fullscreennotification.cpp Example File

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  #include "fullscreennotification.h"

  #include <QGraphicsOpacityEffect>
  #include <QPropertyAnimation>
  #include <QSequentialAnimationGroup>

  FullScreenNotification::FullScreenNotification(QWidget *parent)
      : QLabel(parent)
      , m_previouslyVisible(false)
  {
      setText(tr("You are now in full screen mode. Press ESC to quit!"));
      setStyleSheet(
          "font-size: 24px;"
          "color: white;"
          "background-color: black;"
          "border-color: white;"
          "border-width: 2px;"
          "border-style: solid;"
          "padding: 100px");
      setAttribute(Qt::WA_TransparentForMouseEvents);

      auto effect = new QGraphicsOpacityEffect;
      effect->setOpacity(1);
      setGraphicsEffect(effect);

      auto animations = new QSequentialAnimationGroup(this);
      animations->addPause(3000);
      auto opacityAnimation = new QPropertyAnimation(effect, "opacity", animations);
      opacityAnimation->setDuration(2000);
      opacityAnimation->setStartValue(1.0);
      opacityAnimation->setEndValue(0.0);
      opacityAnimation->setEasingCurve(QEasingCurve::OutQuad);
      animations->addAnimation(opacityAnimation);

      connect(this, &FullScreenNotification::shown,
              [animations](){ animations->start(); });

      connect(animations, &QAbstractAnimation::finished,
              [this](){ this->hide(); });
  }

  void FullScreenNotification::showEvent(QShowEvent *event)
  {
      QLabel::showEvent(event);
      if (!m_previouslyVisible && isVisible())
          emit shown();
      m_previouslyVisible = isVisible();
  }