【Swift】電卓アプリのサンプルコード（Storyboard未使用、PureLayout）

# 概要
電卓アプリのサンプルコードです。
[PureLayout](https://github.com/PureLayout/PureLayout)を利用し、今回もStoryboardは未使用です。

# github
https://github.com/menomoto/Sample_Apps/tree/master/calc
* ViewController全体で280行
* Auto Layout設定が約80行

# 結果
![サンプル](http://i.imgur.com/N5t1c4J.gif)

# Auto Layout設定
```
    private func addConstraints() {
        let buttonWidth =
            (UIScreen.mainScreen().bounds.width - 10 * 5) / 4

        displayLabel.autoPinToTopLayoutGuideOfViewController(self, withInset: 30)
        displayLabel.autoPinEdgeToSuperviewEdge(.Left, withInset: 10)
        displayLabel.autoPinEdgeToSuperviewEdge(.Right, withInset: 10)
        
        // MARK : - Line 1
        button7.autoPinEdge(.Top, toEdge: .Bottom, ofView: displayLabel, withOffset: 10)
        button7.autoPinEdgeToSuperviewEdge(.Left, withInset: 10)
        button7.autoSetDimension(.Width, toSize: buttonWidth)

        button8.autoPinEdge(.Top, toEdge: .Bottom, ofView: displayLabel, withOffset: 10)
        button8.autoPinEdge(.Leading, toEdge: .Trailing, ofView: button7, withOffset: 10)
        button8.autoSetDimension(.Width, toSize: buttonWidth)
        
        button9.autoPinEdge(.Top, toEdge: .Bottom, ofView: displayLabel, withOffset: 10)
        button9.autoPinEdge(.Leading, toEdge: .Trailing, ofView: button8, withOffset: 10)
        button9.autoSetDimension(.Width, toSize: buttonWidth)

        buttonPlus.autoPinEdge(.Top, toEdge: .Bottom, ofView: displayLabel, withOffset: 10)
        buttonPlus.autoPinEdge(.Leading, toEdge: .Trailing, ofView: button9, withOffset: 10)
        buttonPlus.autoSetDimension(.Width, toSize: buttonWidth)
        buttonPlus.autoPinEdgeToSuperviewEdge(.Right, withInset: 10)

        // MARK : - Line 2
        button4.autoPinEdge(.Top, toEdge: .Bottom, ofView: button7, withOffset: 10)
        button4.autoPinEdgeToSuperviewEdge(.Left, withInset: 10)
        button4.autoSetDimension(.Width, toSize: buttonWidth)
        
        button5.autoPinEdge(.Top, toEdge: .Bottom, ofView: button8, withOffset: 10)
        button5.autoPinEdge(.Leading, toEdge: .Trailing, ofView: button4, withOffset: 10)
        button5.autoSetDimension(.Width, toSize: buttonWidth)
        
        button6.autoPinEdge(.Top, toEdge: .Bottom, ofView: button9, withOffset: 10)
        button6.autoPinEdge(.Leading, toEdge: .Trailing, ofView: button5, withOffset: 10)
        button6.autoSetDimension(.Width, toSize: buttonWidth)
        
        buttonMinus.autoPinEdge(.Top, toEdge: .Bottom, ofView: buttonPlus, withOffset: 10)
        buttonMinus.autoPinEdge(.Leading, toEdge: .Trailing, ofView: button6, withOffset: 10)
        buttonMinus.autoSetDimension(.Width, toSize: buttonWidth)
        buttonMinus.autoPinEdgeToSuperviewEdge(.Right, withInset: 10)

        // MARK : - Line 3
        button1.autoPinEdge(.Top, toEdge: .Bottom, ofView: button4, withOffset: 10)
        button1.autoPinEdgeToSuperviewEdge(.Left, withInset: 10)
        button1.autoSetDimension(.Width, toSize: buttonWidth)
        
        button2.autoPinEdge(.Top, toEdge: .Bottom, ofView: button5, withOffset: 10)
        button2.autoPinEdge(.Leading, toEdge: .Trailing, ofView: button1, withOffset: 10)
        button2.autoSetDimension(.Width, toSize: buttonWidth)
        
        button3.autoPinEdge(.Top, toEdge: .Bottom, ofView: button6, withOffset: 10)
        button3.autoPinEdge(.Leading, toEdge: .Trailing, ofView: button2, withOffset: 10)
        button3.autoSetDimension(.Width, toSize: buttonWidth)
        
        buttonMultiply.autoPinEdge(.Top, toEdge: .Bottom, ofView: buttonMinus, withOffset: 10)
        buttonMultiply.autoPinEdge(.Leading, toEdge: .Trailing, ofView: button3, withOffset: 10)
        buttonMultiply.autoSetDimension(.Width, toSize: buttonWidth)
        buttonMultiply.autoPinEdgeToSuperviewEdge(.Right, withInset: 10)

        // MARK : - Line 4
        button0.autoPinEdge(.Top, toEdge: .Bottom, ofView: button1, withOffset: 10)
        button0.autoPinEdgeToSuperviewEdge(.Left, withInset: 10)
        button0.autoSetDimension(.Width, toSize: buttonWidth)
        
        buttonClear.autoPinEdge(.Top, toEdge: .Bottom, ofView: button2, withOffset: 10)
        buttonClear.autoPinEdge(.Leading, toEdge: .Trailing, ofView: button0, withOffset: 10)
        buttonClear.autoSetDimension(.Width, toSize: buttonWidth)
        
        buttonEqual.autoPinEdge(.Top, toEdge: .Bottom, ofView: button3, withOffset: 10)
        buttonEqual.autoPinEdge(.Leading, toEdge: .Trailing, ofView: buttonClear, withOffset: 10)
        buttonEqual.autoSetDimension(.Width, toSize: buttonWidth)
        
        buttonDevide.autoPinEdge(.Top, toEdge: .Bottom, ofView: buttonMultiply, withOffset: 10)
        buttonDevide.autoPinEdge(.Leading, toEdge: .Trailing, ofView: buttonEqual, withOffset: 10)
        buttonDevide.autoSetDimension(.Width, toSize: buttonWidth)
        buttonDevide.autoPinEdgeToSuperviewEdge(.Right, withInset: 10)
    }
```