mapbox · mateuszmackowiak · Oct 24, 2019
@@ -8,6 +8,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 FOUNDATION_EXTERN MGL_EXPORT MGLExceptionName const MGLInvalidOfflinePackException;
 
+@class MGLOfflinePack;
+
 /**
  The state an offline pack is currently in.
  */
@@ -96,6 +98,12 @@ typedef struct __attribute__((objc_boxable)) MGLOfflinePackProgress {
     uint64_t maximumResourcesExpected;
 } MGLOfflinePackProgress;
 
+@protocol MGLOfflinePackObserver <NSObject>
+
+-(void)didUpdateStateForMGLOfflinePack:(MGLOfflinePack*)offlinePack;
+
+@end
+
 /**
  An `MGLOfflinePack` represents a collection of resources necessary for viewing
  a region offline to a local database.
@@ -200,4 +208,13 @@ MGL_EXPORT
 
 @end
 
+
+@interface MGLOfflinePack (Observers)
+
+-(void)addObserver:(id<MGLOfflinePackObserver>)observer;
+
+-(void)removeObserver:(id<MGLOfflinePackObserver>)observer;
+
+@end
+
 NS_ASSUME_NONNULL_END
@@ -54,6 +54,7 @@ @interface MGLOfflinePack ()
 
 @property (nonatomic, nullable, readwrite) mbgl::OfflineRegion *mbglOfflineRegion;
 @property (nonatomic, readwrite) MGLOfflinePackProgress progress;
+@property (nonatomic, strong) NSHashTable<id<MGLOfflinePackObserver>>* observers;
 
 @end
 
@@ -76,6 +77,7 @@ - (instancetype)initWithMBGLRegion:(mbgl::OfflineRegion *)region {
         _mbglOfflineRegion = region;
         _state = MGLOfflinePackStateUnknown;
 
+        _observers = [NSHashTable hashTableWithOptions:NSPointerFunctionsWeakMemory];
         _mbglFileSource = [[MGLOfflineStorage sharedOfflineStorage] mbglFileSource];
         _mbglFileSource->setOfflineRegionObserver(*_mbglOfflineRegion, std::make_unique<MBGLOfflineRegionObserver>(self));
     }
@@ -161,20 +163,34 @@ - (void)setState:(MGLOfflinePackState)state {
     if (!_isSuspending || state != MGLOfflinePackStateActive) {
         _isSuspending = NO;
         _state = state;
+        for (id<MGLOfflinePackObserver> observer in self.observers) {
+            if ([observer conformsToProtocol:@protocol(MGLOfflinePackObserver)]) {
+                [observer didUpdateStateForMGLOfflinePack:self];
+            } else {
+                MGLLogError(@"One of observers of MGLOfflinePack was dealoceted and not removed form observers.");
+            }
+        }
     }
 }
 
 - (void)requestProgress {
+    [self requestProgressWithCompletionHandler:^{}];
+}
+
+- (void)requestProgressWithCompletionHandler:(void (^)())completion {
     MGLLogInfo(@"Requesting pack progress.");
     MGLAssertOfflinePackIsValid();
 
     __weak MGLOfflinePack *weakSelf = self;
-    _mbglFileSource->getOfflineRegionStatus(*_mbglOfflineRegion, [&, weakSelf](mbgl::expected<mbgl::OfflineRegionStatus, std::exception_ptr> status) {
+    _mbglFileSource->getOfflineRegionStatus(*_mbglOfflineRegion, [&, weakSelf, completion](mbgl::expected<mbgl::OfflineRegionStatus, std::exception_ptr> status) {
         if (status) {
             mbgl::OfflineRegionStatus checkedStatus = *status;
             dispatch_async(dispatch_get_main_queue(), ^{
                 MGLOfflinePack *strongSelf = weakSelf;
                 [strongSelf offlineRegionStatusDidChange:checkedStatus];
+                if (completion) {
+                    completion();
+                }
             });
         }
     });
@@ -280,3 +296,15 @@ - (void)didReceiveMaximumAllowedMapboxTiles:(uint64_t)limit {
         [weakPack didReceiveMaximumAllowedMapboxTiles:limit];
     });
 }
+
+@implementation MGLOfflinePack (Observers)
+
+-(void)addObserver:(id<MGLOfflinePackObserver>)observer {
+    [self.observers addObject:observer];
+}
+
+-(void)removeObserver:(id<MGLOfflinePackObserver>)observer {
+    [self.observers removeObject:observer];
+}
+
+@end
@@ -12,6 +12,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)initWithMBGLRegion:(mbgl::OfflineRegion *)region;
 
+- (void)requestProgressWithCompletionHandler:(void (^)())completion;
+
 /**
  Invalidates the pack and ensures that no future progress update can ever
  revalidate it. This method must be called before the pack is deallocated.

