musicplayer.cpp Example File

musicplayer/musicplayer.cpp 
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 #include "musicplayer.h"
 #include "volumebutton.h"

 #include <QtWidgets>
 #include <QtWinExtras>

 MusicPlayer::MusicPlayer(QWidget *parent) : QWidget(parent)
 {
     createWidgets();
     createShortcuts();
     createJumpList();
     createTaskbar();
     createThumbnailToolBar();

     connect(&mediaPlayer, &QMediaPlayer::positionChanged, this, &MusicPlayer::updatePosition);
     connect(&mediaPlayer, &QMediaPlayer::durationChanged, this, &MusicPlayer::updateDuration);
     connect(&mediaPlayer, &QMediaObject::metaDataAvailableChanged, this, &MusicPlayer::updateInfo);

     connect(&mediaPlayer, QOverload<QMediaPlayer::Error>::of(&QMediaPlayer::error),
             this, &MusicPlayer::handleError);
     connect(&mediaPlayer, &QMediaPlayer::stateChanged,
             this, &MusicPlayer::updateState);

     stylize();
     setAcceptDrops(true);
 }

 QStringList MusicPlayer::supportedMimeTypes()
 {
     QStringList result = QMediaPlayer::supportedMimeTypes();
     if (result.isEmpty())
         result.append(QStringLiteral("audio/mpeg"));
     return result;
 }

 void MusicPlayer::openFile()
 {
     QFileDialog fileDialog(this);
     fileDialog.setAcceptMode(QFileDialog::AcceptOpen);
     fileDialog.setWindowTitle(tr("Open File"));
     fileDialog.setMimeTypeFilters(MusicPlayer::supportedMimeTypes());
     fileDialog.setDirectory(QStandardPaths::standardLocations(QStandardPaths::MusicLocation).value(0, QDir::homePath()));
     if (fileDialog.exec() == QDialog::Accepted)
         playUrl(fileDialog.selectedUrls().constFirst());
 }

 void MusicPlayer::playUrl(const QUrl &url)
 {
     playButton->setEnabled(true);
     if (url.isLocalFile()) {
         const QString filePath = url.toLocalFile();
         setWindowFilePath(filePath);
         infoLabel->setText(QDir::toNativeSeparators(filePath));
         fileName = QFileInfo(filePath).fileName();
     } else {
         setWindowFilePath(QString());
         infoLabel->setText(url.toString());
         fileName.clear();
     }
     mediaPlayer.setMedia(url);
     mediaPlayer.play();
 }

 void MusicPlayer::togglePlayback()
 {
     if (mediaPlayer.mediaStatus() == QMediaPlayer::NoMedia)
         openFile();
     else if (mediaPlayer.state() == QMediaPlayer::PlayingState)
         mediaPlayer.pause();
     else
         mediaPlayer.play();
 }

 void MusicPlayer::seekForward()
 {
     positionSlider->triggerAction(QSlider::SliderPageStepAdd);
 }

 void MusicPlayer::seekBackward()
 {
     positionSlider->triggerAction(QSlider::SliderPageStepSub);
 }

 bool MusicPlayer::event(QEvent *event)
 {
     if (event->type() == QWinEvent::CompositionChange || event->type() == QWinEvent::ColorizationChange)
         stylize();
     return QWidget::event(event);
 }

 static bool canHandleDrop(const QDropEvent *event)
 {
     const QList<QUrl> urls = event->mimeData()->urls();
     if (urls.size() != 1)
         return false;
     QMimeDatabase mimeDatabase;
     return MusicPlayer::supportedMimeTypes().
         contains(mimeDatabase.mimeTypeForUrl(urls.constFirst()).name());
 }

 void MusicPlayer::dragEnterEvent(QDragEnterEvent *event)
 {
     event->setAccepted(canHandleDrop(event));
 }

 void MusicPlayer::dropEvent(QDropEvent *event)
 {
     event->accept();
     playUrl(event->mimeData()->urls().constFirst());
 }

 void MusicPlayer::mousePressEvent(QMouseEvent *event)
 {
     offset = event->globalPos() - pos();
     event->accept();
 }

 void MusicPlayer::mouseMoveEvent(QMouseEvent *event)
 {
     move(event->globalPos() - offset);
     event->accept();
 }

 void MusicPlayer::mouseReleaseEvent(QMouseEvent *event)
 {
     offset = QPoint();
     event->accept();
 }

 void MusicPlayer::stylize()
 {
     if (QOperatingSystemVersion::current() < QOperatingSystemVersion::Windows8) {
         // Set styling options relevant only to Windows 7.
         if (QtWin::isCompositionEnabled()) {
             QtWin::extendFrameIntoClientArea(this, -1, -1, -1, -1);
             setAttribute(Qt::WA_TranslucentBackground, true);
             setAttribute(Qt::WA_NoSystemBackground, false);
             setStyleSheet(QStringLiteral("MusicPlayer { background: transparent; }"));
         } else {
             QtWin::resetExtendedFrame(this);
             setAttribute(Qt::WA_TranslucentBackground, false);
             setStyleSheet(QStringLiteral("MusicPlayer { background: %1; }").arg(QtWin::realColorizationColor().name()));
         }
         volumeButton->stylize();
     }
 }

