[core] Prepare style observer interfaces for source reloading

* Renamed {Source,Tile}Observer::onNeedsRepaint to onTileUpdated. Messages should be in terms of what happened to the observed object, not in terms of what the observer needs to do. This also removes a confusing overlap of virtual methods on StyleObserver.
* Added style::Observer::onUpdate(Update). This is also a violation of the above rule, but I'm hopeful that it will disappear when update batching is implemented.

1 files changed, 8 insertions, 9 deletions

diff --git a/src/mbgl/map/map.cpp b/src/mbgl/map/map.cpp
index 5c58893b5a..fe0be15b87 100644
--- a/src/mbgl/map/map.cpp
+++ b/src/mbgl/map/map.cpp
@@ -37,7 +37,7 @@ class Map::Impl : public style::Observer {
 public:
     Impl(View&, FileSource&, MapMode, GLContextMode, ConstrainMode, ViewportMode);
 
-    void onNeedsRepaint() override;
+    void onUpdate(Update) override;
     void onStyleError() override;
     void onResourceError(std::exception_ptr) override;
 
@@ -149,12 +149,7 @@ void Map::renderStill(StillImageCallback callback) {
 }
 
 void Map::update(Update flags) {
-    if (flags & Update::Dimensions) {
-        impl->transform.resize(impl->view.getSize());
-    }
-
-    impl->updateFlags |= flags;
-    impl->asyncUpdate.send();
+    impl->onUpdate(flags);
 }
 
 void Map::render() {
@@ -905,8 +900,12 @@ void Map::onLowMemory() {
     impl->view.invalidate();
 }
 
-void Map::Impl::onNeedsRepaint() {
-    updateFlags |= Update::Repaint;
+void Map::Impl::onUpdate(Update flags) {
+    if (flags & Update::Dimensions) {
+        transform.resize(view.getSize());
+    }
+
+    updateFlags |= flags;
     asyncUpdate.send();
 }