path: root/doc/src/platforms/platform-notes.qdoc

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/*!
    \group platform-specific
    \title Platform-Specific Documentation
    \brief Documents describing platform-specific features of Qt.

    These documents describe platform-specific features provided by Qt, and
    discuss issues related to particular platforms and environments.

    \generatelist{related}
*/

/*!
    \page platform-notes.html
    \ingroup platform-specific
    \title Platform and Compiler Notes
    \brief Information about the platforms on which Qt can be used.

    This page contains information about the platforms Qt is currently known
    to run on, with links to platform-specific notes, including any known bugs
    or incompatibilities.

    Information about the combinations of platforms and compilers
    supported by Qt can be found on the \l{Supported Platforms} page.

    \list
    \o \l{Platform and Compiler Notes - X11}
    \tableofcontents{1 Platform and Compiler Notes - X11}
    \o \l{Platform and Compiler Notes - Windows}
    \tableofcontents{1 Platform and Compiler Notes - Windows}
    \o \l{Platform and Compiler Notes - Mac OS X}
    \tableofcontents{1 Platform and Compiler Notes - Mac OS X}
    \o \l{Platform and Compiler Notes - Symbian}
    \tableofcontents{1 Platform and Compiler Notes - Symbian}
    \o \l{Platform and Compiler Notes - Embedded Linux}
    \tableofcontents{1 Platform and Compiler Notes - Embedded Linux}
    \o \l{Platform and Compiler Notes - Windows CE}
    \tableofcontents{1 Platform and Compiler Notes - Windows CE}
    \o \l{Platform and Compiler Notes - QNX}
    \tableofcontents{1 Platform and Compiler Notes - QNX}
    \o \l{Platform and Compiler Notes - VxWorks}
    \tableofcontents{1 Platform and Compiler Notes - VxWorks}
    \endlist

    \section1 General Compiler Notes

    \section2 Supported Features

    Not all compilers used to build Qt are able to compile all modules. The following table
    shows the compiler support for five modules that are not uniformly available for all
    platforms and compilers.

    \table
    \header \o Compiler \o{5,1} Features
    \header \o                  \o Concurrent \o XmlPatterns \o WebKit(*)   \o CLucene  \o Phonon
    \row    \o g++ 3.3          \o            \o \bold{X}    \o          \o \bold{X} \o \bold{X}
    \row    \o g++ 3.4 and up   \o \bold{X}   \o \bold{X}    \o \bold{X} \o \bold{X} \o \bold{X}
    \row    \o SunCC 5.5        \o            \o             \o          \o \bold{X} \o \bold{X}
    \row    \o aCC series 3     \o            \o             \o          \o \bold{X} \o \bold{X}
    \row    \o aCC series 6     \o \bold{X}   \o \bold{X}    \o \bold{X} \o \bold{X} \o \bold{X}
    \row    \o xlC 6            \o            \o             \o          \o \bold{X} \o \bold{X}
    \row    \o Intel CC 10      \o \bold{X}   \o \bold{X}    \o \bold{X} \o \bold{X} \o \bold{X}
    \row    \o MSVC 2003        \o \bold{X}   \o \bold{X}    \o          \o \bold{X} \o \bold{X}
    \row    \o MSVC 2005 and up \o \bold{X}   \o \bold{X}    \o \bold{X} \o \bold{X} \o \bold{X}
    \endtable

    * WebKit is only supported as a dynamically built library. Static linkage is not supported.

    \section2 GCC 3.4.6 (Debian 3.4.6-5) on AMD64 (x86_64)

    This compiler is known to miscompile some parts of Qt when doing a
    release build. There are several workarounds:

    \list 1
    \o Use a debug build instead.
    \o For each miscompilation encountered, recompile the file, removing the \c{-O2} option.
    \o Add \c{-fno-gcse} to the
       \l{qmake Variable Reference#QMAKE_CXXFLAGS_RELEASE}{QMAKE_CXXFLAGS_RELEASE} qmake
       variable.
    \endlist

    \section2 GCC 4.0.0

    The released package of the compiler has some bugs that lead to
    miscompilations.  We recommend using GCC 4.0.1 or later, or to use
    a recent CVS snapshot of the GCC 4.0 branch. The version of GCC
    4.0.0 that is shipped with Mac OS X 10.4 "Tiger" is known to work
    with Qt for Mac OS X.

