src/Tools/jEdit/src/token_markup.scala

more robust display of bidirectional Unicode text: enforce left-to-right;

/*  Title:      Tools/jEdit/src/token_markup.scala
    Author:     Makarius

Outer syntax token markup.
*/

package isabelle.jedit


import isabelle._

import java.awt.{Font, Color}
import java.awt.font.TextAttribute
import java.awt.geom.AffineTransform

import org.gjt.sp.util.SyntaxUtilities
import org.gjt.sp.jedit.{jEdit, Mode, Buffer}
import org.gjt.sp.jedit.syntax.{Token => JEditToken, TokenMarker, TokenHandler, DummyTokenHandler,
  ParserRuleSet, ModeProvider, XModeHandler, SyntaxStyle}
import org.gjt.sp.jedit.textarea.{TextArea, Selection}
import org.gjt.sp.jedit.buffer.JEditBuffer

import javax.swing.text.Segment


object Token_Markup
{
  /* editing support for control symbols */

  def edit_control_style(text_area: TextArea, control: String)
  {
    GUI_Thread.assert {}

    val buffer = text_area.getBuffer

    val control_decoded = Isabelle_Encoding.maybe_decode(buffer, control)

    def update_style(text: String): String =
    {
      val result = new StringBuilder
      for (sym <- Symbol.iterator(text) if !HTML.control.isDefinedAt(sym)) {
        if (Symbol.is_controllable(sym)) result ++= control_decoded
        result ++= sym
      }
      result.toString
    }

    text_area.getSelection.foreach(sel => {
      val before = JEdit_Lib.point_range(buffer, sel.getStart - 1)
      JEdit_Lib.try_get_text(buffer, before) match {
        case Some(s) if HTML.control.isDefinedAt(s) =>
          text_area.extendSelection(before.start, before.stop)
        case _ =>
      }
    })

    text_area.getSelection.toList match {
      case Nil =>
        text_area.setSelectedText(control_decoded)
      case sels =>
        JEdit_Lib.buffer_edit(buffer) {
          sels.foreach(sel =>
            text_area.setSelectedText(sel, update_style(text_area.getSelectedText(sel))))
        }
    }
  }


  /* extended syntax styles */

  private val plain_range: Int = JEditToken.ID_COUNT
  private val full_range = 6 * plain_range + 1
  private def check_range(i: Int) { require(0 <= i && i < plain_range) }

  def subscript(i: Byte): Byte = { check_range(i); (i + plain_range).toByte }
  def superscript(i: Byte): Byte = { check_range(i); (i + 2 * plain_range).toByte }
  def bold(i: Byte): Byte = { check_range(i); (i + 3 * plain_range).toByte }
  def user_font(idx: Int, i: Byte): Byte = { check_range(i); (i + (4 + idx) * plain_range).toByte }
  val hidden: Byte = (6 * plain_range).toByte

  private def font_style(style: SyntaxStyle, f: Font => Font): SyntaxStyle =
    new SyntaxStyle(style.getForegroundColor, style.getBackgroundColor, f(style.getFont))

  private def script_style(style: SyntaxStyle, i: Int): SyntaxStyle =
  {
    font_style(style, font0 =>
      {
        import scala.collection.JavaConversions._
        val font1 = font0.deriveFont(Map(TextAttribute.SUPERSCRIPT -> new java.lang.Integer(i)))

        def shift(y: Float): Font =
          GUI.transform_font(font1, AffineTransform.getTranslateInstance(0.0, y.toDouble))

        val m0 = GUI.line_metrics(font0)
        val m1 = GUI.line_metrics(font1)
        val a = m1.getAscent - m0.getAscent
        val b = (m1.getDescent + m1.getLeading) - (m0.getDescent + m0.getLeading)
        if (a > 0.0f) shift(a)
        else if (b > 0.0f) shift(- b)
        else font1
      })
  }

  private def bold_style(style: SyntaxStyle): SyntaxStyle =
    font_style(style, font => font.deriveFont(if (font.isBold) Font.PLAIN else Font.BOLD))

  val hidden_color: Color = new Color(255, 255, 255, 0)

  class Style_Extender extends SyntaxUtilities.StyleExtender
  {
    val max_user_fonts = 2
    if (Symbol.font_names.length > max_user_fonts)
      error("Too many user symbol fonts (" + max_user_fonts + " permitted): " +
        Symbol.font_names.mkString(", "))

