[ios, macos] Added layers property to MGLStyle

The property is KVO compliant with all the mutable to-many methods.

Fixes #6003.

include/mbgl/map/map.hpp

@@ -157,7 +157,9 @@ class Map : private util::noncopyable {
     void removeSource(const std::string& sourceID);
 
     // Layers
+    std::vector<style::Layer*> getLayers();
     style::Layer* getLayer(const std::string& layerID);
+    void setLayers(std::vector<style::Layer*>&);
     void addLayer(std::unique_ptr<style::Layer>, const optional<std::string>& beforeLayerID = {});
     void removeLayer(const std::string& layerID);
 

platform/darwin/src/MGLStyle.h

@@ -200,6 +200,8 @@ static const NSInteger MGLStyleDefaultVersion = 9;
 
 #pragma mark Managing Style Layers
 
+@property (nonatomic, strong) NS_MUTABLE_ARRAY_OF(MGLStyleLayer *) *layers;
+
 /**
  Returns a style layer with the given identifier in the current style.
  

platform/darwin/src/MGLStyle.mm

@@ -148,13 +148,77 @@ - (void)removeSource:(MGLSource *)source
 
 #pragma mark Style layers
 
-- (MGLStyleLayer *)layerWithIdentifier:(NSString *)identifier
+- (NSMutableArray<MGLStyleLayer *> *)layers
 {
-    auto mbglLayer = self.mapView.mbglMap->getLayer(identifier.UTF8String);
-    if (!mbglLayer) {
+    auto layers = self.mapView.mbglMap->getLayers();
+    NSMutableArray *styleLayers = [NSMutableArray arrayWithCapacity:layers.size()];
+    for (auto &layer : layers) {
+        MGLStyleLayer *styleLayer = [self layerFromMBGLLayer:layer];
+        [styleLayers addObject:styleLayer];
+    }
+    return styleLayers;
+}
+
+- (void)setLayers:(NSMutableArray<MGLStyleLayer *> *)layers {
+    std::vector<mbgl::style::Layer *> rawLayers;
+    rawLayers.reserve(layers.count);
+    for (MGLStyleLayer *layer in layers) {
+        rawLayers.push_back(layer.layer);
+    }
+    self.mapView.mbglMap->setLayers(rawLayers);
+}
+
+- (NSUInteger)countOfLayers
+{
+    return self.mapView.mbglMap->getLayers().size();
+}
+
+- (MGLStyleLayer *)objectInLayersAtIndex:(NSUInteger)index
+{
+    auto layers = self.mapView.mbglMap->getLayers();
+    auto layer = layers.at(index);
+    if (layer) {
+        return [self layerFromMBGLLayer:layer];
+    } else {
+        [NSException raise:NSRangeException
+                    format:@"No style layer at index %lu", (unsigned long)index];
         return nil;
     }
+}
+
+- (void)getLayers:(MGLStyleLayer **)buffer range:(NSRange)inRange
+{
+    auto layers = self.mapView.mbglMap->getLayers();
+    NSUInteger i = 0;
+    for (auto layer = *(layers.begin() + inRange.location); i < inRange.length; ++layer, ++i) {
+        MGLStyleLayer *styleLayer = [self layerFromMBGLLayer:layer];
+        buffer[i] = styleLayer;
+    }
+}
+
+- (void)insertObject:(MGLStyleLayer *)styleLayer inLayersAtIndex:(NSUInteger)index
+{
+    auto layers = self.mapView.mbglMap->getLayers();
+    if (index == layers.size()) {
+        [self addLayer:styleLayer];
+    } else {
+        auto layerAbove = layers.at(index);
+        self.mapView.mbglMap->addLayer(std::unique_ptr<mbgl::style::Layer>(styleLayer.layer), layerAbove->getID());
+    }
+}
+
+- (void)removeObjectFromLayersAtIndex:(NSUInteger)index
+{
+    auto layers = self.mapView.mbglMap->getLayers();
+    auto layer = layers.at(index);
+    self.mapView.mbglMap->removeLayer(layer->getID());
+}
 
