littlema0404 / 35.tipcalculator

A single-page app could easily calculator tip through slide bar and shortcut

TipCalculator

一個簡單快速的小費計算工具 App

Features

• 計算資訊
  • 輸入內容
  • 小費金額
  • 總計結果
• 小費比例
  • Slider bar 快速調整
  • 按鈕微調
  • 選取 / 加入 常用比例
• 客製化鍵盤
  • 支援四則運算
  • 支援小數點

Key Skills Gained

將各個鍵盤按鈕以 PressType enum 管理

enum PressType: String {
    case zero = "0"
    case one = "1"
    case two = "2"
    case three = "3"
    case four = "4"
    case five = "5"
    case six = "6"
    case seven = "7"
    case eight = "8"
    case nine = "9"
    case addition = "+"
    case subtraction = "-"
    case multiplication = "×"
    case division = "÷"
    case point = "."
    case delete = "⌫"
}

擴充 PressType 功能，透過 operation 可知按鈕運算類型，state 運算方式

extension PressType {
    var name: String {
        return rawValue
    }
    
    var operation: OperationType {
        switch self {
        case .zero, .one, .two, .three, .four, .five, .six, .seven, .eight, .nine:
            return .number
        case .addition, .subtraction, .multiplication, .division:
            return .command
        case .delete:
            return .delete
        case .point:
            return .point
        }
    }
    
    var state: OperationState {
        switch self {
        case .zero, .one, .two, .three, .four, .five, .six, .seven, .eight, .nine:
            return NumberPress()
        case .addition, .subtraction, .multiplication, .division:
            return CommandPress()
        case .delete:
            return DeletePress()
        case .point:
            return PointPress()
        }
    }
}

實作 pressKeyboard 函式，完成實際運算功能

protocol NumberOperationState: OperationState {}

extension NumberOperationState {
    func pressKeyboard(press: PressType, data: inout PressData) {
        if data.status.last == .null {
            data.inputHistory.append(press.name)
            if press == .zero {
                data.status.append(.zero)
            } else {
                data.status.append(.number)
            }
        } else if data.status.last == .zero, press != .zero {
            let index = data.inputHistory.count - 1
            data.inputHistory[index] = press.name
            data.status.removeLast()
            data.status.append(.number)
        } else if data.status.last == .number {
            let index = data.inputHistory.count - 1
            data.inputHistory[index] += press.name
            data.status.append(.number)
        }
    }
}

Requirements

• iOS 12
• Xcode 10

Contact

[email protected]