commit 2e6e0b9c36fbf92d0d551aca077580e7a57c266a
Author:     ManoloFLTK <41016272+ManoloFLTK@users.noreply.github.com>
AuthorDate: Thu Feb 3 07:03:26 2022 +0100
Commit:     ManoloFLTK <41016272+ManoloFLTK@users.noreply.github.com>
CommitDate: Thu Feb 3 07:03:44 2022 +0100

    Reorganize classes Fl_System_Driver and Fl_Screen_Driver
    
    These virtual members are moved from Fl_Screen_Driver to Fl_System_Driver
    - wait(double)
    - ready()
    
    These virtual members are moved from Fl_System_Driver to Fl_Screen_Driver
    - copy(const char *stuff, int len, int clipboard, const char *type)
    - void paste(Fl_Widget &widget, int clipboard, const char *type)
    - clipboard_contains(const char *type)
    - clipboard_notify_change()
    
    These members are moved from Fl_X11_Screen_Driver to Fl_X11_System_Driver
    - poll_or_select_with_delay(double time_to_wait)
    - poll_or_select()
    and are made virtual in preparation for the introduction of class
    Fl_Unix_System_Driver.

 src/Fl.cxx                                   | 16 ++++++++--------
 src/Fl_Screen_Driver.H                       | 10 ++++++++--
 src/Fl_System_Driver.H                       | 10 ++--------
 src/Fl_cocoa.mm                              | 10 +++++-----
 src/Fl_win32.cxx                             | 14 +++++++-------
 src/Fl_x.cxx                                 | 14 +++++++-------
 src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H   |  5 +++--
 src/drivers/Darwin/Fl_Darwin_System_Driver.H |  5 ++---
 src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.H | 10 ++++++++--
 src/drivers/WinAPI/Fl_WinAPI_System_Driver.H | 10 ++--------
 src/drivers/X11/Fl_X11_Screen_Driver.H       | 12 ++++++++----
 src/drivers/X11/Fl_X11_Screen_Driver.cxx     | 28 ----------------------------
 src/drivers/X11/Fl_X11_System_Driver.H       | 13 +++++--------
 src/drivers/X11/Fl_X11_System_Driver.cxx     | 27 +++++++++++++++++++++++++++
 14 files changed, 92 insertions(+), 92 deletions(-)

diff --git src/Fl.cxx src/Fl.cxx
index a37e1a1..28fc04c 100644
--- src/Fl.cxx
+++ src/Fl.cxx
@@ -389,7 +389,7 @@ void Fl::add_clipboard_notify(Fl_Clipboard_Notify_Handler h, void *data) {
 
   clip_notify_list = node;
 
-  Fl::system_driver()->clipboard_notify_change();
+  Fl::screen_driver()->clipboard_notify_change();
 }
 
 void Fl::remove_clipboard_notify(Fl_Clipboard_Notify_Handler h) {
@@ -402,7 +402,7 @@ void Fl::remove_clipboard_notify(Fl_Clipboard_Notify_Handler h) {
       *prev = node->next;
       delete node;
 
-      Fl::system_driver()->clipboard_notify_change();
+      Fl::screen_driver()->clipboard_notify_change();
 
       return;
     }
@@ -502,7 +502,7 @@ double Fl::wait(double time_to_wait) {
 
   // platform dependent part:
 
-  return screen_driver()->wait(time_to_wait);
+  return system_driver()->wait(time_to_wait);
 }
 
 #define FOREVER 1e20
@@ -589,7 +589,7 @@ int Fl::check() {
 */
 int Fl::ready()
 {
-  return screen_driver()->ready();
+  return system_driver()->ready();
 }
 
 int Fl::program_should_quit_ = 0;
@@ -1444,12 +1444,12 @@ void Fl::selection(Fl_Widget &owner, const char* text, int len) {
   \see Fl::paste(Fl_Widget &receiver, int clipboard, const char* type)
 */
 void Fl::paste(Fl_Widget &receiver) {
-  Fl::system_driver()->paste(receiver, 0, Fl::clipboard_plain_text);
+  Fl::screen_driver()->paste(receiver, 0, Fl::clipboard_plain_text);
 }
 
 void Fl::paste(Fl_Widget &receiver, int clipboard, const char *type)
 {
-  Fl::system_driver()->paste(receiver, clipboard, type);
+  Fl::screen_driver()->paste(receiver, clipboard, type);
 }
 
