ccmake: Check for curses more robustly before enabling

Compute a default for `BUILD_CursesDialog` by building a small test
project that uses curses.  Disable `ccmake` by default if it fails,
and do not search for Curses as part of the main build.  This avoids
creating FindCurses cache entries when we are not considering ccmake.

If `BUILD_CursesDialog` is enabled (e.g. by the user) then warn if
curses cannot be found.

2 files changed, 40 insertions, 0 deletions

diff --git a/Source/Checks/Curses/CMakeLists.txt b/Source/Checks/Curses/CMakeLists.txt
new file mode 100644
index 0000000..17318a3
--- /dev/null
+++ b/Source/Checks/Curses/CMakeLists.txt
@@ -0,0 +1,25 @@
+cmake_minimum_required(VERSION 3.1)
+if(POLICY CMP0060)
+  cmake_policy(SET CMP0060 NEW)
+endif()
+project(CheckCurses C)
+
+set(CURSES_NEED_NCURSES TRUE)
+find_package(Curses)
+if(NOT CURSES_FOUND)
+  return()
+endif()
+include_directories(${CURSES_INCLUDE_DIRS})
+add_executable(CheckCurses CheckCurses.c)
+target_link_libraries(CheckCurses ${CURSES_LIBRARIES})
+
+foreach(h
+    CURSES_HAVE_CURSES_H
+    CURSES_HAVE_NCURSES_H
+    CURSES_HAVE_NCURSES_NCURSES_H
+    CURSES_HAVE_NCURSES_CURSES_H
+    )
+  if(${h})
+    target_compile_definitions(CheckCurses PRIVATE ${h})
+  endif()
+endforeach()
diff --git a/Source/Checks/Curses/CheckCurses.c b/Source/Checks/Curses/CheckCurses.c
new file mode 100644
index 0000000..857ae28
--- /dev/null
+++ b/Source/Checks/Curses/CheckCurses.c
@@ -0,0 +1,15 @@
+#if defined(CURSES_HAVE_NCURSES_H)
+#include <ncurses.h>
+#elif defined(CURSES_HAVE_NCURSES_NCURSES_H)
+#include <ncurses/ncurses.h>
+#elif defined(CURSES_HAVE_NCURSES_CURSES_H)
+#include <ncurses/curses.h>
+#else
+#include <curses.h>
+#endif
+
+int main()
+{
+  curses_version();
+  return 0;
+}