Qt Reference Documentation

Currently, the Qt Reference Documentation is not shipped with the OS/2 version of the Qt Toolkit (it will be done later).

You can view it online using this link:

Known Bugs and Limitations

The OS/2 version of the Qt Library is not yet complete. Some features are still under development and there are some known bugs. They are briefly described below.

Missing features

1 Drag & Drop (QT_NO_DRAGANDDROP is constantly defined for now)
2 OS/2 widget style (a native look and feel of buttons, combo boxes and other common widgets)
3 Printing support (QPrinter class is absent, QT_NO_PRINTER is constantly defined for now)
4 Process management (QProcess class is absent)
5 Audio support (QSound class)
6 sql module (QSql class and friends)
7 table module (QTable class, depends only on Drag & Drop)
8 iconview module (QIconView class, depends only on Drag & Drop)
9 canvas module (QCanvas and friends)
10 OpenGL module (QGL class and friends)
11 Plugin support
12 Qt Designer tool (depends only on Drag & Drop)
13 Qt Linguist tool (depends only on Drag & Drop)
14 Qt Assistant tool (depends only on Drag & Drop)

Know Bugs and Limitations

1 Unicode is not fully supported in GUI, to the effect that only the symbols from the current (system) 8-bit charset can appear in widgets and when drawing text.
2 Alpha blending for pixmaps is not yet implemented [themes example].
3 Complex text transformations (rotation etc.) don't work correctly with the FreeType2 rendering engine. Most likely a bug or a limitation of FreeType2 [xform example].
4 Text rotation to values greater than 90 degrees clockwise doesn't work with truetype fonts and the standard TTF rendering engine. This seems like an OS/2 bug [xform example].
5 Stay-on-top is not supported system-wide.

GNUMAKE backend for qmake

The GNUMAKE backend generates makefiles for the GNU Make utility from qmake's project files. A separate generator became necessary because the previously used MINGW generator has some problems and limitations that make it impossible to generate correct makefiles in several situations. This new generator is primarily intended to be used with GNU Make under OS/2, but theoretically can be used on any platform after some modifications. However, its usage under other platforms is not tested and not supported.

The GNUMAKE backend was initially based on the existing MINGW backend, so here is the list of its differences and improvements comparing to the MINGW backend:

1. QMAKE_LINK_OBJECT_MAX, QMAKE_LINK_OBJECT_SCRIPT, QMAKE_LINK_OBJMOC_SCRIPT are no longer supported, since the OS/2 version of GNU LD (linker) seems not to support object link scripts. The OS/2 CMD.EXE command line length limitation (1024 chars) is worked around in a different way (see the \mkspecs\os2-g++\qmake.conf if interested).

2. Added new qmake varibales QMAKE_RUN_LINK and QMAKE_RUN_LIB (intended to be used in qmake.conf) to explicitly specify the command to execute the linker and the librarian, respectively. These variables are optional and have the following defaults:



4. Leaving QMAKE_LIBS_QT_ENTRY empty does not produce a qmake warning any more.

5. Added the new qmake variable QMAKE_RUN_IMPLIB used to produce the import library when the target is the dynamic link library. It is expected that this variable specifies the output import library name with the $(TARGET_IMPLIB) macro, which is defined by qmake as the project's target dll full basename with the .lib extension.

6. Added new qmake variables QMAKE_RUN_GENDEF and QMAKE_GENDEF_DEPS. They are intended to generate a .def file containing a list of DLL exports when the target is the dynamic link library (i.e. when TEMPLATE = lib and CONFIG contains dll) and the DEF_FILE variable is empty or not specified in the project file. In this case, the DEF_FILE macro is defined by qmake as the project's target full basename with the .def extension. QMAKE_RUN_GENDEF is the command to generate this DEF_FILE (its output must go to $(DEF_FILE)). QMAKE_GENDEF_DEPS is the list of dependencies for the DEF_FILE.

7. Empty OBJECTS_DIR and MOC_DIR qmake variables do not cause GNU Make to print warnings any more.

8. Fixed the dist makefile target: the generated zip didn't have the name (only extension).

9. Commands for custom (user defined) targets and for extra compilers (i.e. values of <my_target>.commands variables) are now splitted at ' ;; ' sequences (a double semicolon surrounded by single spaces) and placed to separate lines in the makefile. For example, the definition '<my_target>.command = c1 ;; c2' will apperar as follows:

<my_target>: <my_target_deps>

10. Added new qmake variables QMAKE_QUIET_CLEAN and QMAKE_IF_FILE_EXISTS. QMAKE_QUIET_CLEAN is similar QMAKE_CLEAN, but adds $(QMAKE_IF_FILE_EXISTS) to the beginning of each $(DEL_FILE) statement to delete a file only if it exists (to avoid system warnings).

