chart.cpp Example File
zoomlinechart/chart.cpp/****************************************************************************** ** ** Copyright (C) 2015 The Qt Company Ltd. ** Contact: http://www.qt.io/licensing/ ** ** This file is part of the Qt Charts module. ** ** $QT_BEGIN_LICENSE:COMM$ ** ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see http://www.qt.io/terms-conditions. For further ** information use the contact form at http://www.qt.io/contact-us. ** ** $QT_END_LICENSE$ ** ******************************************************************************/ #include "chart.h" #include <QtWidgets/QGesture> #include <QtWidgets/QGraphicsScene> #include <QtWidgets/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); } Chart::~Chart() { } 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)) { QPanGesture *pan = static_cast<QPanGesture *>(gesture); QChart::scroll(-(pan->delta().x()), pan->delta().y()); } if (QGesture *gesture = event->gesture(Qt::PinchGesture)) { QPinchGesture *pinch = static_cast<QPinchGesture *>(gesture); if (pinch->changeFlags() & QPinchGesture::ScaleFactorChanged) QChart::zoom(pinch->scaleFactor()); } return true; }