Files
letro-ios/ElementX/Sources/Services/AppLock/AppLockTimer.swift
Doug 5bb85257e2 Add support for Face ID/Touch ID to app lock. (#1966)
* Fix biometrics with low grace period and backgrounding before unlocked.

* Trigger permissions alert when enabling Face ID.
2023-10-27 09:09:12 +00:00

63 lines
2.3 KiB
Swift

//
// Copyright 2023 New Vector Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
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.
///
/// 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?
/// 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) {
// 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 on foregrounding.
func computeLockState(willEnterForegroundAt date: Date) -> Bool {
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
}
}