Refactor the macOS packaging process

[juananpe]

I have created this new issue to discuss this comment (I'd like to take a stab at it):

I am working on the packaging bits of the maintenance release 2.8.11. macOS packaging is a pain (as usually). Distro with the bundled JRE will most likely be the default option (~100Mb download, ~180Mb on disk). However, the existing users may want to use their existing Java Runtime. I recently had some success with Platypus which just executes a shell script. So the remaining part is to update the shell script so that it searched executable java everywhere: first in PATH, then in JAVA_HOME, then using /usr/libexec/java_home, then in all possible locations which I am aware of, and finally, if it fails to find executable java, make it showing an alert popup with some instructions for the user.

Originally posted by @dbarashev in https://github.com/bardsoftware/ganttproject/issues/1712#issuecomment-590578737

[dbarashev]

Hi @juananpe, did you have any success with this launcher?

[juananpe]

Hi @dbarashev , no, I've had a hard time coping with other works in this strange month, sorry. I've looked at Platypus and it seems that I could use the profile that you are using right now with GanttProject, could you share it here?

OTOH, I've been having a look at jlink and jpackage, could they be a viable alternative?

[1] https://jdk.java.net/jpackage/ [2] https://walczak.it/blog/distributing-javafx-desktop-applications-without-requiring-jvm-using-jlink-and-jpackage [3] https://badass-jlink-plugin.beryx.org/releases/latest/