Merge pull request #37 from p-x9/feature/delegate

Delegate

Example/Example/ViewController.swift

@@ -37,6 +37,8 @@ class ViewController: UIViewController {
         setupViews()
         setupViewConstraints()
         setupNavigationItems()
+
+        appContainer.delegates.add(self)
     }
 
     override func viewWillAppear(_ animated: Bool) {
@@ -285,7 +287,7 @@ extension ViewController {
             print("container will change")
         }
 
-        let didChangeObservation = notificationCenter.addObserver(forName: AppContainer.containerWillChangeNotification, object: nil, queue: .current) { _ in
+        let didChangeObservation = notificationCenter.addObserver(forName: AppContainer.containerDidChangeNotification, object: nil, queue: .current) { _ in
             print("container did change")
         }
 
@@ -299,6 +301,15 @@ extension ViewController {
     }
 }
 
+extension ViewController: AppContainerDelegate {
+    func appContainer(_ appContainer: AppContainer, willChangeTo toContainer: Container, from fromContainer: Container?) {
+        print(#function, (fromContainer?.name ?? "") + " -> " + (toContainer.name ?? ""))
+    }
+
+    func appContainer(_ appContainer: AppContainer, didChangeTo toContainer: Container, from fromContainer: Container?) {
+        print(#function, (fromContainer?.name ?? "") + " -> " + (toContainer.name ?? ""))
+    }
+}
 
 extension ViewController {
     class View: UIView {

README.ja.md

@@ -106,6 +106,49 @@ try AppContainer.standard.cleanContainer(uuid: uuid)
 try AppContainer.standard.reset()
 ```
 
+### 通知(Notification)
+コンテナ切り替え時に通知を受け取ることができます。  
+厳密に、切り替え前および切り替え後に行いたい処理を追加する場合は、後述するdelegateを使用してください。
+
+- containerWillChangeNotification
+コンテナ切り替え前
+- containerDidChangeNotification
+コンテナ切り替え後
+### 委譲(Delegate)
+Delegateを使用して、コンテナの切り替え時に、任意の処理を追加することができます。
+以下の順で処置が行われます。
+
+``` swift
+// `activate`メソッドが呼び出される
+
+// ↓↓↓↓↓↓↓↓↓↓
+
+
+func appContainer(_ appContainer: AppContainer, willChangeTo toContainer: Container, from fromContainer: Container?) // Delegate(コンテナ切り替え前)
+
+// ↓↓↓↓↓↓↓↓↓↓
+
+// コンテナの切り替え処理(ライブラリ)
+
+// ↓↓↓↓↓↓↓↓↓↓
+
+func appContainer(_ appContainer: AppContainer, didChangeTo toContainer: Container, from fromContainer: Container?) // Delegate(コンテナ切り替え後)
+```
+
+このライブラリでは複数のdelegateを設定できるようになっています。 
+以下のように追加します。
+```swift
+AppContainer.standard.delegates.add(self) // selfがAppContainerDelegateに準拠している場合
+```
+弱参照で保持されており、オブジェクトが解放された場合は自動で解除されます。  
+もし、delegateの設定を解除したい場合は以下のように書きます。
+```swift
+AppContainer.standard.delegates.remove(self) // selfがAppContainerDelegateに準拠している場合
+```
+
+### AppContainerUI
+AppContainerを扱うためのUIを提供しています。  
+SwiftUIおよびUIKitに対応しています。
 #### SwiftUI
 ```swift
 import AppContainerUI

