Make the article icon code specify the desired article so that it can't pull the wrong one by mistake. Issue #1707

iOS/AppDelegate.swift

@@ -58,8 +58,6 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
 		super.init()
 		appDelegate = self
 
-		// Force lazy initialization of the web view provider so that it can warm up the queue of prepared web views
-		let _ = WebViewProvider.shared
 		AccountManager.shared = AccountManager()
 		
 		NotificationCenter.default.addObserver(self, selector: #selector(unreadCountDidChange(_:)), name: .UnreadCountDidChange, object: nil)

iOS/Article/ArticleIconSchemeHandler.swift

@@ -0,0 +1,58 @@
+//
+//  ArticleIconSchemeHandler.swift
+//  NetNewsWire-iOS
+//
+//  Created by Maurice Parker on 1/27/20.
+//  Copyright © 2020 Ranchero Software. All rights reserved.
+//
+
+import Foundation
+import WebKit
+import Articles
+
+class ArticleIconSchemeHandler: NSObject, WKURLSchemeHandler {
+	
+	let coordinator: SceneCoordinator
+	
+	init(coordinator: SceneCoordinator) {
+		self.coordinator = coordinator
+	}
+	
+	func webView(_ webView: WKWebView, start urlSchemeTask: WKURLSchemeTask) {
+
+		guard let url = urlSchemeTask.request.url else {
+			urlSchemeTask.didFailWithError(URLError(.fileDoesNotExist))
+			return
+		}
+		
+		let articleID = url.absoluteString.stripping(prefix: "\(ArticleRenderer.imageIconScheme)://")
+		
+		guard let iconImage = coordinator.articleFor(articleID)?.iconImage() else {
+			urlSchemeTask.didFailWithError(URLError(.fileDoesNotExist))
+			return
+		}
+
+		let iconView = IconView(frame: CGRect(x: 0, y: 0, width: 48, height: 48))
+		iconView.iconImage = iconImage
+		let renderedImage = iconView.asImage()
+		
+		guard let data = renderedImage.dataRepresentation() else {
+			urlSchemeTask.didFailWithError(URLError(.fileDoesNotExist))
+			return
+		}
+		
+		let headerFields = ["Cache-Control": "no-cache"]
+		if let response = HTTPURLResponse(url: url, statusCode: 200, httpVersion: nil, headerFields: headerFields) {
+			urlSchemeTask.didReceive(response)
+			urlSchemeTask.didReceive(data)
+			urlSchemeTask.didFinish()
+		}
+
+	}
+	
+	func webView(_ webView: WKWebView, stop urlSchemeTask: WKURLSchemeTask) {
+		urlSchemeTask.didFailWithError(URLError(.unknown))
+	}
+	
+}
+

iOS/Article/WebViewController.swift

@@ -83,7 +83,7 @@ class WebViewController: UIViewController {
 			webView.configuration.userContentController.removeScriptMessageHandler(forName: MessageName.imageWasClicked)
 			webView.configuration.userContentController.removeScriptMessageHandler(forName: MessageName.imageWasShown)
 			webView.removeFromSuperview()
-			WebViewProvider.shared.enqueueWebView(webView)
+			coordinator.webViewProvider.enqueueWebView(webView)
 			webView = nil
 		}
 	}
@@ -96,7 +96,7 @@ class WebViewController: UIViewController {
 		NotificationCenter.default.addObserver(self, selector: #selector(faviconDidBecomeAvailable(_:)), name: .FaviconDidBecomeAvailable, object: nil)
 		NotificationCenter.default.addObserver(self, selector: #selector(contentSizeCategoryDidChange(_:)), name: UIContentSizeCategory.didChangeNotification, object: nil)
 
-		WebViewProvider.shared.dequeueWebView() { webView in
+		coordinator.webViewProvider.dequeueWebView() { webView in
 			