 void MusicPlayer::updateState(QMediaPlayer::State state)
 {
     if (state == QMediaPlayer::PlayingState) {
         playButton->setToolTip(tr("Pause"));
         playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPause));
     } else {
         playButton->setToolTip(tr("Play"));
         playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
     }
 }

 static QString formatTime(qint64 timeMilliSeconds)
 {
     qint64 seconds = timeMilliSeconds / 1000;
     const qint64 minutes = seconds / 60;
     seconds -= minutes * 60;
     return QStringLiteral("%1:%2")
         .arg(minutes, 2, 10, QLatin1Char('0'))
         .arg(seconds, 2, 10, QLatin1Char('0'));
 }

 void MusicPlayer::updatePosition(qint64 position)
 {
     positionSlider->setValue(position);
     positionLabel->setText(formatTime(position));
 }

 void MusicPlayer::updateDuration(qint64 duration)
 {
     positionSlider->setRange(0, duration);
     positionSlider->setEnabled(duration > 0);
     positionSlider->setPageStep(duration / 10);
     updateInfo();
 }

 void MusicPlayer::setPosition(int position)
 {
     // avoid seeking when the slider value change is triggered from updatePosition()
     if (qAbs(mediaPlayer.position() - position) > 99)
         mediaPlayer.setPosition(position);
 }

 void MusicPlayer::updateInfo()
 {
     QStringList info;
     if (!fileName.isEmpty())
         info.append(fileName);
     if (mediaPlayer.isMetaDataAvailable()) {
         QString author = mediaPlayer.metaData(QStringLiteral("Author")).toString();
         if (!author.isEmpty())
             info.append(author);
         QString title = mediaPlayer.metaData(QStringLiteral("Title")).toString();
         if (!title.isEmpty())
             info.append(title);
     }
     info.append(formatTime(mediaPlayer.duration()));
     infoLabel->setText(info.join(tr(" - ")));
 }

 void MusicPlayer::handleError()
 {
     playButton->setEnabled(false);
     const QString errorString = mediaPlayer.errorString();
     infoLabel->setText(errorString.isEmpty()
                        ? tr("Unknown error #%1").arg(int(mediaPlayer.error()))
                        : tr("Error: %1").arg(errorString));
 }

 void MusicPlayer::updateTaskbar()
 {
     switch (mediaPlayer.state()) {
     case QMediaPlayer::PlayingState:
         taskbarButton->setOverlayIcon(style()->standardIcon(QStyle::SP_MediaPlay));
         taskbarProgress->show();
         taskbarProgress->resume();
         break;
     case QMediaPlayer::PausedState:
         taskbarButton->setOverlayIcon(style()->standardIcon(QStyle::SP_MediaPause));
         taskbarProgress->show();
         taskbarProgress->pause();
         break;
     case QMediaPlayer::StoppedState:
         taskbarButton->setOverlayIcon(style()->standardIcon(QStyle::SP_MediaStop));
         taskbarProgress->hide();
         break;
     }
 }

 void MusicPlayer::updateThumbnailToolBar()
 {
     playToolButton->setEnabled(mediaPlayer.duration() > 0);
     backwardToolButton->setEnabled(mediaPlayer.position() > 0);
     forwardToolButton->setEnabled(mediaPlayer.position() < mediaPlayer.duration());

     if (mediaPlayer.state() == QMediaPlayer::PlayingState) {
         playToolButton->setToolTip(tr("Pause"));
         playToolButton->setIcon(style()->standardIcon(QStyle::SP_MediaPause));
     } else {
         playToolButton->setToolTip(tr("Play"));
         playToolButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
     }
 }

 void MusicPlayer::createWidgets()
 {
     playButton = new QToolButton(this);
     playButton->setEnabled(false);
     playButton->setToolTip(tr("Play"));
     playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
     connect(playButton, &QAbstractButton::clicked, this, &MusicPlayer::togglePlayback);

     QAbstractButton *openButton = new QToolButton(this);
     openButton->setText(tr("..."));
     openButton->setToolTip(tr("Open a file..."));
     openButton->setFixedSize(playButton->sizeHint());
     connect(openButton, &QAbstractButton::clicked, this, &MusicPlayer::openFile);

     volumeButton = new VolumeButton(this);
     volumeButton->setToolTip(tr("Adjust volume"));
     volumeButton->setVolume(mediaPlayer.volume());
     connect(volumeButton, &VolumeButton::volumeChanged, &mediaPlayer, &QMediaPlayer::setVolume);

     positionSlider = new QSlider(Qt::Horizontal, this);
     positionSlider->setEnabled(false);
     positionSlider->setToolTip(tr("Seek"));
     connect(positionSlider, &QAbstractSlider::valueChanged, this, &MusicPlayer::setPosition);

     infoLabel = new QLabel(this);
     positionLabel = new QLabel(tr("00:00"), this);
     positionLabel->setMinimumWidth(positionLabel->sizeHint().width());