11. Object files are no more forced to have the .o extension. The standard qmake QMAKE_EXT_OBJ variable is used instead (by default, on OS/2 it equals to .obj). QMAKE_EXT_CPP variable is regarded as well.

12. Library files now have the .lib extension (instead of .a), and the lib... prefix is no more prepended.

13. Added new QMAKE_CFLAGS_INCDIR, QMAKE_LFLAGS_LIBDIR, QMAKE_LFLAGS_LIB qmake variables to make it possible to customize the coorresponding flags (i.e., -I, -L and -l, as for GCC) in the .conf file.

14. Added new QMAKE_LIBS_QT_DLL and QMAKE_LIBS_QT_THREAD_DLL qmake variables to specify the list of libraries required when the application is linked against the DLL version of Qt, separately from the list of libraries required for linking against the static Qt library.

15. The QMAKESPECDIR variable is defined in the generated makefile and points to the directory where a qmake.conf file being used was read from.

16. Added new qmake variables DEF_FILE_TEMPLATE and DEF_FILE_MAP. When the target is the dynamic link library and DEF_FILE is not defined in the project file, these variables (when defined) go to the generated makefile w/o any changes. They are also appended (as GNU make variables) to the contents of the QMAKE_GENDEF_DEPS variable (see 6). DEF_FILE_TEMPLATE is intended to point to an existing template for a .def file. DEF_FILE_MAP should point to an existing file used to store ordinals assigned to exported symbols (to make assignments persistent from build to build). The backend itself doesn't use these variables, they are used only to pass the information from the project file to the generated makefile. It is the responsibility of the .conf file to implement the described functionality.

17. Objects defining custom targets got the .extradeps attribute. This attrubute allows to specify additional target dependencies that are not followed by commands. That is, if you have the following extra target definition: = somefile
my_target.depends = anotherfile
my_target.extradeps = export SOMETHING = something
my_target.commands = coolcmd > $$

you'll get in the generated makefile:

somefile : export SOMETHING = something
somefile : anotherfile
    coolcmd > somefile

Note that if you two or more additional dependencies each placed on a separate line, you can separate them using ' ;; ' (a double semicolon surrounded by single spaces) in the definition of the .extradeps attribute.

18. Besides the standard INCPATH make variable that defines a list of include directories for the C/C++ compiler (separated by spaces and usually prepended with a compiler switch), all generated makefiles contain the INCLUDEPATH make variable that defines the same list of directories but separated by semicolons (and therefore suitable for assigning to PATH-like environment variables).

19. Added internal qmake variables QMAKE_RUN_RC_RES and QMAKE_RUN_RC_EXE necessary to implement the support for RC_FILE and RES_FILE project variables. QMAKE_RUN_RC_RES defines a command line to generate a project .res file from an .rc file specified in RC_FILE. It should use $(RC_FILE) as a source and $(RES_FILE) as a target of the operation. This command is used only when the RC_FILE project variable is not empty. QMAKE_RUN_RC_EXE defines a command line to bind a .res file to the project executable. It should use $(RES_FILE) to specify the .res file to bind and $(TARGET) to specify the executable file name.

20. Added the internal qmake variable QMAKE_LIBDIR_QT_DEBUG. It defines where to place the Qt library when the debug version is being built, and also where to search for it when the project file of an application contains qt and debug keywords in the CONFIG statement.

21. The VERSION project variable is copied by qmake (as is) to the generated makefile. Note that its value does not affect the name of the generated DLL target anymore (for projects with the lib template and with the dll keyword in CONFIG), as opposed to other qmake backends. Appending a version number to the DLL name could implicitly lead to running out of the 8x3 naming limit that is still present in OS/2 for DLLs loaded by module name (the most common case). Instead, the VERSION macro can be used by qmake compiler specifications to embed the version to the generated DLL file itself (as the GCC specification does).

22. Added the internal qmake variable QMAKE_DEFINES_QT. It is intended to list a set of C/C++ defines to be used during compilation of C/C++ sources when either qt, qtinc or build_qt is present in the CONFIG statement. Using this variable instead of DEFINES keeps non-Qt projects free from Qt-only related defines (otherwise added to every Makefile generated by qmake from any project file).