Generate FL/fl_config.h rather than FL/abi-version.h

... as discussed in fltk.coredev in thread "RFC: introduce public
config header <FL/fl_config.h>", see:
https://groups.google.com/g/fltkcoredev/c/xLCs1AIXMVo/m/MHZpQggzAQAJ

- Rename abi-version.h to fl_config.h, rename input files,
  update dependencies, .gitignore, CMake, configure and Makefiles.

- Include Cairo options in FL/fl_config.h

- Rename FLTK_USE_CAIRO to FLTK_HAVE_CAIROEXT for consistency.

- Include <FL/fl_config.h> in config.h and wherever necessary,
  fix include order (move FL/Fl.H to the top) and more.

- Move USE_X11 to fl_config.h and rename to FLTK_USE_X11

- Do not include <config.h> in Cairo demo program which is no
  longer required in Cairo programs since FLTK 1.4.0

.gitignore

@@ -42,7 +42,7 @@ etc/FLTKConfig.cmake
 /TAGS
 
 # /FL
-/FL/abi-version.h
+/FL/fl_config.h
 /FL/Makefile
 /FL/*.bck
 

CMake/android.cmake

@@ -31,8 +31,8 @@ configure_file(
 
 # create a custom abi file for this setup
 configure_file(
-  "${CMAKE_CURRENT_SOURCE_DIR}/abi-version.cmake.in"
-  "${CMAKE_CURRENT_BINARY_DIR}/AndroidStudio/FL/abi-version.h"
+  "${CMAKE_CURRENT_SOURCE_DIR}/fl_config.cmake.in"
+  "${CMAKE_CURRENT_BINARY_DIR}/AndroidStudio/FL/fl_config.h"
   @ONLY
 )
 

CMake/fl_create_example.cmake

@@ -116,6 +116,11 @@ macro (CREATE_EXAMPLE NAME SOURCES LIBRARIES)
   set_target_properties   (${TARGET_NAME} PROPERTIES OUTPUT_NAME ${NAME})
   target_link_libraries   (${TARGET_NAME} ${LIBRARIES})
 
+  # we must link all programs with fltk_cairo if option CAIROEXT is enabled
+  if (FLTK_HAVE_CAIROEXT)
+    target_link_libraries (${TARGET_NAME} fltk_cairo cairo)
+  endif ()
+
   if (FLTK_HAVE_CAIRO)
     fl_target_link_directories (${TARGET_NAME} PRIVATE "${PKG_CAIRO_LIBRARY_DIRS}")
   endif ()

CMake/install.cmake

@@ -34,7 +34,7 @@ install (DIRECTORY
   DESTINATION ${FLTK_INCLUDEDIR} USE_SOURCE_PERMISSIONS
   FILES_MATCHING
     PATTERN "*.[hH]"
-    PATTERN "abi-version.h" EXCLUDE
+    PATTERN "fl_config.h" EXCLUDE
 )
 
 install (DIRECTORY

CMake/options.cmake

@@ -76,7 +76,7 @@ set (PATH_TO_XLIBS)
 if ((NOT APPLE OR OPTION_APPLE_X11) AND NOT WIN32)
   include (FindX11)
   if (X11_FOUND)
-    set (USE_X11 1)
+    set (FLTK_USE_X11 1)
     list (APPEND FLTK_LDLIBS -lX11)
     if (X11_Xext_FOUND)
       list (APPEND FLTK_LDLIBS -lXext)
@@ -164,7 +164,7 @@ option (OPTION_CAIROEXT
 )
 
 set (FLTK_HAVE_CAIRO 0)
-set (FLTK_USE_CAIRO 0)
+set (FLTK_HAVE_CAIROEXT 0)
 
 if (OPTION_CAIRO OR OPTION_CAIROEXT)
   pkg_search_module (PKG_CAIRO cairo)
@@ -174,7 +174,7 @@ if (OPTION_CAIRO OR OPTION_CAIROEXT)
   if (PKG_CAIRO_FOUND)
     set (FLTK_HAVE_CAIRO 1)
     if (OPTION_CAIROEXT)
-      set (FLTK_USE_CAIRO 1)
+      set (FLTK_HAVE_CAIROEXT 1)
     endif (OPTION_CAIROEXT)
     add_subdirectory (cairo)
 

