Fl_Window_Driver::set_popup_window(), Fl_Screen_Driver::screen_boundaries_known()

Fl_Window_Driver::set_popup_window() is to be used to declare a window should be
positioned relatively to a previously mapped other window.  This allows a platform
to process such windows differently from other windows if needed.
Menu and tooltip windows are so declared.

A call to Fl_Window_Driver::set_popup_window() also allows to distinguish a real
menu or tooltip window from a window marked by Fl_Window::set_menu_window()
or by Fl_Window::set_tooltip_window() but that's not a real menu or tooltip.

New member function bool Fl_Screen_Driver::screen_boundaries_known() returns
true by default. A platform where the position of windows inside a screen is hidden
(e.g., Wayland) returns false. This allows FLTK to refrain from trying to make sure
a computed position is inside a screen.

FL/Fl_Widget.H

@@ -1,7 +1,7 @@
 //
 // Widget header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2023 by Bill Spitzak and others.
+// Copyright 1998-2024 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
@@ -181,6 +181,7 @@ protected:
         DEIMAGE_BOUND   = 1<<22,  ///< bind the inactive image to the widget, so the widget deletes the image when it is no longer needed
         AUTO_DELETE_USER_DATA = 1<<23, ///< automatically call `delete` on the user_data pointer when destroying this widget; if set, user_data must point to a class derived from the class Fl_Callback_User_Data
         MAXIMIZED       = 1<<24,  ///< a maximized Fl_Window
+        POPUP           = 1<<25,  ///< popup window (i.e., positioned relatively to another mapped window)
         // Note to devs: add new FLTK core flags above this line (up to 1<<28).
 
         // Three more flags, reserved for user code

src/Fl_Menu.cxx

@@ -1,7 +1,7 @@
 //
 // Menu code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2023 by Bill Spitzak and others.
+// Copyright 1998-2024 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
@@ -115,7 +115,7 @@ protected:
     Fl_Menu_Window(X, Y, W, H, 0) {
       menu = m;
       set_menu_window();
-      Fl_Window_Driver::driver(this)->popup_window(true);
+      Fl_Window_Driver::driver(this)->set_popup_window();
       end();
       set_modal();
       clear_border();

src/Fl_Screen_Driver.H

@@ -1,7 +1,7 @@
 //
 // All screen related calls in a driver style class.
 //
-// Copyright 1998-2022 by Bill Spitzak and others.
+// Copyright 1998-2024 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
@@ -123,6 +123,7 @@ public:
     H = 600;
   }
   void screen_xywh(int &X, int &Y, int &W, int &H, int mx, int my, int mw, int mh);
+  virtual bool screen_boundaries_known() { return true; }
   virtual int screen_num(int x, int y);
   virtual int screen_num(int x, int y, int w, int h);
   virtual void screen_dpi(float &h, float &v, int n = 0) { // FL_OVERRIDE in driver!

src/Fl_Tooltip.cxx

@@ -1,7 +1,7 @@
 //
 // Tooltip source file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2015 by Bill Spitzak and others.
+// Copyright 1998-2024 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
@@ -21,6 +21,7 @@
 #include <FL/fl_string_functions.h>
 #include "Fl_System_Driver.H"
 #include "Fl_Window_Driver.H"
+#include "Fl_Screen_Driver.H"
 
 #include <stdio.h>
 
@@ -51,7 +52,7 @@ public:
   Fl_TooltipBox() : Fl_Menu_Window(0, 0) {
     set_override();
     set_tooltip_window();
-    Fl_Window_Driver::driver(this)->popup_window(true);
+    Fl_Window_Driver::driver(this)->set_popup_window();
     end();
   }
   void draw() FL_OVERRIDE;
@@ -91,24 +92,27 @@ void Fl_TooltipBox::layout() {
   hh += (Fl_Tooltip::margin_height() * 2);
 
   // find position on the screen of the widget:
-  int ox = Fl::event_x_root();
+  int ox = Fl::event_x_root(), oy;
-  int oy = currentTooltipY + currentTooltipH+2;
-  for (Fl_Widget* p = Fl_Tooltip::current(); p; p = p->window()) {
-    oy += p->y();
-  }
-  int scr_x = -100000, scr_y = -100000, scr_w = 1000000, scr_h = 1000000;
-  if (!Fl_Window_Driver::driver(this)->popup_window()) {
-    Fl::screen_xywh(scr_x, scr_y, scr_w, scr_h);
-  }
-  if (ox+ww > scr_x+scr_w) ox = scr_x+scr_w - ww;
-  if (ox < scr_x) ox = scr_x;
   if (currentTooltipH > 30) {
     oy = Fl::event_y_root()+13;
-    if (oy+hh > scr_y+scr_h) oy -= 23+hh;
   } else {
-    if (oy+hh > scr_y+scr_h) oy -= (4+hh+currentTooltipH);
+    oy = currentTooltipY + currentTooltipH+2;
+    for (Fl_Widget* p = Fl_Tooltip::current(); p; p = p->window()) {
+      oy += p->y();
+    }
+  }
+  if (Fl::screen_driver()->screen_boundaries_known()) {
+    int scr_x, scr_y, scr_w, scr_h;
+    Fl::screen_xywh(scr_x, scr_y, scr_w, scr_h);
+    if (ox+ww > scr_x+scr_w) ox = scr_x+scr_w - ww;
+    if (ox < scr_x) ox = scr_x;
+    if (currentTooltipH > 30) {
+      if (oy+hh > scr_y+scr_h) oy -= 23+hh;
+    } else {
+      if (oy+hh > scr_y+scr_h) oy -= (4+hh+currentTooltipH);
+    }
+    if (oy < scr_y) oy = scr_y;
   }
-  if (oy < scr_y) oy = scr_y;
 
   resize(ox, oy, ww, hh);
 }

src/Fl_Window_Driver.H

@@ -2,7 +2,7 @@
 // A base class for platform specific window handling code
 // for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010-2023 by Bill Spitzak and others.
+// Copyright 2010-2024 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 +129,8 @@ public:
   }
 
   void resize_after_scale_change(int ns, float old_f, float new_f);
+  void set_popup_window() { pWindow->set_flag(Fl_Window::POPUP); }
+  bool popup_window() const {return pWindow->flags() & Fl_Window::POPUP;}
 
