modern-linbo-gui/sources/qmodernpushbuttonoverlay.cpp

    #include "../headers/qmodernpushbuttonoverlay.h"

QModernPushButtonOverlay::QModernPushButtonOverlay(QWidget* overlayWidget, QObject *parent) : QObject(parent)
{
    this->widget = overlayWidget;
    this->widget->setVisible(false);

    this->effect = new QGraphicsOpacityEffect(overlayWidget);
    this->effect->setOpacity(0);
    this->effect->setEnabled(false);
    this->widget->setGraphicsEffect(this->effect);

    this->animation = new QPropertyAnimation(this->effect, "opacity");
    this->animation->setDuration(400);
    this->animation->setEasingCurve(QEasingCurve(QEasingCurve::InOutQuad));

    this->setEffectEnabled(false);

    connect(this->animation, SIGNAL(stateChanged(QAbstractAnimation::State, QAbstractAnimation::State)), this, SLOT(handleAnimationStateChanged(QAbstractAnimation::State, QAbstractAnimation::State)));
}


void QModernPushButtonOverlay::setAnimationDuration(int duration) {
    this->animation->setDuration(duration);
}

void QModernPushButtonOverlay::setVisible(bool visible) {
    if(this->widget->isVisible() == visible)
        return;

    int startValue = visible ? 0:1;
    this->animation->setStartValue(startValue);
    this->animation->setEndValue(1-startValue);
    this->animation->start();
}

void QModernPushButtonOverlay::setEffectEnabled(bool enabled) {
    if(enabled) {
        this->effect->setEnabled(true);
        this->widget->setVisible(true);
    }
    else {
        this->widget->setVisible(this->effect->opacity() > 0);
        this->effect->setEnabled(false);
    }
}

void QModernPushButtonOverlay::handleAnimationStateChanged(QAbstractAnimation::State newState, QAbstractAnimation::State) {
    switch (newState) {
    case QAbstractAnimation::Running:
        this->setEffectEnabled(true);
        break;
    case QAbstractAnimation::Stopped:
        this->setEffectEnabled(false);
        break;
    default:
        break;
    }
}