Size edge scroll after window, not remote session

This should scale with the rest of the visible interface, not the
invisible stuff that might vary wildely. In the most extreme cases,
there is no usable area left as everything on screen becomes "edge".

Author: CendioOssman

vncviewer/DesktopWindow.cxx

@@ -58,8 +58,8 @@
 #endif
 
 // width of each "edge" region where scrolling happens,
-// as a ratio compared to the viewport size
-// default: 1/16th of the viewport size
+// as a ratio compared to the window size
+// default: 1/16th of the window size
 #define EDGE_SCROLL_SIZE 16
 // edge width is calculated at runtime; these values are just examples
 static int edge_scroll_size_x = 128;
@@ -863,9 +863,9 @@ int DesktopWindow::handle(int event)
     }
     if (fullscreen_active()) {
       // calculate width of "edge" regions
-      edge_scroll_size_x = viewport->w() / EDGE_SCROLL_SIZE;
-      edge_scroll_size_y = viewport->h() / EDGE_SCROLL_SIZE;
-      // if cursor is near the edge of the viewport, scroll
+      edge_scroll_size_x = w() / EDGE_SCROLL_SIZE;
+      edge_scroll_size_y = h() / EDGE_SCROLL_SIZE;
+      // if cursor is near the edge of the window, scroll
       if (((viewport->x() < 0) && (Fl::event_x() < edge_scroll_size_x)) ||
           ((viewport->x() + viewport->w() >= w()) && (Fl::event_x() >= w() - edge_scroll_size_x)) ||
           ((viewport->y() < 0) && (Fl::event_y() < edge_scroll_size_y)) ||