Merge branch 'charlesmchen/screenLock5'

Signal/src/util/OWSScreenLockUI.m

@@ -19,6 +19,10 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic) BOOL hasUnlockedScreenLock;
 @property (nonatomic) BOOL isShowingScreenLockUI;
 
+@property (nonatomic, nullable) NSTimer *screenLockUITimer;
+@property (nonatomic, nullable) NSDate *lastUnlockAttemptDate;
+@property (nonatomic, nullable) NSDate *lastUnlockSuccessDate;
+
 @end
 
 #pragma mark -
@@ -132,41 +136,8 @@ NS_ASSUME_NONNULL_BEGIN
         return;
     }
 
-    BOOL shouldHaveScreenLock = NO;
-    if (![TSAccountManager isRegistered]) {
-        // Don't show 'Screen Lock' if user is not registered.
-    } else if (!OWSScreenLock.sharedManager.isScreenLockEnabled) {
-        // Don't show 'Screen Lock' if 'Screen Lock' isn't enabled.
-    } else if (self.hasUnlockedScreenLock) {
-        // Don't show 'Screen Lock' if 'Screen Lock' has been unlocked.
-    } else if (self.appIsInBackground) {
-        // Don't show 'Screen Lock' if app is in background.
-    } else if (self.appIsInactive) {
-        // Don't show 'Screen Lock' if app is inactive.
-    } else if (!self.appBecameInactiveDate) {
-        // Show 'Screen Lock' if app has just launched.
-        shouldHaveScreenLock = YES;
-    } else {
-        OWSAssert(self.appBecameInactiveDate);
-
-        NSTimeInterval screenLockInterval = fabs([self.appBecameInactiveDate timeIntervalSinceNow]);
-        NSTimeInterval screenLockTimeout = OWSScreenLock.sharedManager.screenLockTimeout;
-        OWSAssert(screenLockInterval >= 0);
-        OWSAssert(screenLockTimeout >= 0);
-        if (screenLockInterval < screenLockTimeout) {
-            // Don't show 'Screen Lock' if 'Screen Lock' timeout hasn't elapsed.
-            shouldHaveScreenLock = NO;
-        } else {
-            // Otherwise, show 'Screen Lock'.
-            shouldHaveScreenLock = YES;
-        }
-    }
-
-    // Show 'Screen Protection' if:
-    //
-    // * App is inactive and...
-    // * 'Screen Protection' is enabled.
-    BOOL shouldHaveScreenProtection = (self.appIsInactive && Environment.preferences.screenSecurityIsEnabled);
+    BOOL shouldHaveScreenLock = self.shouldHaveScreenLock;
+    BOOL shouldHaveScreenProtection = self.shouldHaveScreenProtection;
 
     BOOL shouldShowBlockWindow = shouldHaveScreenProtection || shouldHaveScreenLock;
     DDLogVerbose(@"%@, shouldHaveScreenProtection: %d, shouldHaveScreenLock: %d, shouldShowBlockWindow: %d",
@@ -176,14 +147,68 @@ NS_ASSUME_NONNULL_BEGIN
         shouldShowBlockWindow);
     self.screenBlockingWindow.hidden = !shouldShowBlockWindow;
 
+    [self.screenLockUITimer invalidate];
+    self.screenLockUITimer = nil;
+
     if (shouldHaveScreenLock) {
-        if (!self.isShowingScreenLockUI) {
+        // In pincode-only mode (e.g. device pincode is set
+        // but Touch ID/Face ID are not configured), the pincode
+        // unlock UI is fullscreen and the app becomes inactive.
+        // Hitting the home button will cancel the authentication
+        // UI but not send the app to the background.  Therefore,
+        // to send the "locked" app to the background, you need
+        // to tap the home button twice.
+        //
+        // Therefore, if our last unlock attempt failed or was
+        // cancelled, wait a couple of second before re-presenting
+        // the "unlock screen lock UI" so that users have a chance
+        // to hit home button again.
+        BOOL shouldDelayScreenLockUI = YES;
+        if (!self.lastUnlockAttemptDate) {
+            shouldDelayScreenLockUI = NO;
+        } else if (self.lastUnlockAttemptDate && self.lastUnlockSuccessDate &&
+            [self.lastUnlockSuccessDate isAfterDate:self.lastUnlockAttemptDate]) {
+            shouldDelayScreenLockUI = NO;
+        }
+
+        if (shouldDelayScreenLockUI) {
+            DDLogVerbose(@"%@, Delaying Screen Lock UI.", self.logTag);
+            self.screenLockUITimer = [NSTimer weakScheduledTimerWithTimeInterval:1.25f
+                                                                          target:self
+                                                                        selector:@selector(tryToPresentScreenLockUI)
+                                                                        userInfo:nil
+                                                                         repeats:NO];
+        } else {
+            [self tryToPresentScreenLockUI];
+        }
+    }
+}
+
+- (void)tryToPresentScreenLockUI
+{
+    OWSAssertIsOnMainThread();
+
+    [self.screenLockUITimer invalidate];
+    self.screenLockUITimer = nil;
+
+    // If we no longer want to present the screen lock UI, abort.
+    if (!self.shouldHaveScreenLock) {
+        return;
+    }
+    if (self.isShowingScreenLockUI) {
+        return;
+    }
+
+    DDLogVerbose(@"%@, try to unlock screen lock", self.logTag);
+
     self.isShowingScreenLockUI = YES;
+    self.lastUnlockAttemptDate = [NSDate new];
 
