Time for action - Using animations to move items smoothly

Let's add a new private member called m_jumpAnimation of the QPropertyAnimation * type, and initialize it in the constructor of MyScene:

m_jumpAnimation = new QPropertyAnimation(this);
m_jumpAnimation->setTargetObject(this);
m_jumpAnimation->setPropertyName("jumpFactor");
m_jumpAnimation->setStartValue(0);
m_jumpAnimation->setKeyValueAt(0.5, 1);
m_jumpAnimation->setEndValue(0);
m_jumpAnimation->setDuration(800);
m_jumpAnimation->setEasingCurve(QEasingCurve::OutInQuad);