// EqualsButton_Click: Checks for the state of the users input and if it's in a valid state, performs an equation,
// saves the input for later use if desired and prints the result to the form.
// Pre: -
// Post: The result of the equation is shown in the TextBox inputTextBox. The numbers and numeric operator used in
// the equation is shown in the TextBox previousInputTextBox and saved to be reused if the user continues to press the
// Equals-button without making any other alterations to their input. In case of either a division by zero or an equation
// leading to the number being represented by ∞, a warning is shown and the calculator is reset.
private void EqualsButton_Click(object sender, EventArgs e)
{
if (LastInputWasOperator || inputTextBox.Text.Last() == ',' || (!OperatorTypeChosen && !PreviousCalulations))
{
return;
}
if (OperatorTypeChosen)
{
TermTwo = Convert.ToDouble(inputTextBox.Text.Split(OperatorType).Last());
PreviousTermTwo = TermTwo;
previousInputTextBox.Text = inputTextBox.Text;
}
else if (!OperatorTypeChosen && PreviousCalulations)
{
TermOne = Answer;
TermTwo = PreviousTermTwo;
previousInputTextBox.Text = PreviousAnswer.ToString() + OperatorType + PreviousTermTwo;
}
CalculateEquation();
if (DivisionByZero() || AnswerIsInfinity())
{
return;
}
inputTextBox.Text = Answer.ToString();
OperatorTypeChosen = false;
PreviousAnswer = Answer;
PreviousCalulations = true;
}
private void ProcessOperatorCommand(string value)
{
try
{
switch (value)
{
case "Clear":
TopInput = "";
OperatorInput = "";
BottomInput = "";
Answer = 0;
ErrorMessage = "";
break;
case "Calculate":
if (!string.IsNullOrEmpty(OperatorInput))
{
switch (OperatorInput)
{
case "+":
Answer = Math.Round(TopInputDecimal() + BottomInputDecimal(), 2);
break;
case "-":
Answer = Math.Round(TopInputDecimal() - BottomInputDecimal(), 2);
break;
case "*":
Answer = Math.Round(TopInputDecimal() * BottomInputDecimal(), 2);
break;
case "/":
Answer = Math.Round(TopInputDecimal() / BottomInputDecimal(), 2);
break;
}
}
else
{
Answer = TopInputDecimal();
}
TopInput = Answer.ToString();
break;
case "+":
case "-":
case "*":
case "/":
BottomInput = "";
OperatorInput = value;
break;
}
}
catch (ArithmeticException e)
{
ErrorMessage = e.Message;
}
catch (Exception e)
{
ErrorMessage = e.Message;
}
}