 			// Add the webview
 			self.webView = webView
@@ -486,7 +486,6 @@ private extension WebViewController {
 
 		restoreWindowScrollY = 0
 		
-		WebViewProvider.shared.articleIconSchemeHandler.currentArticle = article
 		webView.scrollView.setZoomScale(1.0, animated: false)
 		webView.evaluateJavaScript(render)
 		

iOS/Article/WebViewProvider.swift

@@ -13,9 +13,7 @@ import WebKit
 /// Keep a queue of WebViews where we've already done a trivial load so that by the time we need them in the UI, they're past the flash-to-shite part of their lifecycle.
 class WebViewProvider: NSObject, WKNavigationDelegate {
 	
-	static let shared = WebViewProvider()
-	
-	let articleIconSchemeHandler = ArticleIconSchemeHandler()
+	let articleIconSchemeHandler: ArticleIconSchemeHandler
 	
 	private let minimumQueueDepth = 3
 	private let maximumQueueDepth = 6
@@ -24,6 +22,12 @@ class WebViewProvider: NSObject, WKNavigationDelegate {
 	private var waitingForFirstLoad = true
 	private var waitingCompletionHandler: ((WKWebView) -> ())?
 
+	init(coordinator: SceneCoordinator) {
+		articleIconSchemeHandler = ArticleIconSchemeHandler(coordinator: coordinator)
+		super.init()
+		replenishQueueIfNeeded()
+	}
+	
 	func dequeueWebView(completion: @escaping (WKWebView) -> ()) {
 		if waitingForFirstLoad {
 			waitingCompletionHandler = completion
@@ -58,11 +62,6 @@ class WebViewProvider: NSObject, WKNavigationDelegate {
 	
 	// MARK: Private
 
-	private override init() {
-		super.init()
-		replenishQueueIfNeeded()
-	}
-
 	private func replenishQueueIfNeeded() {
 		while queue.count < minimumQueueDepth {
 			let preferences = WKPreferences()

iOS/SceneCoordinator.swift

@@ -30,6 +30,8 @@ class SceneCoordinator: NSObject, UndoableCommandRunner, UnreadCountProvider {
 		return rootSplitViewController.undoManager
 	}
 	
+	lazy var webViewProvider = WebViewProvider(coordinator: self)
+	
 	private var panelMode: PanelMode = .unset
 	
 	private var activityManager = ActivityManager()
@@ -255,9 +257,19 @@ class SceneCoordinator: NSObject, UndoableCommandRunner, UnreadCountProvider {
 	private(set) var articles = ArticleArray() {
 		didSet {
 			timelineMiddleIndexPath = nil
+			articleDictionaryNeedsUpdate = true
 		}
 	}
-	
+
+	private var articleDictionaryNeedsUpdate = true
+	private var _idToArticleDictionary = [String: Article]()
+	private var idToAticleDictionary: [String: Article] {
+		if articleDictionaryNeedsUpdate {
+			rebuildArticleDictionaries()
+		}
+		return _idToArticleDictionary
+	}
+
 	private var currentArticleRow: Int? {
 		guard let article = currentArticle else { return nil }
 		return articles.firstIndex(of: article)
@@ -572,6 +584,10 @@ class SceneCoordinator: NSObject, UndoableCommandRunner, UnreadCountProvider {
 		return shadowTable[section]
 	}
 	
+	func articleFor(_ articleID: String) -> Article? {
+		return idToAticleDictionary[articleID]
+	}
+	
 	func cappedIndexPath(_ indexPath: IndexPath) -> IndexPath {
 		guard indexPath.section < shadowTable.count && indexPath.row < shadowTable[indexPath.section].count else {
 			return IndexPath(row: shadowTable[shadowTable.count - 1].count - 1, section: shadowTable.count - 1)
@@ -1222,6 +1238,17 @@ private extension SceneCoordinator {
 		unreadCount = count
 	}
 	
+	func rebuildArticleDictionaries() {
+		var idDictionary = [String: Article]()
+
+		articles.forEach { article in
+			idDictionary[article.articleID] = article
+		}
+
+		_idToArticleDictionary = idDictionary
+		articleDictionaryNeedsUpdate = false
+	}
+
 	func rebuildBackingStores(initialLoad: Bool = false, updateExpandedNodes: (() -> Void)? = nil) {
 		if !animatingChanges && !BatchUpdate.shared.isPerforming {
 			treeController.rebuild()