Andrej Mihajlov
631286e2d1
When the variable goes out of scope, the observer isn't removed unless an explicit call is made to the token. Signed-off-by: Andrej Mihajlov <and@mullvad.net>
34 lines
1.2 KiB
Swift
34 lines
1.2 KiB
Swift
// SPDX-License-Identifier: MIT
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// Copyright © 2018-2020 WireGuard LLC. All Rights Reserved.
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import Foundation
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/// This source file contains bits of code from:
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/// https://oleb.net/blog/2018/01/notificationcenter-removeobserver/
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/// Wraps the observer token received from
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/// `NotificationCenter.addObserver(forName:object:queue:using:)`
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/// and unregisters it in deinit.
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final class NotificationToken {
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let notificationCenter: NotificationCenter
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let token: Any
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init(notificationCenter: NotificationCenter = .default, token: Any) {
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self.notificationCenter = notificationCenter
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self.token = token
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}
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deinit {
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notificationCenter.removeObserver(token)
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}
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}
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extension NotificationCenter {
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/// Convenience wrapper for addObserver(forName:object:queue:using:)
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/// that returns our custom `NotificationToken`.
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func observe(name: NSNotification.Name?, object obj: Any?, queue: OperationQueue?, using block: @escaping (Notification) -> Void) -> NotificationToken {
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let token = addObserver(forName: name, object: obj, queue: queue, using: block)
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return NotificationToken(notificationCenter: self, token: token)
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}
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}
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