snap to a line

[dynvec gmail com]

Hello,

As this is my first message to this list, let me thank you for providing
a way to give user support.

I'm creating a UML diagram and I need to add an Association Class so
I'll need to link the class to the previous association (of 2 other
classes). I looked at the definitions of the tools on the UML sheet and
nothing seemed to fit so I used a line (on top of the sheet selector),
although I would've preferred to use a UML tool, so I snap one side to
the Association Class and the other I try the best to snap to the middle
colored dot that I hope would have served as an anchor but it seem
there's no way to snap it on the association line. I'm reminded of my
failure each time I move one of the 2 previous classes and there's a gap
between the lines. How would you suggest I proceed?

Another point, although less problematic, the best way I found to create
associations is to use the Aggregation tool then (in its properties)
choose the type none. Is there a better way to create association?

Thank you kindly
DynV