Missing UNDO

fferegrino · Dec 14, 2016 · 265bc2a · 265bc2a
1 parent 246709d
commit 265bc2a
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Showing 3 changed files with 43 additions and 18 deletions.
diff --git a/Calculator/CalculatorBrain.cs b/Calculator/CalculatorBrain.cs
@@ -31,7 +31,7 @@ internal void SetOperand(string variableName)
 			}
 
 			lastVariable = variableName;
-			_internalProgram.Enqueue(variableName);
+			_internalProgram.Push(variableName);
 
 		}
 
@@ -45,13 +45,14 @@ internal void SetOperand(double operand)
 				_description = $"{_accumulator}";
 			}
 			lastVariable = null;
-			_internalProgram.Enqueue(operand);
+			_internalProgram.Push(operand);
         }
 
         enum Operation
         {
             Constant,
-            UnaryOperation,
+			UnaryOperation,
+			UnaryOperationPostFix,
             BinaryOperation,
             Equals,
             Clear
@@ -91,8 +92,8 @@ void PerformPendingOperation()
             { "cos", Operation.UnaryOperation  },
             { "sin", Operation.UnaryOperation },
             { "tan", Operation.UnaryOperation  },
-			{ "^2", Operation.UnaryOperation },
-			{ "^3", Operation.UnaryOperation },
+			{ "^2", Operation.UnaryOperationPostFix },
+			{ "^3", Operation.UnaryOperationPostFix },
             { "×", Operation.BinaryOperation },
             { "÷", Operation.BinaryOperation },
             { "−", Operation.BinaryOperation },
@@ -103,7 +104,7 @@ void PerformPendingOperation()
         internal void PerformOperation(string symbol)
         {
             Operation op;
-			_internalProgram.Enqueue(symbol);
+			_internalProgram.Push(symbol);
             if (operations.TryGetValue(symbol, out op))
             {
                 AddOperationToDescription(symbol, op);
@@ -112,7 +113,8 @@ internal void PerformOperation(string symbol)
                     case Operation.Constant:
                         _accumulator = constants[symbol];
                         break;
-                    case Operation.UnaryOperation:
+					case Operation.UnaryOperation:
+					case Operation.UnaryOperationPostFix:
 						PerformPendingOperation();
                         _accumulator = unaries[symbol](_accumulator);
                         break;
@@ -160,17 +162,22 @@ private void AddOperationToDescription(string symbol, Operation operation)
                     else
                         _description = $"{symbol}";
                     break;
-                case Operation.UnaryOperation:
+				case Operation.UnaryOperation:
+				case Operation.UnaryOperationPostFix:
 					if (lastVariable != null)
 					{
 						_description += " " + lastVariable;
 						lastVariable = null;
 					}
-                    _description = $" {symbol} ({_description ?? _accumulator.ToString()})";
+					if(operation== Operation.UnaryOperation)
+                    	_description = $" {symbol}({_description ?? _accumulator.ToString()})";
+					else
+						_description = $"({_description ?? _accumulator.ToString()}){symbol}";
+
                     break;
                 case Operation.BinaryOperation:
                     if (IsPartialResult) break;
-                    _description = $"({_description ?? _accumulator.ToString()}) {symbol} ";
+                    _description = $"{_description ?? _accumulator.ToString()} {symbol} ";
                     break;
                 case Operation.Equals:
 					if (_previousOperation.HasValue)
@@ -194,16 +201,26 @@ private void AddOperationToDescription(string symbol, Operation operation)
 
         }
 
+
+		internal void UndoLastOperation()
+		{
+			if (_internalProgram.Count != 0)
+				_internalProgram.Pop();//throw new NotImplementedException();
+			else
+				System.Diagnostics.Debug.WriteLine("No hay más operaciones");
+		}
+
 		public void ReRunProgram()
 		{
-
+			var newProgram = Program;
+			Program = newProgram;
 		}
 
-		private Queue<Object> _internalProgram  = new Queue<Object>();
-		public Object Program { get { return new Queue<object>(_internalProgram); } set 
+		private Stack<Object> _internalProgram  = new Stack<Object>();
+		public Object Program { get { return new Stack<object>(_internalProgram); } set 
 			{
 				Clear();
-				var program = value as Queue<Object>;
+				var program = value as Stack<Object>;
 				if (program != null)
 				{
 					foreach (var item in program)
@@ -216,7 +233,7 @@ public void ReRunProgram()
 							continue;
 						}
 
-						if(symbol != null)
+						if (symbol != null)
 						{
 							SetOperand(symbol);
 							continue;

diff --git a/Calculator/CalculatorBrainDictionaries.cs b/Calculator/CalculatorBrainDictionaries.cs
@@ -30,5 +30,5 @@ public partial class CalculatorBrain
 			{ "−", (a,b) => a - b },
 			{ "+", (a,b) => a + b },
 		};
-	}
+}
 }
diff --git a/Calculator/ViewController.cs b/Calculator/ViewController.cs
@@ -27,16 +27,24 @@ partial void Undo(){
 			if (userIsInTheMiddleOfTyping)
 			{
 				var l = display.Text.Length;
-				if (l > 0)
+				if (l == 1)
+				{
+					brain.UndoLastOperation();
+					display.Text = "0";
+					userIsInTheMiddleOfTyping = false;
+				}
+				else if (l > 1)
 				{
 					display.Text = display.Text.Substring(0, l - 1);
 				}
+				brain.SetOperand(DisplayValue);
 			}
 			else 
 			{
 				brain.UndoLastOperation();
-				brain.Program = brain.Program;
+				brain.ReRunProgram();
 			}
+			SetResult();
 		}
 
 		partial void RestoreMemory(UIKit.UIButton sender)