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#include <QtGui>

#include "addtorrentdialog.h"

#include "mainwindow.h"

#include "ratecontroller.h"

#include "torrentclient.h"

// TorrentView extends QTreeWidget to allow drag and drop.

class TorrentView : public QTreeWidget

{

    Q_OBJECT

public:

    TorrentView(QWidget *parent = 0);

signals:

    void fileDropped(const QString &fileName);

protected:

    void dragMoveEvent(QDragMoveEvent *event);

    void dropEvent(QDropEvent *event);

};

// TorrentViewDelegate is used to draw the progress bars.

class TorrentViewDelegate : public QItemDelegate

{

    Q_OBJECT

public:

    inline TorrentViewDelegate(MainWindow *mainWindow) : QItemDelegate(mainWindow) {}

    inline void paint(QPainter *painter, const QStyleOptionViewItem &option,

                      const QModelIndex &index ) const

    {

        if (index.column() != 2) {

            QItemDelegate::paint(painter, option, index);

            return;

        }

        // Set up a QStyleOptionProgressBar to precisely mimic the

        // environment of a progress bar.

        QStyleOptionProgressBar progressBarOption;

        progressBarOption.state = QStyle::State_Enabled;

        progressBarOption.direction = QApplication::layoutDirection();

        progressBarOption.rect = option.rect;

        progressBarOption.fontMetrics = QApplication::fontMetrics();

        progressBarOption.minimum = 0;

        progressBarOption.maximum = 100;

        progressBarOption.textAlignment = Qt::AlignCenter;

        progressBarOption.textVisible = true;

        // Set the progress and text values of the style option.

        int progress = qobject_cast<MainWindow *>(parent())->clientForRow(index.row())->progress();

        progressBarOption.progress = progress < 0 ? 0 : progress;

        progressBarOption.text = QString().sprintf("%d%%", progressBarOption.progress);

        // Draw the progress bar onto the view.

        QApplication::style()->drawControl(QStyle::CE_ProgressBar, &progressBarOption, painter);

    }

};

MainWindow::MainWindow(QWidget *parent)

    : QMainWindow(parent), quitDialog(0), saveChanges(false)

{

    // Initialize some static strings

    QStringList headers;

    headers << tr("Torrent") << tr("Peers/Seeds") << tr("Progress")

            << tr("Down rate") << tr("Up rate") << tr("Status");

    // Main torrent list

    torrentView = new TorrentView(this);

    torrentView->setItemDelegate(new TorrentViewDelegate(this));

    torrentView->setHeaderLabels(headers);

    torrentView->setSelectionBehavior(QAbstractItemView::SelectRows);

    torrentView->setAlternatingRowColors(true);

    torrentView->setRootIsDecorated(false);

    setCentralWidget(torrentView);

    // Set header resize modes and initial section sizes

    QFontMetrics fm = fontMetrics();

    QHeaderView *header = torrentView->header();

    header->resizeSection(0, fm.width("typical-name-for-a-torrent.torrent"));

    header->resizeSection(1, fm.width(headers.at(1) + "  "));

    header->resizeSection(2, fm.width(headers.at(2) + "  "));

    header->resizeSection(3, qMax(fm.width(headers.at(3) + "  "), fm.width(" 1234.0 KB/s ")));

    header->resizeSection(4, qMax(fm.width(headers.at(4) + "  "), fm.width(" 1234.0 KB/s ")));

    header->resizeSection(5, qMax(fm.width(headers.at(5) + "  "), fm.width(tr("Downloading") + "  ")));

    // Create common actions

    QAction *newTorrentAction = new QAction(QIcon(":/icons/bottom.png"), tr("Add &new torrent"), this);

    pauseTorrentAction = new QAction(QIcon(":/icons/player_pause.png"), tr("&Pause torrent"), this);

    removeTorrentAction = new QAction(QIcon(":/icons/player_stop.png"), tr("&Remove torrent"), this);

