Update LineView.java

Using Android studio this was causing null pointer exception during the layout preview.
This small fix is preventing it, I just hope it is not breaking anything else ...
Update BarView.java

Using Android studio this was causing null pointer exception during the layout preview.
This small fix is preventing it, I just hope it is not breaking anything else ...
Merge pull request #4 from RomanRogue/master

Minor change to improve Android studio compatibility.