Calculator finished

Calculator/CalculatorBrain.cs

@@ -1,28 +1,63 @@
 
 using System;
+using System.Linq;
 using System.Collections.Generic;
 
 namespace Calculator
 {
 	public class CalculatorBrain
 	{
 		double _accumulator;
+		bool _hasSetDot;
+		double DecimalPositions = 10;
+		const double IntegerPositions = 10;
+		const int MaxMemory = 10;
+		Queue<string> _operations = new Queue<string>(MaxMemory);
 
-		internal void SetOperand(double operand)
+
+		internal void AddOperand(double operand, bool userIsInTheMiddleOfTyping)
 		{
-			_accumulator = operand;
+			if (userIsInTheMiddleOfTyping)
+			{
+				if (!_hasSetDot)
+				{
+					_accumulator = _accumulator * IntegerPositions + operand;
+					//_integerPositions *= 10;
+				}
+				else
+				{
+					_accumulator = _accumulator + operand / DecimalPositions;
+					DecimalPositions *= 10;
+				}
+			}
+			else
+			{
+				DecimalPositions = 10;
+				if (!_hasSetDot)
+				{
+					_accumulator = operand;
+					//_integerPositions *= 10;
+				}
+				else
+				{
+					_accumulator = operand / DecimalPositions;
+					DecimalPositions *= 10;
+				}
+			}
 		}
 
 		enum Operation
 		{
 			Constant,
 			UnaryOperation,
 			BinaryOperation,
-			Equals
+			Equals,
+			Dot,
+			Clear
 		}
 
 		struct PendingOperationInfo
-		{ 
+		{
 			public PendingOperationInfo(Func<double, double, double> binaryOperation, double firstOperand)
 			{
 				BinaryOperation = binaryOperation;
@@ -49,13 +84,19 @@ void PerformPendingOperation()
 		{
 			{ "π", Operation.Constant },
 			{ "e", Operation.Constant },
+			{ "C", Operation.Clear },
 			{ "√", Operation.UnaryOperation },
 			{ "±", Operation.UnaryOperation },
+			{ "cos", Operation.UnaryOperation  },
+			{ "sin", Operation.UnaryOperation },
+			{ "tan", Operation.UnaryOperation  },
+			{ "x!", Operation.UnaryOperation },
 			{ "×", Operation.BinaryOperation },
 			{ "÷", Operation.BinaryOperation },
 			{ "−", Operation.BinaryOperation },
 			{ "+", Operation.BinaryOperation },
-			{ "=", Operation.Equals }
+			{ "=", Operation.Equals },
+			{ ".", Operation.Dot }
 		};
 
 		Dictionary<string, double> constants = new Dictionary<string, double>
@@ -68,9 +109,13 @@ void PerformPendingOperation()
 		{
 			{ "√", Math.Sqrt },
 			{ "±", (d ) => -1 * d },
+			{ "cos", Math.Cos },
+			{ "sin", Math.Sin},
+			{ "tan", Math.Tan },
+			{ "x!", (d) => d }
 		};
 
-		Dictionary<string, Func<double,double,double>> binaries = new Dictionary<string, Func<double, double, double>>
+		Dictionary<string, Func<double, double, double>> binaries = new Dictionary<string, Func<double, double, double>>
 		{
 			{ "×", (a,b) => a * b },
 			{ "÷", (a,b) => a / b },
@@ -83,6 +128,7 @@ internal void PerformOperation(string symbol)
 			Operation op;
 			if (operations.TryGetValue(symbol, out op))
 			{
+				AddRecentOp(symbol);
 				switch (op)
 				{
 					case Operation.Constant:
@@ -92,18 +138,51 @@ internal void PerformOperation(string symbol)
 						_accumulator = unaries[symbol](_accumulator);
 						break;
 					case Operation.BinaryOperation:
+
+						_hasSetDot = false;
 						PerformPendingOperation();
 						_pendingOperation = new PendingOperationInfo(binaries[symbol], _accumulator);
+
 						break;
 					case Operation.Equals:
 						PerformPendingOperation();
 						break;
+					case Operation.Dot:
+						if (!_hasSetDot)
+						{
+							_hasSetDot = true;
+						}
+						break;
+					case Operation.Clear:
+						Clear();
+						break;
 					default:
 						break;
 				}
 			}
 		}
 
+		void Clear()
+		{
+			_hasSetDot = false;
+			_accumulator = 0;
+			_pendingOperation = null;
+			DecimalPositions = 10;
+		}
+
+
+		internal String RecentOperations
+		{
+			get { return String.Join(" ", _operations); }
+		}
+
+		private void AddRecentOp(string op)
+		{
+			if(_operations.Count == MaxMemory)
+				_operations.Dequeue();
+			_operations.Enqueue(op);
+		}
+
 		internal Double Result
 		{
 			get { return _accumulator; }