cd46a2daf5
Update files using old header.LGPL3 to header.LGPL Update files using old FDL template to use new one Update files using old BSD template to use new one Change-Id: I36a78272516f9953d02956522f285b40adfc8915 Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>
96 lines
4.1 KiB
C++
96 lines
4.1 KiB
C++
/****************************************************************************
|
|
**
|
|
** Copyright (C) 2016 The Qt Company Ltd.
|
|
** Contact: https://www.qt.io/licensing/
|
|
**
|
|
** This file is part of the examples of the Qt Toolkit.
|
|
**
|
|
** $QT_BEGIN_LICENSE:BSD$
|
|
** 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.
|
|
**
|
|
** BSD License Usage
|
|
** Alternatively, you may use this file under the terms of the BSD license
|
|
** as follows:
|
|
**
|
|
** "Redistribution and use in source and binary forms, with or without
|
|
** modification, are permitted provided that the following conditions are
|
|
** met:
|
|
** * Redistributions of source code must retain the above copyright
|
|
** notice, this list of conditions and the following disclaimer.
|
|
** * Redistributions in binary form must reproduce the above copyright
|
|
** notice, this list of conditions and the following disclaimer in
|
|
** the documentation and/or other materials provided with the
|
|
** distribution.
|
|
** * Neither the name of The Qt Company Ltd nor the names of its
|
|
** contributors may be used to endorse or promote products derived
|
|
** from this software without specific prior written permission.
|
|
**
|
|
**
|
|
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
|
|
**
|
|
** $QT_END_LICENSE$
|
|
**
|
|
****************************************************************************/
|
|
|
|
#include "graphicsview.h"
|
|
|
|
#include <QScrollBar>
|
|
#include <QTouchEvent>
|
|
|
|
GraphicsView::GraphicsView(QGraphicsScene *scene, QWidget *parent)
|
|
: QGraphicsView(scene, parent), totalScaleFactor(1)
|
|
{
|
|
viewport()->setAttribute(Qt::WA_AcceptTouchEvents);
|
|
setDragMode(ScrollHandDrag);
|
|
}
|
|
|
|
bool GraphicsView::viewportEvent(QEvent *event)
|
|
{
|
|
switch (event->type()) {
|
|
case QEvent::TouchBegin:
|
|
case QEvent::TouchUpdate:
|
|
case QEvent::TouchEnd:
|
|
{
|
|
QTouchEvent *touchEvent = static_cast<QTouchEvent *>(event);
|
|
QList<QTouchEvent::TouchPoint> touchPoints = touchEvent->touchPoints();
|
|
if (touchPoints.count() == 2) {
|
|
// determine scale factor
|
|
const QTouchEvent::TouchPoint &touchPoint0 = touchPoints.first();
|
|
const QTouchEvent::TouchPoint &touchPoint1 = touchPoints.last();
|
|
qreal currentScaleFactor =
|
|
QLineF(touchPoint0.pos(), touchPoint1.pos()).length()
|
|
/ QLineF(touchPoint0.startPos(), touchPoint1.startPos()).length();
|
|
if (touchEvent->touchPointStates() & Qt::TouchPointReleased) {
|
|
// if one of the fingers is released, remember the current scale
|
|
// factor so that adding another finger later will continue zooming
|
|
// by adding new scale factor to the existing remembered value.
|
|
totalScaleFactor *= currentScaleFactor;
|
|
currentScaleFactor = 1;
|
|
}
|
|
setTransform(QTransform().scale(totalScaleFactor * currentScaleFactor,
|
|
totalScaleFactor * currentScaleFactor));
|
|
}
|
|
return true;
|
|
}
|
|
default:
|
|
break;
|
|
}
|
|
return QGraphicsView::viewportEvent(event);
|
|
}
|