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/*!

    \page developing-on-mac.html

    \title Developing Qt Applications on Mac OS X

    \brief A overview of items to be aware of when developing Qt applications

        on 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 4.6, 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?

    Historically, Qt has used the Carbon toolkit, which supports 32-bit

    applications on Mac OS X 10.4 and up. Qt 4.5 and up has support for the Cocoa

    toolkit, which requires 10.5 and provides 64-bit support.

    This detail is typically not important to Qt application developers.  Qt is

    cross-platform across Carbon and Cocoa, and Qt applications behave

    the same way when configured for either one. Eventually, the Carbon

    version will be discontinued. This is something to keep in mind when you

    consider writing code directly against native APIs.

    The current binary for Qt is built in two flavors, 32-bit Carbon and full

    universal Cocoa (32-bit and 64-bit). If you want a different setup for

    Qt will use, you must build from scratch. Carbon or Cocoa is chosen when

    configuring the package for building. The configure process selects Carbon

    by default, to specify Cocoa use the \c{-cocoa} flag.  configure for a

    64-bit architecture using one of the \c{-arch} flags (see \l{universal

    binaries}{Universal Binaries}).

    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 you are starting a new application and can target 10.5 and

    up, then please consider Cocoa only. If you have an existing application or

    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 with the appropriate checks in your code to

    choose the right path based on where you are running the 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.

    \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 for the 32-bit

    architecture, if you are currently on one. 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

    \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}.

*/