Im working on a ScatterVBO and I want to add a AWTColorBarLegend to it. When refreshing the chart and its legend getImageGenerator() is called at multiple times, for example to get the dimension of the image :

AWTColorbarImageGenerator gen = getImageGenerator();

    // We add the margin width because margin is handled by this viewport
    // and not included inside the generated image.
    int w = gen.getPreferredWidth(painter) + margin.getWidth();

The problem is that the imageGenerator is null and never initialized because ScatterVBO isn’t an instance of IMultiColorable.

protected void initImageGenerator(Drawable parent, ITickProvider provider,
      ITickRenderer renderer) {
    if (parent != null && parent instanceof IMultiColorable) {
      IMultiColorable mc = ((IMultiColorable) parent);
      if (mc.getColorMapper() != null) {
        imageGenerator = new maser.customjzy3d.AWTColorbarImageGenerator(mc.getColorMapper(), provider, renderer);
        if (font != null)
          imageGenerator.setFont(font);
      }
    }
    if (imageGenerator == null) {
      LogManager.getLogger(this.getClass()).info(
          "Passed a drawable object that is not IMultiColorable or has no ColorMapper defined");
    }
  }

Is there a way to make ScatterVBO instanceof IMultiColorable or any other solution ? I would be very grateful for some help.

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