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     2 **

     3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

     4 ** All rights reserved.

     5 ** Contact: Nokia Corporation (qt-info@nokia.com)

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     7 ** This file is part of the Qt Mobility Components.

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    16 ** GNU Lesser General Public License Usage

    17 ** Alternatively, this file may be used under the terms of the GNU Lesser

    18 ** General Public License version 2.1 as published by the Free Software

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    38 ** $QT_END_LICENSE$

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    40 ****************************************************************************/

    41 

    42 #include "qcvdisplaylink.h"

    43 

    44 #include <QtCore/qcoreapplication.h>

    45 #include <QtCore/qdebug.h>

    46 

    47 QTM_USE_NAMESPACE

    48 

    49 static CVReturn CVDisplayLinkCallback(CVDisplayLinkRef displayLink,

    50                                  const CVTimeStamp *inNow,

    51                                  const CVTimeStamp *inOutputTime,

    52                                  CVOptionFlags flagsIn,

    53                                  CVOptionFlags *flagsOut,

    54                                  void *displayLinkContext)

    55 {

    56     Q_UNUSED(displayLink);

    57     Q_UNUSED(inNow);

    58     Q_UNUSED(flagsIn);

    59     Q_UNUSED(flagsOut);

    60 

    61     QCvDisplayLink *link = (QCvDisplayLink *)displayLinkContext;

    62 

    63     link->displayLinkEvent(inOutputTime);

    64     return kCVReturnSuccess;

    65 }

    66 

    67 

    68 QCvDisplayLink::QCvDisplayLink(QObject *parent)

    69     :QObject(parent),

    70     m_pendingDisplayLinkEvent(false),

    71     m_isActive(false)

    72 {

    73     // create display link for the main display

    74     CVDisplayLinkCreateWithCGDisplay(kCGDirectMainDisplay, &m_displayLink);

    75     if (m_displayLink) {

    76         // set the current display of a display link.

    77         CVDisplayLinkSetCurrentCGDisplay(m_displayLink, kCGDirectMainDisplay);

    78 

    79         // set the renderer output callback function

    80         CVDisplayLinkSetOutputCallback(m_displayLink, &CVDisplayLinkCallback, this);

    81     }

    82 }

    83 

    84 QCvDisplayLink::~QCvDisplayLink()

    85 {

    86     if (m_displayLink) {

    87         CVDisplayLinkStop(m_displayLink);

    88         CVDisplayLinkRelease(m_displayLink);

    89         m_displayLink = NULL;

    90     }

    91 }

    92 

    93 bool QCvDisplayLink::isValid()

    94 {

    95     return m_displayLink != 0;

    96 }

    97 

    98 bool QCvDisplayLink::isActive() const

    99 {

   100     return m_isActive;

   101 }

   102 

   103 void QCvDisplayLink::start()

   104 {

   105      if (m_displayLink && !m_isActive) {

   106         CVDisplayLinkStart(m_displayLink);

   107         m_isActive = true;

   108      }

   109 }

   110 

   111 void QCvDisplayLink::stop()

   112 {

   113     if (m_displayLink && m_isActive) {

   114         CVDisplayLinkStop(m_displayLink);

   115         m_isActive = false;

   116     }

   117 }

   118 

   119 void QCvDisplayLink::displayLinkEvent(const CVTimeStamp *ts)

   120 {

   121     // This function is called from a

   122     // thread != gui thread. So we post the event.

   123     // But we need to make sure that we don't post faster

   124     // than the event loop can eat:

   125     m_displayLinkMutex.lock();

   126     bool pending = m_pendingDisplayLinkEvent;

   127     m_pendingDisplayLinkEvent = true;

   128     m_frameTimeStamp = *ts;

   129     m_displayLinkMutex.unlock();

   130 

   131     if (!pending)

   132         qApp->postEvent(this, new QEvent(QEvent::User), Qt::HighEventPriority);

   133 }

   134 

   135 bool QCvDisplayLink::event(QEvent *event)

   136 {

   137     switch (event->type()){

   138         case QEvent::User:  {

   139                 m_displayLinkMutex.lock();

   140                 m_pendingDisplayLinkEvent = false;

   141                 CVTimeStamp ts = m_frameTimeStamp;

   142                 m_displayLinkMutex.unlock();

   143 

   144                 emit tick(ts);

   145 

   146                 return false;

   147             }

   148             break;

   149         default:

   150             break;

   151     }

   152     return QObject::event(event);

   153 }

   154 

   155 #include "moc_qcvdisplaylink.cpp"

   156