Revision control
++ // Copyright (C) 2023 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ #include "chart.h"
++
++ #include <QGesture>
++ #include <QGraphicsScene>
++ #include <QGraphicsView>
++
++ Chart::Chart(QGraphicsItem *parent, Qt::WindowFlags wFlags)
++ : QChart(QChart::ChartTypeCartesian, parent, wFlags)
++ {
++ // Seems that QGraphicsView (QChartView) does not grab gestures.
++ // They can only be grabbed here in the QGraphicsWidget (QChart).
++ grabGesture(Qt::PanGesture);
++ grabGesture(Qt::PinchGesture);
++ }
++
++ //![1]
++ bool Chart::sceneEvent(QEvent *event)
++ {
++ if (event->type() == QEvent::Gesture)
++ return gestureEvent(static_cast<QGestureEvent *>(event));
++ return QChart::event(event);
++ }
++
++ bool Chart::gestureEvent(QGestureEvent *event)
++ {
++ if (QGesture *gesture = event->gesture(Qt::PanGesture)) {
++ auto pan = static_cast<QPanGesture *>(gesture);
++ QChart::scroll(-(pan->delta().x()), pan->delta().y());
++ }
++
++ if (QGesture *gesture = event->gesture(Qt::PinchGesture)) {
++ auto pinch = static_cast<QPinchGesture *>(gesture);
++ if (pinch->changeFlags() & QPinchGesture::ScaleFactorChanged)
++ QChart::zoom(pinch->scaleFactor());
++ }
++
++ return true;
++ }
++ //![1]