private boolean isLargeEnough(){
  int x0=leftMargin;
  int x1=getWidth() - rightMargin;
  int y0=getHeight() - bottomMargin;
  int y1=topMargin;
  return x0 < x1 && y0 > y1;
}

private boolean isLargeEnough ( ) { int x0 = leftMargin ; int x1 = getWidth ( ) - rightMargin ; int y0 = getHeight ( ) - bottomMargin ; int y1 = topMargin ; return x0 < x1 && y0 > y1 ; }
is canvas large enough to draw chart ?
