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Qt/Mac Issues

This file will outline known issues and possible workarounds for limitations on Mac OS X with Qt. This list will not always be complete, so please contact Trolltech support with issues you find to be missing.

See also the document Qt/Mac is Mac OS X Native.

GUI Applications

GUI Applications must be run out of a bundle (something like widgets.app/) or using the open(1) command. Mac OS X needs this to dispatch events correctly, as well as gaining access to the menubar. If using GDB you must run with the full path to the executable.

QCursor

Due to Mac OS X having only 16x16 custom cursors QCursor is limited by this as well. For now the only workaround to this problem is to use a small cursor (16x16).

Anti-aliased text

Qt/Mac (starting with 3.0.5) has introduced some support for smooth text as suggested by Apple's Aqua Style Guildelines. This support is limited to Mac OS X >10.1.4, when this version is not detected it will fallback to the old text rendering library.

Library Support

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.

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_LFFLAGS_SONAME setting:

QMAKE_LFLAGS_SONAME  = -Wl,-install_name,@executable_path/../Frameworks/

In case of Project Builder, you set the Library targets to have their install path (in the Build Settings of the target) set to "@executable_path/.../Frameworks". You also need to add a custom build setting called "SKIP_INSTALL" and set this to YES. In the Application target you need to add a Copy Files build phase that will copy the library product into the applications wrapper's Framework sub-folder.

Note that DYLD_LIBRARY_PATH environment variables will override these settings, same with any other default paths such as a lookup of dynamic libraries inside /usr/lib and similar default locations.

We still strongly recommend to build static applications where the library code is incorporated into the Mac OS X binary. However, in case you ship applications that require plugin support,then you need to use dynamic libraries as part of your application.

Combining Libraries

If you want to build a new dynamic library combining the Qt 3.1 dynamic libraries, you need to introduce the ld -r flag so that 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).

Plugin Support

Note that it is not possible to build Qt plugins using Project Builder or Xcode. Use qmake to configure and build plugins.

Compiler Settings

Compile-time Flags

If you want to wrap any specific Mac OS X code in a define, use the Q_OS_MACX flag, as in:

#if defined(Q_OS_MACX)
// the code used
#endif

Note that when you build under Mac OS X 10.2, then the MACOSX_102 flag is automatically included in the make builds.

Building and Configuring Qt/Mac

Problems building a static configuration

If a static build fails with the following error messages during the designer make phase:

QWidget::sizeHint() const referenced from libqui expected to be defined in @executable_path/../Frameworks/libqt-mt.3.dylib
non-virtual thunk [nv:-40] to QWidget::metric(int) const referenced from libqui
 expected to be defined in @executable_path/../Frameworks/libqt-mt.3.dylib

then ensure that your library path does not have libqui libraries or symbolic links. If you remove these, then the build will continue.

Macintosh Native API Access

Accessing the Bundle Path

The Macintosh application is actually a directory (ending with .app). This directory has various other sub-directories and sources. In case you want to place for example the plugin directory inside this bundle, then you need to find out where the bundle resides on the disk. The following code will do this:

        CFURLRef pluginRef = CFBundleCopyBundleURL(CFBundleGetMainBundle());
        CFStringRef macPath = CFURLCopyFileSystemPath(pluginRef, 
                                               kCFURLPOSIXPathStyle);
        const char *pathPtr = CFStringGetCStringPtr(macPath, 
                                               CFStringGetSystemEncoding());
        qDebug("Path = %s", pathPtr);
        CFRelease(pluginRef);
        CFRelease(macPath);

Do not forget to enclosure this in an #if defined(Q_OS_MACX) macro statement.

Translating the Application Menu and native dialogs

You need to do a little extra to get the Application Menu and native dialogs localized. This is a requirement of Mac OS X and not of Qt.

First, you must add a localized resource folder inside the Bundle see:

http://developer.apple.com/documentation/CoreFoundation/Conceptual/CFBundles/index.html

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:

<?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 popup 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.

Menubar

Qt/Mac will automatically detect your menubars for you and turn them into Mac native menubars. Fitting this into your existing Qt application will normally be automatic, however, if you have special needs the Qt/Mac implementation currently selects a menubar by starting at the active window (ie QApplication::activeWindow()), and applying:

1) If the window has a QMenuBar then it is used. 2) If the window is a modal then its menubar is used. If no menubar is specified then a default menubar is used (as documented below) 3) If the window has no parent then the default menubar is used (as documented below).

The above 3 steps are applied all the way up the parent window chain until one of the above are satisifed. If all else fails a default menubar will be created, the default menubar on Qt/Mac is an empty menubar, however you can create a different default menubar by creating a parentless QMenuBar, the first one created will thus be designated the default menubar, and will be used whenever a default menubar is needed.

Limitations

MenuItems

Unsupported Native Widgets

Qt/Mac 3.x has no support for sheets or drawers. Support for these types of windows is provided in Qt/Mac 4.x.


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Qt 3.3.8