- Qt 5.5
- Qt Multimedia Widgets
- Media Player Example
- playercontrols.cpp Example File
- Qt 5.5.1 Reference Documentation

# playercontrols.cpp Example File

player/playercontrols.cpp

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    ** This file is part of the examples of the Qt Toolkit.
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    #include "playercontrols.h"

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

    PlayerControls::PlayerControls(QWidget *parent)
        : QWidget(parent)
        , playerState(QMediaPlayer::StoppedState)
        , playerMuted(false)
        , playButton(0)
        , stopButton(0)
        , nextButton(0)
        , previousButton(0)
        , muteButton(0)
        , volumeSlider(0)
        , rateBox(0)
    {
        playButton = new QToolButton(this);
        playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));

        connect(playButton, SIGNAL(clicked()), this, SLOT(playClicked()));

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

        connect(stopButton, SIGNAL(clicked()), this, SIGNAL(stop()));

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

        connect(nextButton, SIGNAL(clicked()), this, SIGNAL(next()));

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

        connect(previousButton, SIGNAL(clicked()), this, SIGNAL(previous()));

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

        connect(muteButton, SIGNAL(clicked()), this, SLOT(muteClicked()));

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

        connect(volumeSlider, SIGNAL(sliderMoved(int)), this, SIGNAL(changeVolume(int)));

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

        connect(rateBox, SIGNAL(activated(int)), SLOT(updateRate()));

        QBoxLayout *layout = new QHBoxLayout;
        layout->setMargin(0);
        layout->addWidget(stopButton);
        layout->addWidget(previousButton);
        layout->addWidget(playButton);
        layout->addWidget(nextButton);
        layout->addWidget(muteButton);
        layout->addWidget(volumeSlider);
        layout->addWidget(rateBox);
        setLayout(layout);
    }

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

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

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

    int PlayerControls::volume() const
    {
        return volumeSlider ? volumeSlider->value() : 0;
    }

    void PlayerControls::setVolume(int volume)
    {
        if (volumeSlider)
            volumeSlider->setValue(volume);
    }

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

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

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

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

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

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

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

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

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