    \section2 Intel C++ Compiler

    Qt supports the Intel C++ compiler on both Windows and Linux.
    However, there are a few issues on Linux; see
    \l{Platform and Compiler Notes - X11#Intel C++ Compiler for Linux}{Intel C++ Compiler for Linux}
    for details.

    \section1 Feedback and Corrections

    If you have anything to add to this list or any of the platform or
    compiler-specific pages, please submit it via the \l{Bug Report Form}
    or through the \l{Public Qt Repository}.
*/

/*!
    \page platform-notes-x11.html
    \title Platform and Compiler Notes - X11
    \contentspage Platform and Compiler Notes

    This page contains information about the X11 platforms Qt is currently
    known to run on, with links to platform-specific notes. More information
    about the combinations of platforms and compilers supported by Qt can be
    found on the \l{Supported Platforms} page.

    \tableofcontents

    \target AIX
    \section1 AIX - 5.2

    Qt has been tested on AIX 5.2, using the xlC compiler.

    \table
    \header \o Compiler \o Notes
    \row    \o xlC
    \o If Qt is built correctly but all symbols are reported to be missing
    when you link an application, your makeC++SharedLib script might be out
    of date. Make sure you have the latest version from the
    \l{http://www-306.ibm.com/software/awdtools/vacpp/support/}{IBM website}.
    \row    \o GCC
    \o We have tested earlier versions of Qt 4 successfully with GCC version
    3.3 and above. Some versions of GCC may fail to link Qt with a "TOC overflow"
    message.
    Fix this by upgrading to the latest maintenance release of the dynamic
    linker. On AIX this is bos.rte.bind_cmds.4.1.5.3 or later.
    Some versions of GCC may fail to build Qt with STL and large-file support
    enabled, due to
    \l{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9551}{a bug in GCC}.
    Fix this by upgrading to the latest maintenance release of the compiler.
    It is also possible to work around this problem by running configure with
    either \c{-no-stl} or \c{-no-largefile}.
    \endtable

    \section2 IBM xlC

    The makeC++SharedLib utility must be in your PATH and be up to date to
    build shared libraries. From IBM's
    \l{http://www.redbooks.ibm.com/abstracts/sg245674.html}{C and C++ Application Development on AIX}
    Redbook:

    \list
    \o "The second step is to use the makeC++SharedLib command to create the
       shared object. The command has many optional arguments, but in its
       simplest form, can be used as follows:"
       \snippet doc/src/snippets/code/doc_src_compiler-notes.qdoc 1
    \o "The full path name to the command is not required; however, to avoid
       this, you will have to add the directory in which it is located to
       your PATH environment variable. The command is located in the
       /usr/vacpp/bin directory with the VisualAge C++ Professional for AIX,
       Version 5 compiler."
    \endlist

    \section2 VisualAge C++ for AIX, Version 6.0

    Make sure you have the
    \l{http://www-1.ibm.com/support/search.wss?rs=32&tc=SSEP5D&dc=D400}{latest upgrades}
    installed.

    \target FreeBSD
    \section1 FreeBSD - 6.0-RELEASE

    \note FreeBSD is a community supported platform. See the
    \l{Supported Platforms} page for more information.

    The system compiler on FreeBSD 4.x is GCC 2.95.4, which is not
    officially supported by Qt 4. We develop using and recommend
    ports/lang/gcc34. You will need to run configure with the
    \c{-platform freebsd-g++34} arguments. Optionally, you may use
    ports/lang/icc.

    The system compiler on FreeBSD 5.x and 6.x is GCC 3.4.4, which should be
    sufficient to build Qt. You do not need to add any special arguments when
    running configure. Optionally, you may use ports/lang/icc.

    Note that we do not actively test FreeBSD 4.x and 5.x. Our developers
    migrated to 6.x after the Qt 4 launch. FreeBSD-CURRENT is not supported.

    \section1 HP-UX

    Qt supports HP-UX on both PA-RISC and the Itanium (IA64) architectures.

    \section2 PA-RISC - B.11.11 or later

    You can configure Qt for aCC in 32 and 64 bit mode (hpux-acc-64 or
    hpux-acc-32), or GCC in 32 bit mode (hpux-g++).  The default platform is
    hpux-acc-32. The minimum required version for aCC (HP ANSI C++) on PA-RISC
    is A.03.57. The supported GCC compiler is GCC 3.4.3.

    \section2 Itanium - B.11.23 or later

    You can configure Qt for aCC in 32 and 64 bit mode (hpuxi-acc-64 or
    hpuxi-acc-32). GCC is currently unsupported.  The default platform is
    hpuxi-acc-64. The minimum required version for aCC (HP ANSI C++) on
    Itanium is A.06.12.

