[Development] qpa api - current status

[Girish Ramakrishnan]

Hi,
Here's the current status of the proposed plan of action for QPA api.

1. We drop _qpa completely. So, it would become qplatformbackingstore.h
Status: Done

2. We teach syncqt that qplatform* is special and we move them all to
a special qpa/ directory. So, instead of #include
<QtGui/private/qplatformbackingstore.h>, it will be #include
<QtGui/qpa/qplatformbackingstore.h>
Status: Done

3. We teach syncqt to create <QtGui/QPA> or #include <QPA> headers. (I
think we need the latter since qpa headers are not restricted to gui)
Status: I haven't created the master headers. I don't think it's
important (will be good to have though).

4. We teach the world that qpa is not meant for apps.
Status: Doc team task ;) But all qpa classes are now marked with \group qpa

5. Add a more benign header pointing out the fact that these files are
qpa files.
Status: Done. qpa headers files don't have the "we mean it" header
anymore. Please use the new header for qpa headers which explicitly
says using api there may result in code breakage in the future.

6. Rename the handle() to platformXXX() since it's easy to educate
that anything that has platform in it is out of reach of app
developers.
Status: In progress, I am atm, marking handle() as obsolete and as an
alias to platformXXX().

The only remaining _qpa.h files are (they don't follow qplatform* convention):
1. qgenericplugin_qpa.h. AFAICT, this doesn't have to do with QPA at
all. So, we can either make it public or private.
2. qwindowsysteminterface_qpa.h. This is a little tricky. We have
qtestlib using it at this point because this is the way to send events
to Qt. The API looks OK, can we make this public?

Thanks,
Girish