README.md

@@ -79,6 +79,48 @@ Specifically, the DEFAULT container will be enabled and all other AppContainer-r
 try AppContainer.standard.reset()
 ```
 
+### Notification
+You can receive notifications when switching containers.  
+If you want to add additional processing to be done strictly before and after the switch, use delegate as described below.
+
+- containerWillChangeNotification
+Before container switching
+- containerDidChangeNotification
+After container change
+
+### Delegate
+Delegate can be used to add optional processing when switching containers.
+The actions are performed in the following order.
+
+``` swift
+// the `activate` method is called
+
+// ↓↓↓↓↓↓↓↓↓↓
+
+
+func appContainer(_ appContainer: AppContainer, willChangeTo toContainer: Container, from fromContainer: Container?) // Delegate(before container switch)
+
+// ↓↓↓↓↓↓↓↓↓↓
+
+// Container switching process (library)
+
+// ↓↓↓↓↓↓↓↓↓↓
+
+func appContainer(_ appContainer: AppContainer, didChangeTo toContainer: Container, from fromContainer: Container?
+```
+
+This library allows multiple delegates to be set. 
+Add the following.
+
+```swift
+AppContainer.standard.delegates.add(self) // if self is AppContainerDelegate compliant
+```
+It is held in a weak reference and will be automatically released when the object is freed.  
+If you want to unset the delegate, write the following.
+```swift
+AppContainer.standard.delegates.remove(self) // if self conforms to AppContainerDelegate
+```
+
 ### AppContainerUI
 #### SwiftUI
 ```swift

Sources/AppContainer/AppContainer.swift

@@ -6,6 +6,8 @@ public class AppContainer {
     /// standard container manager
     public static let standard = AppContainer()
 
+    public var delegates: WeakHashTable<AppContainerDelegate> = .init()
+
     private let fileManager = FileManager.default
 
     private let notificationCenter = NotificationCenter.default
@@ -103,7 +105,12 @@ public class AppContainer {
             return
         }
 
+        let fromContainer = self.activeContainer
+
         notificationCenter.post(name: Self.containerWillChangeNotification, object: nil)
+        delegates.objects.forEach {
+            $0.appContainer(self, willChangeTo: container, from: fromContainer)
+        }
 
         try exportUserDefaults()
         exportCookies()
@@ -125,6 +132,9 @@ public class AppContainer {
         try? updateInfo(of: container, keyValue: .init(\.lastActivatedDate, Date()))
 
         notificationCenter.post(name: Self.containerDidChangeNotification, object: nil)
+        delegates.objects.forEach {
+            $0.appContainer(self, didChangeTo: container, from: fromContainer)
+        }
     }
 
     /// activate selected container

Sources/AppContainer/AppContainerDelegate.swift

@@ -0,0 +1,19 @@
+//
+//  AppContainerDelegate.swift
+//  
+//
+//  Created by p-x9 on 2023/03/06.
+//  
+//
+
+import Foundation
+
+public protocol AppContainerDelegate: AnyObject {
+    func appContainer(_ appContainer: AppContainer, willChangeTo toContainer: Container, from fromContainer: Container?)
+    func appContainer(_ appContainer: AppContainer, didChangeTo toContainer: Container, from fromContainer: Container?)
+}
+
+extension AppContainerDelegate {
+    public func appContainer(_ appContainer: AppContainer, willChangeTo toContainer: Container, from fromContainer: Container?) {}
+    public func appContainer(_ appContainer: AppContainer, didChangeTo toContainer: Container, from fromContainer: Container?) {}
+}

Sources/AppContainer/Util/WeakHashTable.swift

@@ -0,0 +1,47 @@
+//
+//  WeakHashTable.swift
+//  
+//
+//  Created by p-x9 on 2023/03/10.
+//
+
+import Foundation
+
+public class WeakHashTable<T> {
+    public var objects: [T] {
+        accessQueue.sync { _objects.allObjects.compactMap { $0 as? T } }
+    }
+
+    private var _objects: NSHashTable<AnyObject> = NSHashTable.weakObjects()
+    private let accessQueue: DispatchQueue = DispatchQueue(label:"com.p-x9.appcintainer.WeakHashTable.\(T.self)",
+                                                           attributes: .concurrent)
+
+    public init() {}
+
+    public init(_ objects: [T]) {
+        for object in objects {
+            _objects.add(object as AnyObject)
+        }
+    }
+
+    public func add(_ object: T?) {
+        accessQueue.sync(flags: .barrier) {
+            _objects.add(object as AnyObject)
+        }
+    }
+
+    public func remove(_ object: T?) {
+        accessQueue.sync(flags: .barrier) {
+            _objects.remove(object as AnyObject)
+        }
+    }
+}
+
+
+extension WeakHashTable : Sequence {
+    public typealias Iterator = Array<T>.Iterator
+
+    public func makeIterator() -> Iterator {
+        return objects.makeIterator()
+    }
+}