    \section2 HP ANSI C++ (aCC)

    The hpux-acc-32 and hpux-acc-64 platforms are tested with aCC A.03.57. The
    hpuxi-acc-32 and hpuxi-acc-64 platforms are tested with aCC A.06.10.

    \section2 GCC

    The hpux-g++ platform is tested with GCC 3.4.4.

    \section2 OpenGL Support

    Qt's \l{QtOpenGL}{OpenGL} module requires GLX 1.3 or later to be installed.
    This is available for HP-UX 11i - see the
    \l{http://docs.hp.com/en/5992-2331/ch04s02.html}{Graphics and Technical Computing Software}
    section of the release notes for more information.

    \target IRIX
    \section1 IRIX - 6.5.x

    \bold{IRIX is an unsupported platform. See the \l{Supported Platforms} page
    and Qt's Software's online \l{Platform Support Policy} page for details.}

    Unpackaging and IRIX tar:
    Because of long filenames some files will be cut off incorrectly with IRIX
    tar. Please use GNU tar to unpack Qt packages.

    \section2 MIPSpro

    Qt 4.4.x requires MIPSpro version 7.4.2m.

    Note that MIPSpro version 7.4.4m is currently not supported, since it has
    introduced a number of problems that have not yet been resolved.
    We recommend using 7.4.2m for Qt development. However, please note the
    unsupported status of this platform.

    \section1 Linux

    There are no known problems with using Qt on production versions of
    Linux/x86, Linux/ppc, Linux/amd64 and Linux/ia64 (including Altix(R)).

    For the GCC compiler, please also see the relevant
    \l{Platform and Compiler Notes#General Compiler Notes}{General Compiler Notes}.

    \section2 Installation problems

    See also the \l{Installation FAQ}.

    If you experience problems when installing new open source versions of Qt
    versions, try to use the open source Qt archives (e.g., RPM)
    provided by your Linux distribution. If you need to install the source (.tgz)
    archive, be aware that you will probably end up with two different
    versions of the Qt library installed on your system, which will probably
    lead to link errors, like this:
    \snippet doc/src/snippets/code/doc_src_platform-notes.qdoc 0
    Fix this by removing the old version of the library.

    If you have problems installing open source versions of Qt
    provided by your Linux distribution (e.g., RPM), please consult the
    maintainers of the distribution, not us.

    Some RPM versions have problems installing some of the Qt RPM archives
    where installation stops with an error message warning about a
    "Failed Dependency". Use the \c{--nodeps} option to \c rpm to workaround
    this problem.

    \section2 Intel C++ Compiler for Linux

    Nokia currently tests the following compilers:

    \list

    \o Intel(R) C++ Compiler for applications running on IA-32,
    Version 10.1 Build 20080602 Package ID: l_cc_p_10.1.017

    \o Intel(R) C++ Compiler for applications running on Intel(R) 64,
    Version 10.1 Build 20080602 Package ID: l_cc_p_10.1.017

    \endlist

    We do not currently test the IA-64 (Itanium) compiler.

    \section2 Known Issues with Intel C++ Compiler for Linux

    \list

    \o Precompiled header support does not work in version 10.0.025
       and older. For these compilers, you should configure Qt with
       -no-pch. Precompiled header support works properly in version
       10.0.026 and later.
    \o Version 10.0.026 for Intel 64 is known to miscompile qmake when
       building in release mode. For now, configure Qt with
       -debug. Version 10.1.008 and later can compile qmake in release
       mode.
    \o Versions 10.1.008 to 10.1.015 for both IA-32 and Intel 64 are
       known crash with "(0): internal error: 0_47021" when compiling
       QtXmlPatterns, QtWebKit, and Designer in release mode. Version
       10.1.017 compiles these modules correctly in release mode.
    \endlist

    \target Solaris
    \section1 Solaris - 9 or later

    \section2 Unpackaging and Solaris tar

    On some Solaris systems, both Solaris tar and GNU tar have been reported
    to truncate long filenames. We recommend using star instead
    (http://star.berlios.de).

    Please note that WebKit is not supported for Solaris, regardless of
    which compiler is used.

    \section2 CC

    See the notes for \l{Forte Developer / Sun Studio}.

    \section2 GCC

    Please use GCC 3.4.2 or later.

    Do not use GCC with Sun's assembler/linker, this will result in link-time
    errors in shared libraries. Use GNU binutils instead. 

