src/Tools/jEdit/src/jedit_lib.scala

refer to parent frame -- relevant for floating dockables in particular;

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

Misc library functions for jEdit.
*/

package isabelle.jedit


import isabelle._

import java.awt.{Component, Container, Frame}

import scala.annotation.tailrec

import org.gjt.sp.jedit.{jEdit, Buffer, View}
import org.gjt.sp.jedit.buffer.JEditBuffer
import org.gjt.sp.jedit.textarea.{JEditTextArea, TextArea}


object JEdit_Lib
{
  /* frames */

  def parent_frame(component: Component): Option[Frame] =
  {
    @tailrec def find(c: Container): Option[Frame] =
      c match {
        case null => None
        case frame: Frame => Some(frame)
        case _ => find(c.getParent)
      }
    find(component.getParent)
  }


  /* buffers */

  def swing_buffer_lock[A](buffer: JEditBuffer)(body: => A): A =
    Swing_Thread.now { buffer_lock(buffer) { body } }

  def buffer_text(buffer: JEditBuffer): String =
    buffer_lock(buffer) { buffer.getText(0, buffer.getLength) }

  def buffer_name(buffer: Buffer): String = buffer.getSymlinkPath

  def buffer_node_dummy(buffer: Buffer): Option[Document.Node.Name] =
    Some(Document.Node.Name(buffer_name(buffer), buffer.getDirectory, buffer.getName))

  def buffer_node_name(buffer: Buffer): Option[Document.Node.Name] =
  {
    val name = buffer_name(buffer)
    Thy_Header.thy_name(name).map(theory => Document.Node.Name(name, buffer.getDirectory, theory))
  }


  /* main jEdit components */

  def jedit_buffers(): Iterator[Buffer] = jEdit.getBuffers().iterator

  def jedit_buffer(name: String): Option[Buffer] =
    jedit_buffers().find(buffer => buffer_name(buffer) == name)

  def jedit_views(): Iterator[View] = jEdit.getViews().iterator

  def jedit_text_areas(view: View): Iterator[JEditTextArea] =
    view.getEditPanes().iterator.map(_.getTextArea)

  def jedit_text_areas(): Iterator[JEditTextArea] =
    jedit_views().flatMap(jedit_text_areas(_))

  def jedit_text_areas(buffer: JEditBuffer): Iterator[JEditTextArea] =
    jedit_text_areas().filter(_.getBuffer == buffer)

  def buffer_lock[A](buffer: JEditBuffer)(body: => A): A =
  {
    try { buffer.readLock(); body }
    finally { buffer.readUnlock() }
  }


  /* point range */

  def point_range(buffer: JEditBuffer, offset: Text.Offset): Text.Range =
    buffer_lock(buffer) {
      def text(i: Text.Offset): Char = buffer.getText(i, 1).charAt(0)
      try {
        val c = text(offset)
        if (Character.isHighSurrogate(c) && Character.isLowSurrogate(text(offset + 1)))
          Text.Range(offset, offset + 2)
        else if (Character.isLowSurrogate(c) && Character.isHighSurrogate(text(offset - 1)))
          Text.Range(offset - 1, offset + 1)
        else Text.Range(offset, offset + 1)
      }
      catch { case _: ArrayIndexOutOfBoundsException => Text.Range(offset, offset + 1) }
    }


  /* proper line range */

  // NB: TextArea.getScreenLineEndOffset of last line is beyond Buffer.getLength
  def proper_line_range(buffer: JEditBuffer, start: Text.Offset, end: Text.Offset): Text.Range =
    Text.Range(start, end min buffer.getLength)


  /* visible text range */

  def visible_range(text_area: TextArea): Option[Text.Range] =
  {
    val buffer = text_area.getBuffer
    val n = text_area.getVisibleLines
    if (n > 0) {
      val start = text_area.getScreenLineStartOffset(0)
      val raw_end = text_area.getScreenLineEndOffset(n - 1)
      Some(proper_line_range(buffer, start, if (raw_end >= 0) raw_end else buffer.getLength))
    }
    else None
  }

  def invalidate_range(text_area: TextArea, range: Text.Range)
  {
    val buffer = text_area.getBuffer
    text_area.invalidateLineRange(
      buffer.getLineOfOffset(range.start),
      buffer.getLineOfOffset(range.stop))
  }


  /* char width */

  def char_width(text_area: TextArea): Int =
  {
    val painter = text_area.getPainter
    val font = painter.getFont
    val font_context = painter.getFontRenderContext
    font.getStringBounds(" ", font_context).getWidth.round.toInt
  }


  /* graphics range */

  class Gfx_Range(val x: Int, val y: Int, val length: Int)

  // NB: jEdit already normalizes \r\n and \r to \n
  // NB: last line lacks \n
  def gfx_range(text_area: TextArea, range: Text.Range): Option[Gfx_Range] =
  {
    val buffer = text_area.getBuffer

    val p = text_area.offsetToXY(range.start)

    val end = buffer.getLength
    val stop = range.stop
    val (q, r) =
      if (stop >= end) (text_area.offsetToXY(end), char_width(text_area))
      else if (stop > 0 && buffer.getText(stop - 1, 1) == "\n")
        (text_area.offsetToXY(stop - 1), char_width(text_area))
      else (text_area.offsetToXY(stop), 0)

    if (p != null && q != null && p.x < q.x + r && p.y == q.y)
      Some(new Gfx_Range(p.x, p.y, q.x + r - p.x))
    else None
  }
}