 ////////////////////////////////////////////////////////////////
@@ -1958,12 +1958,12 @@ const char * fl_filename_name(const char *name) {
 }
 
 void Fl::copy(const char *stuff, int len, int clipboard, const char *type) {
-  Fl::system_driver()->copy(stuff, len, clipboard, type);
+  Fl::screen_driver()->copy(stuff, len, clipboard, type);
 }
 
 int Fl::clipboard_contains(const char *type)
 {
-  return Fl::system_driver()->clipboard_contains(type);
+  return Fl::screen_driver()->clipboard_contains(type);
 }
 
 
diff --git src/Fl_Screen_Driver.H src/Fl_Screen_Driver.H
index fae5b0f..e7a64b5 100644
--- src/Fl_Screen_Driver.H
+++ src/Fl_Screen_Driver.H
@@ -105,8 +105,6 @@ public:
   virtual void beep(int) {}
   // --- global events
   virtual void flush() {}                                  // must override
-  virtual double wait(double) { return 0.0; } // must override
-  virtual int ready() { return 0; }                        // must override
   virtual void grab(Fl_Window *) {}
   // --- global colors
   /* the default implementation of parse_color() may be enough */
@@ -203,6 +201,14 @@ public:
   virtual void default_icons(const Fl_RGB_Image *icons[], int count);
   // this one is implemented in print_button.cxx
   static int print_or_copy_window(Fl_Window*, bool, int);
+  // implement to support copy-to-clipboard
+  virtual void copy(const char */*stuff*/, int /*len*/, int /*clipboard*/, const char */*type*/) {}
+  // implement to support paste-from-clipboard
+  virtual void paste(Fl_Widget &, int /*clipboard*/, const char */*type*/) {}
+  // implement to support paste-from-clipboard
+  virtual int clipboard_contains(const char */*type*/) {return 0;}
+  //  implement to support paste-from-clipboard
+  virtual void clipboard_notify_change() {}
 };
 
 #endif // !FL_SCREEN_DRIVER_H
diff --git src/Fl_System_Driver.H src/Fl_System_Driver.H
index 37b5486..e010212 100644
--- src/Fl_System_Driver.H
+++ src/Fl_System_Driver.H
@@ -225,14 +225,6 @@ public:
   static const char * const tree_close_xpm[]; // used by tree_closepixmap()
   // the default implementation of tree_connector_style() is in Fl_Tree_Prefs.cxx and can be enough
   virtual int tree_connector_style();
-  // implement to support copy-to-clipboard
-  virtual void copy(const char */*stuff*/, int /*len*/, int /*clipboard*/, const char */*type*/) {}
-  // implement to support paste-from-clipboard
-  virtual void paste(Fl_Widget &, int /*clipboard*/, const char */*type*/) {}
-  // implement to support paste-from-clipboard
-  virtual int clipboard_contains(const char */*type*/) {return 0;}
-  //  implement to support paste-from-clipboard
-  virtual void clipboard_notify_change() {}
   virtual void add_fd(int fd, int when, Fl_FD_Handler cb, void* = 0);
   virtual void add_fd(int fd, Fl_FD_Handler cb, void* = 0);
   virtual void remove_fd(int, int when);
@@ -249,6 +241,8 @@ public:
   virtual Fl_Sys_Menu_Bar_Driver *sys_menu_bar_driver() { return NULL; }
   virtual void lock_ring() {}
   virtual void unlock_ring() {}
+  virtual double wait(double) { return 0.0; } // must override
+  virtual int ready() { return 0; }                        // must override
 };
 
 #endif // FL_SYSTEM_DRIVER_H
diff --git src/Fl_cocoa.mm src/Fl_cocoa.mm
index d4a155a..1b86fd4 100644
--- src/Fl_cocoa.mm
+++ src/Fl_cocoa.mm
@@ -439,7 +439,7 @@ void Fl_Darwin_System_Driver::remove_fd(int n)
 /*
  * Check if there is actually a message pending
  */
-int Fl_Cocoa_Screen_Driver::ready()
+int Fl_Darwin_System_Driver::ready()
 