    GCC 3.2.* is known to miscompile Qt due to an optimizer bug that will
    cause the resulting binaries to hang.

    \section2 Forte Developer / Sun Studio

    Qt is tested using Sun Studio 12 (Sun CC 5.9). Go to
    \l{Sun Studio Patches} page on Sun's Web site to download
    the latest patches for your Sun compiler.

    Please note that Qt 4.6 is stricter in its STL requirements and
    that the default STL implementation used by Sun CC does not pass
    those requirements. This does not affect binary compatibility and
    you can continue to use STL in your own code, but Qt's
    STL-compatibility functions will be disabled.

    Sun CC ships with a secondary STL implementation (called stlport4)
    which is standards-compliant and can be used by Qt. You can enable
    it by passing the -library=stlport4 option to the compiler. Note
    that this does not affect Qt's binary compatibility, but it may
    affect that of other libraries and programs that use STL.

    \section2 Sun WorkShop 5.0

    Sun WorkShop 5.0 is not supported with Qt 4.
*/

/*!
    \page platform-notes-windows.html
    \title Platform and Compiler Notes - Windows
    \contentspage Platform and Compiler Notes

    This page contains information about the Windows platforms Qt is currently
    known to run on, with links to platform-specific notes. More information
    about the combinations of platforms and compilers supported by Qt can be
    found on the \l{Supported Platforms} page.

    \tableofcontents

    \section1 Windows Vista

    At the time Qt %VERSION% was released, there were no known Vista-specific issues.

    \target Windows NT
    \section1 Windows XP, Windows 2000 and Windows NT

    \section2 Installation location

    Installing Qt into a directory with spaces, e.g. C:\\Program Files, may
    cause linker errors like the following:
    \snippet doc/src/snippets/code/doc_src_platform-notes.qdoc 2

    Install Qt into a subdirectory without spaces to avoid this problem.

    \section2 Possible GL conflict

    There is a known issue with running Microsoft NetMeeting, Lotus SameTime
    and other applications that require screen grabbing while direct
    rendering is enabled. Other GL-applications may not work as expected,
    unless direct rendering is disabled.

    \section2 GCC (MinGW)

    We have tested Qt with this compiler on Windows XP.
    The minimal version of MinGW supported is GCC 4.4.

    \note For users of the MinGW binary package: This package is now
    based on MinGW 4.4. The installer no longer offers to download
    MinGW for you, but rather offers to use a version of MinGW that
    you already have installed on your machine. You just tell the
    installer which directory MinGW is installed in. If you don't
    already have MinGW 4.4 installed, you can download a .zip archive
    from our \l{ftp://ftp.trolltech.com/misc/MinGW-gcc440_1.zip}{FTP
    site}. This archive provides fixes to MinGW and support for
    missing API, See the _patches directory in the archive for
    details.

    \note A MinGW installation is only needed to build against the
    binary package, not to run the pre-compiled binaries that are in
    the package.

    \section2 Intel C++ Compiler (Windows, Altix)

    Qt 4 has been tested successfully with:

    \list
    \o Windows - Intel(R) C++ Compiler for 32-bit applications,
       Version 9.1.040.
    \o Altix - Intel(R) C++ Itanium(R) Compiler for Itanium(R)-based
       applications Version 8.1 Build 20050406 Package ID: l_cc_pc_8.1.030
    \endlist

    We currently only test the Intel compiler on 32-bit Windows versions.

    \section2 Visual Studio (Windows)

    We do most of our Windows development on Windows XP, using Microsoft
    Visual Studio .NET 2005 and Visual Studio 2008 (both the 32- and 64-bit
    versions).

    Qt works with the Standard Edition, the Professional Edition and Team
    System Edition of Visual Studio 2005.

    In order to use Qt with the Visual Studio 2005/2008 Express Edition you need
    to download and install the platform SDK. Due to limitations in the
    Express Edition it is not possible for us to install the Qt Visual
    Studio Integration. You will need to use our command line tools to
    build Qt applications with this edition.

    The Visual C++ Linker doesn't understand filenames with spaces (as in
    \c{C:\Program files\Qt\}) so you will have to move it to another place,
    or explicitly set the path yourself; for example:

    \snippet doc/src/snippets/code/doc_src_compiler-notes.qdoc 0

    If you are experiencing strange problems with using special flags that
    modify the alignment of structure and union members (such as \c{/Zp2})
    then you will need to recompile Qt with the flags set for the
    application as well.

