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Diffstat (limited to 'doc/src/snippets/gestures/imageviewer/tapandholdgesture.cpp')
| -rw-r--r-- | doc/src/snippets/gestures/imageviewer/tapandholdgesture.cpp | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/doc/src/snippets/gestures/imageviewer/tapandholdgesture.cpp b/doc/src/snippets/gestures/imageviewer/tapandholdgesture.cpp new file mode 100644 index 0000000..03898dc --- /dev/null +++ b/doc/src/snippets/gestures/imageviewer/tapandholdgesture.cpp @@ -0,0 +1,159 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the examples of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at http://qt.nokia.com/contact. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "tapandholdgesture.h" + +#include <QtGui/qevent.h> + +// #define TAPANDHOLD_USING_MOUSE + +/*! + \class TapAndHoldGesture + \since 4.6 + + \brief The TapAndHoldGesture class represents a Tap-and-Hold gesture, + providing additional information. +*/ + +const int TapAndHoldGesture::iterationCount = 40; +const int TapAndHoldGesture::iterationTimeout = 50; + +/*! + Creates a new Tap and Hold gesture handler object and marks it as a child + of \a parent. + + On some platforms like Windows there is a system-wide tap and hold gesture + that cannot be overriden, hence the gesture might never trigger and default + context menu will be shown instead. +*/ +TapAndHoldGesture::TapAndHoldGesture(QWidget *parent) + : QGesture(parent), iteration(0) +{ +} + +/*! \internal */ +bool TapAndHoldGesture::filterEvent(QEvent *event) +{ + if (!event->spontaneous()) + return false; + const QTouchEvent *ev = static_cast<const QTouchEvent*>(event); + switch (event->type()) { + case QEvent::TouchBegin: { + if (timer.isActive()) + timer.stop(); + timer.start(TapAndHoldGesture::iterationTimeout, this); + const QPoint p = ev->touchPoints().at(0).pos().toPoint(); + position = p; + break; + } + case QEvent::TouchUpdate: + if (ev->touchPoints().size() == 1) { + const QPoint startPos = ev->touchPoints().at(0).startPos().toPoint(); + const QPoint pos = ev->touchPoints().at(0).pos().toPoint(); + if ((startPos - pos).manhattanLength() > 15) + reset(); + } else { + reset(); + } + break; + case QEvent::TouchEnd: + reset(); + break; +#ifdef TAPANDHOLD_USING_MOUSE + case QEvent::MouseButtonPress: { + if (timer.isActive()) + timer.stop(); + timer.start(TapAndHoldGesture::iterationTimeout, this); + const QPoint p = static_cast<QMouseEvent*>(event)->pos(); + position = startPosition = p; + break; + } + case QEvent::MouseMove: { + const QPoint startPos = startPosition; + const QPoint pos = static_cast<QMouseEvent*>(event)->pos(); + if ((startPos - pos).manhattanLength() > 15) + reset(); + break; + } + case QEvent::MouseButtonRelease: + reset(); + break; +#endif // TAPANDHOLD_USING_MOUSE + default: + break; + } + return false; +} + +/*! \internal */ +void TapAndHoldGesture::timerEvent(QTimerEvent *event) +{ + if (event->timerId() != timer.timerId()) + return; + if (iteration == TapAndHoldGesture::iterationCount) { + timer.stop(); + updateState(Qt::GestureFinished); + } else { + updateState(Qt::GestureUpdated); + } + ++iteration; +} + +/*! \internal */ +//! [tapandhold-reset] +void TapAndHoldGesture::reset() +{ + timer.stop(); + iteration = 0; + position = startPosition = QPoint(); + updateState(Qt::NoGesture); +} +//! [tapandhold-reset] + +/*! + \property TapAndHoldGesture::pos + + \brief The position of the gesture. +*/ +QPoint TapAndHoldGesture::pos() const +{ + return position; +} |