Unfortunately (sigh), the KDE Wayland compositor does not seem to support
correctly, that is, as described by the Wayland protocol, popup windows
that are taller than the display : there is no means to make it draw such popup
so that part of it is above the screen top, whereas the 3 other tested compositors
(Mutter, Weston, Sway) don't have this problem.
This commit implements a new approach to draw tall menu windows, and uses
it only with the KDE compositor : instead of asking the compositor to slide the
menu window up, the menu window remains at a fixed position and the graphics
inside the window is slided up.
This requires to add a member variable, int offset_y, to class menuwindow, that
gets used only for the Wayland platform and that contains the vertical offset by which
graphics to the menu window is moved, expressed in FLTK units. An accessor
to the address of this member variable is added to class Fl_Window_Driver.
Pure platform specific files like 'src/*_win32.cxx' are excluded from
doxygen processing and don't need doxygen specific guard macros.
Document this fact prominently at the beginning of each file.
Fix exclude patterns and remove duplicates from Doxyfile.in.
Currently 'fluid' comes as up to three different targets, compiled
from the same source files (fluid, fluid-cmd, and fluid-shared).
The object library is built from all source files except fluid.cxx
and finally all 'fluid*' programs are linked with this library.
This avoids compiling the same source files multiple times.
... if _WIN32_IE is not defined. Older MinGW versions would
otherwise not define SHGFP_TYPE_CURRENT which is needed since
commit 5a4e7caa54 that fixes
GitHub issue #710: "Fl_Preferences not stored on Windows 10".
This commit is based on Ian's work as discussed in fltk.coredev, thread
"fltk-1.4 build error in Fl_WinAPI_System_Driver.cxx with 32-bit mingw"
on Apr 20, 2023.
This initialization would prevent changing the 'selectbox' type
automatically when changing the FLTK scheme.
It would also require to set the FLTK scheme *before* the constructor
of Fl_Tree_Prefs (i.e. Fl_Tree) is executed which is unexpected and
error prone for user code.
It is up to the user program to set another boxtype after the
constructor if needed.
