private void openParenthesis()
{
Symbol sym = new OpenParenthesis();
if (ERROR_MESSAGE.Equals(_equationText) ||
"0".Equals(_equationText))
{
changeEquationText(sym.ToString());
return;
}
var eq = new Equation(_equationText);
if (!eq.HasFinalOperator())
{
// Disallow a number followed by an open parenthesis
return;
}
changeEquationText(_equationText + sym.ToString());
}
private void operator operatorButtonClicked(Symbol op)
{
if (ERROR_MESSAGE.Equals(_equationText))
{
changeEquationText("0" + op.ToString());
return;
}
var eq = new Equation(_equationText);
if (eq.HasFinalOperator())
{
changeEquationText(eq.ReplaceFinalOperator(op));
} else
{
changeEquationText(_equationText
+ op.ToString());
}
}
protected void OnButtonDotClicked(object sender, System.EventArgs e)
{
if (ERROR_MESSAGE.Equals(_equationText))
{
changeEquationText("0.");
return;
}
var eq = new Equation(_equationText);
if (!eq.HasFinalOperator())
{
changeEquationText(_equationText + ".");
}
}