@@ -469,6 +469,15 @@ MGL_EXPORT
      URLForResourceOfKind:(MGLResourceKind)kind
                   withURL:(NSURL *)url;
 
+@optional
+/**
+ Notifies about package reload
+
+ @param storage The storage object processing the reload.
+
+ */
+- (void)didReloadPackagesForOfflineStorage:(MGLOfflineStorage *)storage;
+
 @end
 
 NS_ASSUME_NONNULL_END
@@ -492,9 +492,42 @@ - (void)reloadPacks {
             [pack invalidate];
         }
         self.packs = [packs mutableCopy];
+        MGLLogInfo(@"Packs reloaded.");
+        __weak MGLOfflineStorage *weakSelf = self;
+        [self requestPackProgressWithCompletionHandler:^{
+            MGLOfflineStorage *strongSelf = weakSelf;
+             if([strongSelf.delegate respondsToSelector:@selector(didReloadPackagesForOfflineStorage:)]) {
+                 [strongSelf.delegate didReloadPackagesForOfflineStorage:strongSelf];
+             }
+        }];
     }];
 }
 
+-(void)requestPackProgressWithCompletionHandler:(void (^)())completion {
+    __block NSUInteger count = 0;
+    __block NSUInteger expectedCount = self.packs.count;
+    if (self.packs == nil) {
+        //TODO: completion with error?
+        return;
+    }
+    if( self.packs.count == 0) {
+        completion();
+        return;
+    }
+    for (MGLOfflinePack *pack in self.packs) {
+        if(pack.state == MGLOfflinePackStateComplete) {
+            count++;
+            return;
+        }
+        [pack requestProgressWithCompletionHandler:^{
+            count++;
+            if(count == expectedCount) {
+                completion();
+            }
+        }];
+    }
+}
+
 - (void)getPacksWithCompletionHandler:(void (^)(NSArray<MGLOfflinePack *> *packs, NSError * _Nullable error))completion {
     _mbglFileSource->listOfflineRegions([&, completion](mbgl::expected<mbgl::OfflineRegions, std::exception_ptr> result) {
         NSError *error;

@@ -10,8 +10,34 @@
 
 #pragma clang diagnostic ignored "-Wshadow"
 
+@interface MGLOfflineStorageBlockDelegate : NSObject <MGLOfflineStorageDelegate>
+@property (nonatomic, copy, nullable) NSURL* (^URLForResourceOfKind)(MGLOfflineStorage *storage, MGLResourceKind kind, NSURL *url);
+@property (nonatomic, copy, nullable) void (^didReloadPackagesForOfflineStorage)(MGLOfflineStorage *storage);
 
-@interface MGLOfflineStorageTests : XCTestCase <MGLOfflineStorageDelegate>
+@end
+
+
+@implementation MGLOfflineStorageBlockDelegate
+
+- (NSURL *)offlineStorage:(MGLOfflineStorage *)storage
+     URLForResourceOfKind:(MGLResourceKind)kind
+                  withURL:(NSURL *)url {
+    if(self.URLForResourceOfKind != nil) {
+        return self.URLForResourceOfKind(storage, kind, url);
+    } else {
+        return url;
+    }
+}
+
+- (void)didReloadPackagesForOfflineStorage:(nonnull MGLOfflineStorage *)storage {
+    if(self.didReloadPackagesForOfflineStorage != nil) {
+        self.didReloadPackagesForOfflineStorage(storage);
+    }
+}
+
+@end
+
+@interface MGLOfflineStorageTests : XCTestCase
 @end
 