 {
   NSEvent *retval = [NSApp nextEventMatchingMask:NSAnyEventMask untilDate:[NSDate dateWithTimeIntervalSinceNow:0]
@@ -773,7 +773,7 @@ static int do_queued_events( double time = 0.0 )
   return got_events;
 }
 
-double Fl_Cocoa_Screen_Driver::wait(double time_to_wait)
+double Fl_Darwin_System_Driver::wait(double time_to_wait)
 {
   if (dropped_files_list) { // when the list of dropped files is not empty, open one and remove it from list
     drain_dropped_files_list();
@@ -3597,7 +3597,7 @@ static void resize_selection_buffer(int len, int clipboard) {
  * len: size of selected data
  * type: always "plain/text" for now
  */
-void Fl_Darwin_System_Driver::copy(const char *stuff, int len, int clipboard, const char *type) {
+void Fl_Cocoa_Screen_Driver::copy(const char *stuff, int len, int clipboard, const char *type) {
   if (!stuff || len<0) return;
   if (clipboard >= 2)
     clipboard = 1; // Only on X11 do multiple clipboards make sense.
@@ -3695,7 +3695,7 @@ static Fl_RGB_Image* get_image_from_clipboard(Fl_Widget *receiver)
 }
 
 // Call this when a "paste" operation happens:
-void Fl_Darwin_System_Driver::paste(Fl_Widget &receiver, int clipboard, const char *type) {
+void Fl_Cocoa_Screen_Driver::paste(Fl_Widget &receiver, int clipboard, const char *type) {
   if (type[0] == 0) type = Fl::clipboard_plain_text;
   if (clipboard) {
     Fl::e_clipboard_type = "";
@@ -3723,7 +3723,7 @@ void Fl_Darwin_System_Driver::paste(Fl_Widget &receiver, int clipboard, const ch
   receiver.handle(FL_PASTE);
 }
 
-int Fl_Darwin_System_Driver::clipboard_contains(const char *type) {
+int Fl_Cocoa_Screen_Driver::clipboard_contains(const char *type) {
   NSString *found = nil;
   if (strcmp(type, Fl::clipboard_plain_text) == 0) {
     found = [[NSPasteboard generalPasteboard] availableTypeFromArray:[NSArray arrayWithObjects:UTF8_pasteboard_type, @"public.utf16-plain-text", @"com.apple.traditional-mac-plain-text", nil]];
diff --git src/Fl_win32.cxx src/Fl_win32.cxx
index b57b81a..cb477d9 100644
--- src/Fl_win32.cxx
+++ src/Fl_win32.cxx
@@ -414,7 +414,7 @@ static void process_awake_handler_requests(void) {
 // It *should* return negative on error, 0 if nothing happens before
 // timeout, and >0 if any callbacks were done.  This version
 // always returns 1.
-double Fl_WinAPI_Screen_Driver::wait(double time_to_wait) {
+double Fl_WinAPI_System_Driver::wait(double time_to_wait) {
 
   int have_message = 0;
 
@@ -518,8 +518,8 @@ double Fl_WinAPI_Screen_Driver::wait(double time_to_wait) {
   return 1;
 }
 
-// just like Fl_WinAPI_Screen_Driver::wait(0.0) except no callbacks are done:
-int Fl_WinAPI_Screen_Driver::ready() {
+// just like Fl_WinAPI_System_Driver::wait(0.0) except no callbacks are done:
+int Fl_WinAPI_System_Driver::ready() {
   if (PeekMessage(&fl_msg, NULL, 0, 0, PM_NOREMOVE))
     return 1;
   if (!nfds)
@@ -764,7 +764,7 @@ void fl_update_clipboard(void) {
 }
 
