libgdx && android && scala && idea

I would like to seriously start learning Scala… So why not try it out to do some Android development? To make it even more funny (… or tragic) lets mix in the libgdx library. I installed Scala and SBT plugins for IntelliJ and started with this description for project setup. Everything works perfectly fine when running:

curl https://raw.github.com/n8han/conscript/master/setup.sh | sh
cs n8han/giter8
g8 ajhager/libgdx-sbt-project

… but the second IntelliJ tries to open the project (or you want to build it with sbt) - bang! - a surprise:

java.lang.RuntimeException: set ANDROID_HOME or run 'android update project -p /home/user/Projects/colors/android'
at scala.sys.package$.error(package.scala:27)
at android.Plugin$$anonfun$allPluginSettings$67$$anonfun$apply$28.apply(rules.scala:350)
at android.Plugin$$anonfun$allPluginSettings$67$$anonfun$apply$28.apply(rules.scala:350)
at scala.Option.getOrElse(Option.scala:120)
at android.Plugin$$anonfun$allPluginSettings$67.apply(rules.scala:350)
at android.Plugin$$anonfun$allPluginSettings$67.apply(rules.scala:342)
at scala.Function2$$anonfun$tupled$1.apply(Function2.scala:54)
at scala.Function2$$anonfun$tupled$1.apply(Function2.scala:53)
at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
at sbt.EvaluateSettings$MixedNode.evaluate0(INode.scala:177)
at sbt.EvaluateSettings$INode.evaluate(INode.scala:135)
at sbt.EvaluateSettings$$anonfun$sbt$EvaluateSettings$$submitEvaluate$1.apply$mcV$sp(INode.scala:67)
at sbt.EvaluateSettings.sbt$EvaluateSettings$$run0(INode.scala:76)
at sbt.EvaluateSettings$$anon$3.run(INode.scala:72)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
[error] set ANDROID_HOME or run 'android update project -p /home/koperek/Projects/colors/android'
[error] Use 'last' for the full log.
Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore? 

So how to bootstrap a working libgdx@scala project?

1. Install conscript and g8 (first two lines of snippet above).
2. Define ANDROID_HOME in idea.sh and .bashrc
3. Use my fork of libgdx template: g8 pkoperek/libgdx-sbt-project
4. Run sbt "project core" gen-idea
5. Open the project in IntelliJ (not import - this doesn’t work - open)
6. After opening in IDEA:
7. In android module settings set the language level to 6.0.
8. In desktop module settings remove null from source roots list.
9. Unmark gen/com as source root.

Fork of template contains following improvements:

1. Fixes project layout (src/main/scala instead of src)
2. Removes test code from APKs (you can add test dependencies to test scope instead of compile + removing by proguard)
3. Updated plugins and libgdx versions
4. Adds scalatest
5. Adds sbt-idea plugin in latest version

Workflow:

• After adding a new dependency remember about sbt update and sbt "project core" gen-idea
• To run app in emulator, start one with AVD and run sbt android/android:run
• To generate a package hit sbt android/android:package