QGraphicsViewEc.cpp

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/*
 * SPDX-FileCopyrightText: 2006-2021 Istituto Italiano di Tecnologia (IIT)
 * SPDX-License-Identifier: GPL-3.0-or-later
 */
 
#include "QGraphicsViewEc.h"
#include "moc_QGraphicsViewEc.cpp"
#include <QWheelEvent>
#include <qmath.h>
 
QGraphicsViewEc::QGraphicsViewEc(QWidget* parent) : QGraphicsView(parent)
{
    setTransformationAnchor(QGraphicsView::AnchorUnderMouse);
}
 
 
void QGraphicsViewEc::wheelEvent(QWheelEvent* event)
{
    qreal scaleFactor = qPow(2.0, event->angleDelta().y() / 240.0); //How fast we zoom
    qreal factor = transform().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width();
    if (0.05 < factor && factor < 10) { //Zoom factor limitation
        scale(scaleFactor, scaleFactor);
    }
}