[core] Adjust layer source properties to better reflect reality

* Layer source ID is immutable; must be provided to the constructor
* Layer source layer is mutable
* Layers with GeoJSON sources do not have a source layer

While here, make Layer::copy impl-private.

6 files changed, 17 insertions, 24 deletions

diff --git a/include/mbgl/style/layers/circle_layer.hpp b/include/mbgl/style/layers/circle_layer.hpp
index 10d281b6ac..9c2b458d4b 100644
--- a/include/mbgl/style/layers/circle_layer.hpp
+++ b/include/mbgl/style/layers/circle_layer.hpp
@@ -13,14 +13,13 @@ namespace style {
 
 class CircleLayer : public Layer {
 public:
-    CircleLayer(const std::string& layerID);
+    CircleLayer(const std::string& layerID, const std::string& sourceID);
     ~CircleLayer() final;
 
     // Source
-
-    void setSource(const std::string& sourceID, const std::string& sourceLayer);
     const std::string& getSourceID() const;
     const std::string& getSourceLayer() const;
+    void setSourceLayer(const std::string& sourceLayer);
 
     void setFilter(const Filter&);
     const Filter& getFilter() const;
diff --git a/include/mbgl/style/layers/fill_layer.hpp b/include/mbgl/style/layers/fill_layer.hpp
index a14bf4a390..90538dd3ea 100644
--- a/include/mbgl/style/layers/fill_layer.hpp
+++ b/include/mbgl/style/layers/fill_layer.hpp
@@ -13,14 +13,13 @@ namespace style {
 
 class FillLayer : public Layer {
 public:
-    FillLayer(const std::string& layerID);
+    FillLayer(const std::string& layerID, const std::string& sourceID);
     ~FillLayer() final;
 
     // Source
-
-    void setSource(const std::string& sourceID, const std::string& sourceLayer);
     const std::string& getSourceID() const;
     const std::string& getSourceLayer() const;
+    void setSourceLayer(const std::string& sourceLayer);
 
     void setFilter(const Filter&);
     const Filter& getFilter() const;
diff --git a/include/mbgl/style/layers/layer.hpp.ejs b/include/mbgl/style/layers/layer.hpp.ejs
index fdf7620892..60365be906 100644
--- a/include/mbgl/style/layers/layer.hpp.ejs
+++ b/include/mbgl/style/layers/layer.hpp.ejs
@@ -22,24 +22,23 @@ namespace style {
 
 class <%- camelize(type) %>Layer : public Layer {
 public:
+<% if (type === 'background') { -%>
     <%- camelize(type) %>Layer(const std::string& layerID);
+<% } else { -%>
+    <%- camelize(type) %>Layer(const std::string& layerID, const std::string& sourceID);
+<% } -%>
     ~<%- camelize(type) %>Layer() final;
 
-<% if (type === 'raster') { -%>
+<% if (type !== 'background') { -%>
     // Source
-
-    void setSource(const std::string& sourceID);
-    const std::string& getSourceID() const;
-
-<% } else if (type !== 'background') { -%>
-    // Source
-
-    void setSource(const std::string& sourceID, const std::string& sourceLayer);
     const std::string& getSourceID() const;
+<% if (type !== 'raster') { -%>
     const std::string& getSourceLayer() const;
+    void setSourceLayer(const std::string& sourceLayer);
 
     void setFilter(const Filter&);
     const Filter& getFilter() const;
+<% } -%>
 
 <% } -%>
 <% if (layoutProperties.length) { -%>
diff --git a/include/mbgl/style/layers/line_layer.hpp b/include/mbgl/style/layers/line_layer.hpp
index fb9e37811a..4ffeee114a 100644
--- a/include/mbgl/style/layers/line_layer.hpp
+++ b/include/mbgl/style/layers/line_layer.hpp
@@ -15,14 +15,13 @@ namespace style {
 
 class LineLayer : public Layer {
 public:
-    LineLayer(const std::string& layerID);
+    LineLayer(const std::string& layerID, const std::string& sourceID);
     ~LineLayer() final;
 
     // Source
-
-    void setSource(const std::string& sourceID, const std::string& sourceLayer);
     const std::string& getSourceID() const;
     const std::string& getSourceLayer() const;
+    void setSourceLayer(const std::string& sourceLayer);
 
     void setFilter(const Filter&);
     const Filter& getFilter() const;
diff --git a/include/mbgl/style/layers/raster_layer.hpp b/include/mbgl/style/layers/raster_layer.hpp
index 6d0c7dd91c..372434e46d 100644
--- a/include/mbgl/style/layers/raster_layer.hpp
+++ b/include/mbgl/style/layers/raster_layer.hpp
@@ -13,12 +13,10 @@ namespace style {
 
 class RasterLayer : public Layer {
 public:
-    RasterLayer(const std::string& layerID);
+    RasterLayer(const std::string& layerID, const std::string& sourceID);
     ~RasterLayer() final;
 
     // Source
-
-    void setSource(const std::string& sourceID);
     const std::string& getSourceID() const;
 
     // Paint properties
diff --git a/include/mbgl/style/layers/symbol_layer.hpp b/include/mbgl/style/layers/symbol_layer.hpp
index 7d98a5ef6b..b21c8deaf7 100644
--- a/include/mbgl/style/layers/symbol_layer.hpp
+++ b/include/mbgl/style/layers/symbol_layer.hpp
@@ -15,14 +15,13 @@ namespace style {
 
 class SymbolLayer : public Layer {
 public:
-    SymbolLayer(const std::string& layerID);
+    SymbolLayer(const std::string& layerID, const std::string& sourceID);
     ~SymbolLayer() final;
 
     // Source
-
-    void setSource(const std::string& sourceID, const std::string& sourceLayer);
     const std::string& getSourceID() const;
     const std::string& getSourceLayer() const;
+    void setSourceLayer(const std::string& sourceLayer);
 
     void setFilter(const Filter&);
     const Filter& getFilter() const;