    // File menu

    QMenu *fileMenu = menuBar()->addMenu(tr("&File"));

    fileMenu->addAction(newTorrentAction);

    fileMenu->addAction(pauseTorrentAction);

    fileMenu->addAction(removeTorrentAction);

    fileMenu->addSeparator();

    fileMenu->addAction(QIcon(":/icons/exit.png"), tr("E&xit"), this, SLOT(close()));

    // Help menu

    QMenu *helpMenu = menuBar()->addMenu(tr("&Help"));

    helpMenu->addAction(tr("&About"), this, SLOT(about()));

    helpMenu->addAction(tr("About &Qt"), qApp, SLOT(aboutQt()));

    // Top toolbar

    QToolBar *topBar = new QToolBar(tr("Tools"));

    addToolBar(Qt::TopToolBarArea, topBar);

    topBar->setMovable(false);

    topBar->addAction(newTorrentAction);

    topBar->addAction(removeTorrentAction);

    topBar->addAction(pauseTorrentAction);

    topBar->addSeparator();

    downActionTool = topBar->addAction(QIcon(tr(":/icons/1downarrow.png")), tr("Move down"));

    upActionTool = topBar->addAction(QIcon(tr(":/icons/1uparrow.png")), tr("Move up"));

    // Bottom toolbar

    QToolBar *bottomBar = new QToolBar(tr("Rate control"));

    addToolBar(Qt::BottomToolBarArea, bottomBar);

    bottomBar->setMovable(false);

    downloadLimitSlider = new QSlider(Qt::Horizontal);

    downloadLimitSlider->setRange(0, 1000);

    bottomBar->addWidget(new QLabel(tr("Max download:")));

    bottomBar->addWidget(downloadLimitSlider);

    bottomBar->addWidget((downloadLimitLabel = new QLabel(tr("0 KB/s"))));

    downloadLimitLabel->setFixedSize(QSize(fm.width(tr("99999 KB/s")), fm.lineSpacing()));

    bottomBar->addSeparator();

    uploadLimitSlider = new QSlider(Qt::Horizontal);

    uploadLimitSlider->setRange(0, 1000);

    bottomBar->addWidget(new QLabel(tr("Max upload:")));

    bottomBar->addWidget(uploadLimitSlider);

    bottomBar->addWidget((uploadLimitLabel = new QLabel(tr("0 KB/s"))));

    uploadLimitLabel->setFixedSize(QSize(fm.width(tr("99999 KB/s")), fm.lineSpacing()));

    // Set up connections

    connect(torrentView, SIGNAL(itemSelectionChanged()),

            this, SLOT(setActionsEnabled()));

    connect(torrentView, SIGNAL(fileDropped(QString)),

            this, SLOT(acceptFileDrop(QString)));

    connect(uploadLimitSlider, SIGNAL(valueChanged(int)),

            this, SLOT(setUploadLimit(int)));

    connect(downloadLimitSlider, SIGNAL(valueChanged(int)),

            this, SLOT(setDownloadLimit(int)));

    connect(newTorrentAction, SIGNAL(triggered()),

            this, SLOT(addTorrent()));

    connect(pauseTorrentAction, SIGNAL(triggered()),

            this, SLOT(pauseTorrent()));

    connect(removeTorrentAction, SIGNAL(triggered()),

            this, SLOT(removeTorrent()));

    connect(upActionTool, SIGNAL(triggered(bool)),

            this, SLOT(moveTorrentUp()));

    connect(downActionTool, SIGNAL(triggered(bool)),

            this, SLOT(moveTorrentDown()));

    // Load settings and start

    setWindowTitle(tr("Torrent Client"));

    setActionsEnabled();

    QMetaObject::invokeMethod(this, "loadSettings", Qt::QueuedConnection);

}

QSize MainWindow::sizeHint() const

{

    const QHeaderView *header = torrentView->header();

    // Add up the sizes of all header sections. The last section is

    // stretched, so its size is relative to the size of the width;

    // instead of counting it, we count the size of its largest value.