    If you're using Visual Studio .NET (2002) Standard Edition, you should be
    using the Qt binary package provided, and not the source package.
    As the Standard Edition does not optimize compiled code, your compiled
    version of Qt would perform suboptimally with respect to speed.

    With Visual Studio 2005 Service Pack 1 a bug was introduced which
    causes Qt not to compile, this has been fixed with a hotfix available
    from Microsoft. See this
    \l{http://qt.nokia.com/developer/faqs/faq.2006-12-18.3281869860}{Knowledge Base entry}
    for more information.

    There currently is a problem when compiling Qt with Visual Studio 2010 for 64-bit.
    Its optimizer causes trouble and generates code that crashes for the release builds.
    To avoid the crashes, You need to apply the hotfix in the following article
    http://support.microsoft.com/kb/2280741.
*/

/*!
    \page platform-notes-mac.html
    \title Platform and Compiler Notes - Mac OS X
    \contentspage Platform and Compiler Notes

    This page contains information about the Mac OS X versions Qt is currently
    known to run on, with links to platform-specific notes. More information
    about the combinations of platforms and compilers supported by Qt can be
    found on the \l{Supported Platforms} page.

    \tableofcontents

    \section1 General Information

    Qt 4.6 applications can only be deployed on Mac OS X 10.4 (Tiger)
    and higher. 

    Qt 4.4 and Qt 4.5 development is only supported on Mac OS X 10.4 and up.
    Applications built against these version of Qt can be deployed on Mac OS X
    10.3, but cannot be developed on that version of the operating system due
    to compiler issues.

    Qt 4.3 has been tested to run on Mac OS X 10.3.9 and up. See notes on
    the binary package for more information.

    Qt 4.1 has been tested to run on Mac OS X 10.2.8 and up. Qt 4.1.4 is the
    last release to work with Mac OS X 10.2.

    \section2 Required GCC version

    Apple's GCC 4 that is shipped with the Xcode Tools for both Mac OS X 10.4
    and 10.5 will compile Qt. There is preliminary support for GCC 4.2 which
    is included with Xcode Tools 3.1+ (configurable with
    \c{-platform macx-g++42}).

    Please use the latest GCC 3.3 from Apple or a later version of GCC 3.
    The GCC 3.3 that is provided with Xcode 1.5 is known to generate bad code.
    Use the November 2004 GCC 3.3 updater \l{http://connect.apple.com}{available from Apple}.

    \section2 Binary Package

    The binary package requires that you have your .qt-license file in your
    home directory. Installer.app cannot complete without a valid .qt-license
    file. Evaluation users of Qt will have information about how to create
    this file in the email they receive.

    The binary package was built on Mac OS X 10.4 with Xcode Tools 2.1
    (GCC 4.0.0) for Qt 4.1.0, Xcode Tools 2.2 (GCC 4.0.1) for Qt 4.1.1-4.1.4
    and Xcode Tools 2.3 for 4.2.0. It will only link executables built
    against 10.4 (or a 10.4 SDK). You should be able to run applications
    linked against these frameworks on Mac OS X 10.3.9 and Mac OS X 10.4+.
    If you require a different configuration, you will have to use the
    source package and build with GCC 3.3.

    \section2 Mac OS X on Intel hardware

    Qt 4 fully supports both the Intel and PowerPC architectures on the Mac.
    As of Qt 4.1 it is possible to support the Intel architecture by
    creating Universal Binaries with qmake. As of Qt 4.1 it is possible to
    build Qt as a set of universal binaries and frameworks from configure by
    adding these extra flags:

    \snippet doc/src/snippets/code/doc_src_platform-notes.qdoc 3

    If you are building on Intel hardware you can omit the sdk parameter, but
    PowerPC hardware requires it.

    You can also generate universal binaries using qmake. Simply add these
    lines to your .pro file:

    \snippet doc/src/snippets/code/doc_src_platform-notes.qdoc 4

    \section2 Build Issues

    If Qt does not build upon executing make, and fails with an error message
    such as

    \snippet doc/src/snippets/code/doc_src_platform-notes.qdoc 5

    this could be an indication you have upgraded your version of Mac OS X
    (e.g. 10.3 to 10.4), without upgrading your Developer Tools (Xcode Tools).
    These must match in order to successfully compile files.

    Please be sure to upgrade both simultaneously. If problems still occur,
    contact support.

