Notification Permission Observer - API update

* Rename observer from `OSPermissionObserver` to `OSNotificationPermissionObserver`
* Rename and change the method from
`onOSPermissionChanged:(OSPermissionStateChanges)` to `onNotificationPermissionDidChange:(BOOL)`
* The `OSObservable` infrastructure works with objects, and even though we use NSNumber to get around this, once we pass an NSNumber to the app developer's method that expects a BOOL, it does not work.
* Therefore, make another OSBoolObservable just for booleans, and use `NSInvocation` instead of `performSelector` because the latter only works with objects.

Author: nan-li

iOS_SDK/OneSignalDevApp/OneSignalDevApp/AppDelegate.h

@@ -31,7 +31,7 @@
 #import <UIKit/UIKit.h>
 #import <OneSignalFramework/OneSignalFramework.h>
 
-@interface AppDelegate : UIResponder <UIApplicationDelegate, OSPermissionObserver, OSInAppMessageLifecycleHandler, OSPushSubscriptionObserver>
+@interface AppDelegate : UIResponder <UIApplicationDelegate, OSNotificationPermissionObserver, OSInAppMessageLifecycleHandler, OSPushSubscriptionObserver>
 
 @property (strong, nonatomic) UIWindow *window;
 

iOS_SDK/OneSignalDevApp/OneSignalDevApp/AppDelegate.m

@@ -117,8 +117,8 @@ + (void) setOneSignalAppId:(NSString*)onesignalAppId {
     // [OneSignal setAppId:onesignalAppId];
 }
 
-- (void)onOSPermissionChanged:(OSPermissionState*)state {
-    NSLog(@"Dev App onOSPermissionChanged: %@", state);
+- (void)onNotificationPermissionDidChange:(BOOL)permission {
+    NSLog(@"Dev App onNotificationPermissionDidChange: %d", permission);
 }
 
 - (void)onOSPushSubscriptionChangedWithStateChanges:(OSPushSubscriptionStateChanges *)stateChanges {

iOS_SDK/OneSignalDevApp/OneSignalDevAppClip/AppDelegate.h

@@ -10,7 +10,7 @@
 #import <OneSignalFramework/OneSignalFramework.h>
 
 // TODO: Add subscription observer
-@interface AppDelegate : UIResponder <UIApplicationDelegate, OSPermissionObserver>
+@interface AppDelegate : UIResponder <UIApplicationDelegate, OSNotificationPermissionObserver>
 
 @property (strong, nonatomic) UIWindow *window;
 

iOS_SDK/OneSignalDevApp/OneSignalDevAppClip/AppDelegate.m

@@ -112,8 +112,8 @@ + (void) setOneSignalAppId:(NSString*)onesignalAppId {
     [OneSignal initialize:onesignalAppId withLaunchOptions:nil];
 }
 
-- (void) onOSPermissionChanged:(OSPermissionState*)state {
-    NSLog(@"onOSPermissionChanged: %@", state);
+- (void)onNotificationPermissionDidChange:(BOOL)permission {
+    NSLog(@"onNotificationPermissionDidChange: %d", permission);
 }
 
 // TODO: Add push sub observer

iOS_SDK/OneSignalSDK/OneSignalCore/Source/OSObservable.h

@@ -40,4 +40,13 @@
 - (BOOL)notifyChange:(ObjectType)state;
 @end
 
+// OSBoolObservable is for BOOL states which OSObservable above does not work with
+
+@interface OSBoolObservable<__covariant ObserverType> : NSObject
+- (instancetype _Nonnull)initWithChangeSelector:(SEL)selector;
+- (void)addObserver:(ObserverType)observer;
+- (void)removeObserver:(ObserverType)observer;
+- (BOOL)notifyChange:(BOOL)state;
+@end
+
 #endif /* OSObservable_h */

iOS_SDK/OneSignalSDK/OneSignalCore/Source/OSObservable.m

@@ -95,3 +95,76 @@ - (void)callObserver:(id)observer withSelector:(SEL)selector withState:(id)state
 #pragma clang diagnostic pop
 
