void MainWindow_OnFoodAddition(Food source, EventArgs e)
{
FoodVisual visual = null;
Dispatcher.Invoke(new Action(() => visual = new FoodVisual(source, new Ellipse())));
foodVisuals.Add(visual);
Dispatcher.Invoke(new Action(() => canvas.Children.Add(visual.getVisual())));
visual.OnSourceEaten += visual_OnSourceEaten;
visual.update();
}
void visual_OnSourceEaten(FoodVisual source, EventArgs e)
{
foodVisuals.Remove(source);
Dispatcher.Invoke(new Action(() => canvas.Children.Remove(source.getVisual())));
}