I am also running another project where I never want a morph to gain mouse
focus from a similar reason. The only Morph in Squeak I remember to never
gain focus is the HaloMorph, what is apparently achieved by an extra-check
in PasteUpMorph>>#filterEvent:for: where the event is ignored in
#tryInvokeHaloFor: before passing it to MouseOverHandler. Manipulating a
PasteUpMorph method does not seem appropriate for a small tool.
tl;dr: Is it possible to forbid a morph to gain focus at the expense of the
current focused morph? If not, would you know any better approach? Or would
this even be a possible feature proposal for squeak/dev? Thanks in advance!