CMake: build shared libs with OPTION_CAIROEXT (issue #250)

- remove separate libfltk_cairo to avoid cyclic dependencies, but
- keep a dummy libfltk_cairo in 1.4.0 for backwards compatibility
- move cairo/Fl_Cairo.cxx to src/Fl_Cairo.cxx
- add preliminary Cairo support for Visual Studio (MSVC)

Static linking is not affected by this change, but users building
with hand-made Makefiles will have to remove libfltk_cairo starting
with FLTK 1.4.0. The dummy library can be linked for backwards
compatibility but it will be removed later (in 1.4.x or 1.5.0).

The shared FLTK library libfltk.{so|dylib|dll|..} depends on libcairo
if and only if FLTK is built with one of the Cairo options. This has
always been the case for OPTION_CAIROEXT but is now also true if only
OPTION_CAIRO is selected, i.e. FLTK programs linked with a Cairo
enabled shared FLTK library will also be linked with libcairo. The same
is true for configure options --enable-cairo and --enable-cairoext,
respectively.

Preliminary Cairo support for MSVC now detects a Cairo installation
using the CMake variable FLTK_CAIRO_DIR which must be set by the user.
Note that this feature is temporary and may be changed in the future
for a better and more comfortable version.

1 files changed, 1 insertions, 1 deletions

diff --git a/test/Makefile b/test/Makefile
index 2a5ea0980..96f8d36ae 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -682,5 +682,5 @@ shape$(EXEEXT): shape.o
 
 cairo_test$(EXEEXT): cairo_test.o
 	echo Linking $@...
-	$(CXX) $(ARCHFLAGS) $(CXXFLAGS) $(CAIROFLAGS) $(LDFLAGS) -o $@ cairo_test.o $(LINKFLTK) $(LINKFLTKCAIRO) $(GLDLIBS)
+	$(CXX) $(ARCHFLAGS) $(CXXFLAGS) $(CAIROFLAGS) $(LDFLAGS) -o $@ cairo_test.o $(LINKFLTK) $(CAIROLIBS) $(GLDLIBS)
 	$(OSX_ONLY) ../fltk-config --post $@