[ios, macos] reversed MGLStyle.layers

3 files changed, 44 insertions, 11 deletions

diff --git a/platform/darwin/src/MGLStyle.h b/platform/darwin/src/MGLStyle.h
index 1e0b87a73f..cc87d7defd 100644
--- a/platform/darwin/src/MGLStyle.h
+++ b/platform/darwin/src/MGLStyle.h
@@ -237,7 +237,7 @@ static const NSInteger MGLStyleDefaultVersion = 9;
 #pragma mark Managing Style Layers
 
 /**
- The layers included in the style, arranged according to their front-to-back
+ The layers included in the style, arranged according to their back-to-front
  ordering on the screen.
  */
 @property (nonatomic, strong) NS_MUTABLE_ARRAY_OF(MGLStyleLayer *) *layers;
diff --git a/platform/darwin/src/MGLStyle.mm b/platform/darwin/src/MGLStyle.mm
index c2ae75ed9c..10f4aabe19 100644
--- a/platform/darwin/src/MGLStyle.mm
+++ b/platform/darwin/src/MGLStyle.mm
@@ -226,18 +226,18 @@ static NSURL *MGLStyleURL_emerald;
 {
     auto layers = self.mapView.mbglMap->getLayers();
     NSMutableArray *styleLayers = [NSMutableArray arrayWithCapacity:layers.size()];
-    for (auto layer = layers.rbegin(); layer != layers.rend(); ++layer) {
-        MGLStyleLayer *styleLayer = [self layerFromMBGLLayer:*layer];
+    for (auto layer : layers) {
+        MGLStyleLayer *styleLayer = [self layerFromMBGLLayer:layer];
         [styleLayers addObject:styleLayer];
     }
     return styleLayers;
 }
 
 - (void)setLayers:(NS_MUTABLE_ARRAY_OF(MGLStyleLayer *) *)layers {
-    for (MGLStyleLayer *layer in self.layers.reverseObjectEnumerator) {
+    for (MGLStyleLayer *layer in self.layers) {
         [self removeLayer:layer];
     }
-    for (MGLStyleLayer *layer in layers.reverseObjectEnumerator) {
+    for (MGLStyleLayer *layer in layers) {
         [self addLayer:layer];
     }
 }
@@ -250,12 +250,12 @@ static NSURL *MGLStyleURL_emerald;
 - (MGLStyleLayer *)objectInLayersAtIndex:(NSUInteger)index
 {
     auto layers = self.mapView.mbglMap->getLayers();
-    if (index > layers.size() - 1) {
+    if (index >= layers.size()) {
         [NSException raise:NSRangeException
                     format:@"No style layer at index %lu.", (unsigned long)index];
         return nil;
     }
-    auto layer = layers.at(layers.size() - 1 - index);
+    auto layer = layers.at(index);
     return [self layerFromMBGLLayer:layer];
 }
 
@@ -287,13 +287,14 @@ static NSURL *MGLStyleURL_emerald;
                     format:@"Cannot insert style layer at out-of-bounds index %lu.", (unsigned long)index];
     } else if (index == 0) {
         try {
-            [styleLayer addToMapView:self.mapView belowLayer:nil];
+            MGLStyleLayer *sibling = layers.size() ? [self layerFromMBGLLayer:layers.at(0)] : nil;
+            [styleLayer addToMapView:self.mapView belowLayer:sibling];
         } catch (const std::runtime_error & err) {
             [NSException raise:@"MGLRedundantLayerIdentifierException" format:@"%s", err.what()];
         }
     } else {
         try {
-            MGLStyleLayer *sibling = [self layerFromMBGLLayer:layers.at(layers.size() - index)];
+            MGLStyleLayer *sibling = [self layerFromMBGLLayer:layers.at(index)];
             [styleLayer addToMapView:self.mapView belowLayer:sibling];
         } catch (std::runtime_error & err) {
             [NSException raise:@"MGLRedundantLayerIdentifierException" format:@"%s", err.what()];
@@ -304,11 +305,11 @@ static NSURL *MGLStyleURL_emerald;
 - (void)removeObjectFromLayersAtIndex:(NSUInteger)index
 {
     auto layers = self.mapView.mbglMap->getLayers();
-    if (index > layers.size() - 1) {
+    if (index >= layers.size()) {
         [NSException raise:NSRangeException
                     format:@"Cannot remove style layer at out-of-bounds index %lu.", (unsigned long)index];
     }
-    auto layer = layers.at(layers.size() - 1 - index);
+    auto layer = layers.at(index);
     MGLStyleLayer *styleLayer = [self layerFromMBGLLayer:layer];
     [styleLayer removeFromMapView:self.mapView];
 }
diff --git a/platform/darwin/test/MGLStyleTests.mm b/platform/darwin/test/MGLStyleTests.mm
index c67497640b..55a5df08ca 100644
--- a/platform/darwin/test/MGLStyleTests.mm
+++ b/platform/darwin/test/MGLStyleTests.mm
@@ -217,4 +217,36 @@
     XCTAssertEqual(image.size.height, styleImage.size.height);
 }
 
+- (void)testLayersOrder {
+    [self.mapView setStyleURL:[MGLStyle streetsStyleURLWithVersion:8]];
+    
+    NSString *filePath = [[NSBundle bundleForClass:self.class] pathForResource:@"amsterdam" ofType:@"geojson"];
+    NSURL *url = [NSURL fileURLWithPath:filePath];
+    MGLShapeSource *source = [[MGLShapeSource alloc] initWithIdentifier:@"sourceID" URL:url options:nil];
+    [self.mapView.style addSource:source];
+    
+    MGLCircleStyleLayer *layer1 = [[MGLCircleStyleLayer alloc] initWithIdentifier:@"layer1" source:source];
+    [self.mapView.style addLayer:layer1];
+    
+    MGLCircleStyleLayer *layer3 = [[MGLCircleStyleLayer alloc] initWithIdentifier:@"layer3" source:source];
+    [self.mapView.style addLayer:layer3];
+    
+    MGLCircleStyleLayer *layer2 = [[MGLCircleStyleLayer alloc] initWithIdentifier:@"layer2" source:source];
+    [self.mapView.style insertLayer:layer2 aboveLayer:layer1];
+    
+    MGLCircleStyleLayer *layer4 = [[MGLCircleStyleLayer alloc] initWithIdentifier:@"layer4" source:source];
+    [self.mapView.style insertLayer:layer4 aboveLayer:layer3];
+    
+    MGLCircleStyleLayer *layer0 = [[MGLCircleStyleLayer alloc] initWithIdentifier:@"layer0" source:source];
+    [self.mapView.style insertLayer:layer0 belowLayer:layer1];
+    
+    NSArray<MGLStyleLayer *> *layers = [self.mapView.style layers];
+    
+    XCTAssert([[layers[0] identifier] isEqualToString:layer0.identifier]);
+    XCTAssert([[layers[1] identifier] isEqualToString:layer1.identifier]);
+    XCTAssert([[layers[2] identifier] isEqualToString:layer2.identifier]);
+    XCTAssert([[layers[3] identifier] isEqualToString:layer3.identifier]);
+    XCTAssert([[layers[4] identifier] isEqualToString:layer4.identifier]);
+}
+
 @end