 @end
+
+
+@implementation OSBoolObservable {
+NSHashTable* observers;
+SEL changeSelector;
+}
+
+- (instancetype _Nonnull)initWithChangeSelector:(SEL)selector {
+    if (self = [super init]) {
+        observers = [NSHashTable weakObjectsHashTable];
+        changeSelector = selector;
+    }
+    return self;
+}
+
+- (instancetype)init {
+    if (self = [super init])
+        observers = [NSHashTable new];
+    return self;
+}
+
+- (void)addObserver:(id)observer {
+    @synchronized(observers) {
+        [observers addObject:observer];
+    }
+}
+
+- (void)removeObserver:(id)observer {
+    @synchronized(observers) {
+        [observers removeObject:observer];
+    }
+}
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
+
+- (BOOL)notifyChange:(BOOL)state {
+    BOOL fired = false;
+    
+    @synchronized(observers) {
+        NSArray *obs = [observers copy];
+        for (id observer in obs) {
+            fired = true;
+            if (changeSelector) {
+                // Any Observable setup to fire a custom selector with changeSelector
+                //  is external to our SDK. Run on the main thread in case the
+                //  app developer needs to update UI elements.
+                
+                [self callObserver:observer withSelector:changeSelector withState:state];
+            }
+        }
+    }
+    
+    return fired;
+}
+
+- (void)callObserver:(id)observer withSelector:(SEL)selector withState:(BOOL)state {
+    [OneSignalCoreHelper dispatch_async_on_main_queue:^{
+        // The following declaration is to resolve: Sending 'const BOOL *' (aka 'const bool *') to parameter of type 'void * _Nonnull' discards qualifiers
+        BOOL boolValue = state;
+
+        NSMethodSignature* signature = [[observer class] instanceMethodSignatureForSelector:self->changeSelector];
+        NSInvocation* invocation = [NSInvocation invocationWithMethodSignature:signature];
+        [invocation setTarget: observer];
+        [invocation setSelector:self->changeSelector];
+        [invocation setArgument: &boolValue atIndex: 2];
+        [invocation invoke];
+    }];
+}
+
+#pragma clang diagnostic pop
+
+@end

iOS_SDK/OneSignalSDK/OneSignalNotifications/OSNotificationsManager.h

@@ -47,8 +47,8 @@ typedef void (^OSNotificationOpenedBlock)(OSNotificationOpenedResult * _Nonnull
 + (void)requestPermission:(OSUserResponseBlock _Nullable )block;
 + (void)requestPermission:(OSUserResponseBlock _Nullable )block fallbackToSettings:(BOOL)fallback;
 + (void)registerForProvisionalAuthorization:(OSUserResponseBlock _Nullable )block NS_REFINED_FOR_SWIFT;
-+ (void)addPermissionObserver:(NSObject<OSPermissionObserver>*_Nonnull)observer NS_REFINED_FOR_SWIFT;
-+ (void)removePermissionObserver:(NSObject<OSPermissionObserver>*_Nonnull)observer NS_REFINED_FOR_SWIFT;
++ (void)addPermissionObserver:(NSObject<OSNotificationPermissionObserver>*_Nonnull)observer NS_REFINED_FOR_SWIFT;
++ (void)removePermissionObserver:(NSObject<OSNotificationPermissionObserver>*_Nonnull)observer NS_REFINED_FOR_SWIFT;
 + (void)clearAll;
 @end
 

iOS_SDK/OneSignalSDK/OneSignalNotifications/OSNotificationsManager.m

@@ -147,7 +147,7 @@ + (OneSignalNotificationSettings *)osNotificationSettings {
 static ObservablePermissionStateChangesType* _permissionStateChangesObserver;
 + (ObservablePermissionStateChangesType*)permissionStateChangesObserver {
     if (!_permissionStateChangesObserver)
-        _permissionStateChangesObserver = [[OSObservable alloc] initWithChangeSelector:@selector(onOSPermissionChanged:)];
+        _permissionStateChangesObserver = [[OSBoolObservable alloc] initWithChangeSelector:@selector(onNotificationPermissionDidChange:)];
     return _permissionStateChangesObserver;
 }
 
