Dactyloidae iOS initial commit

mobile/ios/Shared/Loader.swift

@@ -0,0 +1,33 @@
+/* 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
+
+/**
+ * Interface for listening to Loader updates.
+ */
+public protocol LoaderListener: class {
+    associatedtype T
+    func loader(dataLoaded data: T)
+}
+
+/**
+ * Base implementation for a "push" data model.
+ * Interested clients add themselves as listeners for data changes.
+ */
+open class Loader<T, ListenerType: LoaderListener> where T == ListenerType.T {
+    private let listeners = WeakList<ListenerType>()
+
+    public init() {}
+
+    open func addListener(_ listener: ListenerType) {
+        listeners.insert(listener)
+    }
+
+    open func load(_ data: T) {
+        for listener in listeners {
+            listener.loader(dataLoaded: data)
+        }
+    }
+}