+- (MGLStyleLayer *)layerFromMBGLLayer:(mbgl::style::Layer *)mbglLayer
+{
+    NSParameterAssert(mbglLayer);
+
+    NSString *identifier = @(mbglLayer->getID().c_str());
     MGLStyleLayer *styleLayer;
     if (auto fillLayer = mbglLayer->as<mbgl::style::FillLayer>()) {
         MGLSource *source = [self sourceWithIdentifier:@(fillLayer->getSourceID().c_str())];
@@ -177,12 +241,18 @@ - (MGLStyleLayer *)layerWithIdentifier:(NSString *)identifier
         NSAssert(NO, @"Unrecognized layer type");
         return nil;
     }
-
+    
     styleLayer.layer = mbglLayer;
-
+    
     return styleLayer;
 }
 
+- (MGLStyleLayer *)layerWithIdentifier:(NSString *)identifier
+{
+    auto mbglLayer = self.mapView.mbglMap->getLayer(identifier.UTF8String);
+    return mbglLayer ? [self layerFromMBGLLayer:mbglLayer] : nil;
+}
+
 - (void)removeLayer:(MGLStyleLayer *)layer
 {
     self.mapView.mbglMap->removeLayer(layer.identifier.UTF8String);

src/mbgl/map/map.cpp

@@ -785,6 +785,10 @@ void Map::removeSource(const std::string& sourceID) {
         impl->style->removeSource(sourceID);
     }
 }
+
+std::vector<style::Layer*> Map::getLayers() {
+    return impl->style ? impl->style->getLayers() : std::vector<style::Layer*>();
+}
 
 style::Layer* Map::getLayer(const std::string& layerID) {
     if (impl->style) {
@@ -794,6 +798,16 @@ style::Layer* Map::getLayer(const std::string& layerID) {
     return nullptr;
 }
 
+void Map::setLayers(std::vector<style::Layer*>& layers) {
+    impl->view.activate();
+
+    impl->style->setLayers(layers);
+    impl->updateFlags |= Update::Classes;
+    impl->asyncUpdate.send();
+
+    impl->view.deactivate();
+}
+
 void Map::addLayer(std::unique_ptr<Layer> layer, const optional<std::string>& before) {
     if (!impl->style) {
         return;

src/mbgl/style/style.cpp

@@ -156,6 +156,15 @@ std::vector<const Layer*> Style::getLayers() const {
     return result;
 }
 
+std::vector<Layer*> Style::getLayers() {
+    std::vector<Layer*> result;
+    result.reserve(layers.size());
+    for (auto& layer : layers) {
+        result.push_back(layer.get());
+    }
+    return result;
+}
+
 std::vector<std::unique_ptr<Layer>>::const_iterator Style::findLayer(const std::string& id) const {
     return std::find_if(layers.begin(), layers.end(), [&](const auto& layer) {
         return layer->baseImpl->id == id;
@@ -167,6 +176,13 @@ Layer* Style::getLayer(const std::string& id) const {
     return it != layers.end() ? it->get() : nullptr;
 }
 
+void Style::setLayers(std::vector<Layer*>& newLayers) {
+    layers.empty();
+    for (auto& layer : newLayers) {
+        addLayer(std::unique_ptr<Layer>(layer));
+    }
+}
+
 Layer* Style::addLayer(std::unique_ptr<Layer> layer, optional<std::string> before) {
     // TODO: verify source
 

src/mbgl/style/style.hpp

@@ -69,7 +69,9 @@ class Style : public GlyphAtlasObserver,
     void removeSource(const std::string& sourceID);
 
     std::vector<const Layer*> getLayers() const;
+    std::vector<Layer*> getLayers();
     Layer* getLayer(const std::string& id) const;
+    void setLayers(std::vector<Layer*>&);
     Layer* addLayer(std::unique_ptr<Layer>,
                     optional<std::string> beforeLayerID = {});
     void removeLayer(const std::string& layerID);