CMakeLists.txt

@@ -142,8 +142,8 @@ include (CMake/variables.cmake)
 include (CMake/export.cmake)
 
 configure_file (
-  ${CMAKE_CURRENT_SOURCE_DIR}/abi-version.cmake.in
-  ${CMAKE_CURRENT_BINARY_DIR}/FL/abi-version.h
+  ${CMAKE_CURRENT_SOURCE_DIR}/fl_config.cmake.in
+  ${CMAKE_CURRENT_BINARY_DIR}/FL/fl_config.h
   @ONLY
 )
 

FL/Enumerations.H

@@ -24,13 +24,13 @@
 /*
  ******************************************************************************
  * FL_ABI_VERSION is defined by configure or CMake since FLTK 1.3.4.
- * It is written to FL/abi-version.h and #included here.
+ * It is written to FL/fl_config.h and #included here.
  ******************************************************************************
  * For more informations on FL_ABI_VERSION see README.abi-version.txt.
  ******************************************************************************
  */
 
-#include <FL/abi-version.h>
+#include <FL/fl_config.h>
 
 #  include "Fl_Export.H"
 #  include "fl_types.h"

FL/Fl.H

@@ -21,6 +21,7 @@
 #ifndef Fl_H
 #  define Fl_H
 
+#include <FL/fl_config.h> // build configuration
 #include <FL/Fl_Export.H>
 #include <FL/platform_types.h> // for FL_SOCKET
 #include <FL/fl_casts.H>       // experimental

FL/Fl_Cairo.H

@@ -1,7 +1,7 @@
 //
 // Main header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2016 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -20,6 +20,9 @@
 
 #ifndef FL_CAIRO_H
 # define FL_CAIRO_H
+
+# include <FL/fl_config.h> // build configuration
+
 # ifdef FLTK_HAVE_CAIRO
 
 // Cairo is currently supported for the following platforms:
@@ -39,7 +42,9 @@
    A private internal & unique corresponding object is created to
    permit cairo context state handling while keeping it opaque.
    For internal use only.
-   \note Only available when configure has the --enable-cairo option
+   \note Only available when configure has the --enable-cairo or
+        --enable-cairoext option or one or both of the CMake options
+        OPTION_CAIRO or OPTION_CAIROEXT is set (ON)
 */
 class FL_EXPORT Fl_Cairo_State {
 public:

FL/Fl_Cairo_Window.H

@@ -1,7 +1,7 @@
 //
-// Main header file for the Fast Light Tool Kit (FLTK).
+// Cairo Window header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2018 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -20,6 +20,9 @@
 
 #ifndef FL_CAIRO_WINDOW_H
 # define FL_CAIRO_WINDOW_H
+
+#include <FL/fl_config.h>
+
 # ifdef FLTK_HAVE_CAIRO
 
 // Cairo is currently supported for the following platforms:

FL/platform.H

@@ -1,7 +1,7 @@
 //
 // Platform header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2020 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -28,6 +28,7 @@
 #if !defined(FL_PLATFORM_H) && !defined(FL_DOXYGEN)
 #  define FL_PLATFORM_H
 
