[Issue] getData() should be nullable

[Paget96]

getData of the chart should be nullable. At some point of time it can be null which will result in app crashing.

Commit is here:
7a9d178#diff-1f5f4cb0c731f19e1875d6ce6640fad605f51bad09f5238d07befd1752b77c89

[hannesa2]

Why should it be nullable ?
The tests are running fine.

[Paget96]

Why should it be nullable ? The tests are running fine.

val data = lineChart.data
We should be able to check are data on the graph are null, especially if we do update graph periodically (each N seconds), that way we can know do we need new dataSet or we can continue updating previous data. As NonNull, we don't have ability to do such check.

[Paget96]

Why should it be nullable ? The tests are running fine.

Actually only these 3 files are extending the mpandroidchart library

https://github.com/stramChen/MPAndroidChart-Bezier-shadow/tree/master/doc

I think you'll be able to easy manipulate these

[hannesa2]

As NonNull, we don't have ability to do such check.

The previous way to have it nullable in Java causes NPE in my Kotlin code.
Btw, you could use these methods to do your stuff as well

[Paget96]

I have added a local variable to check is graph initialized. This will be temporary fix until I find better one