    int width = fontMetrics().width(tr("Downloading") + "  ");

    for (int i = 0; i < header->count() - 1; ++i)

        width += header->sectionSize(i);

    return QSize(width, QMainWindow::sizeHint().height())

        .expandedTo(QApplication::globalStrut());

}

const TorrentClient *MainWindow::clientForRow(int row) const

{

    // Return the client at the given row.

    return jobs.at(row).client;

}

int MainWindow::rowOfClient(TorrentClient *client) const

{

    // Return the row that displays this client's status, or -1 if the

    // client is not known.

    int row = 0;

    foreach (Job job, jobs) {

        if (job.client == client)

            return row;

        ++row;

    }

    return -1;

}

void MainWindow::loadSettings()

{

    // Load base settings (last working directory, upload/download limits).

    QSettings settings("Trolltech", "Torrent");

    lastDirectory = settings.value("LastDirectory").toString();

    if (lastDirectory.isEmpty())

        lastDirectory = QDir::currentPath();

    int up = settings.value("UploadLimit").toInt();

    int down = settings.value("DownloadLimit").toInt();

    uploadLimitSlider->setValue(up ? up : 170);

    downloadLimitSlider->setValue(down ? down : 550);

    // Resume all previous downloads.

    int size = settings.beginReadArray("Torrents");

    for (int i = 0; i < size; ++i) {

        settings.setArrayIndex(i);

        QByteArray resumeState = settings.value("resumeState").toByteArray();

        QString fileName = settings.value("sourceFileName").toString();

        QString dest = settings.value("destinationFolder").toString();

        if (addTorrent(fileName, dest, resumeState)) {

            TorrentClient *client = jobs.last().client;

            client->setDownloadedBytes(settings.value("downloadedBytes").toLongLong());

            client->setUploadedBytes(settings.value("uploadedBytes").toLongLong());

        }

    }

}

bool MainWindow::addTorrent()

{

    // Show the file dialog, let the user select what torrent to start downloading.

    QString fileName = QFileDialog::getOpenFileName(this, tr("Choose a torrent file"),

                                                    lastDirectory,

                                                    tr("Torrents (*.torrent);;"

                                                       " All files (*.*)"));

    if (fileName.isEmpty())

        return false;

    lastDirectory = QFileInfo(fileName).absolutePath();

    // Show the "Add Torrent" dialog.

    AddTorrentDialog *addTorrentDialog = new AddTorrentDialog(this);

    addTorrentDialog->setTorrent(fileName);

    addTorrentDialog->deleteLater();

    if (!addTorrentDialog->exec())

        return false;

    // Add the torrent to our list of downloads

    addTorrent(fileName, addTorrentDialog->destinationFolder());

    if (!saveChanges) {

        saveChanges = true;

        QTimer::singleShot(1000, this, SLOT(saveSettings()));

    }

    return true;

}

void MainWindow::removeTorrent()

{

    // Find the row of the current item, and find the torrent client

    // for that row.

    int row = torrentView->indexOfTopLevelItem(torrentView->currentItem());

    TorrentClient *client = jobs.at(row).client;

    // Stop the client.

    client->disconnect();

    connect(client, SIGNAL(stopped()), this, SLOT(torrentStopped()));

    client->stop();

    // Remove the row from the view.

    delete torrentView->takeTopLevelItem(row);

    jobs.removeAt(row);

    setActionsEnabled();

    saveChanges = true;

    saveSettings();

}

void MainWindow::torrentStopped()

{

    // Schedule the client for deletion.

    TorrentClient *client = qobject_cast<TorrentClient *>(sender());

    client->deleteLater();

    // If the quit dialog is shown, update its progress.

    if (quitDialog) {

        if (++jobsStopped == jobsToStop)

            quitDialog->close();

    }

}

void MainWindow::torrentError(TorrentClient::Error)

{

    // Delete the client.

