/**
   * Provides a mapping from the view coordinate space to the logical coordinate space of the model.
   *
   * @param fx the X coordinate >= 0
   * @param fy the Y coordinate >= 0
   * @param a the allocated region to render into
   * @return the location within the model that best represents the given point in the view >= 0
   */
  @Override
  public int viewToModel(float fx, float fy, Shape a, Position.Bias[] bias) {

    bias[0] = Position.Bias.Forward;

    Rectangle alloc = a.getBounds();
    RSyntaxDocument doc = (RSyntaxDocument) getDocument();
    int x = (int) fx;
    int y = (int) fy;

    // If they're asking about a view position above the area covered by
    // this view, then the position is assumed to be the starting position
    // of this view.
    if (y < alloc.y) {
      return getStartOffset();
    }

    // If they're asking about a position below this view, the position
    // is assumed to be the ending position of this view.
    else if (y > alloc.y + alloc.height) {
      return host.getLastVisibleOffset();
    }

    // They're asking about a position within the coverage of this view
    // vertically.  So, we figure out which line the point corresponds to.
    // If the line is greater than the number of lines contained, then
    // simply use the last line as it represents the last possible place
    // we can position to.
    else {

      Element map = doc.getDefaultRootElement();
      int lineIndex = Math.abs((y - alloc.y) / lineHeight); // metrics.getHeight() );
      FoldManager fm = host.getFoldManager();
      // System.out.print("--- " + lineIndex);
      lineIndex += fm.getHiddenLineCountAbove(lineIndex, true);
      // System.out.println(" => " + lineIndex);
      if (lineIndex >= map.getElementCount()) {
        return host.getLastVisibleOffset();
      }

      Element line = map.getElement(lineIndex);

      // If the point is to the left of the line...
      if (x < alloc.x) {
        return line.getStartOffset();
      } else if (x > alloc.x + alloc.width) {
        return line.getEndOffset() - 1;
      } else {
        // Determine the offset into the text
        int p0 = line.getStartOffset();
        Token tokenList = doc.getTokenListForLine(lineIndex);
        tabBase = alloc.x;
        int offs = tokenList.getListOffset((RSyntaxTextArea) getContainer(), this, tabBase, x);
        return offs != -1 ? offs : p0;
      }
    } // End of else.
  }
  /**
   * Determines the position in the model that is closest to the given view location in the row
   * below. The component given must have a size to compute the result. If the component doesn't
   * have a size a value of -1 will be returned.
   *
   * @param c the editor
   * @param offs the offset in the document >= 0
   * @param x the X coordinate >= 0
   * @return the position >= 0 if the request can be computed, otherwise a value of -1 will be
   *     returned.
   * @exception BadLocationException if the offset is out of range
   */
  public static final int getPositionBelow(RSyntaxTextArea c, int offs, float x, TabExpander e)
      throws BadLocationException {

    TokenOrientedView tov = (TokenOrientedView) e;
    Token token = tov.getTokenListForPhysicalLineBelow(offs);
    if (token == null) return -1;

    // A line containing only Token.NULL is an empty line.
    else if (token.type == Token.NULL) {
      int line = c.getLineOfOffset(offs); // Sure to be > c.getLineCount()-1 ??
      return c.getLineStartOffset(line + 1);
    } else {
      return token.getListOffset(c, e, 0, x);
    }
  }
    /**
     * Provides a mapping from the view coordinate space to the logical coordinate space of the
     * model.
     *
     * @param fx the X coordinate
     * @param fy the Y coordinate
     * @param a the allocated region to render into
     * @return the location within the model that best represents the given point in the view
     * @see View#viewToModel
     */
    @Override
    public int viewToModel(float fx, float fy, Shape a, Position.Bias[] bias) {

      // PENDING(prinz) implement bias properly
      bias[0] = Position.Bias.Forward;

      Rectangle alloc = (Rectangle) a;
      RSyntaxDocument doc = (RSyntaxDocument) getDocument();
      int x = (int) fx;
      int y = (int) fy;
      if (y < alloc.y) {
        // above the area covered by this icon, so the the position
        // is assumed to be the start of the coverage for this view.
        return getStartOffset();
      } else if (y > alloc.y + alloc.height) {
        // below the area covered by this icon, so the the position
        // is assumed to be the end of the coverage for this view.
        return getEndOffset() - 1;
      } else {

        // positioned within the coverage of this view vertically,
        // so we figure out which line the point corresponds to.
        // if the line is greater than the number of lines
        // contained, then simply use the last line as it represents
        // the last possible place we can position to.

        RSyntaxTextArea textArea = (RSyntaxTextArea) getContainer();
        alloc.height = textArea.getLineHeight();
        int p1 = getEndOffset();

        // Get the token list for this line so we don't have to keep
        // recomputing it if this logical line spans multiple
        // physical lines.
        Element map = doc.getDefaultRootElement();
        int p0 = getStartOffset();
        int line = map.getElementIndex(p0);
        Token tlist = doc.getTokenListForLine(line);

        // Look at each physical line-chunk of this logical line.
        while (p0 < p1) {

          // We can always use alloc.x since we always break
          // lines so they start at the beginning of a physical
          // line.
          TokenSubList subList =
              TokenUtils.getSubTokenList(
                  tlist, p0, WrappedSyntaxView.this, textArea, alloc.x, lineCountTempToken);
          tlist = subList != null ? subList.tokenList : null;
          int p = calculateBreakPosition(p0, tlist, alloc.x);

          // If desired view position is in this physical chunk.
          if ((y >= alloc.y) && (y < (alloc.y + alloc.height))) {

            // Point is to the left of the line
            if (x < alloc.x) {
              return p0;
            }

            // Point is to the right of the line
            else if (x > alloc.x + alloc.width) {
              return p - 1;
            }

            // Point is in this physical line!
            else {

              // Start at alloc.x since this chunk starts
              // at the beginning of a physical line.
              int n = tlist.getListOffset(textArea, WrappedSyntaxView.this, alloc.x, x);

              // NOTE:  We needed to add the max() with
              // p0 as getTokenListForLine returns -1
              // for empty lines (just a null token).
              // How did this work before?
              // FIXME:  Have null tokens have their
              // offset but a -1 length.
              return Math.max(Math.min(n, p1 - 1), p0);
            } // End of else.
          } // End of if ((y>=alloc.y) && ...

          p0 = (p == p0) ? p1 : p;
          alloc.y += alloc.height;
        } // End of while (p0<p1).

        return getEndOffset() - 1;
      } // End of else.
    }