Dactyloidae iOS initial commit

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

@@ -0,0 +1,50 @@
+/* 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 Shared
+
+class SessionData: NSObject, NSCoding {
+    let currentPage: Int
+    let urls: [URL]
+    let lastUsedTime: Timestamp
+
+    var jsonDictionary: [String: Any] {
+        return [
+            "currentPage": String(self.currentPage),
+            "lastUsedTime": String(self.lastUsedTime),
+            "urls": urls.map { $0.absoluteString }
+        ]
+    }
+
+    /**
+        Creates a new SessionData object representing a serialized tab.
+
+        - parameter currentPage:     The active page index. Must be in the range of (-N, 0],
+                                where 1-N is the first page in history, and 0 is the last.
+        - parameter urls:            The sequence of URLs in this tab's session history.
+        - parameter lastUsedTime:    The last time this tab was modified.
+    **/
+    init(currentPage: Int, urls: [URL], lastUsedTime: Timestamp) {
+        self.currentPage = currentPage
+        self.urls = urls
+        self.lastUsedTime = lastUsedTime
+
+        assert(urls.count > 0, "Session has at least one entry")
+        assert(currentPage > -urls.count && currentPage <= 0, "Session index is valid")
+    }
+
+    required init?(coder: NSCoder) {
+        self.currentPage = coder.decodeAsInt(forKey: "currentPage")
+        self.urls = coder.decodeObject(forKey: "urls") as? [URL] ?? []
+        self.lastUsedTime = coder.decodeAsUInt64(forKey: "lastUsedTime")
+    }
+
+    func encode(with coder: NSCoder) {
+        coder.encode(currentPage, forKey: "currentPage")
+        coder.encode(urls, forKey: "urls")
+        coder.encode(Int64(lastUsedTime), forKey: "lastUsedTime")
+    }
+}