This is the init function of the extended class:

setFitAll(true);
setShowScrollbars(true);
setDimColor(ADColors.DIAGRAM_OVERVIEW_DIM);
setBackground(ADColors.DIAGRAM_BACKGROUND);
setDocument(_chart);
setTrackingRectPen(new Pen(0, ADColors.DIAGRAM_OVERVIEW_SELECTION));
setPreferredSize(new Dimension(DiagramViewPanel.RIGHT_PANEL_WIDTH,DiagramViewPanel.OVERVIEW_HEIGHT));


Besides the init, I have another method:
public float getAspectRatio() {
  Rectangle bounds = this.getVisibleRect();
  return (float)bounds.width / (float)bounds.height;
}


That's it.

Hi,

I've tried running it - and it showed fine.
I tried loading my chart. That was a bit difficult because the tags my boxes have are complex obkects. I replace all tags with null, saved it and reopenned in your sample - and the Overview looked fine.
Are you doing something with the tags in the Overview? Maybe this caused an exception?