[darwin] Introduce MGLAssertStyleSourceIsValid() macro and use it

8 files changed, 41 insertions, 2 deletions

diff --git a/platform/darwin/src/MGLComputedShapeSource.mm b/platform/darwin/src/MGLComputedShapeSource.mm
index 5110435b03..a04181af2f 100644
--- a/platform/darwin/src/MGLComputedShapeSource.mm
+++ b/platform/darwin/src/MGLComputedShapeSource.mm
@@ -199,6 +199,7 @@ mbgl::style::CustomGeometrySource::Options MBGLCustomGeometrySourceOptionsFromDi
 }
 
 - (void)setFeatures:(NSArray<MGLShape <MGLFeature> *>*)features inTileAtX:(NSUInteger)x y:(NSUInteger)y zoomLevel:(NSUInteger)zoomLevel {
+    MGLAssertStyleSourceIsValid();
     mbgl::CanonicalTileID tileID = mbgl::CanonicalTileID((uint8_t)zoomLevel, (uint32_t)x, (uint32_t)y);
     mbgl::FeatureCollection featureCollection;
     featureCollection.reserve(features.count);
@@ -236,10 +237,12 @@ mbgl::style::CustomGeometrySource::Options MBGLCustomGeometrySourceOptionsFromDi
 }
 
 - (void) invalidateBounds:(MGLCoordinateBounds)bounds {
+    MGLAssertStyleSourceIsValid();
     ((mbgl::style::CustomGeometrySource *)self.rawSource)->invalidateRegion(MGLLatLngBoundsFromCoordinateBounds(bounds));
 }
 
 - (void) invalidateTileAtX:(NSUInteger)x y:(NSUInteger)y zoomLevel:(NSUInteger)z {
+    MGLAssertStyleSourceIsValid();
     ((mbgl::style::CustomGeometrySource *)self.rawSource)->invalidateTile(mbgl::CanonicalTileID(z, (unsigned int)x, (unsigned int)y));
 }
 
diff --git a/platform/darwin/src/MGLImageSource.mm b/platform/darwin/src/MGLImageSource.mm
index 351247e901..50422ccedc 100644
--- a/platform/darwin/src/MGLImageSource.mm
+++ b/platform/darwin/src/MGLImageSource.mm
@@ -45,11 +45,13 @@
 }
 
 - (NSURL *)URL {
+    MGLAssertStyleSourceIsValid();
     auto url = self.rawSource->getURL();
     return url ? [NSURL URLWithString:@(url->c_str())] : nil;
 }
 
 - (void)setURL:(NSURL *)url {
+    MGLAssertStyleSourceIsValid();
     if (url) {
         self.rawSource->setURL(url.mgl_URLByStandardizingScheme.absoluteString.UTF8String);
         _image = nil;
@@ -59,6 +61,7 @@
 }
 
 - (void)setImage:(MGLImage *)image {
+    MGLAssertStyleSourceIsValid();
     if (image != nullptr) {
         self.rawSource->setImage(image.mgl_premultipliedImage);
     } else {
@@ -68,10 +71,12 @@
 }
 
 - (MGLCoordinateQuad)coordinates {
+    MGLAssertStyleSourceIsValid();
     return MGLCoordinateQuadFromLatLngArray(self.rawSource->getCoordinates());
 }
 
 - (void)setCoordinates: (MGLCoordinateQuad)coordinateQuad {
+    MGLAssertStyleSourceIsValid();
     self.rawSource->setCoordinates(MGLLatLngArrayFromCoordinateQuad(coordinateQuad));
 }
 
@@ -85,6 +90,7 @@
 }
 
 - (NSString *)attributionHTMLString {
+    MGLAssertStyleSourceIsValid();
     auto attribution = self.rawSource->getAttribution();
     return attribution ? @(attribution->c_str()) : nil;
 }
diff --git a/platform/darwin/src/MGLRasterTileSource.mm b/platform/darwin/src/MGLRasterTileSource.mm
index 61e9ef97fd..e89367711e 100644
--- a/platform/darwin/src/MGLRasterTileSource.mm
+++ b/platform/darwin/src/MGLRasterTileSource.mm
@@ -65,11 +65,13 @@ static const CGFloat MGLRasterTileSourceRetinaTileSize = 512;
 }
 
 - (NSURL *)configurationURL {
+    MGLAssertStyleSourceIsValid();
     auto url = self.rawSource->getURL();
     return url ? [NSURL URLWithString:@(url->c_str())] : nil;
 }
 
 - (NSString *)attributionHTMLString {
+    MGLAssertStyleSourceIsValid();
     auto attribution = self.rawSource->getAttribution();
     return attribution ? @(attribution->c_str()) : nil;
 }
diff --git a/platform/darwin/src/MGLShapeSource.mm b/platform/darwin/src/MGLShapeSource.mm
index fc526f9850..19aad56182 100644
--- a/platform/darwin/src/MGLShapeSource.mm
+++ b/platform/darwin/src/MGLShapeSource.mm
@@ -150,11 +150,13 @@ mbgl::style::GeoJSONOptions MGLGeoJSONOptionsFromDictionary(NSDictionary<MGLShap
 }
 
 - (NSURL *)URL {
+    MGLAssertStyleSourceIsValid();
     auto url = self.rawSource->getURL();
     return url ? [NSURL URLWithString:@(url->c_str())] : nil;
 }
 
