[Qt-interest] How does qfontdatabase_qws.cpp access private data from qfontdatabase.h?

[Andreas Pakulat]

On 09.07.09 11:38:45, Linda Maria wrote:
> Hi
> 
> I thought I knew how to read C++ code, but obviously I was wrong. I cannot
> figure out how private data from qfontdatabase.cpp can be accessed from
> qfontdatabase.h. For example:
> 
> 
> QFontDatabasePrivate is delclared and partly implemented in
> qfontdatabase.cpp and only forward declared in qfontdatabase.h. Then,
> qfontdatabase_qws.cpp starts accessing the QFontDatabasePrivate
> implementation. How is this done?
> 
> It would be nice if Qt used more of pure C++ code rather than showing off
> with macro definitions.

There is no macro magic done here, no idea where you get that from.
qfontdatabase_x11.cpp (and presumably all others) use a simple privateDb()
function to get access to the FondDataBasePrivate instance.

And that works without forward declaration because the platform-specific
cpp files are #include'ed into qfontdatabase.cpp.

Andreas

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