 // call this when you create a selection:
-void Fl_WinAPI_System_Driver::copy(const char *stuff, int len, int clipboard, const char *type) {
+void Fl_WinAPI_Screen_Driver::copy(const char *stuff, int len, int clipboard, const char *type) {
   if (!stuff || len < 0)
     return;
   if (clipboard >= 2)
@@ -789,7 +789,7 @@ void Fl_WinAPI_System_Driver::copy(const char *stuff, int len, int clipboard, co
 }
 
 // Call this when a "paste" operation happens:
-void Fl_WinAPI_System_Driver::paste(Fl_Widget &receiver, int clipboard, const char *type) {
+void Fl_WinAPI_Screen_Driver::paste(Fl_Widget &receiver, int clipboard, const char *type) {
   if (!clipboard || (fl_i_own_selection[clipboard] && strcmp(type, Fl::clipboard_plain_text) == 0)) {
     // We already have it, do it quickly without window server.
     // Notice that the text is clobbered if set_selection is
@@ -940,7 +940,7 @@ void Fl_WinAPI_System_Driver::paste(Fl_Widget &receiver, int clipboard, const ch
   }
 }
 
-int Fl_WinAPI_System_Driver::clipboard_contains(const char *type) {
+int Fl_WinAPI_Screen_Driver::clipboard_contains(const char *type) {
   int retval = 0;
   if (!OpenClipboard(NULL))
     return 0;
@@ -1008,7 +1008,7 @@ void fl_clipboard_notify_retarget(HWND wnd) {
     fl_clipboard_notify_target(fl_xid(Fl::first_window()));
 }
 
-void Fl_WinAPI_System_Driver::clipboard_notify_change() {
+void Fl_WinAPI_Screen_Driver::clipboard_notify_change() {
   // untarget clipboard monitor if no handlers are registered
   if (clipboard_wnd != NULL && fl_clipboard_notify_empty()) {
     fl_clipboard_notify_untarget(clipboard_wnd);
diff --git src/Fl_x.cxx src/Fl_x.cxx
index ff48df4..abbc27a 100644
--- src/Fl_x.cxx
+++ src/Fl_x.cxx
@@ -235,7 +235,7 @@ void (*fl_unlock_function)() = nothing;
 // This is never called with time_to_wait < 0.0:
 // It should return negative on error, 0 if nothing happens before
 // timeout, and >0 if any callbacks were done.
-int Fl_X11_Screen_Driver::poll_or_select_with_delay(double time_to_wait) {
+int Fl_X11_System_Driver::poll_or_select_with_delay(double time_to_wait) {
 
   // OpenGL and other broken libraries call XEventsQueued
   // unnecessarily and thus cause the file descriptor to not be ready,
@@ -288,8 +288,8 @@ int Fl_X11_Screen_Driver::poll_or_select_with_delay(double time_to_wait) {
   return n;
 }
 
-// just like Fl_X11_Screen_Driver::poll_or_select_with_delay(0.0) except no callbacks are done:
-int Fl_X11_Screen_Driver::poll_or_select() {
+// just like Fl_X11_System_Driver::poll_or_select_with_delay(0.0) except no callbacks are done:
+int Fl_X11_System_Driver::poll_or_select() {
   if (XQLength(fl_display)) return 1;
   if (!nfds) return 0; // nothing to select or poll
 #  if USE_POLL
@@ -879,7 +879,7 @@ static Fl_RGB_Image *own_bmp_to_RGB(char *bmp) {
 }
 
 // Call this when a "paste" operation happens:
-void Fl_X11_System_Driver::paste(Fl_Widget &receiver, int clipboard, const char *type) {
+void Fl_X11_Screen_Driver::paste(Fl_Widget &receiver, int clipboard, const char *type) {
   if (fl_i_own_selection[clipboard]) {
     // We already have it, do it quickly without window server.
     if (type == Fl::clipboard_plain_text && fl_selection_type[clipboard] == type) {
@@ -908,7 +908,7 @@ void Fl_X11_System_Driver::paste(Fl_Widget &receiver, int clipboard, const char
                     fl_xid(Fl::first_window()), fl_event_time);
 }
 
