1 files changed, 124 insertions, 0 deletions
diff --git a/src/Fl_Screen_Driver.cxx b/src/Fl_Screen_Driver.cxx
new file mode 100644
index 000000000..46e9e5d2c
--- /dev/null
+++ b/src/Fl_Screen_Driver.cxx
@@ -0,0 +1,124 @@
+//
+// "$Id$"
+//
+// All screen related calls in a driver style class.
+//
+// Copyright 1998-2016 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
+// file is missing or damaged, see the license at:
+//
+//     http://www.fltk.org/COPYING.php
+//
+// Please report all bugs and problems on the following page:
+//
+//     http://www.fltk.org/str.php
+//
+
+
+#include "config_lib.h"
+#include <FL/Fl_Screen_Driver.H>
+#include <FL/Fl.H>
+
+
+Fl_Screen_Driver::Fl_Screen_Driver() :
+num_screens(-1)
+{
+}
+
+
+void Fl_Screen_Driver::screen_xywh(int &X, int &Y, int &W, int &H)
+{
+  int x, y;
+  Fl::get_mouse(x, y);
+  screen_xywh(X, Y, W, H, x, y);
+}
+
+
+void Fl_Screen_Driver::screen_xywh(int &X, int &Y, int &W, int &H, int mx, int my)
+{
+  screen_xywh(X, Y, W, H, screen_num(mx, my));
+}
+
+
+void Fl_Screen_Driver::screen_work_area(int &X, int &Y, int &W, int &H)
+{
+  int x, y;
+  Fl::get_mouse(x, y);
+  screen_work_area(X, Y, W, H, x, y);
+}
+
+
+void Fl_Screen_Driver::screen_work_area(int &X, int &Y, int &W, int &H, int mx, int my)
+{
+  screen_work_area(X, Y, W, H, screen_num(mx, my));
+}
+
+
+int Fl_Screen_Driver::screen_count()
+{
+  if (num_screens < 0)
+    init();
+  return num_screens ? num_screens : 1;
+}
+
+
+void Fl_Screen_Driver::screen_xywh(int &X, int &Y, int &W, int &H, int mx, int my, int mw, int mh)
+{
+  screen_xywh(X, Y, W, H, screen_num(mx, my, mw, mh));
+}
+
+
+int Fl_Screen_Driver::screen_num(int x, int y)
+{
+  int screen = 0;
+  if (num_screens < 0) init();
+
+  for (int i = 0; i < num_screens; i ++) {
+    int sx, sy, sw, sh;
+    Fl::screen_xywh(sx, sy, sw, sh, i);
+    if ((x >= sx) && (x < (sx+sw)) && (y >= sy) && (y < (sy+sh))) {
+      screen = i;
+      break;
+    }
+  }
+  return screen;
+}
+
+
+// Return the number of pixels common to the two rectangular areas
+static inline float fl_intersection(int x1, int y1, int w1, int h1,
+                                    int x2, int y2, int w2, int h2)
+{
+  if(x1+w1 < x2 || x2+w2 < x1 || y1+h1 < y2 || y2+h2 < y1)
+    return 0.;
+  int int_left = x1 > x2 ? x1 : x2;
+  int int_right = x1+w1 > x2+w2 ? x2+w2 : x1+w1;
+  int int_top = y1 > y2 ? y1 : y2;
+  int int_bottom = y1+h1 > y2+h2 ? y2+h2 : y1+h1;
+  return (float)(int_right - int_left) * (int_bottom - int_top);
+}
+
+
+int Fl_Screen_Driver::screen_num(int x, int y, int w, int h)
+{
+  int best_screen = 0;
+  float best_intersection = 0.;
+  for (int i = 0; i < num_screens; i++) {
+    int sx = 0, sy = 0, sw = 0, sh = 0;
+    screen_xywh(sx, sy, sw, sh, i);
+    float sintersection = fl_intersection(x, y, w, h, sx, sy, sw, sh);
+    if (sintersection > best_intersection) {
+      best_screen = i;
+      best_intersection = sintersection;
+    }
+  }
+  return best_screen;
+}
+
+
+
+//
+// End of "$Id$".
+//