     QBoxLayout *controlLayout = new QHBoxLayout;
     controlLayout->setMargin(0);
     controlLayout->addWidget(openButton);
     controlLayout->addWidget(playButton);
     controlLayout->addWidget(positionSlider);
     controlLayout->addWidget(positionLabel);
     controlLayout->addWidget(volumeButton);

     QBoxLayout *mainLayout = new QVBoxLayout(this);
     mainLayout->addWidget(infoLabel);
     mainLayout->addLayout(controlLayout);
 }

 void MusicPlayer::createShortcuts()
 {
     QShortcut *quitShortcut = new QShortcut(QKeySequence::Quit, this);
     connect(quitShortcut, &QShortcut::activated, QCoreApplication::quit);

     QShortcut *openShortcut = new QShortcut(QKeySequence::Open, this);
     connect(openShortcut, &QShortcut::activated, this, &MusicPlayer::openFile);

     QShortcut *toggleShortcut = new QShortcut(Qt::Key_Space, this);
     connect(toggleShortcut, &QShortcut::activated, this, &MusicPlayer::togglePlayback);

     QShortcut *forwardShortcut = new QShortcut(Qt::Key_Right, this);
     connect(forwardShortcut, &QShortcut::activated, this, &MusicPlayer::seekForward);

     QShortcut *backwardShortcut = new QShortcut(Qt::Key_Left, this);
     connect(backwardShortcut, &QShortcut::activated, this, &MusicPlayer::seekBackward);

     QShortcut *increaseShortcut = new QShortcut(Qt::Key_Up, this);
     connect(increaseShortcut, &QShortcut::activated, volumeButton, &VolumeButton::increaseVolume);

     QShortcut *decreaseShortcut = new QShortcut(Qt::Key_Down, this);
     connect(decreaseShortcut, &QShortcut::activated, volumeButton, &VolumeButton::descreaseVolume);
 }

 void MusicPlayer::createJumpList()
 {
     QWinJumpList jumplist;
     jumplist.recent()->setVisible(true);
 }

 void MusicPlayer::createTaskbar()
 {
     taskbarButton = new QWinTaskbarButton(this);
     taskbarButton->setWindow(windowHandle());

     taskbarProgress = taskbarButton->progress();
     connect(positionSlider, &QAbstractSlider::valueChanged, taskbarProgress, &QWinTaskbarProgress::setValue);
     connect(positionSlider, &QAbstractSlider::rangeChanged, taskbarProgress, &QWinTaskbarProgress::setRange);

     connect(&mediaPlayer, &QMediaPlayer::stateChanged, this, &MusicPlayer::updateTaskbar);
 }

 void MusicPlayer::createThumbnailToolBar()
 {
     thumbnailToolBar = new QWinThumbnailToolBar(this);
     thumbnailToolBar->setWindow(windowHandle());

     playToolButton = new QWinThumbnailToolButton(thumbnailToolBar);
     playToolButton->setEnabled(false);
     playToolButton->setToolTip(tr("Play"));
     playToolButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
     connect(playToolButton, &QWinThumbnailToolButton::clicked, this, &MusicPlayer::togglePlayback);

     forwardToolButton = new QWinThumbnailToolButton(thumbnailToolBar);
     forwardToolButton->setEnabled(false);
     forwardToolButton->setToolTip(tr("Fast forward"));
     forwardToolButton->setIcon(style()->standardIcon(QStyle::SP_MediaSeekForward));
     connect(forwardToolButton, &QWinThumbnailToolButton::clicked, this, &MusicPlayer::seekForward);

     backwardToolButton = new QWinThumbnailToolButton(thumbnailToolBar);
     backwardToolButton->setEnabled(false);
     backwardToolButton->setToolTip(tr("Rewind"));
     backwardToolButton->setIcon(style()->standardIcon(QStyle::SP_MediaSeekBackward));
     connect(backwardToolButton, &QWinThumbnailToolButton::clicked, this, &MusicPlayer::seekBackward);

     thumbnailToolBar->addButton(backwardToolButton);
     thumbnailToolBar->addButton(playToolButton);
     thumbnailToolBar->addButton(forwardToolButton);

     connect(&mediaPlayer, &QMediaPlayer::positionChanged, this, &MusicPlayer::updateThumbnailToolBar);
     connect(&mediaPlayer, &QMediaPlayer::durationChanged, this, &MusicPlayer::updateThumbnailToolBar);
     connect(&mediaPlayer, &QMediaPlayer::stateChanged, this, &MusicPlayer::updateThumbnailToolBar);
 }

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