
            //    "the current directory. Overwrite?").arg(fileName),
              //  QMessageBox::Yes|QMessageBox::No, QMessageBox::No)
                //== QMessageBox::No)
                //return;
        QFile::remove(fileName);
    }

    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;
    }

    // used for progressDialog
    // This will be set true when canceled from progress dialog
    httpRequestAborted = false;

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

    // download button disabled after requesting download
    ui->downloadButton->setEnabled(false);

    startRequest(url);
    }
}

void HttpDownload::httpReadyRead()
{
    // this slot gets called every time the QNetworkReply has new data.
    // We read all of its new data and write it into the file.
    // That way we use less RAM than when reading it at the finished()
    // signal of the QNetworkReply
    if (file)
        file->write(reply->readAll());
}

void HttpDownload::updateDownloadProgress(qint64 bytesRead, qint64 totalBytes)
{
    if (httpRequestAborted)
        return;

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

void HttpDownload::on_quitButton_clicked()
{
    this->close();
}

/*void HttpDownload::on_urlList_returnPressed()
{
    on_downloadButton_clicked();
}*/

void HttpDownload::enableDownloadButton()
{
    //ui->downloadButton->setEnabled(!(ui->urlEdit->text()).isEmpty());
    ui->downloadButton->setEnabled((ui->urlList->itemText(ui->urlList->currentIndex())).isEmpty());
}

// During the download progress, it can be canceled
void HttpDownload::cancelDownload()
{
    ui->statusLabel->setText(tr("Download canceled."));
    httpRequestAborted = true;
    reply->abort();
    ui->downloadButton->setEnabled(true);
}

// When download finished or canceled, this will be called
void HttpDownload::httpDownloadFinished()
{
    // when canceled
    if (httpRequestAborted) {
        if (file) {
            file->close();
            file->remove();
            delete file;
            file = 0;
        }
        reply->deleteLater();
        progressDialog->hide();
        return;
    }

    // download finished normally
    progressDialog->hide();
    file->flush();
    file->close();

    // get redirection url
    QVariant redirectionTarget = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
    if (reply->error()) {
        file->remove();
        QMessageBox::information(this, tr("HTTP"),
                                 tr("Download failed: %1.")
                                 .arg(reply->errorString()));
        ui->downloadButton->setEnabled(true);
    } else if (!redirectionTarget.isNull()) {
        QUrl newUrl = url.resolved(redirectionTarget.toUrl());
        if (QMessageBox::question(this, tr("HTTP"),
                                  tr("Redirect to %1 ?").arg(newUrl.toString()),
                                  QMessageBox::Yes | QMessageBox::No) == QMessageBox::Yes) {
            url = newUrl;
            reply->deleteLater();
            file->open(QIODevice::WriteOnly);
            file->resize(0);
            startRequest(url);
            return;
        }
    } else {
        //QString fileName = QFileInfo(QUrl(ui->urlEdit->text()).path()).fileName();
         QString fileName = QFileInfo(QUrl(ui->urlList->itemText(ui->urlList->currentIndex())).path()).fileName();
         //qDebug() << fileName;
        //ui->downloadButton->setEnabled((ui->urlList->itemText(ui->urlList->currentIndex())));
        ui->statusLabel->setText(tr("Downloaded %1 to %2.").arg(fileName).arg(QDir::currentPath()));
        ui->downloadButton->setEnabled(true);
    }

    reply->deleteLater();
    reply = 0;
    delete file;
    file = 0;
    manager = 0;
    emit dl_ready(ui->urlList->itemText(ui->urlList->currentIndex()));
}

// This will be called when download button is clicked
void HttpDownload::startRequest(QUrl url)
{
    // get() method posts a request
    // to obtain the contents of the target request
    // and returns a new QNetworkReply object
    // opened for reading which emits
    // the readyRead() signal whenever new data arrives.
    reply = manager->get(QNetworkRequest(url));

    // Whenever more data is received from the network,
    // this readyRead() signal is emitted
    connect(reply, SIGNAL(readyRead()),
            this, SLOT(httpReadyRead()));

    // Also, downloadProgress() signal is emitted when data is received
    connect(reply, SIGNAL(downloadProgress(qint64,qint64)),
            this, SLOT(updateDownloadProgress(qint64,qint64)));

    // This signal is emitted when the reply has finished processing.
    // After this signal is emitted,
    // there will be no more updates to the reply's data or metadata.
    connect(reply, SIGNAL(finished()),
            this, SLOT(httpDownloadFinished()));
}