    override def extendStyles(styles: Array[SyntaxStyle]): Array[SyntaxStyle] =
    {
      val new_styles = new Array[SyntaxStyle](full_range)
      for (i <- 0 until plain_range) {
        val style = styles(i)
        new_styles(i) = style
        new_styles(subscript(i.toByte)) = script_style(style, -1)
        new_styles(superscript(i.toByte)) = script_style(style, 1)
        new_styles(bold(i.toByte)) = bold_style(style)
        for (idx <- 0 until max_user_fonts)
          new_styles(user_font(idx, i.toByte)) = style
        for ((family, idx) <- Symbol.font_index)
          new_styles(user_font(idx, i.toByte)) = font_style(style, GUI.imitate_font(_, family))
      }
      new_styles(hidden) =
        new SyntaxStyle(hidden_color, null,
          { val font = styles(0).getFont
            GUI.transform_font(new Font(font.getFamily, 0, 1),
              AffineTransform.getScaleInstance(1.0, font.getSize.toDouble)) })
      new_styles
    }
  }

  def extended_styles(text: CharSequence): Map[Text.Offset, Byte => Byte] =
  {
    // FIXME Symbol.bsub_decoded etc.
    def control_style(sym: String): Option[Byte => Byte] =
      if (sym == Symbol.sub_decoded) Some(subscript(_))
      else if (sym == Symbol.sup_decoded) Some(superscript(_))
      else if (sym == Symbol.bold_decoded) Some(bold(_))
      else None

    var result = Map[Text.Offset, Byte => Byte]()
    def mark(start: Text.Offset, stop: Text.Offset, style: Byte => Byte)
    {
      for (i <- start until stop) result += (i -> style)
    }
    var offset = 0
    var control = ""
    for (sym <- Symbol.iterator(text)) {
      if (control_style(sym).isDefined) control = sym
      else if (control != "") {
        if (Symbol.is_controllable(sym) && sym != "\"" && !Symbol.fonts.isDefinedAt(sym)) {
          mark(offset - control.length, offset, _ => hidden)
          mark(offset, offset + sym.length, control_style(control).get)
        }
        control = ""
      }
      Symbol.lookup_font(sym) match {
        case Some(idx) => mark(offset, offset + sym.length, user_font(idx, _))
        case _ =>
      }
      offset += sym.length
    }
    result
  }


  /* line context */

  private val context_rules = new ParserRuleSet("isabelle", "MAIN")

  object Line_Context
  {
    val init = new Line_Context(Some(Scan.Finished), Outer_Syntax.Line_Structure.init)
  }

  class Line_Context(
      val context: Option[Scan.Line_Context],
      val structure: Outer_Syntax.Line_Structure)
    extends TokenMarker.LineContext(context_rules, null)
  {
    override def hashCode: Int = (context, structure).hashCode
    override def equals(that: Any): Boolean =
      that match {
        case other: Line_Context => context == other.context && structure == other.structure
        case _ => false
      }
  }

  def buffer_line_context(buffer: JEditBuffer, line: Int): Line_Context =
  {
    val line_mgr = JEdit_Lib.buffer_line_manager(buffer)
    def context =
      line_mgr.getLineContext(line) match {
        case c: Line_Context => Some(c)
        case _ => None
      }
    context getOrElse {
      buffer.markTokens(line, DummyTokenHandler.INSTANCE)
      context getOrElse Line_Context.init
    }
  }


  /* tokens from line (inclusive) */

  private def try_line_tokens(syntax: Outer_Syntax, buffer: JEditBuffer, line: Int)
    : Option[List[Token]] =
  {
    val line_context =
      if (line == 0) Line_Context.init
      else buffer_line_context(buffer, line - 1)
    for {
      ctxt <- line_context.context
      text <- JEdit_Lib.try_get_text(buffer, JEdit_Lib.line_range(buffer, line))
    } yield Token.explode_line(syntax.keywords, text, ctxt)._1
  }

