package sbt
object SelectMainClass
{
def apply(promptIfMultipleChoices: Option[String => Option[String]], mainClasses: Seq[String]): Option[String] =
{
mainClasses.toList match
{
case Nil => None
case head :: Nil => Some(head)
case multiple =>
promptIfMultipleChoices flatMap { prompt =>
println("\nMultiple main classes detected, select one to run:\n")
for( (className, index) <- multiple.zipWithIndex )
println(" [" + (index+1) + "] " + className)
val line = trim(prompt("\nEnter number: "))
println("")
toInt(line, multiple.length) map multiple.apply
}
}
}
private def trim(s: Option[String]) = s.getOrElse("")
private def toInt(s: String, size: Int) =
try
{
val i = s.toInt
if(i > 0 && i <= size)
Some(i-1)
else
{
println("Number out of range: was " + i + ", expected number between 1 and " + size)
None
}
}
catch
{
case nfe: NumberFormatException =>
println("Invalid number: " + nfe.toString)
None
}
}