    TorrentClient *client = qobject_cast<TorrentClient *>(sender());

    int row = rowOfClient(client);

    QString fileName = jobs.at(row).torrentFileName;

    jobs.removeAt(row);

    // Display the warning.

    QMessageBox::warning(this, tr("Error"),

                         tr("An error occurred while downloading %0: %1")

                         .arg(fileName)

                         .arg(client->errorString()));

    delete torrentView->takeTopLevelItem(row);

    client->deleteLater();

}

bool MainWindow::addTorrent(const QString &fileName, const QString &destinationFolder,

                            const QByteArray &resumeState)

{

    // Check if the torrent is already being downloaded.

    foreach (Job job, jobs) {

        if (job.torrentFileName == fileName && job.destinationDirectory == destinationFolder) {

            QMessageBox::warning(this, tr("Already downloading"),

                                 tr("The torrent file %1 is "

                                    "already being downloaded.").arg(fileName));

            return false;

        }

    }

    // Create a new torrent client and attempt to parse the torrent data.

    TorrentClient *client = new TorrentClient(this);

    if (!client->setTorrent(fileName)) {

        QMessageBox::warning(this, tr("Error"),

                             tr("The torrent file %1 cannot not be opened/resumed.").arg(fileName));

        delete client;

        return false;

    }

    client->setDestinationFolder(destinationFolder);

    client->setDumpedState(resumeState);

    // Setup the client connections.

    connect(client, SIGNAL(stateChanged(TorrentClient::State)), this, SLOT(updateState(TorrentClient::State)));

    connect(client, SIGNAL(peerInfoUpdated()), this, SLOT(updatePeerInfo()));

    connect(client, SIGNAL(progressUpdated(int)), this, SLOT(updateProgress(int)));

    connect(client, SIGNAL(downloadRateUpdated(int)), this, SLOT(updateDownloadRate(int)));

    connect(client, SIGNAL(uploadRateUpdated(int)), this, SLOT(updateUploadRate(int)));

    connect(client, SIGNAL(stopped()), this, SLOT(torrentStopped()));

    connect(client, SIGNAL(error(TorrentClient::Error)), this, SLOT(torrentError(TorrentClient::Error)));

    // Add the client to the list of downloading jobs.

    Job job;

    job.client = client;

    job.torrentFileName = fileName;

    job.destinationDirectory = destinationFolder;

    jobs << job;

    // Create and add a row in the torrent view for this download.

    QTreeWidgetItem *item = new QTreeWidgetItem(torrentView);

    QString baseFileName = QFileInfo(fileName).fileName();

    if (baseFileName.toLower().endsWith(".torrent"))

        baseFileName.remove(baseFileName.size() - 8);

    item->setText(0, baseFileName);

    item->setToolTip(0, tr("Torrent: %1<br>Destination: %2")

                     .arg(baseFileName).arg(destinationFolder));

    item->setText(1, tr("0/0"));

    item->setText(2, "0");

    item->setText(3, "0.0 KB/s");

    item->setText(4, "0.0 KB/s");

    item->setText(5, tr("Idle"));

    item->setFlags(item->flags() & ~Qt::ItemIsEditable);

    item->setTextAlignment(1, Qt::AlignHCenter);

    if (!saveChanges) {

        saveChanges = true;

        QTimer::singleShot(5000, this, SLOT(saveSettings()));

    }

    client->start();

    return true;

}

void MainWindow::saveSettings()

{

    if (!saveChanges)

      return;

    saveChanges = false;

    // Prepare and reset the settings

    QSettings settings("Trolltech", "Torrent");

    settings.clear();

    settings.setValue("LastDirectory", lastDirectory);

    settings.setValue("UploadLimit", uploadLimitSlider->value());

    settings.setValue("DownloadLimit", downloadLimitSlider->value());

    // Store data on all known torrents

    settings.beginWriteArray("Torrents");

    for (int i = 0; i < jobs.size(); ++i) {

        settings.setArrayIndex(i);

        settings.setValue("sourceFileName", jobs.at(i).torrentFileName);

        settings.setValue("destinationFolder", jobs.at(i).destinationDirectory);

        settings.setValue("uploadedBytes", jobs.at(i).client->uploadedBytes());

        settings.setValue("downloadedBytes", jobs.at(i).client->downloadedBytes());

        settings.setValue("resumeState", jobs.at(i).client->dumpedState());

    }

    settings.endArray();

    settings.sync();

}

void MainWindow::updateState(TorrentClient::State)

{

    // Update the state string whenever the client's state changes.

