diff options
Diffstat (limited to 'src/corelib/kernel/qwineventnotifier.cpp')
| -rw-r--r-- | src/corelib/kernel/qwineventnotifier.cpp | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/src/corelib/kernel/qwineventnotifier.cpp b/src/corelib/kernel/qwineventnotifier.cpp new file mode 100644 index 0000000000..55daeaa579 --- /dev/null +++ b/src/corelib/kernel/qwineventnotifier.cpp @@ -0,0 +1,221 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** GNU Lesser General Public License Usage +** 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. +** +** 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. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms and +** conditions contained in a signed written agreement between you and Nokia. +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qwineventnotifier.h" + +#include "qeventdispatcher_win_p.h" +#include "qcoreapplication.h" + +#include <private/qthread_p.h> + +QT_BEGIN_NAMESPACE + +/* + \class QWinEventNotifier + \brief The QWinEventNotifier class provides support for the Windows Wait functions. + + The QWinEventNotifier class makes it possible to use the wait + functions on windows in a asynchronous manner. With this class + you can register a HANDLE to an event and get notification when + that event becomes signalled. The state of the event is not modified + in the process so if it is a manual reset event you will need to + reset it after the notification. + + Once you have created a event object using Windows API such as + CreateEvent() or OpenEvent(), you can create an event notifier to + monitor the event handle. If the event notifier is enabled, it will + emit the activated() signal whenever the corresponding event object + is signalled. + + The setEnabled() function allows you to disable as well as enable the + event notifier. It is generally advisable to explicitly enable or + disable the event notifier. A disabled notifier does nothing when the + event object is signalled(the same effect as not creating the + event notifier). Use the isEnabled() function to determine the + notifier's current status. + + Finally, you can use the setHandle() function to register a new event + object, and the handle() function to retrieve the event handle. + + \bold{Further information:} + Although the class is called QWinEventNotifier, it can be used for + certain other objects which are so-called synchronization + objects, such as Processes, Threads, Waitable timers. + + \warning This Class is only available on Windows. +*/ + +/*! + \fn void QWinEventNotifier::activated(HANDLE hEvent) + + This signal is emitted whenever the event notifier is enabled and + the corresponding HANDLE is signalled. + + The state of the event is not modified in the process, so if it is a + manual reset event, you will need to reset it after the notification. + + The object is passed in the \a hEvent parameter. + + \sa handle() +*/ + +/*! + Constructs an event notifier with the given \a parent. +*/ + +QWinEventNotifier::QWinEventNotifier(QObject *parent) + : QObject(parent), handleToEvent(0), enabled(false) +{} + +/*! + Constructs an event notifier with the given \a parent. It enables + the \a notifier, and watches for the event \a hEvent. + + The notifier is enabled by default, i.e. it emits the activated() signal + whenever the corresponding event is signalled. However, it is generally + advisable to explicitly enable or disable the event notifier. + + \sa setEnabled(), isEnabled() +*/ + +QWinEventNotifier::QWinEventNotifier(HANDLE hEvent, QObject *parent) + : QObject(parent), handleToEvent(hEvent), enabled(false) +{ + Q_D(QObject); + QEventDispatcherWin32 *eventDispatcher = qobject_cast<QEventDispatcherWin32 *>(d->threadData->eventDispatcher); + Q_ASSERT_X(eventDispatcher, "QWinEventNotifier::QWinEventNotifier()", + "Cannot create a win event notifier without a QEventDispatcherWin32"); + eventDispatcher->registerEventNotifier(this); + enabled = true; +} + +/*! + Destroys this notifier. +*/ + +QWinEventNotifier::~QWinEventNotifier() +{ + setEnabled(false); +} + +/*! + Register the HANDLE \a hEvent. The old HANDLE will be automatically + unregistered. + + \bold Note: The notifier will be disabled as a side effect and needs + to be re-enabled. + + \sa handle(), setEnabled() +*/ + +void QWinEventNotifier::setHandle(HANDLE hEvent) +{ + setEnabled(false); + handleToEvent = hEvent; +} + +/*! + Returns the HANDLE that has been registered in the notifier. + + \sa setHandle() +*/ + +HANDLE QWinEventNotifier::handle() const +{ + return handleToEvent; +} + +/*! + Returns true if the notifier is enabled; otherwise returns false. + + \sa setEnabled() +*/ + +bool QWinEventNotifier::isEnabled() const +{ + return enabled; +} + +/*! + If \a enable is true, the notifier is enabled; otherwise the notifier + is disabled. + + \sa isEnabled(), activated() +*/ + +void QWinEventNotifier::setEnabled(bool enable) +{ + if (enabled == enable) // no change + return; + enabled = enable; + + Q_D(QObject); + QEventDispatcherWin32 *eventDispatcher = qobject_cast<QEventDispatcherWin32 *>(d->threadData->eventDispatcher); + if (!eventDispatcher) // perhaps application is shutting down + return; + + if (enabled) + eventDispatcher->registerEventNotifier(this); + else + eventDispatcher->unregisterEventNotifier(this); +} + +/*!\reimp +*/ + +bool QWinEventNotifier::event(QEvent * e) +{ + if (e->type() == QEvent::ThreadChange) { + if (enabled) { + QMetaObject::invokeMethod(this, "setEnabled", Qt::QueuedConnection, + Q_ARG(bool, enabled)); + setEnabled(false); + } + } + QObject::event(e); // will activate filters + if (e->type() == QEvent::WinEventAct) { + emit activated(handleToEvent); + return true; + } + return false; +} + +QT_END_NAMESPACE |