public override ICalculator numericButtonPressed(int button)
{
if (ScreenText.Length < maxDigitsOnScreen)
{
if (ScreenText.Equals("0"))
{
ScreenValue = button;
}
else
{
ScreenText = ScreenText + button;
}
}
return(new ScreenViewCalculatorState(AccumulatorValue, ScreenText, calculatorOperator, maxDigitsOnScreen));
}
public override ICalculator invertSignButtonPressed()
{
log.Debug("Wcisnieto przycisk odwrocenia znaku ");
String newScreenValue = "?";
if (ScreenText.StartsWith("-"))
{
newScreenValue = ScreenText.Substring(1);
}
else if (!ScreenText.Equals("0"))
{
newScreenValue = '-' + ScreenText;
}
else
{
newScreenValue = ScreenText;
}
return(new ScreenViewCalculatorState(AccumulatorValue, newScreenValue, calculatorOperator, maxDigitsOnScreen));
}
