Is it possible to re-size a list (increase/decrease) in proportion to widget pane?

Hello all,

Before I try to explain what I am asking here...it may be eastier to take a look at the 2 pictures (a before and after) that I've attached.

I'm basically trying to figure out why the list (in this case a list of layers) is not expanding with the widget panel when I re-size the pane. When the layer names are past a certain length, they get cut off. I'm basically trying to expand the widget panel so that the list expands with it. I can attach code or whatever is needed.

Thanks,

Jesse

Attached Thumbnails