Improve display of groups and keywords in entry editor

[tobiasdiez]

Our custom TagBar should be replaced by the ChipView of jfoenix and this control should be used to display groups and keywords in the entry editor.

(Related Javascript library: https://dragonofmercy.github.io/Tokenize2/)

[dextep]

I'd like to work on that. It's will be my first issue so im open to additional tips :)

[tobiasdiez]

Thanks for your interest @dextep! First of all have a look at our contribution guide and follow the instructions given there to setup a local working environment.

Coding-wise: The editor for the keyword field is described here https://github.com/JabRef/jabref/blob/master/src/main/java/org/jabref/gui/fieldeditors/KeywordsEditor.java. As of now this class is very simple. A good starting point is probably to migrate the related https://github.com/JabRef/jabref/blob/master/src/main/java/org/jabref/gui/fieldeditors/LinkedEntriesEditor.java to the ChipView instead of the TagBar.

Please create a PR as soon as possible so that we can discuss your progress and give early feedback. Moreover, feel free to drop by in our developer chat if you have questions! Finally: Happy Coding! 🎉