OK - but for the avoidance of any doubt here, I feel it is worth emphasising that the "modal-ness" of a window has three states, not two, so a binary true/false option may not cover it. Does the Rust port also provide a method to remove the "modality" altogether and set the window back to normal?  (cf;  Fl_Window::clear_modal_states(); )

For those following along who may be unfamiliar with the (somewhat odd, in my opinion) terminology, it comes out as something like:

modal - a window that remains on top of its parent, and grabs the focus so that all interactions go to that window rather than the parent (menus, alert dialogs, etc.)

non-modal -  a window that remains on top of its parent, but DOES NOT grab the focus so  that the parent can still be used (toolboxes, typically and other types of dialog)

normal - a regular window, that does not remain on top or prevent access to its peers: this is the default for a window

So... I'm still not really clear on why Mark had a non-modal window at all; it seemed like a normal window would have been what was wanted?

Anyway, notwithstanding, it sounds like it has been sorted out anyway, which is good.