sdrangel/sdrgui/gui/graphicsviewzoom.h

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2.2 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2021 Jon Beniston, M7RCE //
// //
// This program 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 as version 3 of the License, or //
// (at your option) any later version. //
// //
// This program 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 V3 for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
///////////////////////////////////////////////////////////////////////////////////
#ifndef SDRGUI_GUI_GRAPHICSVIEWZOOM_H
#define SDRGUI_GUI_GRAPHICSVIEWZOOM_H
#include <QObject>
#include <QGraphicsView>
#include "export.h"
// GraphicsView that allows scroll wheel and pinch gesture to be used for zoom
// https://stackoverflow.com/questions/19113532/qgraphicsview-zooming-in-and-out-under-mouse-position-using-mouse-wheel
class SDRGUI_API GraphicsViewZoom : public QObject {
Q_OBJECT
public:
GraphicsViewZoom(QGraphicsView* view);
void gentleZoom(double factor);
void setModifiers(Qt::KeyboardModifiers modifiers);
void setZoomFactorBase(double value);
private:
QGraphicsView* m_view;
Qt::KeyboardModifiers m_modifiers;
double m_zoomFactorBase;
QPointF m_targetScenePos, m_targetViewportPos;
bool eventFilter(QObject* object, QEvent* event) override;
signals:
void zoomed();
};
#endif // SDRGUI_GUI_GRAPHICSVIEWZOOM_H