volumebutton.cpp Example File

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 #include "volumebutton.h"

 #include <QtWidgets>
 #include <QtWinExtras>

 VolumeButton::VolumeButton(QWidget *parent) :
     QToolButton(parent)
 {
     setIcon(style()->standardIcon(QStyle::SP_MediaVolume));
     setPopupMode(QToolButton::InstantPopup);

     QWidget *popup = new QWidget(this);

     slider = new QSlider(Qt::Horizontal, popup);
     slider->setRange(0, 100);
     connect(slider, &QAbstractSlider::valueChanged, this, &VolumeButton::volumeChanged);

     label = new QLabel(popup);
     label->setAlignment(Qt::AlignCenter);
     label->setNum(100);
     label->setMinimumWidth(label->sizeHint().width());

     connect(slider, &QAbstractSlider::valueChanged, label, QOverload<int>::of(&QLabel::setNum));

     QBoxLayout *popupLayout = new QHBoxLayout(popup);
     popupLayout->setMargin(2);
     popupLayout->addWidget(slider);
     popupLayout->addWidget(label);

     QWidgetAction *action = new QWidgetAction(this);
     action->setDefaultWidget(popup);

     menu = new QMenu(this);
     menu->addAction(action);
     setMenu(menu);

     stylize();
 }

 void VolumeButton::increaseVolume()
 {
     slider->triggerAction(QSlider::SliderPageStepAdd);
 }

 void VolumeButton::descreaseVolume()
 {
     slider->triggerAction(QSlider::SliderPageStepSub);
 }

 int VolumeButton::volume() const
 {
     return slider->value();
 }

 void VolumeButton::setVolume(int volume)
 {
     slider->setValue(volume);
 }

 void VolumeButton::stylize()
 {
     if (QOperatingSystemVersion::current() < QOperatingSystemVersion::Windows8) {
         // Set styling options relevant only to Windows 7.
         if (QtWin::isCompositionEnabled()) {
             QtWin::enableBlurBehindWindow(menu);
             QString css("QMenu { border: 1px solid %1; border-radius: 2px; background: transparent; }");
             menu->setStyleSheet(css.arg(QtWin::realColorizationColor().name()));
         } else {
             QtWin::disableBlurBehindWindow(menu);
             QString css("QMenu { border: 1px solid black; background: %1; }");
             menu->setStyleSheet(css.arg(QtWin::realColorizationColor().name()));
         }
     }
 }