   // --- window data
   virtual int decorated_w() { return w(); } // default, should be overidden by driver
@@ -213,8 +215,6 @@ public:
   static void scroll_to_selected_item(Fl_Window *);
 
   virtual fl_uintptr_t os_id() { return 0; }
-  virtual void popup_window(bool v) {}
-  virtual bool popup_window() { return false; }
 };
 
 #endif // FL_WINDOW_DRIVER_H

src/drivers/Wayland/Fl_Wayland_Screen_Driver.H

@@ -2,7 +2,7 @@
 // Definition of the Wayland Screen interface
 // for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010-2023 by Bill Spitzak and others.
+// Copyright 2010-2024 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
@@ -170,6 +170,7 @@ public:
   int get_key(int k) FL_OVERRIDE;
   void enable_im() FL_OVERRIDE;
   void disable_im() FL_OVERRIDE;
+  bool screen_boundaries_known() FL_OVERRIDE { return false; }
 
   // overridden functions from parent class Fl_Unix_Screen_Driver
   int poll_or_select_with_delay(double time_to_wait) FL_OVERRIDE;

src/drivers/Wayland/Fl_Wayland_Window_Driver.H

@@ -1,7 +1,7 @@
 //
 // Definition of Wayland window driver for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010-2023 by Bill Spitzak and others.
+// Copyright 2010-2024 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
@@ -132,8 +132,6 @@ public:
   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) FL_OVERRIDE;
   void wait_for_expose() FL_OVERRIDE;
-  void popup_window(bool v) FL_OVERRIDE;
-  bool popup_window() FL_OVERRIDE;
   // menu-related stuff
   void reposition_menu_window(int x, int y) FL_OVERRIDE;
   void menu_window_area(int &X, int &Y, int &W, int &H, int nscreen = -1) FL_OVERRIDE;

src/drivers/Wayland/Fl_Wayland_Window_Driver.cxx

@@ -1,7 +1,7 @@
 //
 // Implementation of the Wayland window driver.
 //
-// Copyright 1998-2023 by Bill Spitzak and others.
+// Copyright 1998-2024 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
@@ -1377,6 +1377,9 @@ void Fl_Wayland_Window_Driver::makeWindow()
   if (pWindow->parent() && !pWindow->window()) return;
   if (pWindow->parent() && !pWindow->window()->shown()) return;
 
+  if (!pWindow->parent() && !popup_window()) {
+    x(0); y(0); // toplevel, non-popup windows must have origin at 0,0
+  }
   new_window = (struct wld_window *)calloc(1, sizeof *new_window);
   new_window->fl_win = pWindow;
   wl_list_init(&new_window->outputs);
@@ -1398,7 +1401,7 @@ void Fl_Wayland_Window_Driver::makeWindow()
   // put transient scale win at center of top window by making it a tooltip of top
     Fl_Screen_Driver::transient_scale_parent = Fl::first_window();
     pWindow->set_tooltip_window();
-    popup_window(true);
+    set_popup_window();
     pWindow->position(
               (Fl_Screen_Driver::transient_scale_parent->w() - pWindow->w())/2 ,
               (Fl_Screen_Driver::transient_scale_parent->h() - pWindow->h())/2);
@@ -1849,20 +1852,12 @@ void Fl_Wayland_Window_Driver::resize(int X, int Y, int W, int H) {
       if (W < 1) W = 1;
       if (H < 1) H = 1;
     }
-    // toplevel, non-popup windows must have origin at 0,0
-    if (!pWindow->parent() && !popup_window()) X = Y = 0;
     pWindow->Fl_Group::resize(X,Y,W,H);
 //fprintf(stderr, "resize: win=%p to %dx%d\n", pWindow, W, H);
     if (shown()) {pWindow->redraw();}
   } else {
-    if (pWindow->parent() || popup_window()) {
+    x(X); y(Y);
-      x(X); y(Y);
 //fprintf(stderr, "move menuwin=%p x()=%d\n", pWindow, X);
-    } else {
-      //"a deliberate design trait of Wayland makes application windows ignorant of
-      // their exact placement on screen"
-      x(0); y(0);
-    }
   }
 
   if (shown()) {
@@ -2167,13 +2162,3 @@ void Fl_Wayland_Window_Driver::un_maximize() {
   struct wld_window *xid = (struct wld_window *)Fl_X::flx(pWindow)->xid;
   if (xid->kind == DECORATED) libdecor_frame_unset_maximized(xid->frame);
 }
-
-
-void Fl_Wayland_Window_Driver::popup_window(bool v) {
-  is_popup_window_ = v;
-}
-
-
-bool Fl_Wayland_Window_Driver::popup_window() {
-  return is_popup_window_;
-}