Why don’t you check the location of the mouse movement? The coordinates are close enough.
> On Jun 6, 2016, at 4:45 PM, David Raymond Christiansen > <da...@davidchristiansen.dk> wrote: > > Hi all, > > I'm looking for a way to check whether a mouse pointer is on top of a > particular pict that has been drawn to a canvas%. > > Right now, the best I've been able to do is to render the pict to two > off-screen bitmaps with different background colors, and then check whether > or not the pixel on each bitmap that corresponds to the mouse location in the > canvas is the same as the bitmap's background color. > > I use two bitmaps in case a region drawn by the pict is the same color as the > background that I have chosen. Given that there's support for the dc pict, > which uses arbitrary imperative commands for drawing, I doubt that I can do > better than this, but I'd appreciate hearing any techniques that I'm missing. > > This is being used to implement something similar to the clickback feature in > Slideshow, but for GUI windows, and with arbitrarily nested clickbacks. > > Thanks! > > /David > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
