class GraphicsGradient {
 
 String _kind;
 num _startX;
 num _startY;
 num _startRadius;
 num _endX;
 num _endY;
 num _endRadius;
 List _colorStops;

 GraphicsGradient.linear(num startX, num startY, num endX, num endY) {
    _kind = "linear";
    _startX = startX;
    _startY = startY;
    _endX = endX;
    _endY = endY;
    _colorStops = new List();
 }

 GraphicsGradient.radial(num startX, num startY, num startRadius, num endX, num endY, num endRadius) {
   _kind = "radial";
   _startX = startX;
   _startY = startY;
   _startRadius = startRadius;
   _endX = endX;
   _endY = endY;
   _endRadius = endRadius;
   _colorStops = new List();
 }

 //-------------------------------------------------------------------------------------------------
 //-------------------------------------------------------------------------------------------------

 void addColorStop(num offset, int color) {
   _colorStops.add({"offset" : offset, "color" : _color2rgba(color)});
 }

 //-------------------------------------------------------------------------------------------------
 //-------------------------------------------------------------------------------------------------

 CanvasGradient getCanvasGradient(CanvasRenderingContext2D context) {
   
   // ToDo: Maybe we should cache the CanvasGradient for a given context.
   // This could improve performance!

   CanvasGradient canvasGradient;

   if (_kind == "linear")
     canvasGradient = context.createLinearGradient(_startX, _startY, _endX, _endY);

   if (_kind == "radial")
     canvasGradient = context.createRadialGradient(_startX, _startY, _startRadius, _endX, _endY, _endRadius);

   for(var colorStop in _colorStops)
     canvasGradient.addColorStop(colorStop["offset"], colorStop["color"]);

   return canvasGradient;
 }


}