    \section2 Fink

    If you have installed the Qt for X11 package from \l{Fink},
    it will set the QMAKESPEC environment variable to darwin-g++. This will
    cause problems when you build the Qt for Mac OS X package. To fix this, simply
    unset your QMAKESPEC or set it to macx-g++ before you run configure.
    You need to have a fresh Qt distribution (make confclean).

    \section2 MySQL and Mac OS X

    There seems to be a issue when both -prebind and -multi_module are
    defined when linking static C libraries into dynamic library. If you
    get the following error message when linking Qt:

    \snippet doc/src/snippets/code/doc_src_platform-notes.qdoc 6

    re-link Qt using -single_module. This is only a problem when building the
    MySQL driver into Qt. It does not affect plugins or static builds.

    \section2 Qt and Precompiled Headers (PCH)

    Starting with Qt 3.3.0 it is possible to use precompiled headers. They
    are not enabled by default as it appears that some versions of Apple's
    GCC and make have problems with this feature. If you want to use
    precompiled headers when building the Qt source package, specify the
    -pch option to configure. If, while using precompiled headers, you
    encounter an internal compile error, try removing the -include header
    statement from the compile line and trying again. If this solves the
    problem, it probably is a good idea to turn off precompiled headers.
    Also, consider filing a bug report with Apple so that they can
    improve support for this feature.

    \section2 Attributes
    The following lists a set of useful attributes that can be used to tweak applications
    on Mac:

    Qt::AA_MacPluginApplication, Qt::AA_DontUseNativeMenuBar, Qt::AA_MacDontSwapCtrlAndMeta
    Qt::WA_MacNoClickThrough, Qt::WA_MacOpaqueSizeGrip, Qt::WA_MacShowFocusRect,
    Qt::WA_MacNormalSize, Qt::WA_MacSmallSize, Qt::WA_MacMiniSize, Qt::WA_MacVariableSize,
    Qt::WA_MacBrushedMetal, Qt::WA_MacAlwaysShowToolWindow, Qt::WA_MacFrameworkScaled,
    Qt::WA_MacNoShadow, Qt::Sheet, Qt::Drawer, Qt::MacWindowToolBarButtonHint, 
    QMainWindow::unifiedTitleAndToolBarOnMac, WA_MacNoCocoaChildWindow 

    \section2 Mixing Qt with native code
    Two classes are awailable for either adding native Cocoa views/controls
    inside a Qt application, or the opposite, embedding Qt into a native
    Cocoa application:

    QMacCocoaViewContainer, QMacNativeWidget 

    \section3 Using native Cocoa panels
    Launching native Cocoa panels from within a Qt application can sometimes
    be problematic. The reason is that Qt's event dispatcher is more flexible
    than what Cocoa offers, and lets the user spin the event dispatcher (and
    running QEventLoop::exec) without having to think about whether or not modal
    dialogs are showing on screen (which is a difference to Cocoa). Therefore
    we need to do special bookkeeping in Qt to handle this correctly, which
    unfortunately make mixing in native panels hard. The best way at the moment
    to do this, is to follow the pattern below, where we post the call to the
    function with native code rather than calling it directly. Then we know that
    Qt has cleanly updated any pending event loop recursions before the native 
    panel is shown:

    \code
        #include <QtGui>

        class NativeProxyObject : public QObject
        {
            Q_OBJECT
        public slots:
            void execNativeDialogLater()
            {
                QMetaObject::invokeMethod(this, "execNativeDialogNow", Qt::QueuedConnection);
            }

            void execNativeDialogNow()
            {
                NSRunAlertPanel(@"A Native dialog", @"", @"OK", @"", @"");
            }

        };

        #include "main.moc"

        int main(int argc, char **argv){
            QApplication app(argc, argv);
            NativeProxyObject proxy;
            QPushButton button("Show native dialog");
            QObject::connect(&button, SIGNAL(clicked()), &proxy, SLOT(execNativeDialogLater()));
            button.show();
            return app.exec();
        }

    \endcode
*/

/*!
    \page platform-notes-windows-ce.html
    \title Platform and Compiler Notes - Windows CE
    \contentspage Platform and Compiler Notes

    This page contains information about the Windows CE and Windows Mobile
    platforms Qt is currently known to run on, with links to platform-specific
    notes. More information about the combinations of platforms and compilers
    supported by Qt can be found on the \l{Supported Platforms} page.
*/

/*!
    \page platform-notes-symbian.html
    \title Platform and Compiler Notes - Symbian
    \contentspage Platform and Compiler Notes
    \ingroup platform-specific
    \brief Information about the state of support for the Symbian platform.