     [OWSScreenLock.sharedManager tryToUnlockScreenLockWithSuccess:^{
         DDLogInfo(@"%@ unlock screen lock succeeded.", self.logTag);
         self.isShowingScreenLockUI = NO;
         self.hasUnlockedScreenLock = YES;
+        self.lastUnlockSuccessDate = [NSDate new];
         [self ensureScreenProtection];
     }
         failure:^(NSError *error) {
@@ -200,8 +225,50 @@ NS_ASSUME_NONNULL_BEGIN
             [self ensureScreenProtection];
         }];
 }
+
+- (BOOL)shouldHaveScreenProtection
+{
+    // Show 'Screen Protection' if:
+    //
+    // * App is inactive and...
+    // * 'Screen Protection' is enabled.
+    BOOL shouldHaveScreenProtection = (self.appIsInactive && Environment.preferences.screenSecurityIsEnabled);
+    return shouldHaveScreenProtection;
+}
+
+- (BOOL)shouldHaveScreenLock
+{
+    BOOL shouldHaveScreenLock = NO;
+    if (![TSAccountManager isRegistered]) {
+        // Don't show 'Screen Lock' if user is not registered.
+    } else if (!OWSScreenLock.sharedManager.isScreenLockEnabled) {
+        // Don't show 'Screen Lock' if 'Screen Lock' isn't enabled.
+    } else if (self.hasUnlockedScreenLock) {
+        // Don't show 'Screen Lock' if 'Screen Lock' has been unlocked.
+    } else if (self.appIsInBackground) {
+        // Don't show 'Screen Lock' if app is in background.
+    } else if (self.appIsInactive) {
+        // Don't show 'Screen Lock' if app is inactive.
+    } else if (!self.appBecameInactiveDate) {
+        // Show 'Screen Lock' if app has just launched.
+        shouldHaveScreenLock = YES;
+    } else {
+        OWSAssert(self.appBecameInactiveDate);
+
+        NSTimeInterval screenLockInterval = fabs([self.appBecameInactiveDate timeIntervalSinceNow]);
+        NSTimeInterval screenLockTimeout = OWSScreenLock.sharedManager.screenLockTimeout;
+        OWSAssert(screenLockInterval >= 0);
+        OWSAssert(screenLockTimeout >= 0);
+        if (screenLockInterval < screenLockTimeout) {
+            // Don't show 'Screen Lock' if 'Screen Lock' timeout hasn't elapsed.
+            shouldHaveScreenLock = NO;
+        } else {
+            // Otherwise, show 'Screen Lock'.
+            shouldHaveScreenLock = YES;
         }
     }
+    return shouldHaveScreenLock;
+}
 
 - (void)showScreenLockFailureAlertWithMessage:(NSString *)message
 {
@@ -266,6 +333,14 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)applicationWillEnterForeground:(NSNotification *)notification
 {
+    // Clear the "delay Screen Lock UI" state; we don't want any
+    // delays when presenting the "unlock screen lock UI" after
+    // returning from background.
+    [self.screenLockUITimer invalidate];
+    self.screenLockUITimer = nil;
+    self.lastUnlockAttemptDate = nil;
+    self.lastUnlockSuccessDate = nil;
+
     self.appIsInBackground = NO;
 }