1 files changed, 63 insertions, 0 deletions
diff --git a/src/repl/scala/tools/nsc/interpreter/ConsoleReaderHelper.scala b/src/repl/scala/tools/nsc/interpreter/ConsoleReaderHelper.scala
new file mode 100644
index 0000000000..48af261937
--- /dev/null
+++ b/src/repl/scala/tools/nsc/interpreter/ConsoleReaderHelper.scala
@@ -0,0 +1,63 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2013 LAMP/EPFL
+ * @author Paul Phillips
+ */
+
+package scala.tools.nsc
+package interpreter
+
+import scala.tools.jline.console.{ ConsoleReader, CursorBuffer }
+
+trait ConsoleReaderHelper extends ConsoleReader {
+  def terminal    = getTerminal()
+  def width       = terminal.getWidth()
+  def height      = terminal.getHeight()
+
+  def readOneKey(prompt: String): Int
+  def eraseLine(): Unit
+
+  private val marginSize = 3
+  private def morePrompt = "--More--"
+  private def emulateMore(): Int = {
+    val key = readOneKey(morePrompt)
+    try key match {
+      case '\r' | '\n'  => 1
+      case 'q'          => -1
+      case _            => height - 1
+    }
+    finally {
+      eraseLine()
+      // TODO: still not quite managing to erase --More-- and get
+      // back to a scala prompt without another keypress.
+      if (key == 'q') {
+        putString(getPrompt())
+        redrawLine()
+        flush()
+      }
+    }
+  }
+
+  override def printColumns(items: JCollection[_ <: CharSequence]): Unit =
+    printColumns(items: List[String])
+
+  def printColumns(items: List[String]): Unit = {
+    if (items forall (_ == ""))
+      return
+
+    val longest    = items map (_.length) max
+    var linesLeft  = if (isPaginationEnabled()) height - 1 else Int.MaxValue
+    val columnSize = longest + marginSize
+    val padded     = items map ("%-" + columnSize + "s" format _)
+    val groupSize  = 1 max (width / columnSize)   // make sure it doesn't divide to 0
+
+    padded grouped groupSize foreach { xs =>
+      println(xs.mkString)
+      linesLeft -= 1
+      if (linesLeft <= 0) {
+        linesLeft = emulateMore()
+        if (linesLeft < 0)
+          return
+      }
+    }
+  }
+}