Hello,
It took me a little more time than expected, but here it is,
the new, clean, and extensible Theme framework !
What's new since my previous posts:
+ The code is in the CVS archive, so take the time to read at least
the documentation in the file "hthemes.h" (the main one), and look
at the modified motif.cc, next.cc, windows.cc and platinum.cc, to
see how it is easy now to add a new theme :)
qwidget.h and qapplication.h have been modified in some places too.
Other minor changes affected many files (the themeable widgets).
+ Everything compiles with egcs-1.1 (2.91.57) or with the latest
snapshot I tried (2.92.16).
+ The 'coolos' app has new labels for its buttons, and are working
("Motif", "NeXT", ... try them :) Hum, I said it works, but from an
optimistic point of view. The event handling for button presses
seems pretty slow. I don't think it has anything to do with my
Themes implementation: when you drag another window above the coolos
window, you can watch the Expose -> paint () sequences going fairly
quick.
Also, the colors in the Motif themes seems messed up.
+ About namespaces.
I've put 2 new macros in hconfig.h:
BEGIN_NAMESPACE(x) and END_NAMESPACE(x).
So you can use the 'x' namespace if your compiler support it. Since
the END_NAMESPACE(x) also does an "using namespace x", all symbols
of that namespace are visible in the global namespace (that is, the
x:: qualifier is not mandatory except for resolving conflicts).
If the compiler doesn't support namespace, then all is defined in
the global namespace, and the apparent behaviour is the same.
This is a temporary solution until we require full namespace support .
Currently, I've defined the Harmony namespace, and each Theme has
its own namespace, inside the Harmony namespace (that is,
Harmony::Motif, Harmony::NeXT, etc.)
It would also be good to put all the Qt-compatibility stuff in a
Qt namespace (if the two letters "Qt" are not trademarked :)
- (Some grins) About * and &
I have applied many trivial changes from * to & in the theme code.
Why? Because all the usages of, say, QPainter *p, where
unchecked. That is, we already assumed that the p pointer is always
valid. That's exactly where the references are useful, because the
compiler can check that this assumption is respected throughout the
code.
There are various places where Qt compatibility impose the choice of
* instead of &, but for Harmony internals at least we should be
cleaner.
- The QWidget needs to be reworked a bit:
As far as I understand the idea is to delay window creation until
the window id is really needed.
So far so good, but this should be done carefully. To take an example,
the setBackgroundPixmap doesn't work if the window is not currently
visible.
Another remark, when you have such complex design in mind, it should
be documented a bit, the way I've done it in the "hthemes.h" file. I
think that rudimentary documentation about the overall layout is
sometimes more useful than a detailed description of the parameters
of the methods (of course, in an ideal situation both should be
available :).
+ Future work on themes
I also integrated the Arrow drawing functions in the theme
framework, for not having theme-dependent code outside of the theme
support file.
A drawing object should also be responsible for allocating the
window of the widget, so that themes using shaped window could be
implemented.
What's still missing is the dynamic loading of new Themes. However,
that should be easier than ever, now.
+ Misc. other stuff done:
- put a little more structure in src/Makefile.am.
- done small hacks on magna to make it compile better.
- some documentation added in qwidget & qapplication
(in particular, created pages with ^L. For the interested
ones, I have a particularly useful (X)Emacs-lisp 'page-menu'
function :)
- random hacks everywhere (and too many 'cout', 'cerr' ...)
My next work will be the integration of Relay++ with Harmony.
-- Christian
