[ios, macos] Make MGLMapView.style property nullable (#7664)

* [ios, macos] Made MGLMapView.style property nullable

MGLMapView’s style property is now nullable (optional in Swift). The property is set to nil while the style loads and in the event that the style has failed to load.

* [ios, macos] Switch to delegate method

* [macos] Create MGLMapView programmatically for layer tests

When MGLMapView is created via a nib, -initWithCoder: is called, causing styleURL to be set to nil, in turn causing the default Streets style to be loaded, fooling MGLStyleLayerTests into thinking one-line has been loaded. Instead, create MGLMapView programmatically, passing the intended style URL into the initializer, preventing Streets from being loaded.

1 files changed, 7 insertions, 8 deletions

diff --git a/platform/ios/src/MGLMapView.mm b/platform/ios/src/MGLMapView.mm
index ddb11ffbb7..f8ca673093 100644
--- a/platform/ios/src/MGLMapView.mm
+++ b/platform/ios/src/MGLMapView.mm
@@ -347,6 +347,11 @@ public:
     return self;
 }
 
++ (NS_SET_OF(NSString *) *)keyPathsForValuesAffectingStyle
+{
+    return [NSSet setWithObject:@"styleURL"];
+}
+
 + (NS_SET_OF(NSString *) *)keyPathsForValuesAffectingStyleURL
 {
     return [NSSet setWithObjects:@"styleURL__", nil];
@@ -369,10 +374,8 @@ public:
     }
 
     styleURL = styleURL.mgl_URLByStandardizingScheme;
-    [self willChangeValueForKey:@"style"];
-    _style = [[MGLStyle alloc] initWithMapView:self];
+    self.style = nil;
     _mbglMap->setStyleURL([[styleURL absoluteString] UTF8String]);
-    [self didChangeValueForKey:@"style"];
 }
 
 - (IBAction)reloadStyle:(__unused id)sender {
@@ -4682,11 +4685,7 @@ public:
         }
         case mbgl::MapChangeDidFinishLoadingStyle:
         {
-            [self.style willChangeValueForKey:@"name"];
-            [self.style willChangeValueForKey:@"sources"];
-            [self.style didChangeValueForKey:@"sources"];
-            [self.style willChangeValueForKey:@"layers"];
-            [self.style didChangeValueForKey:@"layers"];
+            self.style = [[MGLStyle alloc] initWithMapView:self];
             if ([self.delegate respondsToSelector:@selector(mapView:didFinishLoadingStyle:)])
             {
                 [self.delegate mapView:self didFinishLoadingStyle:self.style];