    TorrentClient *client = qobject_cast<TorrentClient *>(sender());

    int row = rowOfClient(client);

    QTreeWidgetItem *item = torrentView->topLevelItem(row);

    if (item) {

        item->setToolTip(0, tr("Torrent: %1<br>Destination: %2<br>State: %3")

                         .arg(jobs.at(row).torrentFileName)

                         .arg(jobs.at(row).destinationDirectory)

                         .arg(client->stateString()));

        item->setText(5, client->stateString());

    }

    setActionsEnabled();

}

void MainWindow::updatePeerInfo()

{

    // Update the number of connected, visited, seed and leecher peers.

    TorrentClient *client = qobject_cast<TorrentClient *>(sender());

    int row = rowOfClient(client);

    QTreeWidgetItem *item = torrentView->topLevelItem(row);

    item->setText(1, tr("%1/%2").arg(client->connectedPeerCount())

                  .arg(client->seedCount()));

}

void MainWindow::updateProgress(int percent)

{

    TorrentClient *client = qobject_cast<TorrentClient *>(sender());

    int row = rowOfClient(client);

    // Update the progressbar.

    QTreeWidgetItem *item = torrentView->topLevelItem(row);

    if (item)

        item->setText(2, QString::number(percent));

}

void MainWindow::setActionsEnabled()

{

    // Find the view item and client for the current row, and update

    // the states of the actions.

    QTreeWidgetItem *item = 0;

    if (!torrentView->selectedItems().isEmpty())

        item = torrentView->selectedItems().first();

    TorrentClient *client = item ? jobs.at(torrentView->indexOfTopLevelItem(item)).client : 0;

    bool pauseEnabled = client && ((client->state() == TorrentClient::Paused)

                                       ||  (client->state() > TorrentClient::Preparing));

    removeTorrentAction->setEnabled(item != 0);

    pauseTorrentAction->setEnabled(item != 0 && pauseEnabled);

    if (client && client->state() == TorrentClient::Paused) {

        pauseTorrentAction->setIcon(QIcon(":/icons/player_play.png"));

        pauseTorrentAction->setText(tr("Resume torrent"));

    } else {

        pauseTorrentAction->setIcon(QIcon(":/icons/player_pause.png"));

        pauseTorrentAction->setText(tr("Pause torrent"));

    }

    int row = torrentView->indexOfTopLevelItem(item);

    upActionTool->setEnabled(item && row != 0);

    downActionTool->setEnabled(item && row != jobs.size() - 1);

}

void MainWindow::updateDownloadRate(int bytesPerSecond)

{

    // Update the download rate.

    TorrentClient *client = qobject_cast<TorrentClient *>(sender());

    int row = rowOfClient(client);

    QString num;

    num.sprintf("%.1f KB/s", bytesPerSecond / 1024.0);

    torrentView->topLevelItem(row)->setText(3, num);

    if (!saveChanges) {

        saveChanges = true;

        QTimer::singleShot(5000, this, SLOT(saveSettings()));

    }

}

void MainWindow::updateUploadRate(int bytesPerSecond)

{

    // Update the upload rate.

    TorrentClient *client = qobject_cast<TorrentClient *>(sender());

    int row = rowOfClient(client);

    QString num;

    num.sprintf("%.1f KB/s", bytesPerSecond / 1024.0);

    torrentView->topLevelItem(row)->setText(4, num);

    if (!saveChanges) {

        saveChanges = true;

        QTimer::singleShot(5000, this, SLOT(saveSettings()));