RenderExecutorComposite re = tile.getRenderExecutor();
if (tile.getRenderState() == Tile.RenderState.INVALID) {
re.setRenderBounds(tile.getReferencedEnvelope());
re.getRenderer().setState(IRenderer.RENDER_REQUEST);
re.render();
} else {
//kick the renderer to refresh the image
re.getRenderer().setState(IRenderer.DONE);
}
tile.setRenderState(Tile.RenderState.RENDERED);