1 #pragma once 2 3 namespace mbgl { 4 namespace style { 5 6 class Layer; 7 8 class LayerObserver { 9 public: 10 virtual ~LayerObserver() = default; 11 onLayerChanged(Layer &)12 virtual void onLayerChanged(Layer&) {} 13 }; 14 15 } // namespace style 16 } // namespace mbgl 17