Fix Scaling window up/down also scales X/Y position on secondary displays only (#925)

4 files changed, 9 insertions, 10 deletions

diff --git a/src/Fl.cxx b/src/Fl.cxx
index 43115cc6a..0501483a6 100644
--- a/src/Fl.cxx
+++ b/src/Fl.cxx
@@ -2274,9 +2274,9 @@ void Fl::screen_scale(int n, float factor) {
   if (!capability || n < 0 || n >= Fl::screen_count()) return;
   if (capability == Fl_Screen_Driver::SYSTEMWIDE_APP_SCALING) {
     for (int s = 0; s < Fl::screen_count(); s++) {
-      Fl::screen_driver()->rescale_all_windows_from_screen(s, factor);
+      Fl::screen_driver()->rescale_all_windows_from_screen(s, factor, factor);
     }
-  } else Fl::screen_driver()->rescale_all_windows_from_screen(n, factor);
+  } else Fl::screen_driver()->rescale_all_windows_from_screen(n, factor, factor);
 }
 
 /**
diff --git a/src/Fl_Screen_Driver.H b/src/Fl_Screen_Driver.H
index 6371e57e9..e57aadcc8 100644
--- a/src/Fl_Screen_Driver.H
+++ b/src/Fl_Screen_Driver.H
@@ -219,7 +219,7 @@ public:
   // compute dimensions of an Fl_Offscreen
   virtual void offscreen_size(Fl_Offscreen, int &/*width*/, int &/*height*/) {}
 
-  void rescale_all_windows_from_screen(int screen, float f);
+  void rescale_all_windows_from_screen(int screen, float f, float old_f);
   static void transient_scale_display(float f, int nscreen);
   // need export to fltk_gl.so because used in glut_compatibility.cxx
   static FL_EXPORT int scale_handler(int event);
diff --git a/src/Fl_Screen_Driver.cxx b/src/Fl_Screen_Driver.cxx
index 12453b89e..f975195ba 100644
--- a/src/Fl_Screen_Driver.cxx
+++ b/src/Fl_Screen_Driver.cxx
@@ -376,10 +376,8 @@ int Fl_Screen_Driver::input_widget_handle_key(int key, unsigned mods, unsigned s
 }
 
 
-void Fl_Screen_Driver::rescale_all_windows_from_screen(int screen, float f)
+void Fl_Screen_Driver::rescale_all_windows_from_screen(int screen, float f, float old_f)
 {
-  float old_f = this->scale(screen);
-  //if (f == old_f) return;
   this->scale(screen, f);
   Fl_Graphics_Driver *d = Fl_Display_Device::display_device()->driver();
   d->scale(f);
@@ -542,11 +540,12 @@ int Fl_Screen_Driver::scale_handler(int event)
     }
     if (f == old_f) return 1;
     if (screen_dr->rescalable() == SYSTEMWIDE_APP_SCALING) {
+      float old_f = screen_dr->scale(0);
       for (int i = 0; i < Fl::screen_count(); i++) {
-        screen_dr->rescale_all_windows_from_screen(i, f * initial_scale);
+        screen_dr->rescale_all_windows_from_screen(i, f * initial_scale, old_f);
       }
     } else {
-      screen_dr->rescale_all_windows_from_screen(screen, f * initial_scale);
+      screen_dr->rescale_all_windows_from_screen(screen, f * initial_scale, screen_dr->scale(screen));
     }
     Fl_Screen_Driver::transient_scale_display(f, screen);
     Fl::handle(FL_ZOOM_EVENT, NULL);
diff --git a/src/Fl_x.cxx b/src/Fl_x.cxx
index 50777e67e..67ed872dc 100644
--- a/src/Fl_x.cxx
+++ b/src/Fl_x.cxx
@@ -1205,7 +1205,7 @@ static void react_to_screen_reconfiguration() {
     float new_scale = Fl::screen_driver()->scale(0);
     for (int screen = 0; screen < Fl::screen_count(); screen++) {
       Fl::screen_driver()->scale(screen, 1);
-      Fl::screen_driver()->rescale_all_windows_from_screen(screen, new_scale);
+      Fl::screen_driver()->rescale_all_windows_from_screen(screen, new_scale, 1);
     }
   }
   delete[] scales;
@@ -1227,7 +1227,7 @@ static void after_display_rescale(float *p_current_xft_dpi) {
         *p_current_xft_dpi = dpi;
         float f = dpi/96.;
         for (int i = 0; i < Fl::screen_count(); i++)
-          Fl::screen_driver()->rescale_all_windows_from_screen(i, f);
+          Fl::screen_driver()->rescale_all_windows_from_screen(i, f, f);
       }
     }
     break;