No pattern. The various ways that the user can manipulate the selection set makes any order meaningless.

Ie: single pick, single pick + CTRL, single pick + SHIFT, Window Right-to-Left pick, Window Right-to-Left pick + CTRL, Window Right-to-Left pick + SHIFT, Window Left-to-Right pick, Window Left-to-Right pick + CTRL, and Window Left-to-Right pick + SHIFT.

Any of these, followed by any other number of them, in whatever order the user may use them, creates a selection set in which the pick order has no importance.

That said, ...

You question indicates you are perhaps trying to program a workflow that would better be implemented as a Ruby Tool, using a Sketchup::PickHelper.

Another alternative might be a Sketchup::SelectionObserver subclass.

Please check messages.

There were many comments, but no useful comments to solve the problem.

I've just found out 'Makeface'(by Todd Burch' on Smustard's homepage. It recognizes the closed area even if its not completely closed. I removed all the faces and used 'Makce face'. Finally, The problem was solved 😄

Thank you for giving me advices. The problem has been partly fixed by myself. Maybe, I have to pay attention to studying ruby more

post a before and an after model. it's really hard to envision what you mean...

john