source: trunk/doc/src/development/developing-on-mac.qdoc@ 846

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/*!
    \page developing-on-mac.html
    \title Developing Qt Applications for Mac OS X
    \brief Information for developing Qt applications for Mac OS X
    \ingroup platform-specific

    \tableofcontents

    Mac OS X is a UNIX platform and behaves similar to other Unix-like
    platforms. The main difference is X11 is not used as the primary windowing
    system. Instead, Mac OS X uses its own native windowing system that is
    accessible through the Carbon and Cocoa APIs.  Application development on
    Mac OS X is done using Xcode Tools, an optional install included on every
    Mac with updates available from \l {http://developer.apple.com}{Apple's
    developer website}. Xcode Tools includes Apple-modified versions of the GCC
    compiler.


    \section1 What Versions of Mac OS X are Supported?

    As of Qt 4.7, Qt supports Mac OS X versions 10.4 and up. It is usually in
    the best interest of the developer and user to be running the latest
    updates to any version. We test internally against Mac OS X 10.4.11 as well
    as the updated release of Mac OS X 10.5 and Mac OS X 10.6.

    \section2 Carbon or Cocoa?
    
    Qt supports building in two flavors, using either the Carbon or Cocoa API.
    Using the Cocoa API, Qt requires 10.5 and provides both 32-bit and 64-bit support. With
    Carbon, Qt can be developed on and deployed to 10.4, but there is no 64-bit
    support.

    Note: There is no accessibility support in the Cocoa version. This is planned
    for Qt 4.8.

    With Qt 4.7 we recommend using the Cocoa version of Qt for development,
    unless you want to target the 10.4 platform. Qt uses Cocoa by default,
    both for the binary package and when configuring Qt from source (using the \c{configure}
    script). To build Qt for Carbon, specify the \c{-carbon} flag to configure.

    There are two versions of the Qt binary, one with x86 and x86_64
    Cocoa and another with x86 and ppc Carbon. If you want a different setup
    you must build Qt yourself using the source package. To explicitly configure
    Qt to build for 34-bit or 64-bit architectures (or both), use
    the \c{-arch} flags (see \l{universal binaries}{Universal Binaries}).
    For the Cocoa version, 64 bit is chosen by default.

    Currently, Apple's default GCC compiler is used by default (GCC 4.0.1 on
    10.4 and 10.5, GCC 4.2 on 10.6). You can specify alternate compilers
    though. For example, on Mac OS X 10.5, Apple's GCC 4.2 is also available
    and selectable with the configure flag: \c{-platform macx-g++42}.  LLVM-GCC
    support is available by passing in the \c{-platform macx-llvm} flag. GCC
    3.x will \e not work. Though they may work, We do not support custom-built
    GCC's.

    The following table summarizes the different versions of Mac OS X and what
    capabilities are used by Qt.

    \table
        \header
            \o Mac OS X Version
            \o Cat Name
            \o Native API Used by Qt
            \o Bits available to address memory
            \o CPU Architecture Supported
            \o Development Platform
        \row
            \o 10.4
            \o Tiger
            \o Carbon
            \o 32
            \o PPC/Intel
            \o Yes
        \row
            \o 10.5
            \o Leopard
            \o Carbon
            \o 32
            \o PPC/Intel
            \o Yes
        \row
            \o 10.5
            \o Leopard
            \o Cocoa
            \o 32/64
            \o PPC/Intel
            \o Yes
        \row
            \o 10.6
            \o Snow Leopard
            \o Cocoa/Carbon
            \o 32
            \o PPC/Intel
            \o Yes
        \row
            \o 10.6
            \o Snow Leopard
            \o Cocoa
            \o 64
            \o Intel
            \o Yes
    \endtable
    
    Note that building for ppc-64 is not supported on 10.6.

    \section2 Which One Should I Use?

    Carbon and Cocoa both have their advantages and disadvantages. Probably the
    easiest way to determine is to look at the version of Mac OS X you are
    targetting. If your application can target 10.5 and up, then we recommend 
    using Cocoa. If you need to target earlier versions of the operating system
    and do not need access to 64-bit or newer Apple technologies, then Carbon 
    is a good fit. If your needs fall in between, you can go with a 64-bit Cocoa and 32-bit
    Carbon universal application.

    For Mac OS X 10.6, Apple has started recommending developers to build their
    applications 64-bit. The main reason is that there is a small speed
    increase due to the extra registers on Intel CPU's, all their machine
    offerings have been 64-bit since 2007, and there is a cost for reading all
    the 32-bit libraries into memory if everything else is 64-bit.  If you want
    to follow this advice, there is only one choice, 64-bit Cocoa.


    \section2 Building Qt statically

    We recommend building Qt as shared frameworks. Static builds are only partially
    supported, meaning that you can build most of Qt statically, but some modules,
    like web-kit and Designer, will fail. You can specify which modules to build
    from configure (e.g. -no-webkit -nomake tools). For Cocoa configurations, both
    static and no-framework builds requires manually copying the
    'src/gui/mac/qt_menu.nib/ directory into the " Resources" directory in
    the application bundle.

