mainchart.cpp

/*
 * Copyright (C) 2020 brian DOT l DOT miller DOT ttu AT gmail DOT com
 * This file is part of QCovidTracker.
 *
 * This program comes with ABSOLUTELY NO WARRANTY
 * QCovidTracker is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * QCovidTracker is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with QCovidTracker.  If not, see <https://www.gnu.org/licenses/.
 */
#include "mainchart.h"
#include <QtWidgets/QGesture>
#include <QtWidgets/QGraphicsScene>
#include <QtWidgets/QGraphicsView>

MainChart::MainChart(QGraphicsItem *parent, Qt::WindowFlags wFlags)
    : QChart(QChart::ChartTypeCartesian, parent, wFlags)
{
    grabGesture(Qt::PanGesture);
    grabGesture(Qt::PinchGesture);
}

bool MainChart::sceneEvent(QEvent *event)
{
    if (event->type() == QEvent::Gesture)
        return gestureEvent(static_cast<QGestureEvent *>(event));
    return QChart::event(event);
}

bool MainChart::gestureEvent(QGestureEvent *event)
{
    qDebug() << "gestureEvent";
    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;
}