PConstants

Exploring using processing [PConstants][pconstants] with JRuby, here is simple project that could help you to understand [propane][propane] and [JRubyArt][jruby_art].

Here only compile the PConstants.java (it has no external dependencies)

Use simplicity of a custom Rakefile

rake

Or Use polyglot maven directly to create a java library

Read more about [polyglot maven here][polyglot]

mvn package

The use ruby minitest to test and explore PConstants

cd test
jruby has_constants_test.rb

What we confirm in the test that under JRuby PConstants is seen as a ruby module, and we only need to include the module to implement the interface. But it could have possible namespace issues.

To experiment with different type of java constants

git checkout final_class # for PConstants as a final class (better practice than using an interface, but still frowned on)
# or
git checkout enum # Where there are enum version of seleceted PConstants (the use of global enum is also considered non-ideal)
# or for alternative means of accessing enums using :constant_missing, makes no sens to me
git checkout constant_missing # does not seem to me to have any advantages over include module method

[pconstants]:https://github.com/processing/processing/blob/master/core/src/processing/core/PConstants.java
[propane]:https://ruby-processing.github.io/propane/
[jruby_art]:https://ruby-processing.github.io/JRubyArt/
[polyglot]:https://github.com/takari/polyglot-maven