Review Changes

MVMCoreUI/Alerts/MVMCoreAlertHandler+Extension.swift

@@ -9,22 +9,20 @@
 import Foundation
 
 public extension MVMCoreAlertHandler {
-    
+
     /// Re-evaluates the queue operations
     @objc func reevaluteQueue() {
-        var higherPriorityOperationIsReady = false
+        var highestReadyOperation: MVMCoreTopAlertOperation?
         var executingOperation: MVMCoreTopAlertOperation?
-        let pageType = (MVMCoreUISplitViewController.main()?.getCurrentDetailViewController() as? MVMCoreViewControllerProtocol)?.pageType
-        let sortedOperations = topAlertQueue.operations.sorted { $0.queuePriority.rawValue > $1.queuePriority.rawValue }
-        for case let operation as MVMCoreTopAlertOperation in sortedOperations {
+        for case let operation as MVMCoreTopAlertOperation in topAlertQueue.operations {
             guard !operation.isCancelled,
                   !operation.isFinished else { continue }
-            updatePageReadiness(for: operation, with: pageType)
+            if operation.isReady,
+               highestReadyOperation == nil || operation.queuePriority.rawValue > highestReadyOperation!.queuePriority.rawValue {
+                highestReadyOperation = operation
+            }
             if operation.isExecuting {
                 executingOperation = operation
-            } else if operation.isReady,
-                      executingOperation == nil {
-                higherPriorityOperationIsReady = true
             }
         }
         guard let currentOperation = executingOperation else { return }
@@ -37,34 +35,30 @@ public extension MVMCoreAlertHandler {
         }
             
         // If the highest priority operation is not executing, and the executing operation is persistent, cancel it.
-        if higherPriorityOperationIsReady,
+        if let newOperation = highestReadyOperation,
+           currentOperation != newOperation,
            currentOperation.topAlertObject.persistent {
             currentOperation.reAddAfterCancel = true
             currentOperation.cancel()
         }
     }
     
-    /// Registers with the notification center to know when pages change.
-    @objc func registerWithNotificationCenter() {
-        NotificationCenter.default.addObserver(self, selector: #selector(viewControllerChanged(notification:)), name: NSNotification.Name(rawValue: MVMCoreNotificationViewControllerChanged), object: nil)
+    /// Registers to know when pages change.
+    @objc func registerForPageChanges() {
+        MVMCoreNavigationHandler.shared()?.addDelegate(self)
     }
-    
-    /// Updates the operation isDisplayable based on the page type.
-    private func updatePageReadiness(for topOperation: MVMCoreTopAlertOperation, with pageType: String?) {
-        guard let pages = topOperation.topAlertObject.json?.optionalArrayForKey("pages") as? [String],
-              pages.count != 0 else {
-            topOperation.isDisplayable = true
-            return
+}
+
+extension MVMCoreAlertHandler: MVMCorePresentationDelegateProtocol {
+    // Update displayable for each top alert operation when page type changes, in top queue priority order.
+    public func navigationController(_ navigationController: UINavigationController, displayedViewController viewController: UIViewController) {
+        guard navigationController == MVMCoreUISplitViewController.main()?.navigationController  else { return }
+        let pageType = (viewController as? MVMCoreViewControllerProtocol)?.pageType
+        let sortedOperations = topAlertQueue.operations.sorted { $0.queuePriority.rawValue > $1.queuePriority.rawValue }
+        for case let operation as MVMCoreTopAlertOperation in sortedOperations {
+            operation.updateDisplayable(byPageType: pageType)
         }
-        guard let pageType = pageType else {
-            topOperation.isDisplayable = false
-            return
-        }
-        topOperation.isDisplayable = pages.contains(pageType)
-    }
-        
-    /// When a detail page changes, check top alerts.
-    @objc private func viewControllerChanged(notification: Notification) {
         reevaluteQueue()
     }
 }
+

MVMCoreUI/Alerts/MVMCoreAlertHandler.m

@@ -42,7 +42,7 @@
         self.popupAlertQueue.maxConcurrentOperationCount = 1;
         self.topAlertQueue = [[NSOperationQueue alloc] init];
         self.topAlertQueue.maxConcurrentOperationCount = 1;
-        [self registerWithNotificationCenter];
+        [self registerForPageChanges];
     }
     return self;
 }
@@ -172,6 +172,9 @@
         alertOperation = nil;
     }];
     
+    NSString *currentPageType = ((UIViewController<MVMCoreViewControllerProtocol> *)[[MVMCoreUISplitViewController mainSplitViewController] getCurrentDetailViewController]).pageType;
+    [alertOperation updateDisplayableByPageType:currentPageType];
+    
     [self.topAlertQueue addOperation:alertOperation];
     [self reevaluteQueue];
 }

MVMCoreUI/TopAlert/MVMCoreTopAlertOperation.h

@@ -27,6 +27,9 @@
 /// Updates the operation with a new object
 - (void)updateWithTopAlertObject:(nonnull MVMCoreTopAlertObject *)topAlertObject;
 
+/// Updates the operation isDisplayable based on the page type.
+- (void)updateDisplayableByPageType:(nullable NSString *)pageType;
+
 // Pauses the operation. Temporarily removes any alert.
 - (void)pause;
 

MVMCoreUI/TopAlert/MVMCoreTopAlertOperation.m

@@ -71,6 +71,19 @@
     }
 }
 
+- (void)updateDisplayableByPageType:(nullable NSString *)pageType {
+    NSArray <NSString *>*pages = [self.topAlertObject.json array:@"pages"];
+    if (pages.count == 0) {
+        self.displayable = YES;
+        return;
+    }
+    if (pageType.length == 0) {
+        self.displayable = NO;
+        return;
+    }
+    self.displayable = [pages containsObject:pageType];
+}
+
 - (BOOL)isPaused {
     __block BOOL isPaused;
     dispatch_sync(self.pausedQueue, ^{

MVMCoreUI/TopAlert/MVMCoreUITopAlertView+Extension.swift

@@ -68,6 +68,8 @@ public extension MVMCoreUITopAlertView {
             guard topAlertObject.json != nil,
                operation.topAlertObject.type == topAlertObject.type else { continue }
             operation.update(with: topAlertObject)
+            let pageType = (MVMCoreUISplitViewController.main()?.getCurrentDetailViewController() as? MVMCoreViewControllerProtocol)?.pageType
+            operation.updateDisplayable(byPageType: pageType)
             MVMCoreAlertHandler.shared()?.reevaluteQueue()
             return true
         }