Random context drawing in RubyMotion

CustomView.rb

class CustomView < UIView

  def gradient
    if @gradient
      puts "Reusing gradient..."
    else
      puts "Creating gradient..."
      colors = Pointer.new(:float, 8)
      colors[0], colors[1] =   0.0/255.0, 1.0
      colors[2], colors[3] = 125.0/255.0, 1.0
      colors[4], colors[5] = 200.0/255.0, 1.0

      locations = Pointer.new(:float, 3)
      locations[0] = 0.05
      locations[1] = 0.45
      locations[2] = 0.95

      colorSpace = CGColorSpaceCreateDeviceGray()
      @gradient = CGGradientCreateWithColorComponents(colorSpace, colors, locations, 3)
      CGColorSpaceRelease(colorSpace)
    end

    @gradient
  end

  def drawRect(rect)
    ctx = UIGraphicsGetCurrentContext()

    startPoint = CGPointMake(CGRectGetMidX(bounds), 0.0)
    endPoint = CGPointMake(CGRectGetMidX(bounds), CGRectGetMaxY(bounds))
    CGContextDrawLinearGradient(ctx, gradient, startPoint, endPoint, 0)

    CGContextSaveGState(ctx)
    CGContextTranslateCTM(ctx, 50.0, 50.0)
    CGContextAddRect(ctx, CGRectMake(0.0, 0.0, 200.0, 200.0))
    CGContextSetFillColorWithColor(ctx, UIColor.redColor.CGColor)
    CGContextFillPath(ctx)
    CGContextRestoreGState(ctx)

    CGContextAddRect(ctx, CGRectMake(0.0, 0.0, 100.0, 100.0))
    CGContextSetFillColorWithColor(ctx, UIColor.greenColor.CGColor)
    CGContextFillPath(ctx)

    CGContextSaveGState(ctx)
    CGContextSetLineCap(ctx, KCGLineCapRound);
    CGContextSetLineWidth(ctx, 4.0);
    CGContextSetRGBStrokeColor(ctx, 0.0, 0.0, 0.0, 1.0);
    CGContextSetStrokeColorWithColor(ctx, UIColor.purpleColor.CGColor);
    CGContextBeginPath(ctx);
    CGContextMoveToPoint(ctx, startPoint.x, startPoint.y);
    CGContextAddLineToPoint(ctx, endPoint.x, endPoint.y);
    CGContextStrokePath(ctx);
    CGContextRestoreGState(ctx)

    super
  end
end