kopia lustrzana https://github.com/f4exb/sdrangel
103 wiersze
3.9 KiB
C++
103 wiersze
3.9 KiB
C++
///////////////////////////////////////////////////////////////////////////////////
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// Copyright (C) 2021 Jon Beniston, M7RCE //
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// //
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// This program is free software; you can redistribute it and/or modify //
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// it under the terms of the GNU General Public License as published by //
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// the Free Software Foundation as version 3 of the License, or //
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// (at your option) any later version. //
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// //
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// This program is distributed in the hope that it will be useful, //
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// but WITHOUT ANY WARRANTY; without even the implied warranty of //
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
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// GNU General Public License V3 for more details. //
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// //
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// You should have received a copy of the GNU General Public License //
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// along with this program. If not, see <http://www.gnu.org/licenses/>. //
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///////////////////////////////////////////////////////////////////////////////////
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#include <QMouseEvent>
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#include <QApplication>
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#include <QScrollBar>
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#include <QGestureEvent>
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#include <QPinchGesture>
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#include <qmath.h>
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#include "graphicsviewzoom.h"
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GraphicsViewZoom::GraphicsViewZoom(QGraphicsView* view) :
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QObject(view),
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m_view(view),
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m_modifiers(Qt::NoModifier),
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m_zoomFactorBase(1.0015)
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{
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m_view->viewport()->installEventFilter(this);
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m_view->setMouseTracking(true);
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m_view->viewport()->grabGesture(Qt::PinchGesture);
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}
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void GraphicsViewZoom::gentleZoom(double factor)
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{
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m_view->scale(factor, factor);
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m_view->centerOn(m_targetScenePos);
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QPointF deltaViewportPos = m_targetViewportPos - QPointF(m_view->viewport()->width() / 2.0,
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m_view->viewport()->height() / 2.0);
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QPointF viewportCenter = m_view->mapFromScene(m_targetScenePos) - deltaViewportPos;
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m_view->centerOn(m_view->mapToScene(viewportCenter.toPoint()));
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emit zoomed();
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}
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void GraphicsViewZoom::setModifiers(Qt::KeyboardModifiers modifiers)
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{
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m_modifiers = modifiers;
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}
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void GraphicsViewZoom::setZoomFactorBase(double value)
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{
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m_zoomFactorBase = value;
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}
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bool GraphicsViewZoom::eventFilter(QObject *object, QEvent *event)
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{
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if (event->type() == QEvent::MouseMove)
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{
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QMouseEvent* mouseEvent = static_cast<QMouseEvent*>(event);
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QPointF delta = m_targetViewportPos - mouseEvent->pos();
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if (qAbs(delta.x()) > 5 || qAbs(delta.y()) > 5)
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{
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m_targetViewportPos = mouseEvent->pos();
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m_targetScenePos = m_view->mapToScene(mouseEvent->pos());
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}
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}
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else if (event->type() == QEvent::Wheel)
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{
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QWheelEvent* wheelEvent = static_cast<QWheelEvent*>(event);
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if (QApplication::keyboardModifiers() == m_modifiers)
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{
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if (wheelEvent->angleDelta().y() != 0)
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{
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double angle = wheelEvent->angleDelta().y();
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double factor = qPow(m_zoomFactorBase, angle);
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gentleZoom(factor);
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return true;
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}
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}
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}
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else if (event->type() == QEvent::Gesture)
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{
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QGestureEvent *gestureEvent = static_cast<QGestureEvent *>(event);
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if (QPinchGesture *pinchGesture = static_cast<QPinchGesture *>(gestureEvent->gesture(Qt::PinchGesture)))
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{
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if (pinchGesture->changeFlags() & QPinchGesture::ScaleFactorChanged)
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{
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m_view->scale(pinchGesture->scaleFactor(), pinchGesture->scaleFactor());
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emit zoomed();
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}
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return true;
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}
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}
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Q_UNUSED(object)
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return false;
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}
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