    \target universal binaries
    \section1 Universal Binaries

    In 2006, Apple begin transitioning from PowerPC (PPC) to Intel (x86)
    systems.  Both architectures are supported by Qt. The release of Mac OS X
    10.5 in October 2007 added the possibility of writing and deploying 64-bit
    GUI applications. Qt 4.5 and up supports both the 32-bit (PPC and x86) and
    64-bit (PPC64 and x86-64) versions of PowerPC and Intel-based systems.

    Universal binaries are used to bundle binaries for more than one
    architecture into a single package, simplifying deployment and
    distribution. When running an application the operating system will select
    the most appropriate architecture. Universal binaries support the following
    architectures; they can be added to the build at configure time using the
    \c{-arch} arguments:

    \table
        \header
            \o Architecture             
            \o Flag
        \row
            \o Intel, 32-bit
            \o \c{-arch x86}
        \row
            \o Intel, 64-bit
            \o \c{-arch x86_64}
        \row
            \o PPC, 32-bit
            \o \c{-arch ppc}
        \row
            \o PPC, 64-bit
            \o \c{-arch ppc64}
    \endtable

    If there are no \c{-arch} flags specified, configure builds Qt for a 32-bit
    architecture when using Carbon, and a 64-bit architecture when using Cocoa. Universal
    binaries were initially
    used to simplify the PPC to Intel migration. You can use \c{-universal} to
    build for both the 32-bit Intel and PPC architectures.

    \note The \c{-arch} flags at configure time only affect how Qt is built.
    Applications are by default built for the 32-bit architecture you are
    currently on. To build a universal binary, add the architectures to the
    CONFIG variable in the .pro file:

    \code
    CONFIG += x86 ppc x86_64 ppc64
    \endcode

    \section2 Working with several versions of Qt
    You can only install one version of Qt at a time when using the binary
    package. The reason for this is that a binary installation will install different parts of Qt
    (frameworks, documentation, examples, tools, etc) to different
    predefined locations on the OS, as described by Apple. If you want
    to work against other versions at the same time, you need
    to build the other versions explicitly from source. When doing so, you can
    provide \c{-prefix} to configure to set install location. 
    The binary package will install Qt to the following locations: 

    \table
        \header
            \o Qt
            \o Location
        \row
            \o Designer, Linguist ...
            \o /Developer/Applications/Qt
        \row
            \o Documentation
            \o /Developer/Documentation/Qt
        \row
            \o Examples
            \o /Developer/Examples/Qt
        \row
            \o Plugins
            \o /Developer/Applications/Qt/Plugins
        \row
            \o Frameworks
            \o /Library/Frameworks
        \row
            \o Libraries
            \o /usr/lib
        \row
            \o qmake, moc, uic ...
            \o /Developer/Tools/Qt (symlink to /usr/bin)
        \row
            \o uninstall-qt.py, uninstall-qtsdk.py
            \o /Developer/Tools
    \endtable

    \section1 Day-to-Day Application Development on OS X

    On the command-line, applications can be built using \c qmake and \c make.
    Optionally, \c qmake can generate project files for Xcode with
    \c{-spec macx-xcode}. If you are using the binary package, \c qmake
    generates Xcode projects by default; use \c{-spec macx-gcc} to generate
    makefiles.

    The result of the build process is an application bundle, which is a
    directory structure that contains the actual application executable. The
    application can be launched by double-clicking it in Finder, or by
    referring directly to its executable from the command line, i. e.
    \c{myApp.app/Contents/MacOS/myApp}.

    If you wish to have a command-line tool that does not use the GUI (e.g.,
    \c moc, \c uic or \c ls), you can tell \c qmake not to execute the bundle
    creating steps by removing it from the \c{CONFIG} in your \c{.pro} file:

    \code
    CONFIG -= app_bundle
    \endcode


    \section1 Deployment - "Compile once, deploy everywhere"

    In general, Qt supports building on one Mac OS X version and deploying on
    all others, both forward and backwards. You can build on 10.4 Tiger and run
    the same binary on 10.5 and up.

    Some restrictions apply:

    \list
        \o  Some functions and optimization paths that exist in later versions
            of Mac OS X will not be available if you build on an earlier
            version of Mac OS X.
        \o  The CPU architecture should match.
        \o  Cocoa support is only available for Mac OS X 10.5 and up.
    \endlist

    Universal binaries can be used to provide a smorgasbord of configurations
    catering to all possible architectures.

    Mac applications are typically deployed as self-contained application
    bundles. The application bundle contains the application executable as well
    as dependencies such as the Qt libraries, plugins, translations and other
    resources you may need. Third party libraries like Qt are normally not
    installed system-wide; each application provides its own copy.

    The most common way to distribute applications is to provide a compressed
    disk image (.dmg file) that the user can mount in Finder. The Mac
    deployment tool (macdeployqt) can be used to create the self-contained bundles, and
    optionally also create a .dmg archive. See the
    \l{Deploying an Application on Mac OS X}{Mac deployment guide} for more
    information about deployment. It is also possible to use an installer
    wizard. More information on this option can be found in
    \l{http://developer.apple.com/mac/}{Apple's documentation}.
*/