PeriodicUpdateWidget.cpp

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#include "PeriodicUpdateWidget.h"
 
#include <cmath>
 
#include <QCheckBox>
#include <QDoubleSpinBox>
#include <QHBoxLayout>
#include <QPushButton>
#include <QTimer>
 
namespace armarx
{
    PeriodicUpdateWidget::PeriodicUpdateWidget(double frequency, double maxFrequency)
    {
        setSizePolicy(QSizePolicy::Policy::Minimum, QSizePolicy::Policy::Minimum);
 
        QLayout* vlayout = new QVBoxLayout();
        QLayout* hlayout = new QHBoxLayout();
        this->setLayout(vlayout);
 
        const int margin = 0;
        hlayout->setContentsMargins(margin, margin, margin, margin);
 
        _updateButton = new QPushButton("Update", this);
        _autoCheckBox = new QCheckBox("Auto Update", this);
        _frequencySpinBox = new QDoubleSpinBox(this);
        _frequencySpinBox->setValue(frequency);
        _frequencySpinBox->setMinimum(0);
        _frequencySpinBox->setMaximum(maxFrequency);
        _frequencySpinBox->setSingleStep(0.5);
        _frequencySpinBox->setSuffix(" Hz");
 
        hlayout->addWidget(_updateButton);
        hlayout->addWidget(_autoCheckBox);
        hlayout->addWidget(_frequencySpinBox);
 
        vlayout->addItem(hlayout);
 
 
        _timer = new QTimer(this);
        _updateTimerFrequency();
        _frequencySpinBox->setEnabled(_autoCheckBox->isChecked());
 
 
        // Private connections.
        connect(_autoCheckBox, &QCheckBox::toggled, this, &This::_toggleAutoUpdates);
        connect(_frequencySpinBox,
                &QDoubleSpinBox::editingFinished,
                this,
                &This::_updateTimerFrequency);
 
        // Public connections.
        connect(_updateButton, &QPushButton::pressed, this, &This::updateSingle);
        connect(_timer, &QTimer::timeout, this, &This::updatePeriodic);
 
        connect(this, &This::updateSingle, this, &This::update);
        connect(this, &This::updatePeriodic, this, &This::update);
 
        // See `startTimerIfEnabled` for the signal reasoning.
        // qOverload is required because `QTimer::start()` is overloaded.
        connect(this, &This::startTimerSignal, _timer, qOverload<>(&QTimer::start));
        connect(this, &This::stopTimerSignal, _timer, &QTimer::stop);
    }
 
    QPushButton*
    PeriodicUpdateWidget::updateButton()
    {
        return _updateButton;
    }
 
    int
    PeriodicUpdateWidget::getUpdateIntervalMs() const
    {
        return static_cast<int>(std::round(1000 / _frequencySpinBox->value()));
    }
 
    void
    PeriodicUpdateWidget::startTimerIfEnabled()
    {
        /* A QTimer can only be started and stopped within its own thread (the thread for which
         * it has the greatest affinity). Since this method can be called from any thread, we
         * need to take a detour through these signals, which can be emitted from any thread and
         * will always be caught in this object's (and thus the timer's) native thread.
         */
        if (_autoCheckBox->isChecked())
        {
            emit startTimerSignal();
        }
        else
        {
            emit stopTimerSignal();
        }
    }
 
    void
    PeriodicUpdateWidget::stopTimer()
    {
        // See `startTimerIfEnabled` for the signal reasoning.
        emit stopTimerSignal();
    }
 
    void
    PeriodicUpdateWidget::_updateTimerFrequency()
    {
        _timer->setInterval(getUpdateIntervalMs());
    }
 
    void
    PeriodicUpdateWidget::_toggleAutoUpdates(bool enabled)
    {
        // This method is already a slot, so it doesn't need to use the timer signals.
        _frequencySpinBox->setEnabled(enabled);
        if (enabled)
        {
            _timer->start();
        }
        else
        {
            _timer->stop();
        }
    }
 
    QCheckBox*
    PeriodicUpdateWidget::autoCheckBox()
    {
        return _autoCheckBox;
    }
 
    QDoubleSpinBox*
    PeriodicUpdateWidget::frequencySpinBox()
    {
        return _frequencySpinBox;
    }
 
    QTimer*
    PeriodicUpdateWidget::timer()
    {
        return _timer;
    }
 
} // namespace armarx