3 files changed, 12 insertions, 3 deletions
diff --git a/src/drivers/Cocoa/Fl_Cocoa_Window_Driver.H b/src/drivers/Cocoa/Fl_Cocoa_Window_Driver.H
index 3003e3904..60569ff3f 100644
--- a/src/drivers/Cocoa/Fl_Cocoa_Window_Driver.H
+++ b/src/drivers/Cocoa/Fl_Cocoa_Window_Driver.H
@@ -2,7 +2,7 @@
 // Definition of Apple Cocoa window driver
 // for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010-2018 by Bill Spitzak and others.
+// Copyright 2010-2022 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
@@ -162,6 +162,8 @@ public:
   //icons
   virtual void icons(const Fl_RGB_Image *icons[], int count);
   NSImage *icon_image;
+  
+  virtual fl_uintptr_t os_id();
 };
 
 class Fl_Cocoa_Plugin : public Fl_Plugin {
diff --git a/src/drivers/X11/Fl_X11_Window_Driver.H b/src/drivers/X11/Fl_X11_Window_Driver.H
index 71370d13a..a8224e8e1 100644
--- a/src/drivers/X11/Fl_X11_Window_Driver.H
+++ b/src/drivers/X11/Fl_X11_Window_Driver.H
@@ -2,7 +2,7 @@
 // Definition of X11 window driver
 // for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010-2018 by Bill Spitzak and others.
+// Copyright 2010-2022 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
@@ -129,6 +129,7 @@ public:
   void set_icons(); // driver-internal support function
   virtual void capture_titlebar_and_borders(Fl_RGB_Image*& top, Fl_RGB_Image*& left, Fl_RGB_Image*& bottom, Fl_RGB_Image*& right);
   virtual int scroll(int src_x, int src_y, int src_w, int src_h, int dest_x, int dest_y, void (*draw_area)(void*, int,int,int,int), void* data);
+  virtual fl_uintptr_t os_id();
 };
 
 
diff --git a/src/drivers/X11/Fl_X11_Window_Driver.cxx b/src/drivers/X11/Fl_X11_Window_Driver.cxx
index a91dadec3..8aad279ac 100644
--- a/src/drivers/X11/Fl_X11_Window_Driver.cxx
+++ b/src/drivers/X11/Fl_X11_Window_Driver.cxx
@@ -1,7 +1,7 @@
 //
 // Definition of X11 window driver.
 //
-// Copyright 1998-2020 by Bill Spitzak and others.
+// Copyright 1998-2022 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
@@ -518,4 +518,10 @@ int Fl_X11_Window_Driver::screen_num() {
   }
   return screen_num_ >= 0 ? screen_num_ : 0;
 }
+
+
+fl_uintptr_t Fl_X11_Window_Driver::os_id() {
+  return fl_xid(pWindow);
+}
+
 #endif // USE_XFT