-int Fl_X11_System_Driver::clipboard_contains(const char *type)
+int Fl_X11_Screen_Driver::clipboard_contains(const char *type)
 {
   if (fl_i_own_selection[1]) {
     return fl_selection_type[1] == type;
@@ -1007,7 +1007,7 @@ static int get_xwinprop(Window wnd, Atom prop, long max_length,
 ////////////////////////////////////////////////////////////////
 // Code for copying to clipboard and DnD out of the program:
 
-void Fl_X11_System_Driver::copy(const char *stuff, int len, int clipboard, const char *type) {
+void Fl_X11_Screen_Driver::copy(const char *stuff, int len, int clipboard, const char *type) {
   if (!stuff || len<0) return;
 
   if (clipboard >= 2) {
@@ -1182,7 +1182,7 @@ static void handle_clipboard_timestamp(int clipboard, Time time)
   fl_trigger_clipboard_notify(clipboard);
 }
 
-void Fl_X11_System_Driver::clipboard_notify_change() {
+void Fl_X11_Screen_Driver::clipboard_notify_change() {
   // Reset the timestamps if we've going idle so that you don't
   // get a bogus immediate trigger next time they're activated.
   if (fl_clipboard_notify_empty()) {
diff --git src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H
index 7dd6fc1..74e1a81 100644
--- src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H
+++ src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H
@@ -75,8 +75,6 @@ public:
   // --- audible output
   virtual void beep(int type);
   // --- global events
-  virtual double wait(double time_to_wait);
-  virtual int ready();
   virtual void grab(Fl_Window* win);
   // --- global colors
   virtual void get_system_colors();
@@ -99,6 +97,9 @@ public:
   virtual void scale(int /*nscreen*/, float f) { scale_ = f;}
   virtual Fl_RGB_Image *read_win_rectangle(int X, int Y, int w, int h, Fl_Window *win, bool may_capture_subwins, bool *did_capture_subwins);
   virtual void default_icons(const Fl_RGB_Image *icons[], int count);
+  virtual void copy(const char *stuff, int len, int clipboard, const char *type);
+  virtual void paste(Fl_Widget &receiver, int clipboard, const char *type);
+  virtual int clipboard_contains(const char *type);
 private:
   float scale_;
 };
diff --git src/drivers/Darwin/Fl_Darwin_System_Driver.H src/drivers/Darwin/Fl_Darwin_System_Driver.H
index 8a2e3b7..19b4dab 100644
--- src/drivers/Darwin/Fl_Darwin_System_Driver.H
+++ src/drivers/Darwin/Fl_Darwin_System_Driver.H
@@ -73,9 +73,6 @@ public:
   static const char * const tree_close_xpm_darwin[]; // used by tree_closepixmap()
   virtual int tree_connector_style();
   virtual const char *filename_name(const char *buf);
-  virtual void copy(const char *stuff, int len, int clipboard, const char *type);
-  virtual void paste(Fl_Widget &receiver, int clipboard, const char *type);
-  virtual int clipboard_contains(const char *type);
   virtual void add_fd(int fd, int when, Fl_FD_Handler cb, void* = 0);
   virtual void add_fd(int fd, Fl_FD_Handler cb, void* = 0);
   virtual void remove_fd(int, int when);
@@ -86,6 +83,8 @@ public:
   virtual const char *alt_name();
   virtual const char *control_name();
   virtual Fl_Sys_Menu_Bar_Driver *sys_menu_bar_driver();
+  virtual double wait(double time_to_wait);
+  virtual int ready();
 };
 
 #endif // FL_DARWIN_SYSTEM_DRIVER_H
diff --git src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.H src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.H
index c621f7e..6754396 100644
--- src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.H
+++ src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.H
@@ -61,8 +61,6 @@ public:
   virtual void beep(int type);
   // --- global events
   virtual void flush();
-  virtual double wait(double time_to_wait);
-  virtual int ready();
   virtual void grab(Fl_Window* win);
   // --- global colors
   virtual void get_system_colors();
@@ -86,6 +84,14 @@ public:
   }
   virtual void desktop_scale_factor();
   virtual void default_icons(const Fl_RGB_Image *icons[], int count);
+  // this one is implemented in Fl_win32.cxx
+  virtual void copy(const char *stuff, int len, int clipboard, const char *type);
+  // this one is implemented in Fl_win32.cxx
+  virtual void paste(Fl_Widget &receiver, int clipboard, const char *type);
+  // this one is implemented in Fl_win32.cxx
+  virtual int clipboard_contains(const char *type);
+  // this one is implemented in Fl_win32.cxx
+  virtual void clipboard_notify_change();
 };
 
