Documentation: details about how to position a window in screens

1 files changed, 14 insertions, 0 deletions

diff --git a/FL/Fl_Window.H b/FL/Fl_Window.H
index a6709a216..d72ca02f8 100644
--- a/FL/Fl_Window.H
+++ b/FL/Fl_Window.H
@@ -159,8 +159,22 @@ public:
   */
     Fl_Window(int w, int h, const char *title = 0);
   /** Creates a window from the given position (x, y), size (w, h) and title.
+   
+   On a multi-screen system, the values computed by
+   Fl::screen_xywh(int &X, int &Y, int &W, int &H, int n) can be used to
+   discover the coordinates of the area of screen #n.
+   When these screens have various scale factor
+   values, an \p (x, y) pair may not be enough to specify the targetted screen
+   for the window, because the same \p (x,y) pair can belong to several screens.
+   In that situation, a call to Fl_Window::screen_num(int) is to be used to identify
+   unambiguously the targetted screen.
 
     \see Fl_Window(int w, int h, const char *title)
+    \see Fl::screen_xywh(int &X, int &Y, int &W, int &H, int n)
+   
+   \note Under Wayland, it's generally not possible for the client app to control
+   the position of a window in the system. It's only possible to specify on what screen
+   should the compositor place a fullscreen window.
   */
     Fl_Window(int x, int y, int w, int h, const char *title = 0);
   /**