Files
letro-ios/ElementX/Sources/Services/AppLock/AppLockTimer.swift
Mauro 6160c44d67 Update copyright holding and dates (#4640)
* Update copyright holding and dates

* compound IDE Macros updated

* update copyright

* update copyrights done

* update templates and README
2025-10-21 14:34:56 +02:00

65 lines
2.4 KiB
Swift

//
// Copyright 2025 Element Creations Ltd.
// Copyright 2023-2025 New Vector Ltd.
//
// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
// Please see LICENSE files in the repository root for full details.
//
import Foundation
/// A timer that adds a grace-period to the app before locking it.
class AppLockTimer {
/// The amount of time the app should remain unlocked for whilst backgrounded.
let gracePeriod: TimeInterval
/// Whether the timer considers the app to be locked or not. Always starts with a locked app.
///
/// Internally this value may be incorrect, always call `needsUnlock` to get the correct value.
private var isLocked = true
/// The date when the app was last backgrounded whilst in an unlocked state.
private var lastUnlockedBackground: Date?
/// Whether or not the app has moved to the background.
///
/// This allows us to distinguish between `willResignActive` and `didEnterBackground`.
private var isInBackground = false
/// Creates a new timer.
/// - Parameter gracePeriod: The amount of time the app should remain unlocked for whilst backgrounded.
init(gracePeriod: TimeInterval) {
self.gracePeriod = gracePeriod
}
/// Signals to the timer to track how long the app will be backgrounded for.
func applicationDidEnterBackground(date: Date = .now) {
isInBackground = true
// Only update the last background date if the app is currently unlocked.
guard !isLocked else { return }
lastUnlockedBackground = date
}
/// Asks the timer to recompute the lock state when active. If ``applicationDidEnterBackground`` hasn't been
/// called since the last computation, then this method won't recompute it, instead directly returning the previous state.
func computeLockState(didBecomeActiveAt date: Date) -> Bool {
guard isInBackground else { return isLocked }
isInBackground = false
guard !isLocked, let lastUnlockedBackground else { return true }
isLocked = date.timeIntervalSince(lastUnlockedBackground) >= gracePeriod
// Don't allow changing the device's clock to unlock the app.
if date < lastUnlockedBackground {
isLocked = true
}
return isLocked
}
/// Registers a successful unlock with the timer.
func registerUnlock() {
isLocked = false
}
}