Dactyloidae iOS initial commit

mobile/ios/Client/Frontend/Browser/HistoryStateHelper.swift

@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import Foundation
+import WebKit
+
+protocol HistoryStateHelperDelegate: class {
+    func historyStateHelper(_ historyStateHelper: HistoryStateHelper, didPushOrReplaceStateInTab tab: Tab)
+}
+
+// This tab helper is needed for injecting a user script into the
+// WKWebView that intercepts calls to `history.pushState()` and
+// `history.replaceState()` so that the BrowserViewController is
+// notified when the user navigates a single-page web application.
+class HistoryStateHelper: TabContentScript {
+    weak var delegate: HistoryStateHelperDelegate?
+    fileprivate weak var tab: Tab?
+    
+    required init(tab: Tab) {
+        self.tab = tab
+        if let path = Bundle.main.path(forResource: "HistoryStateHelper", ofType: "js") {
+            if let source = try? NSString(contentsOfFile: path, encoding: String.Encoding.utf8.rawValue) as String {
+                let userScript = WKUserScript(source: source, injectionTime: WKUserScriptInjectionTime.atDocumentEnd, forMainFrameOnly: true)
+                tab.webView!.configuration.userContentController.addUserScript(userScript)
+            }
+        }
+    }
+    
+    func scriptMessageHandlerName() -> String? {
+        return "historyStateHelper"
+    }
+    
+    func userContentController(_ userContentController: WKUserContentController, didReceiveScriptMessage message: WKScriptMessage) {
+        if let tab = tab {
+            DispatchQueue.main.async {
+                self.delegate?.historyStateHelper(self, didPushOrReplaceStateInTab: tab)
+            }
+        }
+    }
+    
+    class func name() -> String {
+        return "HistoryStateHelper"
+    }
+}