  def line_token_iterator(
      syntax: Outer_Syntax,
      buffer: JEditBuffer,
      start_line: Int,
      end_line: Int): Iterator[Text.Info[Token]] =
    for {
      line <- Range(start_line max 0, end_line min buffer.getLineCount).iterator
      tokens <- try_line_tokens(syntax, buffer, line).iterator
      starts =
        tokens.iterator.scanLeft(buffer.getLineStartOffset(line))(
          (i, tok) => i + tok.source.length)
      (i, tok) <- starts zip tokens.iterator
    } yield Text.Info(Text.Range(i, i + tok.source.length), tok)

  def line_token_reverse_iterator(
      syntax: Outer_Syntax,
      buffer: JEditBuffer,
      start_line: Int,
      end_line: Int): Iterator[Text.Info[Token]] =
    for {
      line <- Range(start_line min (buffer.getLineCount - 1), end_line max -1, -1).iterator
      tokens <- try_line_tokens(syntax, buffer, line).iterator
      stops =
        tokens.reverseIterator.scanLeft(buffer.getLineEndOffset(line) min buffer.getLength)(
          (i, tok) => i - tok.source.length)
      (i, tok) <- stops zip tokens.reverseIterator
    } yield Text.Info(Text.Range(i - tok.source.length, i), tok)


  /* tokens from offset (inclusive) */

  def token_iterator(syntax: Outer_Syntax, buffer: JEditBuffer, offset: Text.Offset):
      Iterator[Text.Info[Token]] =
    if (JEdit_Lib.buffer_range(buffer).contains(offset))
      line_token_iterator(syntax, buffer, buffer.getLineOfOffset(offset), buffer.getLineCount).
        dropWhile(info => !info.range.contains(offset))
    else Iterator.empty

  def token_reverse_iterator(syntax: Outer_Syntax, buffer: JEditBuffer, offset: Text.Offset):
      Iterator[Text.Info[Token]] =
    if (JEdit_Lib.buffer_range(buffer).contains(offset))
      line_token_reverse_iterator(syntax, buffer, buffer.getLineOfOffset(offset), -1).
        dropWhile(info => !info.range.contains(offset))
    else Iterator.empty


  /* command spans */

  def command_span(syntax: Outer_Syntax, buffer: JEditBuffer, offset: Text.Offset)
    : Option[Text.Info[Command_Span.Span]] =
  {
    def maybe_command_start(i: Text.Offset): Option[Text.Info[Token]] =
      token_reverse_iterator(syntax, buffer, i).
        find(info => info.info.is_command_modifier || info.info.is_command)

    def maybe_command_stop(i: Text.Offset): Option[Text.Info[Token]] =
      token_iterator(syntax, buffer, i).
        find(info => info.info.is_command_modifier || info.info.is_command)

    if (JEdit_Lib.buffer_range(buffer).contains(offset)) {
      val start_info =
      {
        val info1 = maybe_command_start(offset)
        info1 match {
          case Some(Text.Info(range1, tok1)) if tok1.is_command =>
            val info2 = maybe_command_start(range1.start - 1)
            info2 match {
              case Some(Text.Info(_, tok2)) if tok2.is_command_modifier => info2
              case _ => info1
            }
          case _ => info1
        }
      }
      val (start_is_command_modifier, start, start_next) =
        start_info match {
          case Some(Text.Info(range, tok)) => (tok.is_command_modifier, range.start, range.stop)
          case None => (false, 0, 0)
        }

      val stop_info =
      {
        val info1 = maybe_command_stop(start_next)
        info1 match {
          case Some(Text.Info(range1, tok1)) if tok1.is_command && start_is_command_modifier =>
            maybe_command_stop(range1.stop)
          case _ => info1
        }
      }
      val stop =
        stop_info match {
          case Some(Text.Info(range, _)) => range.start
          case None => buffer.getLength
        }

      val text = JEdit_Lib.try_get_text(buffer, Text.Range(start, stop)).getOrElse("")
      val spans = syntax.parse_spans(text)

