/*  Title:      Tools/jEdit/src/isabelle_encoding.scala

     Author:     Makarius

 Isabelle encoding -- based on UTF-8.

 */

 package isabelle.jedit

 import isabelle._

 import org.gjt.sp.jedit.io.Encoding

 import org.gjt.sp.jedit.buffer.JEditBuffer

 import java.nio.charset.{Charset, CodingErrorAction}

 import java.io.{InputStream, OutputStream, Reader, Writer, InputStreamReader, OutputStreamWriter,

   CharArrayReader, ByteArrayOutputStream}

 import scala.io.{Codec, Source, BufferedSource}

 object Isabelle_Encoding

 {

   val NAME = "UTF-8-Isabelle"

   def is_active(buffer: JEditBuffer): Boolean =

     buffer.getStringProperty(JEditBuffer.ENCODING).asInstanceOf[String] == NAME

 }

 class Isabelle_Encoding extends Encoding

 {

   private val BUFSIZE = 32768

   private def text_reader(in: InputStream, codec: Codec): Reader =

   {

     val source = new BufferedSource(in)(codec)

     new CharArrayReader(Symbol.decode(source.mkString).toArray)

   }

   override def getTextReader(in: InputStream): Reader =

     text_reader(in, Standard_System.codec())

   override def getPermissiveTextReader(in: InputStream): Reader =

   {

     val codec = Standard_System.codec()

     codec.onMalformedInput(CodingErrorAction.REPLACE)

     codec.onUnmappableCharacter(CodingErrorAction.REPLACE)

     text_reader(in, codec)

   }

   override def getTextWriter(out: OutputStream): Writer =

   {

     val buffer = new ByteArrayOutputStream(BUFSIZE) {

       override def flush()

       {

         val text = Symbol.encode(toString(Standard_System.charset_name))

         out.write(text.getBytes(Standard_System.charset))

         out.flush()

       }

       override def close() { out.close() }

     }

     new OutputStreamWriter(buffer, Standard_System.charset.newEncoder())

   }

 }