Qt 5.11 | Qt Multimedia | Media Player Example | playercontrols.cpp Example File

Qt 5.11.3 Reference Documentation

# playercontrols.cpp Example File

multimediawidgets/player/playercontrols.cpp

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      #include "playercontrols.h"

      #include <QBoxLayout>
      #include <QSlider>
      #include <QStyle>
      #include <QToolButton>
      #include <QComboBox>
      #include <QAudio>

      PlayerControls::PlayerControls(QWidget *parent)
          : QWidget(parent)
      {
          m_playButton = new QToolButton(this);
          m_playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));

          connect(m_playButton, &QAbstractButton::clicked, this, &PlayerControls::playClicked);

          m_stopButton = new QToolButton(this);
          m_stopButton->setIcon(style()->standardIcon(QStyle::SP_MediaStop));
          m_stopButton->setEnabled(false);

          connect(m_stopButton, &QAbstractButton::clicked, this, &PlayerControls::stop);

          m_nextButton = new QToolButton(this);
          m_nextButton->setIcon(style()->standardIcon(QStyle::SP_MediaSkipForward));

          connect(m_nextButton, &QAbstractButton::clicked, this, &PlayerControls::next);

          m_previousButton = new QToolButton(this);
          m_previousButton->setIcon(style()->standardIcon(QStyle::SP_MediaSkipBackward));

          connect(m_previousButton, &QAbstractButton::clicked, this, &PlayerControls::previous);

          m_muteButton = new QToolButton(this);
          m_muteButton->setIcon(style()->standardIcon(QStyle::SP_MediaVolume));

          connect(m_muteButton, &QAbstractButton::clicked, this, &PlayerControls::muteClicked);

          m_volumeSlider = new QSlider(Qt::Horizontal, this);
          m_volumeSlider->setRange(0, 100);

          connect(m_volumeSlider, &QSlider::valueChanged, this, &PlayerControls::onVolumeSliderValueChanged);

          m_rateBox = new QComboBox(this);
          m_rateBox->addItem("0.5x", QVariant(0.5));
          m_rateBox->addItem("1.0x", QVariant(1.0));
          m_rateBox->addItem("2.0x", QVariant(2.0));
          m_rateBox->setCurrentIndex(1);

          connect(m_rateBox, QOverload<int>::of(&QComboBox::activated), this, &PlayerControls::updateRate);

          QBoxLayout *layout = new QHBoxLayout;
          layout->setMargin(0);
          layout->addWidget(m_stopButton);
          layout->addWidget(m_previousButton);
          layout->addWidget(m_playButton);
          layout->addWidget(m_nextButton);
          layout->addWidget(m_muteButton);
          layout->addWidget(m_volumeSlider);
          layout->addWidget(m_rateBox);
          setLayout(layout);
      }

      QMediaPlayer::State PlayerControls::state() const
      {
          return m_playerState;
      }

      void PlayerControls::setState(QMediaPlayer::State state)
      {
          if (state != m_playerState) {
              m_playerState = state;

              switch (state) {
              case QMediaPlayer::StoppedState:
                  m_stopButton->setEnabled(false);
                  m_playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
                  break;
              case QMediaPlayer::PlayingState:
                  m_stopButton->setEnabled(true);
                  m_playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPause));
                  break;
              case QMediaPlayer::PausedState:
                  m_stopButton->setEnabled(true);
                  m_playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
                  break;
              }
          }
      }

      int PlayerControls::volume() const
      {
          qreal linearVolume =  QAudio::convertVolume(m_volumeSlider->value() / qreal(100),
                                                      QAudio::LogarithmicVolumeScale,
                                                      QAudio::LinearVolumeScale);

          return qRound(linearVolume * 100);
      }

      void PlayerControls::setVolume(int volume)
      {
          qreal logarithmicVolume = QAudio::convertVolume(volume / qreal(100),
                                                          QAudio::LinearVolumeScale,
                                                          QAudio::LogarithmicVolumeScale);

          m_volumeSlider->setValue(qRound(logarithmicVolume * 100));
      }

      bool PlayerControls::isMuted() const
      {
          return m_playerMuted;
      }

      void PlayerControls::setMuted(bool muted)
      {
          if (muted != m_playerMuted) {
              m_playerMuted = muted;

              m_muteButton->setIcon(style()->standardIcon(muted
                      ? QStyle::SP_MediaVolumeMuted
                      : QStyle::SP_MediaVolume));
          }
      }

      void PlayerControls::playClicked()
      {
          switch (m_playerState) {
          case QMediaPlayer::StoppedState:
          case QMediaPlayer::PausedState:
              emit play();
              break;
          case QMediaPlayer::PlayingState:
              emit pause();
              break;
          }
      }

      void PlayerControls::muteClicked()
      {
          emit changeMuting(!m_playerMuted);
      }

      qreal PlayerControls::playbackRate() const
      {
          return m_rateBox->itemData(m_rateBox->currentIndex()).toDouble();
      }

      void PlayerControls::setPlaybackRate(float rate)
      {
          for (int i = 0; i < m_rateBox->count(); ++i) {
              if (qFuzzyCompare(rate, float(m_rateBox->itemData(i).toDouble()))) {
                  m_rateBox->setCurrentIndex(i);
                  return;
              }
          }

          m_rateBox->addItem(QString("%1x").arg(rate), QVariant(rate));
          m_rateBox->setCurrentIndex(m_rateBox->count() - 1);
      }

      void PlayerControls::updateRate()
      {
          emit changeRate(playbackRate());
      }

      void PlayerControls::onVolumeSliderValueChanged()
      {
          emit changeVolume(volume());
      }