musicplayer.cpp Example File

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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);
  }