 @implementation MGLOfflineStorageTests
@@ -33,26 +59,6 @@ + (void)tearDown {
     XCTAssertFalse([[NSFileManager defaultManager] fileExistsAtPath:cacheURL.path], @"Cache subdirectory should not exist.");
 }
 
-- (void)setUp {
-    [super setUp];
-
-    static dispatch_once_t onceToken;
-    dispatch_once(&onceToken, ^{
-        XCTestExpectation *expectation = [self keyValueObservingExpectationForObject:[MGLOfflineStorage sharedOfflineStorage] keyPath:@"packs" handler:^BOOL(id _Nonnull observedObject, NSDictionary * _Nonnull change) {
-            const auto changeKind = static_cast<NSKeyValueChange>([change[NSKeyValueChangeKindKey] unsignedLongValue]);
-            return changeKind == NSKeyValueChangeSetting;
-        }];
-        if ([MGLOfflineStorage sharedOfflineStorage].packs) {
-            [expectation fulfill];
-            [self waitForExpectationsWithTimeout:0 handler:nil];
-        } else {
-            [self waitForExpectationsWithTimeout:10 handler:nil];
-        }
-
-        XCTAssertNotNil([MGLOfflineStorage sharedOfflineStorage].packs, @"Shared offline storage object should have a non-nil collection of packs by this point.");
-    });
-}
-
 - (void)testSharedObject {
     XCTAssertEqual([MGLOfflineStorage sharedOfflineStorage], [MGLOfflineStorage sharedOfflineStorage], @"There should only be one shared offline storage object.");
 }
@@ -506,19 +512,17 @@ - (void)testCountOfBytesCompleted {
     XCTAssertGreaterThan([MGLOfflineStorage sharedOfflineStorage].countOfBytesCompleted, 0UL);
 }
 
-- (NSURL *)offlineStorage:(MGLOfflineStorage *)storage
-     URLForResourceOfKind:(MGLResourceKind)kind
-                  withURL:(NSURL *)url {
-    if ([url.scheme isEqual: @"test"] && [url.host isEqual: @"api"]) {
-        return [NSURL URLWithString:@"https://api.mapbox.com"];
-    } else {
-        return url;
-    }
-}
-
 - (void)testResourceTransform {
     MGLOfflineStorage *os = [MGLOfflineStorage sharedOfflineStorage];
-    [os setDelegate:self];
+    MGLOfflineStorageBlockDelegate* delegate = [[MGLOfflineStorageBlockDelegate alloc] init];
+    delegate.URLForResourceOfKind = ^NSURL *(MGLOfflineStorage *storage, MGLResourceKind kind, NSURL *url) {
+        if ([url.scheme isEqual: @"test"] && [url.host isEqual: @"api"]) {
+            return [NSURL URLWithString:@"https://api.mapbox.com"];
+        } else {
+            return url;
+        }
+    };
+    [os setDelegate:delegate];
 
     auto fs = os.mbglFileSource;
 
@@ -534,8 +538,27 @@ - (void)testResourceTransform {
     });
 
     CFRunLoopRun();
+    [os setDelegate:nil];
+}
+
+-(void)testDidCallReloadPackagesForOfflineStorage {
+    __block XCTestExpectation* didReceiveCallbackExpectation = [self expectationWithDescription:@"didReceiveCallback"];
+    MGLOfflineStorageBlockDelegate* delegate = [[MGLOfflineStorageBlockDelegate alloc] init];
+    delegate.URLForResourceOfKind = ^NSURL *(MGLOfflineStorage *storage, MGLResourceKind kind, NSURL *url) {
+        return [NSURL URLWithString:@"https://api.mapbox.com"];
+    };
+    delegate.didReloadPackagesForOfflineStorage = ^void(MGLOfflineStorage *storage) {
+        [didReceiveCallbackExpectation fulfill];
+    };
+
+    MGLOfflineStorage *os = [MGLOfflineStorage sharedOfflineStorage];
+    [os setDelegate:delegate];
+
+    [self waitForExpectationsWithTimeout:60 handler:nil];
 
+    XCTAssertNotNil(os.packs);
     [os setDelegate:nil];
+    NSLog(@"Delegate %@ didReceiveCallback was called for packages %@", delegate, os.packs);
 }
 
 - (void)testAddFileContent {