 
diff --git src/drivers/WinAPI/Fl_WinAPI_System_Driver.H src/drivers/WinAPI/Fl_WinAPI_System_Driver.H
index 60dca9d..3e6a866 100644
--- src/drivers/WinAPI/Fl_WinAPI_System_Driver.H
+++ src/drivers/WinAPI/Fl_WinAPI_System_Driver.H
@@ -107,14 +107,6 @@ public:
   virtual int case_insensitive_filenames() {return 1;}
   // this one is implemented in Fl_win32.cxx
   virtual const char *filename_name(const char *buf);
-  // this one is implemented in Fl_win32.cxx
-  virtual void copy(const char *stuff, int len, int clipboard, const char *type);
-  // this one is implemented in Fl_win32.cxx
-  virtual void paste(Fl_Widget &receiver, int clipboard, const char *type);
-  // this one is implemented in Fl_win32.cxx
-  virtual int clipboard_contains(const char *type);
-  // this one is implemented in Fl_win32.cxx
-  virtual void clipboard_notify_change();
   virtual void add_fd(int fd, int when, Fl_FD_Handler cb, void* = 0);
   virtual void add_fd(int fd, Fl_FD_Handler cb, void* = 0);
   virtual void remove_fd(int, int when);
@@ -123,6 +115,8 @@ public:
   virtual char* strdup(const char *s) { return ::_strdup(s); }
   virtual void lock_ring();
   virtual void unlock_ring();
+  virtual double wait(double time_to_wait);
+  virtual int ready();
 };
 
 #endif // FL_WINAPI_SYSTEM_DRIVER_H
diff --git src/drivers/X11/Fl_X11_Screen_Driver.H src/drivers/X11/Fl_X11_Screen_Driver.H
index c8676f3..4b877c9 100644
--- src/drivers/X11/Fl_X11_Screen_Driver.H
+++ src/drivers/X11/Fl_X11_Screen_Driver.H
@@ -45,8 +45,6 @@ protected:
   } FLScreenInfo;
   FLScreenInfo screens[MAX_SCREENS];
   float dpi[MAX_SCREENS][2];
-  int poll_or_select();
-  int poll_or_select_with_delay(double time_to_wait);
   int get_mouse_unscaled(int &xx, int &yy);
 
 public:
@@ -78,8 +76,6 @@ public:
   virtual void beep(int type);
   // --- global events
   virtual void flush();
-  virtual double wait(double time_to_wait);
-  virtual int ready();
   virtual void grab(Fl_Window* win);
   // --- global colors
   virtual int parse_color(const char* p, uchar& r, uchar& g, uchar& b);
@@ -98,6 +94,14 @@ public:
   // --- compute dimensions of an Fl_Offscreen
   virtual void offscreen_size(Fl_Offscreen o, int &width, int &height);
   virtual void default_icons(const Fl_RGB_Image *icons[], int count);
+  // this one is in Fl_x.cxx
+  virtual void copy(const char *stuff, int len, int clipboard, const char *type);
+  // this one is in Fl_x.cxx
+  virtual void paste(Fl_Widget &receiver, int clipboard, const char *type);
+  // this one is in Fl_x.cxx
+  virtual int clipboard_contains(const char *type);
+  // this one is in Fl_x.cxx
+  virtual void clipboard_notify_change();
 };
 
 
diff --git src/drivers/X11/Fl_X11_Screen_Driver.cxx src/drivers/X11/Fl_X11_Screen_Driver.cxx
index 3e7edf8..d033f4c 100644
--- src/drivers/X11/Fl_X11_Screen_Driver.cxx
+++ src/drivers/X11/Fl_X11_Screen_Driver.cxx
@@ -365,34 +365,6 @@ void Fl_X11_Screen_Driver::flush()
 }
 
