playercontrols.cpp Example File

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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)
    , 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(valueChanged(int)), this, SLOT(onVolumeSliderValueChanged()));
    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
{
    qreal linearVolume =  QAudio::convertVolume(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);
    volumeSlider->setValue(qRound(logarithmicVolume * 100));
}
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());
}
void PlayerControls::onVolumeSliderValueChanged()
{
    emit changeVolume(volume());
}