CMake: Deprecate FLTK_USE_FILE (UseFLTK.cmake)

Cherry-pick the essential changes from FLTK 1.3 since this change
had not been ported to 1.4 yet.

To do: my current plan is to consolidate 1.3 and 1.4 CMake files
as far as possible (with the exceptions of source files, obviously)
and to redesign / refactor CMake files later in this process or
maybe only for 1.4 if it turns out to be too much to backport.

3 files changed, 49 insertions, 29 deletions

diff --git a/CMake/FLTKConfig.cmake.in b/CMake/FLTKConfig.cmake.in
index baa25a6d2..2fafb4b7a 100644
--- a/CMake/FLTKConfig.cmake.in
+++ b/CMake/FLTKConfig.cmake.in
@@ -1,16 +1,42 @@
 #
 # FLTKConfig.cmake - FLTK CMake configuration file for external projects.
 #
-# This file is generated by CMake and used to load FLTK's settings for an external project.
-# It defines the following variables
-#  FLTK_INCLUDE_DIRS - FLTK include directories
-#  FLTK_LIBRARIES    - list of FLTK libraries built
-#  FLTK_FLUID_EXECUTABLE needed by fltk_wrap_ui()
-#  FLTK_USE_FILE - sets things up to use FLTK
+# This file is generated by CMake and used to load FLTK's settings for
+# an external project.
+#
+# It defines the following variables:
+#
+#  FLTK_INCLUDE_DIRS     - FLTK include directories
+#  FLTK_LIBRARIES        - list of FLTK libraries built (not yet implemented)
+#  FLTK_FLUID_EXECUTABLE - needed by the function FLTK_RUN_FLUID
+#                          (or the deprecated fltk_wrap_ui() CMake command)
+#
+#  FLTK_USE_FILE - previously used to set things up to use FLTK
+#                - deprecated since FLTK 1.3.4
+#                - will be removed in FLTK 1.4.0 or later
+
+set (FLTK_VERSION @FLTK_VERSION_FULL@)
 
-set(FLTK_VERSION @FLTK_VERSION_FULL@)
+include (${CMAKE_CURRENT_LIST_DIR}/FLTK-Targets.cmake)
 
-include(${CMAKE_CURRENT_LIST_DIR}/FLTK-Targets.cmake)
+set (FLTK_INCLUDE_DIRS "@INCLUDE_DIRS@")
+set (FLTK_USE_FILE ${CMAKE_CURRENT_LIST_DIR}/UseFLTK.cmake)
 
-set(FLTK_INCLUDE_DIRS "@INCLUDE_DIRS@")
-set(FLTK_USE_FILE ${CMAKE_CURRENT_LIST_DIR}/UseFLTK.cmake)
+if (CMAKE_CROSSCOMPILING)
+  find_file(FLUID_PATH
+    NAMES fluid fluid.exe
+    PATHS ENV PATH
+    NO_CMAKE_FIND_ROOT_PATH
+  )
+  add_executable(fluid IMPORTED)
+  set_target_properties(fluid
+    PROPERTIES IMPORTED_LOCATION ${FLUID_PATH}
+  )
+  set (FLTK_FLUID_EXECUTABLE ${FLUID_PATH})
+else ()
+  set (FLTK_FLUID_EXECUTABLE fluid)
+endif (CMAKE_CROSSCOMPILING)
+
+#
+# End of file
+#
diff --git a/CMake/UseFLTK.cmake.in b/CMake/UseFLTK.cmake.in
index ed26f8815..20ecb85d6 100644
--- a/CMake/UseFLTK.cmake.in
+++ b/CMake/UseFLTK.cmake.in
@@ -1,25 +1,19 @@
 #
 # UseFLTK.CMake - FLTK CMake environment configuration file for external projects.
 #
-# This file is generated by CMake and used to set FLTK's environment for an external project.
+# This file is deprecated and will be removed in FLTK 1.4.0 or later
 #
 # automatically generated - do not edit
+#
 
-include_directories("@INCLUDE_DIRS@")
+include_directories("@FLTK_INCLUDE_DIRS@")
 
-if(CMAKE_CROSSCOMPILING)
-   find_file(FLUID_PATH
-      NAMES fluid fluid.exe
-      PATHS ENV PATH
-      NO_CMAKE_FIND_ROOT_PATH
-   )
-   add_executable(fluid IMPORTED)
-   set_target_properties(fluid
-      PROPERTIES IMPORTED_LOCATION ${FLUID_PATH}
-   )
-   set(FLTK_FLUID_EXECUTABLE ${FLUID_PATH})
-else()
-   set(FLTK_FLUID_EXECUTABLE fluid)
-endif(CMAKE_CROSSCOMPILING)
+message(AUTHOR_WARNING
+" * Warning: UseFLTK.cmake is deprecated and will be removed in FLTK 1.4.0
+ * or later. Please use 'include_directories(\${FLTK_INCLUDE_DIRS})' or
+ * 'target_include_directories(<target> PUBLIC|PRIVATE \${FLTK_INCLUDE_DIRS})'
+ * instead of 'include(\${FLTK_USE_FILE})'.")
 
-set(FLTK_WRAP_UI TRUE)
+#
+# End of file
+#
diff --git a/README.CMake.txt b/README.CMake.txt
index 3c221ecb4..370e97e43 100644
--- a/README.CMake.txt
+++ b/README.CMake.txt
@@ -495,8 +495,8 @@ a Windows GUI app.  It is ignored on other platforms and should always be
 present with FLTK GUI programs for better portability.
 
 Note: the variable FLTK_USE_FILE used to include another file in
-previous FLTK versions was deprecated since FLTK 1.3.4 and was removed
-in FLTK 1.4.0.
+previous FLTK versions was deprecated since FLTK 1.3.4 and will be
+removed in FLTK 1.4.0 (this version) or later (maybe 1.4.1).
 
 
  3.1  Library Names