"Final Exam" -- updated Calculator.

Calculator/Controller/ViewController.swift

@@ -13,61 +13,62 @@ class ViewController: UIViewController {
     @IBOutlet weak var displayLabel: UILabel!
 
     private var isFinishedTypingNumber: Bool = true
+    private var calculator = CalculatorLogic()
+
 
-    private var displayValue: Double {
+    private var displayValue : Double {
         get {
             guard let number = Double(displayLabel.text!) else {
-                fatalError("Cannot convert display label text to a Double.")
+                fatalError("Cannot convert string to Double")
             }
             return number
         }
         set {
+            let isInteger = floor(newValue) == newValue
+            if isInteger {
+                displayLabel.text = String(Int(newValue))
+            } else {
             displayLabel.text = String(newValue)
+            }
         }
     }
 
-    private var calculator = CalculatorLogic()
-
     @IBAction func calcButtonPressed(_ sender: UIButton) {
-
-        //What should happen when a non-number button is pressed
-
         isFinishedTypingNumber = true
-
-        calculator.setNumber(displayValue)
-
-        if let calcMethod = sender.currentTitle {
-
-            if let result = calculator.calculate(symbol: calcMethod) {
-                displayValue = result
-            }
+        calculator.inputValue = displayValue
+        if sender.currentTitle! == "+/-" || sender.currentTitle! == "%" {
+            calculator.otherOps(operation: sender.currentTitle!)
+        } else {
+            calculator.calculate(operation: sender.currentTitle!)
         }
+        displayValue = calculator.totalValue ?? 0
+
     }
 
-
     @IBAction func numButtonPressed(_ sender: UIButton) {
 
-        //What should happen when a number is entered into the keypad
-
-        if let numValue = sender.currentTitle {
-
+        if let numString = sender.currentTitle {
             if isFinishedTypingNumber {
-                displayLabel.text = numValue
+                displayLabel.text = numString
                 isFinishedTypingNumber = false
+                calculator.percentHasBeenUsed = false
+                calculator.operatorLastTouched = false
             } else {
-
-                if numValue == "." {
-
-                    let isInt = floor(displayValue) == displayValue
-
-                    if !isInt {
+                if numString == "." {
+                    if displayLabel.text!.contains(".") {
                         return
                     }
                 }
-                displayLabel.text = displayLabel.text! + numValue
+                displayLabel.text = displayLabel.text! + numString
             }
         }
     }
-
+
+    @IBAction func clearPressed(_ sender: UIButton) {
+        // resets errrerything
+        calculator.reset()
+        isFinishedTypingNumber = true
+        displayLabel.text = "0"
+    }
+
 }
-

Calculator/Model/CalculatorLogic.swift

@@ -1,61 +1,95 @@
-//
-//  CalculatorLogic.swift
-//  Calculator
-//
-//  Created by Angela Yu on 18/09/2019.
-//  Copyright © 2019 London App Brewery. All rights reserved.
-//
-
 import Foundation
 
 struct CalculatorLogic {
 
-    private var number: Double?
+    var totalValue: Double?
+    private var storedValue: Double?
+    private var storedOp: String?
+    private var storedOpForReturn: String?
+    var inputValue: Double = 0
 
-    private var intermediateCalculation: (n1: Double, calcMethod: String)?
+    var operatorLastTouched: Bool = false
+    var percentHasBeenUsed: Bool = false
 
-    mutating func setNumber(_ number: Double) {
-        self.number = number
+    mutating func reset() {
+        totalValue = nil
+        storedValue = nil
+        storedOp = nil
+        inputValue = 0
+        operatorLastTouched = false
+        percentHasBeenUsed = false
     }
 
-    mutating func calculate(symbol: String) -> Double? {
-
-        if let n = number {
-            switch symbol {
-            case "+/-":
-                return n * -1
-            case "AC":
-                return 0
-            case "%":
-                return n * 0.01
-            case "=":
-                return performTwoNumCalculation(n2: n)
-            default:
-                intermediateCalculation = (n1: n, calcMethod: symbol)
-            }
+    mutating func math(passOp: String, inputOrStoredValue: Double) {
+        switch passOp {
+        case "÷":
+            totalValue = totalValue! / inputOrStoredValue
+        case "×":
+            totalValue = totalValue! * inputOrStoredValue
+        case "-":
+            totalValue = totalValue! - inputOrStoredValue
+        case "+":
+            totalValue = totalValue! + inputOrStoredValue
+        case "=":
+            return
+        default:
+            return
         }
-        return nil 
     }
 
-    private func performTwoNumCalculation(n2: Double) -> Double? {
-
-        if let n1 = intermediateCalculation?.n1,
-            let operation = intermediateCalculation?.calcMethod {
-
-            switch operation {
-            case "+":
-                return n1 + n2
-            case "-":
-                return n1 - n2
-            case "×":
-                return n1 * n2
-            case "÷":
-                return n1 / n2
-            default:
-                fatalError("The operation passed in does not match any of the cases.")
+    mutating func calculate(operation: String) {
+        // when user clicks an operate button the first time
+        // 12 +
+        if totalValue == nil {
+            totalValue = inputValue
+            storedOp = operation
+            inputValue = 0
+            return
+        }
+        // following should only go through if the SAME op is pressed twice in a row.
+        if operatorLastTouched {
+            if storedOp == operation {
+                if storedOp == "=" {
+                    math(passOp: storedOpForReturn!, inputOrStoredValue: storedValue!)
+                } else {
+                math(passOp: operation, inputOrStoredValue: storedValue!)
+                }
+            } else {
+                return
+            }
+        } else {
+            operatorLastTouched = true
+            // stores the current input value and operation in case the user
+            // wants to repeat the Operation.
+            math(passOp: storedOp!, inputOrStoredValue: inputValue)
+            if operation == "=" {
+                storedOpForReturn = storedOp
+                storedOp = operation
+            } else {
+                storedOp = operation
             }
+            storedValue = inputValue
         }
-        return nil
+
     }
 
+    mutating func otherOps(operation: String) {
+        // having this in the same function as the math makes a conflict
+        // with "operatorLastTouched" so you can't use this
+        // after you hit an operator.
+        // (like if you hit divide when you meant to hit percent)
+        // keeping it separated solves this issue
+        switch operation {
+        case "+/-":
+            totalValue = totalValue! * -1
+        case "%" :
+            if percentHasBeenUsed {
+                return
+            }
+            totalValue = inputValue * 0.01
+            percentHasBeenUsed = true
+        default:
+            return
+        }
+    }
 }

Calculator/View/Base.lproj/Main.storyboard

@@ -1,10 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="14313.18" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="ey4-0b-agg">
-    <device id="retina4_7" orientation="portrait">
-        <adaptation id="fullscreen"/>
-    </device>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="16097" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="ey4-0b-agg">
+    <device id="retina4_7" orientation="portrait" appearance="light"/>
     <dependencies>
-        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="14283.14"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="16087"/>
         <capability name="Safe area layout guides" minToolsVersion="9.0"/>
         <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
@@ -49,7 +47,7 @@
                                                     <color key="titleColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                                                 </state>
                                                 <connections>
-                                                    <action selector="calcButtonPressed:" destination="ey4-0b-agg" eventType="touchUpInside" id="V8L-uc-4VH"/>
+                                                    <action selector="clearPressed:" destination="ey4-0b-agg" eventType="touchUpInside" id="Icn-wV-Vcm"/>
                                                 </connections>
                                             </button>
                                             <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="9KY-Qg-57t">