Missing pictures listing on the bottom of the dialog doesn't dynamically update

I appreciate that the picture dialog now notifies users if pictures requested by the project are not found by PTXprint. This is very helpful.

This list is apparently only updated after we hit the "Print (Make PDF)" button. For example, if I uncheck the "Exclude Subfolders" option (see bug #984), the highlighted picture instantly shows up on the right side (good!), but the Missing Pictures list does update. This is pretty confusing. The picture is showing, so we know PTXprint can find it, yet the list says the picture is still missing. It took me a while to realize the list would only refresh if I hit the "Print" button -- but printing sometimes take a while and I'd rather not have to run the entire print process to verify the pictures are now working.

I have no simple solution. But maybe if PTXprint would auto refresh whenever the user messes with any of the picture location options, or maybe add a "refresh list" button in that notification area?

Start at the PTXprint picture dialog and trace how changes to picture location options affect the highlighted picture and the Missing Pictures list. Reproduce the issue by changing “Exclude Subfolders,” then verify that the list refreshes without pressing “Print (Make PDF)” and that the displayed entries match the pictures PTXprint can find.