/**
   * 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.
  }
  @Override
  public int viewToModel(float x, float y, Shape a, Position.Bias[] bias) {

    int offs = -1;

    if (!isAllocationValid()) {
      Rectangle alloc = a.getBounds();
      setSize(alloc.width, alloc.height);
    }

    // Get the child view for the line at (x,y), and ask it for the
    // specific offset.
    Rectangle alloc = getInsideAllocation(a);
    View v = getViewAtPoint((int) x, (int) y, alloc);
    if (v != null) {
      offs = v.viewToModel(x, y, alloc, bias);
    }

    // Code folding may have hidden the last line.  If so, return the last
    // visible offset instead of the last offset.
    if (host.isCodeFoldingEnabled()
        && v == getView(getViewCount() - 1)
        && offs == v.getEndOffset() - 1) {
      offs = host.getLastVisibleOffset();
    }

    return offs;
  }