+#   include <FL/fl_config.h>
 #   include <FL/Fl_Export.H>
 #   include <FL/platform_types.h>
 #   include <FL/fl_types.h> // for uchar
@@ -42,9 +43,6 @@ class Fl_Window;
 #  else // X11
 #   include <FL/fl_types.h>
 #   include <FL/Enumerations.H>
-#    if !defined(USE_X11)
-#      define USE_X11 1
-#    endif
 #    if defined(_ABIN32) || defined(_ABI64) // fix for broken SGI Irix X .h files
 #      pragma set woff 3322
 #    endif
@@ -125,7 +123,7 @@ public:
   // static variables, static functions and member functions
   static Fl_X* first;
   static Fl_X* i(const Fl_Window* w) {return (Fl_X*)w->i;}
-#  if defined(USE_X11) // for backward compatibility
+#  if defined(FLTK_USE_X11) // for backward compatibility
   static void make_xid(Fl_Window*, XVisualInfo* =fl_visual, Colormap=fl_colormap);
   static Fl_X* set_xid(Fl_Window*, Window);
 #  endif

Makefile

@@ -68,7 +68,7 @@ distclean: clean
 	$(RM) fltk-config fltk.list makeinclude
 	$(RM) fltk.spec
 	$(RM) FL/Makefile
-	$(RM) FL/abi-version.h
+	$(RM) FL/fl_config.h
 	$(RM) documentation/*.$(CAT1EXT)
 	$(RM) documentation/*.$(CAT3EXT)
 	$(RM) documentation/*.$(CAT6EXT)

README.Cairo.txt

@@ -83,36 +83,6 @@ For more details, please have a look to the doxygen documentation,
 in the Modules section.
 
 
- Future considerations
------------------------
-
-From Bill:
-First there is the FLTK_HAVE_CAIRO configuration option. This indicates that
-any Cairo calls are available. In this case you get something like this:
-
-// static variable holding the last Cairo context FLTK set:
-cairo_t* Fl::cr;
-
-// Make cr draw in this window. This hides the ugly platform-dependent
-// part of getting Cairo going:
-void Fl::cairo_make_current(Fl_Window*)
-
-*** POST 1.3 potential Cairo use:
-// Set cr to something you made yourself. This lets you reuse functions
-// that use cr, and also tells FLTK that cr is not one of its own and
-// thus cannot be destroyed or reused for a different window:
-void Fl::cairo_make_current(cairo_t*)
-
-Second there is the FLTK_USE_CAIRO configuration option. This means that all
-drawing is done using Cairo. In this case when a widget draw() method is
-called, it is exactly as though cairo_make_current(window) has been done.
-***
-
-Note that it should be possible to compile so FLTK_HAVE_CAIRO works even
-if FLTK_USE_CAIRO does not, and so that turning on FLTK_USE_CAIRO does not
-break any programs written for FLTK_HAVE_CAIRO.
-
-
  PLATFORM SPECIFIC NOTES
 =========================
 

README.Windows.txt

@@ -2,6 +2,15 @@
 ------------------------------------------------------------
 
 
+
+
+––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
+***   CAUTION: This file is outdated. This needs a major rework!   ***
+––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
+
+
+
+
  CONTENTS
 ==========
 
@@ -413,10 +422,9 @@ without adding link and include paths to the solution.
 
   copy the entire FL directory into the include path
 
-  add all files from ide\VisualC2008\FL to the FL directory copied above
-    (this is currently only one file: abi-version.h)
+  add <build_dir>/FL/fl_config.h
 
-  copy all .lib files from the fltk lib directory to the VC lib directory
+  copy all .lib files from the fltk build directory to the VC lib directory
 
   copy fluid.exe in the fluid directory to the bin directory
 

README.abi-version.txt

@@ -40,7 +40,7 @@ and '1' is the major version number.
 The default ABI version for all FLTK 1.4.x versions is 10400 (the binary
 version of FLTK 1.4.0), but you can configure another version, e.g.
 10401 for FLTK 1.4.1 to enable the ABI features of FLTK 1.4.1 and all
-previous versions. See CHANGES file.
+previous versions. See CHANGES.txt file.
 
 
 Depending on how you build FLTK, there are two different ways to configure
@@ -57,7 +57,7 @@ the version number.
         ./configure --with-abiversion=10401
         make
 
-    This will generate FL/abi-version.h and build FLTK as usual.
+    This will generate FL/fl_config.h and build FLTK as usual.
 
