<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body text="#000000" bgcolor="#FFFFFF"> Hi Juan, I am not sure what is best, overwriting the processMouseMove:localPosition: or use the Phil suggestion. The former is more efficient but the later better for future code evolution in the system processMouseMove:localPosition: . For Cuis itself, there is may be an issue to fill to keep an eye on this race condition in the step system Hilaire <div class="moz-cite-prefix">Le 24/08/2021 à 20:23, Juan Vuletich a écrit : </div> <blockquote type="cite" cite="mid:6125393E.5020008@jvuletich.org">Now I see. Thanks. Running exactly the same code as you makes it easy to understand. The problem is that DrGDrawable is inheriting #processMouseMove:localPosition: from Morph, that is also doing `self startStepping: #processMouseStillDown stepTime: 1`. If I copy down that method to DrGDrawable and remove the last two lines, I get the behavior you want. I'm not sure if this is the right solution, as DrGDrawable has many methods related to event handling, and I only spent a few minutes here. </blockquote> <pre class="moz-signature" cols="72">-- GNU Dr. Geo <a class="moz-txt-link-freetext" href="http://drgeo.eu">http://drgeo.eu</a> <a class="moz-txt-link-freetext" href="http://blog.drgeo.eu">http://blog.drgeo.eu</a></pre> </body> </html>