chart.cpp Example File

zoomlinechart/chart.cpp
/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the Qt Charts module of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:GPL$ ** 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 https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 3 or (at your option) any later version ** approved by the KDE Free Qt Foundation. The licenses are as published by ** the Free Software Foundation and appearing in the file LICENSE.GPL3 ** included in the packaging of this file. Please review the following ** information to ensure the GNU General Public License requirements will ** be met: https://www.gnu.org/licenses/gpl-3.0.html. ** ** $QT_END_LICENSE$ ** ****************************************************************************/
#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; }