public void EqualsButtonClick()
{
/* Method invoked when the "Equals" button is pressed. */
// If the calculator is in an error state, then don't do anything.
if (errorState == ErrorState.None)
{
// Variable to store the number currently being displayed.
double number;
// Parse and store the number currently being displayed.
if (double.TryParse(DisplayString, out number))
{
// If the current number is the first number in the current computation (ie. the selected operator is undefined), then store this number in "result".
if (selectedOperator == Operator.Undefined)
{
result = number;
}
// Otherwise, perform the selected operation and store the result in the "result" member.
else
{
switch (selectedOperator)
{
case Operator.Addition:
result = BasicMath.Add(result, number);
break;
case Operator.Subtraction:
result = BasicMath.Subtract(result, number);
break;
case Operator.Multiplication:
result = BasicMath.Multiply(result, number);
break;
case Operator.Division:
// If dividing by 0, set the calculator to error state
if (number == 0)
{
errorState = ErrorState.DivisionByZero;
}
else
{
result = BasicMath.Divide(result, number);
}
break;
}
// Set the display accordingly
if (errorState != ErrorState.None)
{
DisplayString = "Error";
}
else
{
DisplayString = $"{result}";
}
}
}
// Reset the selected operator to "Undefined" and update last button pressed and last dependency button pressed.
selectedOperator = Operator.Undefined;
lastDepButtonPressed = ButtonType.Equals;
lastDepButtonPressed2 = ButtonType.Equals;
}
}