Thanks, at least I know where to look. I have also been looking at 'wxs_madm.cc'  specifically; > static Scheme_Object * os_wxMediaAdminScrollTo (int n , Scheme_Object * p [] ) { I'm having trouble making sense of it because I have no experience in c++, and the code lacks any comments. Is there any documentation to this stuff. s. <div class="gmail_quote">On Jan 18, 2008 2:14 PM, Matthew Flatt <<a href="mailto:mflatt@cs.utah.edu">mflatt@cs.utah.edu</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> <div class="Ih2E3d">At Thu, 17 Jan 2008 15:44:20 +0000, "Stephen De Gabrielle" wrote: > I'm trying to implement a 'grab and scroll' method that lets the > canvas be moved by the mouse pointer. > > I'm pretty happy with getting the location via   get-x  get-y and > dc-location-to-editor-location, > but I'm trying to find an alternative to the 'scroll-to' to actually > do the moving? > > (The idea is that while the left mouse button is down, the mouse > position is static with respect to the pasteboard position, but moves > with respect to the canvas.) </div>I think there's isn't really an alternative to `scroll-to'. The `scroll-to' method of a pasteboard mostly just sends on the request to its administrator's `scroll-to' method, which is the only interface for talking about the relative position of the editor in the display. Matthew </blockquote></div> -- Cheers, Stephen -- Stephen De Gabrielle <a href="mailto:s.degabrielle@ucl.ac.uk">s.degabrielle@ucl.ac.uk </a> Telephone +44 (0)20 7679 5242 (x45242) Mobile                  079 851 890 45 Project: Making Sense of Information (MaSI) <a href="http://www.uclic.ucl.ac.uk/annb/MaSI.html">http://www.uclic.ucl.ac.uk/annb/MaSI.html </a> UCLIC: University College London Interaction Centre <a href="http://www.uclic.ucl.ac.uk/">http://www.uclic.ucl.ac.uk/</a> Remax House - 31/32 Alfred Place London - WC1E 7DP