iPhone-swift-weight-limit-chart

iPhone weight/limit chart with color area. Different color area for upper limit, lower limit and normal values.

func drawChart(){
    
    if((tfUpperLimit.text?.characters.count)! <= 0
        || (tfLowerLimit.text?.characters.count)! <= 0
        || (tfCurrentValue.text?.characters.count)! <= 0
        ){
        return;
    }
 
    chartView.upperLimit = getCGFloat(str: tfUpperLimit.text!);
    chartView.lowerLimit = getCGFloat(str: tfLowerLimit.text!);
    chartView.currentValue = getCGFloat(str: tfCurrentValue.text!);
    
    chartView.setNeedsDisplay();        
}

func getCGFloat(str: String) -> CGFloat{
    return CGFloat(Float(str)!);
}