Currently Manjaro does not come with a pre-installed java. So the first step is to install a jdk we currently recommend installing hotspot adopt-openjdk11 from the AdoptOpenJDK project (there may be issues with distro version). Setting the JDK_HOME environment (easiest done /etc/profile.d) and then manually install the latest JRuby. It is probably worth creating a symbolic links to /usr/bin/jruby and /usr/bin/jgem from wherever you installed jruby eg /opt folder.

mkdir -p ~/.gem/jruby/2.5.0

Now set your GEM_HOME, GEM_PATH and amend your PATH as follows:-

echo "export GEM_HOME=\"\${HOME}/.gem/ruby/${MRI_RUBY}\"" >> ~/.bashrc
echo "export GEM_PATH=\"\${HOME}/.gem/ruby/${MRI_RUBY}\"" >> ~/.bashrc
echo "export PATH=\"\${PATH}:\${GEM_PATH}/bin\"" >> ~/.bashrc
source ~/.bashrc # to update environment without re-logging in

Now should be ready to install picrate and other gems. Install a local version of rake:-

jgem install rake

To install latest picrate and its dependencies:-

jgem install picrate

For a first install:-

picrate --install # no args, install samples and geany config
# or
picrate -i Samples # to omit geany config

This installs example sketches in ~/projects/examples and ties them into a geany project examples.geany. It should also be possible to run sketches from the geany ide. Sketches need to be run in VTE terminal on Manjaro ARM the terminal emulator, does not give access to local environment variables in the version of Geany supplied.

To create a template sketch from the command line:-

picrate -c my_sketch 600 400

creates file my_sketch.rb

#!/usr/bin/env jruby
# frozen_string_literal: false
require 'picrate'

class MySketch < Processing::App
  def settings
    size 200, 200
  end

  def setup
    sketch_title 'My Sketch'
  end

  def draw

  end
end
MySketch.new

Edit in vim (at command line) or geany (gui), you may need to install vim

vim my_sketch.rb
:!jruby % # from vim runs the sketch

To run sketches from command line:-

jruby my_sketch.rb

Or even chmod +x my_sketch.rb to make an executable script.

See editors geany, for how to run sketches from a gui.

JWishy Sketch Running on RaspberryPI

jwishy_buster