InsertNewLineAbove mini-plugin for https://github.com/dkandalov/live-plugin

plugin.scala

import com.intellij.openapi.actionSystem.{AnActionEvent, AnAction}
import com.intellij.openapi.application.ApplicationManager
import com.intellij.openapi.command.{UndoConfirmationPolicy, CommandProcessor}
import groovy.lang.Closure
import liveplugin.PluginUtil._

// This action inserts new line above current line.
// It's a follow-up for these posts:
//   http://martinfowler.com/bliki/InternalReprogrammability.html
//   http://nealford.com/memeagora/2013/01/22/why_everyone_eventually_hates_maven.html
// Note that there is "Start New Line Before Current" action (ctrl + alt + enter) which does almost the same thing.

implicit def asGroovyClosure_WithActionEventParam[F](f: (AnActionEvent) => F) = new Closure[F]() { def doCall(event: AnActionEvent): F = f(event) }
implicit def asGroovyClosure_WithNoParams[F](f: () => F) = new Closure[F]() { def doCall(arg: Any): F = f() }

registerAction("InsertNewLineAbove", "alt shift ENTER", (event: AnActionEvent) => {
  runDocumentWriteAction(event.getProject, () => {
    val editor = currentEditorIn(event.getProject)
    val offset = editor.getCaretModel.getOffset

    val currentLine = editor.getCaretModel.getLogicalPosition.line
    val lineStartOffset = editor.getDocument.getLineStartOffset(currentLine)

    editor.getDocument.insertString(lineStartOffset, "\n")
    editor.getCaretModel.moveToOffset(offset + 1)
  })
})

show("Loaded 'InsertNewLineAbove' action<br/>Use 'Alt+Shift+Enter' to run it")