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3** Copyright (C) 2016 The Qt Company Ltd.
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6** This file is part of the Qt Charts module of the Qt Toolkit.
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29
30#include "chart.h"
31#include <QtWidgets/QGesture>
32#include <QtWidgets/QGraphicsScene>
33#include <QtWidgets/QGraphicsView>
34
35Chart::Chart(QGraphicsItem *parent, Qt::WindowFlags wFlags)
36 : QChart(QChart::ChartTypeCartesian, parent, wFlags)
37{
38 // Seems that QGraphicsView (QChartView) does not grab gestures.
39 // They can only be grabbed here in the QGraphicsWidget (QChart).
40 grabGesture(type: Qt::PanGesture);
41 grabGesture(type: Qt::PinchGesture);
42}
43
44Chart::~Chart()
45{
46
47}
48
49//![1]
50bool Chart::sceneEvent(QEvent *event)
51{
52 if (event->type() == QEvent::Gesture)
53 return gestureEvent(event: static_cast<QGestureEvent *>(event));
54 return QChart::event(event);
55}
56
57bool Chart::gestureEvent(QGestureEvent *event)
58{
59 if (QGesture *gesture = event->gesture(type: Qt::PanGesture)) {
60 QPanGesture *pan = static_cast<QPanGesture *>(gesture);
61 QChart::scroll(dx: -(pan->delta().x()), dy: pan->delta().y());
62 }
63
64 if (QGesture *gesture = event->gesture(type: Qt::PinchGesture)) {
65 QPinchGesture *pinch = static_cast<QPinchGesture *>(gesture);
66 if (pinch->changeFlags() & QPinchGesture::ScaleFactorChanged)
67 QChart::zoom(factor: pinch->scaleFactor());
68 }
69
70 return true;
71}
72//![1]
73

source code of qtcharts/examples/charts/zoomlinechart/chart.cpp