always use our text painter;

--- a/src/Tools/jEdit/src/text_painter.scala	Mon Jun 13 12:29:26 2011 +0200
+++ b/src/Tools/jEdit/src/text_painter.scala	Mon Jun 13 12:33:53 2011 +0200
@@ -29,77 +29,70 @@
     }
   }
 
-  var use = false
-
   override def paintScreenLineRange(gfx: Graphics2D,
     first_line: Int, last_line: Int, physical_lines: Array[Int],
     start: Array[Int], end: Array[Int], y: Int, line_height: Int)
   {
-    if (use) {
-      val buffer = text_area.getBuffer
-      Isabelle.swing_buffer_lock(buffer) {
-        val painter = text_area.getPainter
-        val font = painter.getFont
-        val font_context = painter.getFontRenderContext
-        val fm = painter.getFontMetrics
+    val buffer = text_area.getBuffer
+    Isabelle.swing_buffer_lock(buffer) {
+      val painter = text_area.getPainter
+      val font = painter.getFont
+      val font_context = painter.getFontRenderContext
+      val fm = painter.getFontMetrics
 
-        // see org.gjt.sp.jedit.textarea.TextArea.propertiesChanged
-        // see org.gjt.sp.jedit.textarea.TextArea.setMaxLineLength
-        val char_width = font.getStringBounds(" ", font_context).getWidth.round.toInt
-        val soft_wrap = buffer.getStringProperty("wrap") == "soft"
-        val wrap_margin =
-        {
-          val max = buffer.getIntegerProperty("maxLineLen", 0)
-          if (max > 0) font.getStringBounds(" " * max, font_context).getWidth.toInt
-          else if (soft_wrap) painter.getWidth - char_width * 3
-          else 0
-        }.toFloat
+      // see org.gjt.sp.jedit.textarea.TextArea.propertiesChanged
+      // see org.gjt.sp.jedit.textarea.TextArea.setMaxLineLength
+      val char_width = font.getStringBounds(" ", font_context).getWidth.round.toInt
+      val soft_wrap = buffer.getStringProperty("wrap") == "soft"
+      val wrap_margin =
+      {
+        val max = buffer.getIntegerProperty("maxLineLen", 0)
+        if (max > 0) font.getStringBounds(" " * max, font_context).getWidth.toInt
+        else if (soft_wrap) painter.getWidth - char_width * 3
+        else 0
+      }.toFloat
 
-        val line_infos: Map[Text.Offset, Chunk] =
-        {
-          val out = new ArrayList[Chunk]
-          val handler = new DisplayTokenHandler
-          val margin = if (soft_wrap) wrap_margin else 0.0f
+      val line_infos: Map[Text.Offset, Chunk] =
+      {
+        val out = new ArrayList[Chunk]
+        val handler = new DisplayTokenHandler
+        val margin = if (soft_wrap) wrap_margin else 0.0f
 
-          var result = Map[Text.Offset, Chunk]()
-          for (line <- physical_lines.iterator.filter(i => i != -1)) {
-            out.clear
-            handler.init(painter.getStyles, font_context, painter, out, margin)
-            buffer.markTokens(line, handler)
+        var result = Map[Text.Offset, Chunk]()
+        for (line <- physical_lines.iterator.filter(i => i != -1)) {
+          out.clear
+          handler.init(painter.getStyles, font_context, painter, out, margin)
+          buffer.markTokens(line, handler)
 
-            val line_start = buffer.getLineStartOffset(line)
-            for (i <- 0 until out.size) {
-              val chunk = out.get(i)
-              result += (line_start + chunk.offset -> chunk)
-            }
+          val line_start = buffer.getLineStartOffset(line)
+          for (i <- 0 until out.size) {
+            val chunk = out.get(i)
+            result += (line_start + chunk.offset -> chunk)
           }
-          result
         }
+        result
+      }
 
-        val clip = gfx.getClip
-        val x0 = text_area.getHorizontalOffset
-        var y0 = y + fm.getHeight - (fm.getLeading + 1) - fm.getDescent
-        for (i <- 0 until physical_lines.length) {
-          if (physical_lines(i) != -1) {
-            line_infos.get(start(i)) match {
-              case Some(chunk) =>
-                val w = Chunk.paintChunkList(chunk, gfx, x0, y0, !Debug.DISABLE_GLYPH_VECTOR).toInt
-                gfx.setFont(font)
-                gfx.clipRect(x0 + w, 0, Integer.MAX_VALUE, Integer.MAX_VALUE)
-                orig_text_painter.paintValidLine(
-                  gfx, first_line + i, physical_lines(i), start(i), end(i), y + line_height * i)
-                gfx.setClip(clip)
+      val clip = gfx.getClip
+      val x0 = text_area.getHorizontalOffset
+      var y0 = y + fm.getHeight - (fm.getLeading + 1) - fm.getDescent
+      for (i <- 0 until physical_lines.length) {
+        if (physical_lines(i) != -1) {
+          line_infos.get(start(i)) match {
+            case Some(chunk) =>
+              val w = Chunk.paintChunkList(chunk, gfx, x0, y0, !Debug.DISABLE_GLYPH_VECTOR).toInt
+              gfx.setFont(font)
+              gfx.clipRect(x0 + w, 0, Integer.MAX_VALUE, Integer.MAX_VALUE)
+              orig_text_painter.paintValidLine(
+                gfx, first_line + i, physical_lines(i), start(i), end(i), y + line_height * i)
+              gfx.setClip(clip)
 
-              case None =>
-            }
+            case None =>
           }
-          y0 += line_height
         }
+        y0 += line_height
       }
     }
-    else
-      orig_text_painter.paintScreenLineRange(
-        gfx, first_line, last_line, physical_lines, start, end, y, line_height)
   }