 
-double Fl_X11_Screen_Driver::wait(double time_to_wait)
-{
-  if (time_to_wait <= 0.0) {
-    // do flush second so that the results of events are visible:
-    int ret = this->poll_or_select_with_delay(0.0);
-    Fl::flush();
-    return ret;
-  } else {
-    // do flush first so that user sees the display:
-    Fl::flush();
-    if (Fl::idle) // 'idle' may have been set within flush()
-      time_to_wait = 0.0;
-    else {
-      Fl_Timeout::elapse_timeouts();
-      time_to_wait = Fl_Timeout::time_to_wait(time_to_wait);
-    }
-    return this->poll_or_select_with_delay(time_to_wait);
-  }
-}
-
-
-int Fl_X11_Screen_Driver::ready() {
-  Fl_Timeout::elapse_timeouts();
-  if (Fl_Timeout::time_to_wait(1.0) <= 0.0) return 1;
-  return this->poll_or_select();
-}
-
-
 extern void fl_fix_focus(); // in Fl.cxx
 
 
diff --git src/drivers/X11/Fl_X11_System_Driver.H src/drivers/X11/Fl_X11_System_Driver.H
index 891c14d..e39f407 100644
--- src/drivers/X11/Fl_X11_System_Driver.H
+++ src/drivers/X11/Fl_X11_System_Driver.H
@@ -54,18 +54,15 @@ public:
   virtual void own_colormap();
   // this one is in Fl_x.cxx
   virtual const char *filename_name(const char *buf);
-  // this one is in Fl_x.cxx
-  virtual void copy(const char *stuff, int len, int clipboard, const char *type);
-  // this one is in Fl_x.cxx
-  virtual void paste(Fl_Widget &receiver, int clipboard, const char *type);
-  // this one is in Fl_x.cxx
-  virtual int clipboard_contains(const char *type);
-  // this one is in Fl_x.cxx
-  virtual void clipboard_notify_change();
   virtual void add_fd(int fd, int when, Fl_FD_Handler cb, void* = 0);
   virtual void add_fd(int fd, Fl_FD_Handler cb, void* = 0);
   virtual void remove_fd(int, int when);
   virtual void remove_fd(int);
+  virtual double wait(double time_to_wait);
+  virtual int ready();
+  // 2 additional virtual members
+  virtual int poll_or_select();
+  virtual int poll_or_select_with_delay(double time_to_wait);
 };
 
 #endif /* FL_X11_SYSTEM_DRIVER_H */
diff --git src/drivers/X11/Fl_X11_System_Driver.cxx src/drivers/X11/Fl_X11_System_Driver.cxx
index 71becad..64cac37 100644
--- src/drivers/X11/Fl_X11_System_Driver.cxx
+++ src/drivers/X11/Fl_X11_System_Driver.cxx
@@ -20,6 +20,7 @@
 #include <FL/fl_string_functions.h>  // fl_strdup
 #include <FL/platform.H>
 #include "../../flstring.h"
+#include "../../Fl_Timeout.h"
 
 #include <X11/Xlib.h>
 #include <locale.h>
@@ -694,4 +695,30 @@ void Fl_X11_System_Driver::own_colormap() {
 #endif // USE_COLORMAP
 }
 
+int Fl_X11_System_Driver::ready() {
+  Fl_Timeout::elapse_timeouts();
+  if (Fl_Timeout::time_to_wait(1.0) <= 0.0) return 1;
+  return this->poll_or_select();
+}
+
+double Fl_X11_System_Driver::wait(double time_to_wait)
+{
+  if (time_to_wait <= 0.0) {
+    // do flush second so that the results of events are visible:
+    int ret = this->poll_or_select_with_delay(0.0);
+    Fl::flush();
+    return ret;
+  } else {
+    // do flush first so that user sees the display:
+    Fl::flush();
+    if (Fl::idle) // 'idle' may have been set within flush()
+      time_to_wait = 0.0;
+    else {
+      Fl_Timeout::elapse_timeouts();
+      time_to_wait = Fl_Timeout::time_to_wait(time_to_wait);
+    }
+    return this->poll_or_select_with_delay(time_to_wait);
+  }
+}
+
 #endif // !defined(FL_DOXYGEN)