 - (void)setURL:(NSURL *)url {
+    MGLAssertStyleSourceIsValid();
     if (url) {
         self.rawSource->setURL(url.mgl_URLByStandardizingScheme.absoluteString.UTF8String);
         _shape = nil;
@@ -164,6 +166,7 @@ mbgl::style::GeoJSONOptions MGLGeoJSONOptionsFromDictionary(NSDictionary<MGLShap
 }
 
 - (void)setShape:(MGLShape *)shape {
+    MGLAssertStyleSourceIsValid();
     self.rawSource->setGeoJSON({ shape.geoJSONObject });
     _shape = shape;
 }
@@ -174,7 +177,7 @@ mbgl::style::GeoJSONOptions MGLGeoJSONOptionsFromDictionary(NSDictionary<MGLShap
 }
 
 - (NSArray<id <MGLFeature>> *)featuresMatchingPredicate:(nullable NSPredicate *)predicate {
-    
+    MGLAssertStyleSourceIsValid();
     mbgl::optional<mbgl::style::Filter> optionalFilter;
     if (predicate) {
         optionalFilter = predicate.mgl_filter;
@@ -190,6 +193,7 @@ mbgl::style::GeoJSONOptions MGLGeoJSONOptionsFromDictionary(NSDictionary<MGLShap
 #pragma mark - MGLCluster management
 
 - (mbgl::optional<mbgl::FeatureExtensionValue>)featureExtensionValueOfCluster:(MGLShape<MGLCluster> *)cluster extension:(std::string)extension options:(const std::map<std::string, mbgl::Value>)options {
+    MGLAssertStyleSourceIsValid();
     mbgl::optional<mbgl::FeatureExtensionValue> extensionValue;
     
     // Check parameters
diff --git a/platform/darwin/src/MGLSource.h b/platform/darwin/src/MGLSource.h
index 7bbf02fa7c..dc92e652e8 100644
--- a/platform/darwin/src/MGLSource.h
+++ b/platform/darwin/src/MGLSource.h
@@ -1,9 +1,12 @@
 #import <Foundation/Foundation.h>
 
 #import "MGLFoundation.h"
+#import "MGLTypes.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
+FOUNDATION_EXTERN MGL_EXPORT MGLExceptionName const MGLInvalidStyleSourceException;
+
 /**
  `MGLSource` is an abstract base class for map content sources. A map content
  source supplies content to be shown on the map. A source is added to an
diff --git a/platform/darwin/src/MGLSource.mm b/platform/darwin/src/MGLSource.mm
index 2c673fbb30..01bcd94fec 100644
--- a/platform/darwin/src/MGLSource.mm
+++ b/platform/darwin/src/MGLSource.mm
@@ -7,6 +7,8 @@
 #include <mbgl/map/map.hpp>
 #include <mbgl/style/source.hpp>
 
+const MGLExceptionName MGLInvalidStyleSourceException = @"MGLInvalidStyleSourceException";
+
 @interface MGLSource ()
 
 // Even though this class is abstract, MGLStyle uses it to represent some
@@ -65,6 +67,7 @@
 }
 
 - (BOOL)removeFromMapView:(MGLMapView *)mapView error:(NSError * __nullable * __nullable)outError {
+    MGLAssertStyleSourceIsValid();
     BOOL removed = NO;
     
     if (self.rawSource == mapView.style.rawStyle->getSource(self.identifier.UTF8String)) {
diff --git a/platform/darwin/src/MGLSource_Private.h b/platform/darwin/src/MGLSource_Private.h
index af14c11b90..2d4b2a3c41 100644
--- a/platform/darwin/src/MGLSource_Private.h
+++ b/platform/darwin/src/MGLSource_Private.h
@@ -2,6 +2,7 @@
 
 #include <memory>
 
+
 NS_ASSUME_NONNULL_BEGIN
 
 namespace mbgl {
@@ -18,6 +19,21 @@ struct SourceWrapper {
     __weak MGLSource *source;
 };
 
+/**
+ Assert that the style source is valid.
+ 
+ This macro should be used at the beginning of any public-facing instance method
+ of `MGLSource` and its subclasses. For private methods, an assertion is more appropriate.
+ */
+#define MGLAssertStyleSourceIsValid() \
+do { \
+if (!self.rawSource) { \
+[NSException raise:MGLInvalidStyleSourceException \
+format: \
+@"-This source got invalidated after the style change "]; \
+} \
+} while (NO);
+
 @class MGLMapView;
 
 @interface MGLSource (Private)
diff --git a/platform/darwin/src/MGLVectorTileSource.mm b/platform/darwin/src/MGLVectorTileSource.mm
index f7a6869ade..85270c4a49 100644
--- a/platform/darwin/src/MGLVectorTileSource.mm
+++ b/platform/darwin/src/MGLVectorTileSource.mm
@@ -38,17 +38,19 @@
 }
 
 - (NSURL *)configurationURL {
+    MGLAssertStyleSourceIsValid();
     auto url = self.rawSource->getURL();
     return url ? [NSURL URLWithString:@(url->c_str())] : nil;
 }
 
 - (NSString *)attributionHTMLString {
+    MGLAssertStyleSourceIsValid();
     auto attribution = self.rawSource->getAttribution();
     return attribution ? @(attribution->c_str()) : nil;
 }
 
 - (NSArray<id <MGLFeature>> *)featuresInSourceLayersWithIdentifiers:(NSSet<NSString *> *)sourceLayerIdentifiers predicate:(nullable NSPredicate *)predicate {
-    
+    MGLAssertStyleSourceIsValid();
     mbgl::optional<std::vector<std::string>> optionalSourceLayerIDs;
     if (sourceLayerIdentifiers) {
         __block std::vector<std::string> layerIDs;