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Diffstat (limited to 'doc/src/snippets/gestures/qgesture.cpp')
| -rw-r--r-- | doc/src/snippets/gestures/qgesture.cpp | 283 |
1 files changed, 0 insertions, 283 deletions
diff --git a/doc/src/snippets/gestures/qgesture.cpp b/doc/src/snippets/gestures/qgesture.cpp deleted file mode 100644 index 77f5cc2..0000000 --- a/doc/src/snippets/gestures/qgesture.cpp +++ /dev/null @@ -1,283 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). -** All rights reserved. -** Contact: Nokia Corporation (qt-info@nokia.com) -** -** This file is part of the QtGui module 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 Technology Preview License Agreement accompanying -** this package. -** -** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package. -** -** If you have questions regarding the use of this file, please contact -** Nokia at qt-info@nokia.com. -** -** -** -** -** -** -** -** -** $QT_END_LICENSE$ -** -****************************************************************************/ - -#include "qgesture.h" -#include <private/qgesture_p.h> -#include "qgraphicsitem.h" - -QT_BEGIN_NAMESPACE - - -class QEventFilterProxyGraphicsItem : public QGraphicsItem -{ -public: - QEventFilterProxyGraphicsItem(QGesture *g) - : gesture(g) - { - } - bool sceneEventFilter(QGraphicsItem *, QEvent *event) - { - return gesture ? gesture->filterEvent(event) : false; - } - QRectF boundingRect() const { return QRectF(); } - void paint(QPainter*, const QStyleOptionGraphicsItem*, QWidget*) { } - -private: - QGesture *gesture; -}; - -/* - \class QGesture - \since 4.6 - - \brief The QGesture class is the base class for implementing custom - gestures. - - This class represents both an object that recognizes a gesture out of a set - of input events (a gesture recognizer), and a gesture object itself that - can be used to get extended information about the triggered gesture. - - The class has a list of properties that can be queried by the user to get - some gesture-specific parameters (for example, an offset of a Pan gesture). - - Usually gesture recognizer implements a state machine, storing its state - internally in the recognizer object. The recognizer receives input events - through the \l{QGesture::}{filterEvent()} virtual function and decides - whether the event should change the state of the recognizer by emitting an - appropriate signal. - - Input events should be either fed to the recognizer one by one with a - filterEvent() function, or the gesture recognizer should be attached to an - object it filters events for by specifying it as a parent object. The - QGesture object installs itself as an event filter to the parent object - automatically, the unsetObject() function should be used to remove an event - filter from the parent object. To make a - gesture that operates on a QGraphicsItem, both the appropriate QGraphicsView - should be passed as a parent object and setGraphicsItem() functions should - be used to attach a gesture to a graphics item. - - This is a base class, to create a custom gesture type, you should subclass - it and implement its pure virtual functions. - - \sa QPanGesture -*/ - -/* \fn bool QGesture::filterEvent(QEvent *event) - - Parses input \a event and emits a signal when detects a gesture. - - In your reimplementation of this function, if you want to filter the \a - event out, i.e. stop it being handled further, return true; otherwise - return false; - - This is a pure virtual function that needs to be implemented in subclasses. -*/ - -/* \fn void QGesture::started() - - The signal is emitted when the gesture is started. Extended information - about the gesture is contained in the signal sender object. - - In addition to started(), a triggered() signal should also be emitted. -*/ - -/* \fn void QGesture::triggered() - - The signal is emitted when the gesture is detected. Extended information - about the gesture is contained in the signal sender object. -*/ - -/* \fn void QGesture::finished() - - The signal is emitted when the gesture is finished. Extended information - about the gesture is contained in the signal sender object. -*/ - -/* \fn void QGesture::cancelled() - - The signal is emitted when the gesture is cancelled, for example the reset() - function is called while the gesture was in the process of emitting a - triggered() signal. Extended information about the gesture is contained in - the sender object. -*/ - - -/* - Creates a new gesture handler object and marks it as a child of \a parent. - - The \a parent object is also the default event source for the gesture, - meaning that the gesture installs itself as an event filter for the \a - parent. - - \sa setGraphicsItem() -*/ -QGesture::QGesture(QObject *parent) - : QObject(*new QGesturePrivate, parent) -{ - if (parent) - parent->installEventFilter(this); -} - -/* \internal - */ -QGesture::QGesture(QGesturePrivate &dd, QObject *parent) - : QObject(dd, parent) -{ - if (parent) - parent->installEventFilter(this); -} - -/* - Destroys the gesture object. -*/ -QGesture::~QGesture() -{ -} - -/* \internal - */ -bool QGesture::eventFilter(QObject *receiver, QEvent *event) -{ - Q_D(QGesture); - if (d->graphicsItem && receiver == parent()) - return false; - return filterEvent(event); -} - -/* - \property QGesture::state - - \brief The current state of the gesture. -*/ - -/* - Returns the gesture recognition state. - */ -Qt::GestureState QGesture::state() const -{ - return d_func()->state; -} - -/* - Sets this gesture's recognition state to \a state and emits appropriate - signals. - - This functions emits the signals according to the old state and the new - \a state, and it should be called after all the internal properties have been - initialized. - - \sa started(), triggered(), finished(), cancelled() - */ -void QGesture::updateState(Qt::GestureState state) -{ - Q_D(QGesture); - if (d->state == state) { - if (state == Qt::GestureUpdated) - emit triggered(); - return; - } - const Qt::GestureState oldState = d->state; - d->state = state; - if (state != Qt::NoGesture && oldState > state) { - // comparing the state as ints: state should only be changed from - // started to (optionally) updated and to finished. - qWarning("QGesture::updateState: incorrect new state"); - return; - } - if (oldState == Qt::NoGesture) - emit started(); - if (state == Qt::GestureUpdated) - emit triggered(); - else if (state == Qt::GestureFinished) - emit finished(); - else if (state == Qt::NoGesture) - emit cancelled(); - - if (state == Qt::GestureFinished) { - // gesture is finished, so we reset the internal state. - d->state = Qt::NoGesture; - } -} - -/* - Sets the \a graphicsItem the gesture is filtering events for. - - The gesture will install an event filter to the \a graphicsItem and - redirect them to the filterEvent() function. - - \sa graphicsItem() -*/ -void QGesture::setGraphicsItem(QGraphicsItem *graphicsItem) -{ - Q_D(QGesture); - if (d->graphicsItem && d->eventFilterProxyGraphicsItem) - d->graphicsItem->removeSceneEventFilter(d->eventFilterProxyGraphicsItem); - d->graphicsItem = graphicsItem; - if (!d->eventFilterProxyGraphicsItem) - d->eventFilterProxyGraphicsItem = new QEventFilterProxyGraphicsItem(this); - if (graphicsItem) - graphicsItem->installSceneEventFilter(d->eventFilterProxyGraphicsItem); -} - -/* - Returns the graphics item the gesture is filtering events for. - - \sa setGraphicsItem() -*/ -QGraphicsItem* QGesture::graphicsItem() const -{ - return d_func()->graphicsItem; -} - -/* \fn void QGesture::reset() - - Resets the internal state of the gesture. This function might be called by - the filterEvent() implementation in a derived class, or by the user to - cancel a gesture. The base class implementation calls - updateState(Qt::NoGesture) which emits the cancelled() - signal if the state() of the gesture indicated it was active. -*/ -void QGesture::reset() -{ - updateState(Qt::NoGesture); -} - -QT_END_NAMESPACE |