src/Tools/jEdit/src/syntax_style.scala

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Tools/jEdit/src/syntax_style.scala	Wed Mar 15 13:35:14 2017 +0100
@@ -0,0 +1,123 @@
+/*  Title:      Tools/jEdit/src/syntax_style.scala
+    Author:     Makarius
+
+Support for extended syntax styles: subscript, superscript, bold, user fonts.
+*/
+
+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.syntax.{Token => JEditToken, SyntaxStyle}
+
+
+object Syntax_Style
+{
+  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 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(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
+  }
+}