     Note: you should always make sure that you compile everything from
     scratch if you change the ABI version or any other configuration
@@ -110,7 +110,7 @@ the version number.
 General note on CMake:
 ----------------------
 
-    CMake generates FL/abi-version.h in the build tree. You may run
+    CMake generates FL/fl_config.h in the build tree. You may run
     'make install' to install the FLTK library including all headers in
     the chosen installation directory, although this is not necessary.
 

cairo/Fl_Cairo.cxx

@@ -24,11 +24,11 @@
 // Cairo is currently supported for the following platforms:
 // Win32, Apple Quartz, X11
 
-#if defined(USE_X11) // X11
+#if defined(FLTK_USE_X11)         // X11
 #  include <cairo-xlib.h>
-#elif defined(_WIN32)
+#elif defined(_WIN32)             // Windows
 #  include <cairo-win32.h>
-#elif defined(__APPLE_QUARTZ__) // PORTME: Cairo Support
+#elif defined(__APPLE_QUARTZ__)   // macOS
 #  include <cairo-quartz.h>
 #else
 #  error Cairo is not supported on this platform.
@@ -43,7 +43,7 @@ Fl_Cairo_State Fl::cairo_state_;        ///< contains all necessary info for cur
 // Fl_Cairo_State class impl
 
 void  Fl_Cairo_State::autolink(bool b)  {
-#ifdef FLTK_USE_CAIRO
+#ifdef FLTK_HAVE_CAIROEXT
   autolink_ = b;
 #else
   Fl::fatal("In Fl::autolink(bool) : Cairo autolink() feature is only "
@@ -86,7 +86,7 @@ cairo_t * Fl::cairo_make_current(Fl_Window* wi) {
 #ifndef __APPLE__
   float scale = Fl::screen_scale(wi->screen_num()); // get the screen scaling factor
 #endif
-#if defined(USE_X11)
+#if defined(FLTK_USE_X11)
   cairo_ctxt = Fl::cairo_make_current(0, wi->w() * scale, wi->h() * scale);
 #else
   // on macOS, scaling is done before by Fl_Window::make_current(), on Windows, the size is not used
@@ -105,7 +105,7 @@ cairo_t * Fl::cairo_make_current(Fl_Window* wi) {
  */
 
 static cairo_surface_t * cairo_create_surface(void * gc, int W, int H) {
-# if defined(USE_X11)
+# if defined(FLTK_USE_X11)
     return cairo_xlib_surface_create(fl_display, fl_window, fl_visual->visual, W, H);
 # elif   defined(_WIN32)
     return cairo_win32_surface_create((HDC) gc);
@@ -123,7 +123,7 @@ static cairo_surface_t * cairo_create_surface(void * gc, int W, int H) {
 */
 cairo_t * Fl::cairo_make_current(void *gc) {
     int W=0,H=0;
-#if defined(USE_X11)
+#if defined(FLTK_USE_X11)
   // FIXME X11 get W,H
   // gc will be the window handle here
   // # warning FIXME get W,H for cairo_make_current(void*)

cairo/makedepend

@@ -1,12 +1,12 @@
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 
 Fl_Cairo.o: ../config.h
-Fl_Cairo.o: ../FL/abi-version.h
 Fl_Cairo.o: ../FL/Enumerations.H
 Fl_Cairo.o: ../FL/Fl.H
 Fl_Cairo.o: ../FL/Fl_Bitmap.H
 Fl_Cairo.o: ../FL/Fl_Cairo.H
 Fl_Cairo.o: ../FL/fl_casts.H
+Fl_Cairo.o: ../FL/fl_config.h
 Fl_Cairo.o: ../FL/Fl_Export.H
 Fl_Cairo.o: ../FL/Fl_Group.H
 Fl_Cairo.o: ../FL/Fl_Image.H