      (spans.iterator.scanLeft(start)(_ + _.length) zip spans.iterator).
        map({ case (i, span) => Text.Info(Text.Range(i, i + span.length), span) }).
        find(_.range.contains(offset))
    }
    else None
  }

  private def _command_span_iterator(
      syntax: Outer_Syntax,
      buffer: JEditBuffer,
      offset: Text.Offset,
      next_offset: Text.Range => Text.Offset): Iterator[Text.Info[Command_Span.Span]] =
    new Iterator[Text.Info[Command_Span.Span]]
    {
      private var next_span = command_span(syntax, buffer, offset)
      def hasNext: Boolean = next_span.isDefined
      def next: Text.Info[Command_Span.Span] =
      {
        val span = next_span.getOrElse(Iterator.empty.next)
        next_span = command_span(syntax, buffer, next_offset(span.range))
        span
      }
    }

  def command_span_iterator(syntax: Outer_Syntax, buffer: JEditBuffer, offset: Text.Offset)
      : Iterator[Text.Info[Command_Span.Span]] =
    _command_span_iterator(syntax, buffer, offset max 0, range => range.stop)

  def command_span_reverse_iterator(syntax: Outer_Syntax, buffer: JEditBuffer, offset: Text.Offset)
      : Iterator[Text.Info[Command_Span.Span]] =
    _command_span_iterator(syntax, buffer,
      (offset min buffer.getLength) - 1, range => range.start - 1)


  /* token marker */

  class Marker(
    protected val mode: String,
    protected val opt_buffer: Option[Buffer]) extends TokenMarker
  {
    override def hashCode: Int = (mode, opt_buffer).hashCode
    override def equals(that: Any): Boolean =
      that match {
        case other: Marker => mode == other.mode && opt_buffer == other.opt_buffer
        case _ => false
      }

    override def toString: String =
      opt_buffer match {
        case None => "Marker(" + mode + ")"
        case Some(buffer) => "Marker(" + mode + "," + JEdit_Lib.buffer_name(buffer) + ")"
      }

    override def markTokens(context: TokenMarker.LineContext,
        handler: TokenHandler, raw_line: Segment): TokenMarker.LineContext =
    {
      val line = if (raw_line == null) new Segment else raw_line
      val line_context = context match { case c: Line_Context => c case _ => Line_Context.init }
      val structure = line_context.structure

      val context1 =
      {
        val opt_syntax =
          opt_buffer match {
            case Some(buffer) => Isabelle.buffer_syntax(buffer)
            case None => Isabelle.mode_syntax(mode)
          }
        val (styled_tokens, context1) =
          (line_context.context, opt_syntax) match {
            case (Some(ctxt), _) if mode == "isabelle-ml" || mode == "sml" =>
              val (tokens, ctxt1) = ML_Lex.tokenize_line(mode == "sml", line, ctxt)
              val styled_tokens = tokens.map(tok => (Rendering.ml_token_markup(tok), tok.source))
              (styled_tokens, new Line_Context(Some(ctxt1), structure))

            case (Some(ctxt), Some(syntax)) if syntax.has_tokens =>
              val (tokens, ctxt1) = Token.explode_line(syntax.keywords, line, ctxt)
              val structure1 = syntax.line_structure(tokens, structure)
              val styled_tokens =
                tokens.map(tok => (Rendering.token_markup(syntax, tok), tok.source))
              (styled_tokens, new Line_Context(Some(ctxt1), structure1))

            case _ =>
              val styled_token = (JEditToken.NULL, line.subSequence(0, line.count).toString)
              (List(styled_token), new Line_Context(None, structure))
          }

        val extended = extended_styles(line)

        var offset = 0
        for ((style, token) <- styled_tokens) {
          val length = token.length
          val end_offset = offset + length
          if ((offset until end_offset) exists
              (i => extended.isDefinedAt(i) || line.charAt(i) == '\t')) {
            for (i <- offset until end_offset) {
              val style1 =
                extended.get(i) match {
                  case None => style
                  case Some(ext) => ext(style)
                }
              handler.handleToken(line, style1, i, 1, context1)
            }
          }
          else handler.handleToken(line, style, offset, length, context1)
          offset += length
        }
        handler.handleToken(line, JEditToken.END, line.count, 0, context1)
        context1
      }

      val context2 = context1.intern
      handler.setLineContext(context2)
      context2
    }
  }


  /* mode provider */

  class Mode_Provider(orig_provider: ModeProvider) extends ModeProvider
  {
    for (mode <- orig_provider.getModes) addMode(mode)

    override def loadMode(mode: Mode, xmh: XModeHandler)
    {
      super.loadMode(mode, xmh)
      Isabelle.mode_token_marker(mode.getName).foreach(mode.setTokenMarker _)
    }
  }
}