    As with any port, the maturity for Qt for Symbian has not yet reached the
    same level as other established Qt ports. This page documents the current
    notes for the Symbian port.

    \section1 Source Compatibility

    Qt for Symbian provides the same level of source compatibility guarantee as
    given for other platforms. That is, a program which compiles against a given
    version of Qt for Symbian will also compile against all future versions of the
    same major release.

    \section1 Binary Compatibility

    As with every supported platform, we will strive to maintain
    application behavior and binary compatibility throughout the lifetime of
    the Qt 4.x series. However, due to the fact that Symbian support is newly
    added in 4.6.0, there is a slight possibility that minor corrections to the
    application binary interface (ABI) might be required in 4.6.1, in order to
    ensure compatibility going forward. Any such change will be clearly
    documented in the release notes for 4.6.1.

    \section1 Supported Devices

    See the list of supported devices at
    http://wiki.forum.nokia.com/index.php/Nokia_Smart_Installer_for_Symbian#Supported_Devices

    \section1 Supported Functionality

    The following technologies and classes are not currently supported:

    \table
    \header \o Technology
            \o Note
    \row    \o QtConcurrent
            \o Planned for future release.
    \row    \o QtDBus
            \o No current plans to support this feature.
    \row    \o Printing support
            \o No current plans to support this feature.
    \row    \o Qt3Support
            \o No current plans to support this feature.
    \endtable

    The following technologies have limited support:

    \table
    \header \o Technology
            \o Note
    \row    \o QtSql
            \o The only driver supported is SQLite.
    \row    \o QtMultimedia
            \o Although the module itself is supported, no backend for Symbian
               is currently available. However, there is a backend available
               for Phonon.
    \endtable

    \section1 Compiler Notes

    \section2 GCCE (Symbian)

    GCCE cannot be used to compile Qt libaries for the Symbian platform, but GCCE is supported
    when compiling Qt applications for the Symbian platform.

    \section1 Known Issues

    Known issues can be found by visiting the
    \l{http://qt.gitorious.org/qt/pages/QtKnownIssues}{wiki page} with an
    up-to-date list of known issues, and the list of bugs can be found by
    \l{http://bugreports.qt.nokia.com/browse/QTBUG/component/19171}{browsing} the
    S60 component in Qt's public task tracker, located at
    \l{http://bugreports.qt.nokia.com/}{http://bugreports.qt.nokia.com/}.

    For information about mixing exceptions with Symbian leaves, see
    \l{Exception Safety with Symbian}.

    \section1 Required Capabilities

    The Qt libraries are typically signed with \c{All -TCB} capabilites, but
    that does not mean your Qt application needs to be signed with the same
    capabilities to function properly. The capabilities your application needs
    to function properly depends on which parts of Qt you use, here is an
    overview:

    \table
    \header \o Module
            \o Required Symbian Capability
    \row    \o QtCore
            \o \c PowerMgmt if QProcess::kill(...) or QProcess::terminate(...) is called.
    \row    \o QtCore
            \o \c AllFiles when \l{http://developer.symbian.org/wiki/index.php/Capabilities_%28Symbian_Signed%29/AllFiles_Capability}{accessing specific areas.}
    \row    \o QtDeclarative
            \o \c NetworkServices is automatically added for this module if no capabilities are explicitly specified.
    \row    \o QtNetwork
            \o \c NetworkServices is automatically added for this module if no capabilities are explicitly specified.
    \row    \o QtNetwork
            \o \c ReadUserData is required to include all the phone's SSL certificates in the system's default CA certificate list
                  (for example those added by the user or stored in the SIM card),
                  without this capability only the CA certs built into the phone are used.
    \row    \o QtMultiMedia
            \o \c UserEnvironment if QAudioInput is used.
    \row    \o QtWebkit
            \o \c NetworkServices is automatically added for this module if no capabilities are explicitly specified.
    \endtable

    \note Some modules rely on other modules. E.g. QtWebkit and QtDeclarative
    depend on QtNetwork and therefore any application that
    depends on these modules is also likely to need \c NetworkServices capability.

    For more information see the documentation of the individual Qt classes. If
    a class does not mention Symbian capabilities, it requires none.

    \section1 Multimedia and Phonon Support

    Qt provides a backend for Qt's Phonon module, which supports
    video and sound playback through Symbian's Multimedia Framework, MMF.

    In this release the support is experimental. Video playback may have
    flickering issues, and support for effects and playback queueing is
    incomplete.

