[plt-scheme] 'grabbing' the canvas/pasteboard? to scroll with the mouse pointer

From: Matthew Flatt (mflatt at cs.utah.edu)
Date: Fri Jan 18 09:14:44 EST 2008

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.)

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.


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