RxSwift のリソース数を Window にオーバーレイ

00_readme.md

これイズ何？

RxSwift のリソース数を可視化する Window を生やします。

右下にあるグラフが実装例。

Resources.total をタイマーで1秒ごとに監視して、もし変更があればグラフ表示を更新します。

UIViewContrller を閉じたときにちゃんとリソースが解放されているかが分かりやすいのでは？と思って作ったのですけれど、いまいち邪魔だったのでお蔵入り。

Resources.total が使えない場合

CocoaPods の場合は忘れました。Carthage の場合は以下の通り。

carthage update --no-use-binaries --configuration Debug RxSwift

ref: Can not use RxSwift.Resources.total with Carthage

余談

縦書きの闇が思ったより深い。

AppDelegate.swift

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?
    
    var rxDebugWindow: UIWindow?

    func application(_ application: UIApplication,
                     didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

        let window = UIWindow(frame: UIScreen.main.bounds)
        window.makeKeyAndVisible()
        self.window = window
        
        window.rootViewController = R.storyboard.main.instantiateInitialViewController()
        
        Fabric.with([Crashlytics.self])
        createRxDebugWindow()
        return true
    }
  
    // こんな感じで使う
    private func createRxDebugWindow() {
        let debugWindowHeight: CGFloat = 150
        let screenBounds = UIScreen.main.bounds
        let debugWindowBounds = CGRect(x: 0, y: screenBounds.height - debugWindowHeight,
                                       width: screenBounds.width, height: debugWindowHeight)
        let rxDebugWindow = UIWindow(frame: debugWindowBounds)
        rxDebugWindow.windowLevel = UIWindowLevelAlert
        rxDebugWindow.rootViewController = RxDebugViewController()
        rxDebugWindow.isUserInteractionEnabled = false
        rxDebugWindow.makeKeyAndVisible()
        
        self.rxDebugWindow = rxDebugWindow
    }
}

RxDebugViewController.swift

import UIKit

class RxDebugViewController: UIViewController {
    
    override func loadView() {
        self.view = RxResourceView()
    }
}

RxResourceView.swift

import UIKit
import RxSwift
import UIFontComplete

class RxResourceView: UIView {
    
    var resourcesCount: [Int32] = []
    let countStringAttributes: [NSAttributedStringKey: Any] = [.font: UIFont(font: Font.georgia, size: 13)!,
                                                               .foregroundColor: R.color.lightPrimary()!]
    let disposeBag = DisposeBag()

    override init(frame: CGRect) {
        super.init(frame: frame)
        commonInit()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }
    
    private func commonInit() {
        isUserInteractionEnabled = false
        backgroundColor = UIColor.clear
        Observable<Int>.interval(1.0, scheduler: MainScheduler.instance)
            .map { _ in return Resources.total }
            .distinctUntilChanged()
            .subscribe(onNext: { [weak self] count in
                guard let strongSelf = self else { return }
                if strongSelf.resourcesCount.count == 50 {
                    strongSelf.resourcesCount = Array(strongSelf.resourcesCount.dropFirst())
                }
                strongSelf.resourcesCount.append(count)
                strongSelf.setNeedsDisplay()
            })
            .disposed(by: disposeBag)
    }
    
    override func draw(_ rect: CGRect) {
        guard let context = UIGraphicsGetCurrentContext() else { return }
        
        let graphRect = rect.insetBy(dx: 20, dy: 20)
        let lineWidth = graphRect.width / 50 - 1
        let maxValue: CGFloat = CGFloat(resourcesCount.max() ?? 0)
        
        context.setLineWidth(lineWidth)
        context.setStrokeColor(R.color.darkPrimary()!.withAlphaComponent(0.2).cgColor)
        
        var index = 0
        var drawX = graphRect.maxX - lineWidth / 2
        for count in resourcesCount.reversed() {
            context.addLines(between: [CGPoint(x: drawX, y: graphRect.maxY),
                                       CGPoint(x: drawX, y: graphRect.maxY - graphRect.height * CGFloat(count) / maxValue)])
            context.strokePath()
            drawX -= (lineWidth + 1)
            index += 1
        }
        
        if let currentCount = resourcesCount.last {
            let countString = "ResourceCount: \(currentCount)" as NSString
            let size = countString.size(withAttributes: countStringAttributes)
            countString.draw(in: CGRect(x: graphRect.maxX - size.width, y: graphRect.maxY, width: size.width, height: size.height),
                             withAttributes: countStringAttributes)
        }
    }
}

Z_Image.png