Add pen/stylus/tablet API and driver for macOS (#1326)

* define the pen/tablet support API
* add pen event handler stub as a fallback
* add pen device test "penpal".
* Add macOS pen/stylus/tablet driver.
* Add Oxygen documentation.

1 files changed, 1 insertions, 1 deletions

diff --git a/FL/Fl.H b/FL/Fl.H
index 60bf6b005..358dde432 100644
--- a/FL/Fl.H
+++ b/FL/Fl.H
@@ -28,6 +28,7 @@
 #include <FL/core/function_types.H>   // widget callbacks and services
 #include <FL/core/events.H>           // global event handling
 #include <FL/core/options.H>          // system and application setting
+#include <FL/core/pen_events.H>       // pen and tablet events
 #include <FL/Fl_Widget_Tracker.H>     // historically included here
 
 #ifdef FLTK_HAVE_CAIRO
@@ -109,7 +110,6 @@ FL_EXPORT extern bool idle();
 FL_EXPORT extern const char* scheme_;
 FL_EXPORT extern Fl_Image* scheme_bg_;
 
-//FL_EXPORT extern int e_original_keysym; // late addition
 FL_EXPORT extern int scrollbar_size_;
 FL_EXPORT extern int menu_linespacing_; // STR #2927
 #endif