    The audio and video formats that Phonon supports depends on what support
    the platform provides for MMF. The emulator is known to have limited
    codec support.

    In addition, there exists a backend for the Helix framework. However, due
    to it not shipping with Qt, its availability depends on the Symbian
    platform in use. If available, it is loaded in preference over the MMF
    plugin. If the Helix plugin fails to load, the MMF plugin, if present on
    the device, will be loaded instead.

    \section1 Hardware Accelerated Rendering

    The default graphics system on Symbian^3 is OpenVG, which uses OpenVG
    hardware to accelerate \l QPainter functions. There are a few exceptions,
    where Qt will use software rendering fallback.

    Devices like the N8 and C7 only have 32Mb of GPU memory and limited support
    for EGL surface transparency. These devices can be identified by querying
    the\c GL_RENDERER or \c VG_RENDERER string which evaluates to \c {VideoCore III}.
    On these devices, Qt will use software rendering in cases listed below.

        \list
        \o Translucent windows
        \o Dialogs
        \o Popups
        \endlist

    \section1 QtOpenGL Support in Symbian

     Qt 4.7 introduces the \l {QtOpenGL} module to Symbian^3. QtOpenGL is
     supported on devices which support OpenGL ES 2.0. Symbian platforms prior
     to Symbian^3 are not supported.

    \l QGLWidget usage as a \l QGraphicsView viewport is not recommended on
    Symbian. The OpenVG graphics system is not able to manage OpenGL graphics
    resources. Also, a QGLWidget object is not able to release its GPU resources
    when the application goes to the background. If OpenGL functionality is
    needed, OpenGL graphics system usage is recommended. If an application
    decides to use QGLWidget, then it is the application's responsibility to
    destroy and release QGLWidget and related OpenGL resources when the
    application goes to the background. Otherwise, the \l{Graphics Out Of Memory monitor}
    may decide to kill the application as it consumes GPU resources while in the
    background.

    \note \l QGLBuffer, \l QGLFramebufferObject, \l QGLPixelBuffer, \l
    QGLShader, and \l QGLShaderProgram are direct GPU resources and it is the
    application's responsibility to manage them.

    \section1 UI Performance in devices prior to Symbian^3

    Qt uses the QPainter class to perform low-level painting on widgets and
    other paint devices. QPainter provides functions to draw complex shapes,
    aligned text and pixmaps. It can also do vector path clipping, coordinate
    transformations and Porter-Duff composition. If the underlying graphics
    architecture does not support all of these operations then Qt uses the
    raster graphics system for rendering.

    Most of the Symbian devices prior to Symbian^3 use a non-ScreenPlay
    graphics architecture which does not have native support for all functions
    provided by QPainter. In non-ScreenPlay devices Qt uses the raster
    graphics system by default which has a performance penalty when compared
    to native Symbian rendering.

    In order to be able to perform all functions provided by QPainter, the
    raster graphics system needs to have pixel level framebuffer access. To
    make this possible in non-ScreenPlay devices Qt has to create an
    additional offscreen buffer that is the target for all Qt rendering
    operations. Qt renders the widget tree to the offscreen buffer and the
    offscreen buffer is blitted to the framebuffer via Symbian Window Server.

    The following table shows the rendering stacks of native Symbian and Qt in
    non-ScreenPlay devices.

    \table
    \header \o Symbian
            \o Qt
    \row    \o \image symbian-rendering-stack-non-screenplay.png
            \o \image symbian-qt-rendering-stack-non-screenplay.png
    \endtable

    The following diagrams show a simplified sequence of drawing a pixmap in
    a non-ScreenPlay device.

    \table
    \header \o Symbian
    \row    \o \image symbian-draw-pixmap-sequence.png
    \endtable

    \table
    \header \o Qt
    \row    \o \image symbian-qt-draw-pixmap-sequence.png
    \endtable

    When compared to a native Symbian application, Qt does an additional blit
    to the offscreen buffer before drawing to the framebuffer. That is the
    performance penalty which needs to be paid to get all functionality
    provided by QPainter in non-ScreenPlay architecture.
*/

/*!
    \page platform-notes-embedded-linux.html
    \title Platform and Compiler Notes - Embedded Linux
    \contentspage Platform and Compiler Notes

    This page contains information about the Embedded Linux platforms Qt is
    currently known to run on, with links to platform-specific notes. More
    information about the combinations of platforms and compilers supported
    by Qt can be found on the \l{Supported Platforms} page.
*/