[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.

1 files changed, 13 insertions, 13 deletions

diff --git a/src/mbgl/style/layers/layer.cpp.ejs b/src/mbgl/style/layers/layer.cpp.ejs
index 633d673804..4f78d6b55e 100644
--- a/src/mbgl/style/layers/layer.cpp.ejs
+++ b/src/mbgl/style/layers/layer.cpp.ejs
@@ -11,11 +11,20 @@
 namespace mbgl {
 namespace style {
 
+<% if (type === 'background') { -%>
 <%- camelize(type) %>Layer::<%- camelize(type) %>Layer(const std::string& layerID)
     : Layer(Type::<%- camelize(type) %>, std::make_unique<Impl>())
     , impl(static_cast<Impl*>(baseImpl.get())) {
     impl->id = layerID;
 }
+<% } else { -%>
+<%- camelize(type) %>Layer::<%- camelize(type) %>Layer(const std::string& layerID, const std::string& sourceID)
+    : Layer(Type::<%- camelize(type) %>, std::make_unique<Impl>())
+    , impl(static_cast<Impl*>(baseImpl.get())) {
+    impl->id = layerID;
+    impl->source = sourceID;
+}
+<% } -%>
 
 <%- camelize(type) %>Layer::<%- camelize(type) %>Layer(const Impl& other)
     : Layer(Type::<%- camelize(type) %>, std::make_unique<Impl>(other))
@@ -28,28 +37,18 @@ std::unique_ptr<Layer> <%- camelize(type) %>Layer::Impl::clone() const {
     return std::make_unique<<%- camelize(type) %>Layer>(*this);
 }
 
-<% if (type === 'raster') { -%>
+<% if (type !== 'background') { -%>
 // Source
 
-void <%- camelize(type) %>Layer::setSource(const std::string& sourceID) {
-    impl->source = sourceID;
-}
-
 const std::string& <%- camelize(type) %>Layer::getSourceID() const {
     return impl->source;
 }
-<% } else if (type !== 'background') { -%>
-// Source
 
-void <%- camelize(type) %>Layer::setSource(const std::string& sourceID, const std::string& sourceLayer) {
-    impl->source = sourceID;
+<% if (type !== 'raster') { -%>
+void <%- camelize(type) %>Layer::setSourceLayer(const std::string& sourceLayer) {
     impl->sourceLayer = sourceLayer;
 }
 
-const std::string& <%- camelize(type) %>Layer::getSourceID() const {
-    return impl->source;
-}
-
 const std::string& <%- camelize(type) %>Layer::getSourceLayer() const {
     return impl->sourceLayer;
 }
@@ -64,6 +63,7 @@ const Filter& <%- camelize(type) %>Layer::getFilter() const {
     return impl->filter;
 }
 <% } -%>
+<% } -%>
 
 // Layout properties