@@ -425,15 +425,15 @@ + (void)setSubscriptionErrorStatus:(int)errorType {
     [self sendNotificationTypesUpdateToDelegate];
 }
 
-// onOSPermissionChanged should only fire if the reachable property changed.
-+ (void)addPermissionObserver:(NSObject<OSPermissionObserver>*)observer {
+// onNotificationPermissionDidChange should only fire if the reachable property changed.
++ (void)addPermissionObserver:(NSObject<OSNotificationPermissionObserver>*)observer {
     [self.permissionStateChangesObserver addObserver:observer];
 
     if (self.currentPermissionState.reachable != self.lastPermissionState.reachable)
         [OSPermissionChangedInternalObserver fireChangesObserver:self.currentPermissionState];
 }
 
-+ (void)removePermissionObserver:(NSObject<OSPermissionObserver>*)observer {
++ (void)removePermissionObserver:(NSObject<OSNotificationPermissionObserver>*)observer {
     [self.permissionStateChangesObserver removeObserver:observer];
 }
 

iOS_SDK/OneSignalSDK/OneSignalNotifications/OSPermission.h

@@ -47,8 +47,9 @@ typedef NS_ENUM(NSInteger, OSNotificationPermission) {
 };
 
 // Permission Classes
+
+// TODO: this object can be REMOVED now that permission is a boolean
 @interface OSPermissionState : NSObject
-// TODO: Decide: remove/change properties after addition of canRequestPermission and permission boolean
 @property (readonly, nonatomic) BOOL permission;
 - (NSDictionary * _Nonnull)jsonRepresentation;
 - (instancetype _Nonnull )initWithPermission:(BOOL)permission;
@@ -87,11 +88,11 @@ typedef OSObservable<NSObject<OSPermissionStateObserver>*, OSPermissionState*> O
 - (NSDictionary * _Nonnull)jsonRepresentation;
 @end
 
-@protocol OSPermissionObserver <NSObject>
-- (void)onOSPermissionChanged:(OSPermissionState * _Nonnull)state;
+@protocol OSNotificationPermissionObserver <NSObject>
+- (void)onNotificationPermissionDidChange:(BOOL)permission;
 @end
 
-typedef OSObservable<NSObject<OSPermissionObserver>*, OSPermissionState*> ObservablePermissionStateChangesType;
+typedef OSBoolObservable<NSObject<OSNotificationPermissionObserver>*> ObservablePermissionStateChangesType;
 
 
 @interface OSPermissionChangedInternalObserver : NSObject<OSPermissionStateObserver>

iOS_SDK/OneSignalSDK/OneSignalNotifications/OSPermission.m

@@ -196,14 +196,11 @@ - (void)onChanged:(OSPermissionStateInternal*)state {
 }
 
 + (void)fireChangesObserver:(OSPermissionStateInternal*)state  {
-    OSPermissionState *externalToState = [state getExternalState];
-    OSPermissionState *externalFromState = [OSNotificationsManager.lastPermissionState getExternalState];
-    
-    if (externalToState.permission == externalFromState.permission) {
+    if (state.reachable == OSNotificationsManager.lastPermissionState.reachable) {
         return;
     }
 
-    BOOL hasReceiver = [OSNotificationsManager.permissionStateChangesObserver notifyChange:externalToState];
+    BOOL hasReceiver = [OSNotificationsManager.permissionStateChangesObserver notifyChange:state.reachable];
     if (hasReceiver) {
         OSNotificationsManager.lastPermissionState = [state copy];
         [OSNotificationsManager.lastPermissionState persistAsFrom];