public void Compute(char theOperator, int operand)
{
ICommand command = new CalculatorCommand(this.calculator, theOperator, operand);
command.Execute();
this.commands.Add(command);
this.currentCommandIndex++;
}
static void Main()
{
var calculator = new Calculator();
CalculatorCommand command = new CalculatorCommand(calculator, '+', 5);
command.Execute(); // Current value = 5 (following + 5)
command.Execute(); // Current value = 10 (following + 5)
command.UnExecute(); // Current value = 5 (following - 5)
// using Invoker
Invoker user = new Invoker();
user.Compute('+', 7); // Current value = 7 (following + 7)
user.Compute('-', 3); // Current value = 4 (following - 3)
user.Compute('*', 12); // Current value = 48 (following * 12)
user.Undo(2); // ---- Undo 2 levels
//Current value = 4 (following / 12)
//Current value = 7 (following + 3)
user.Redo(1); //---- Redo 1 levels
// Current value = 4 (following - 3)
}
