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A description of issues with Qt that are specific to Mac OS X. This file outlines known issues and possible workarounds for limitations on Mac OS X with Qt. Contact Trolltech support if you find additional issues which are not covered here.
See also the document Qt/Mac is Mac OS X Native.
If you are using older versions of GDB you must run with the full path to the executable. Later versions allow you to pass the bundle name on the command line. In general, this shouldn't be an issue as qmake will take care of the specifics for you. However, there are a couple of things you need to keep in mind when using frameworks over normal dynamic libraries. Most are included in the Framework Programming Guide, but one that you may not be aware of is that: frameworks will always link with the "release" version of a library. This means that if you want to actually use a "debug" version of a Qt framework, you must make sure that the application actually loads the debug version. This is usually done by using the DYLD_IMAGE_SUFFIX environment variables. However, for several reasons, this typically doesn't work so well. Instead, you can temporarily swap your debug and release versions. This is documented in Apple's "Debugging Magic" technical note. If you do not wish to use frameworks simply configure Qt with -no-framework. The application finds these dynamic libraries if the libraries have an install name of "@executable_path/../Frameworks/libname.dylib. If you use qmake and Makefiles, use the QMAKE_LFLAGS_SONAME setting: Note that the DYLD_LIBRARY_PATH environment variable will override these settings, and any other default paths such as a lookup of dynamic libraries inside /usr/lib and similar default locations. If you desire to define for specific versions of Mac OS X, use the availability macros defined in /usr/include/AvailabilityMacros.h. See QSysInfo for information on runtime version checking. And look for the heading: Adding Localized Resources The main thing you need to do is create a file called locversion.plist. Here is an example one for Norwegian: Painting
Mac OS X always double buffers the screen so the Qt::WA_PaintOnScreen attribute has no effect. Also it is impossible to paint outside of a paint event so Qt::WA_PaintOutsidePaintEvent has no effect either.Library Support
Qt libraries as frameworks
By default, Qt is built as a set of frameworks. This is the Mac OS X "preferred" way of distributing libraries (and there are some definite advantages to using them) see Apple's Framework Programming Guide for more info. Bundle-Based Libraries
If you want to incorporate dynamic libraries as part of your Mac OS X application bundle (the application directory), then you place these into a directory called Frameworks, a subdirectory of the application bundle.
QMAKE_LFLAGS_SONAME = -Wl,-install_name,@executable_path/../Frameworks/
Alternatively you can modify the intall name using the install_name_tool(1) command line tool. See its manpage for more information. Combining Libraries
If you want to build a new dynamic library combining the Qt 4 dynamic libraries, you need to introduce the ld -r flag. Then relocation information is stored in the the output file, so that this file could be the subject of another ld run. This is done by setting the -r flag in the .pro file, and the LFLAGS settings.Initialization Order
dyld(1) will call global static initializers in the order in which they are linked into your application. If a library links against Qt and references globals in Qt (from global initializers in your own library) you should be sure to link against Qt before your library, otherwise the result will be undefined (as Qt's global initializers have not been called yet).Compiler Settings
Compile-Time Flags
There are two flags that are helpful when wanting to define Mac OS X specific code:
Q_OS_MAC is defined as a convenience and is available whenever Q_OS_DARWIN is defined. Mac OS X Native API Access
Accessing the Bundle Path
The Mac OS X application is actually a directory (ending with .app). This directory has various sub-directories and sources. It may be useful to place items (e.g. plugins, online-documentation, etc.) inside this bundle. You will then you need to find out where the bundle resides on the disk. The following code will return the path of the application bundle:
#ifdef Q_WS_MAC
CFURLRef appUrlRef = CFBundleCopyBundleURL(CFBundleGetMainBundle());
CFStringRef macPath = CFURLCopyFileSystemPath(appUrlRef,
kCFURLPOSIXPathStyle);
const char *pathPtr = CFStringGetCStringPtr(macPath,
CFStringGetSystemEncoding());
qDebug("Path = %s", pathPtr);
CFRelease(appUrlRef);
CFRelease(macPath);
#endif
More information about using the CFBundle API is available on Apple's Developer Website.Translating the Application Menu and Native Dialogs
The items in the Application Menu will be merged correctly for your localized application, but they will not show up translated until you add a localized resource folder inside the Bundle:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN"
"http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>LprojCompatibleVersion</key>
<string>123</string>
<key>LprojLocale</key>
<string>no</string>
<key>LprojRevisionLevel</key>
<string>1</string>
<key>LprojVersion</key>
<string>123</string>
</dict>
</plist>
Then when you run the application with your preferred language set to Norwegian you should see menu items like "Avslutt" instead of "Quit".User Interface
Right-Mouse Clicks
If you want to provide right-mouse click support for Mac OS X, use the QContextMenuEvent class. This will map to a context menu event, in other words a menu that will display a pop-up selection. This is the most common use of right-mouse clicks, and maps to a control-click with the Mac OS X one-button mouse support.Menu Bar
Qt/Mac will automatically detect your menu bars for you and turn them into Mac native menu bars. Fitting this into your existing Qt application will normally be automatic, however, if you have special needs the Qt/Mac implementation currently selects a menu bar by starting at the active window (i.e. QApplication::activeWindow()), and applying the following tests:
These tests are followed all the way up the parent window chain until one of the above is satisifed. If all else fails a default menu bar will be created, the default menu bar on Qt/Mac is an empty menu bar, however you can create a different default menu bar by creating a parentless QMenuBar; the first one created will be designated the default menu bar, and will be used whenever a default menu bar is needed.
Note that using native menu bars introduces certain limitations on Qt classes. See the list of limitations below for more information about these.Special Keys
To provide the expected behavior for Qt applications on Mac OS X, the Qt::Meta, Qt::MetaModifier, and Qt::META enum values correspond to the Control keys on the standard Macintosh keyboard, and the Qt::Control, Qt::ControlModifier, and Qt::CTRL enum values correspond to the Command keys.Limitations
Menu Actions
Native Widgets
Qt/Mac has support for sheets and drawers, represented in the window flags by Qt::Sheet and Qt::Drawer respectiviely. Brushed metal windows can also be created by using the Qt::WA_MacMetalStyle window attribute.
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