[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.

3 files changed, 3 insertions, 3 deletions

diff --git a/src/mbgl/tile/geometry_tile.cpp b/src/mbgl/tile/geometry_tile.cpp
index d353acf574..ef5b2eb280 100644
--- a/src/mbgl/tile/geometry_tile.cpp
+++ b/src/mbgl/tile/geometry_tile.cpp
@@ -213,7 +213,7 @@ void GeometryTile::redoPlacement() {
         if (placedConfig != targetConfig) {
             redoPlacement();
         } else {
-            observer->onNeedsRepaint();
+            observer->onTileUpdated(*this);
         }
     });
 }
diff --git a/src/mbgl/tile/tile.cpp b/src/mbgl/tile/tile.cpp
index 6595c314ee..632e271093 100644
--- a/src/mbgl/tile/tile.cpp
+++ b/src/mbgl/tile/tile.cpp
@@ -18,7 +18,7 @@ void Tile::setObserver(TileObserver* observer_) {
 
 void Tile::setTriedOptional() {
     triedOptional = true;
-    observer->onNeedsRepaint();
+    observer->onTileUpdated(*this);
 }
 
 void Tile::dumpDebugLogs() const {
diff --git a/src/mbgl/tile/tile_observer.hpp b/src/mbgl/tile/tile_observer.hpp
index 96ded11fbb..ef412f0fb3 100644
--- a/src/mbgl/tile/tile_observer.hpp
+++ b/src/mbgl/tile/tile_observer.hpp
@@ -12,7 +12,7 @@ public:
 
     virtual void onTileLoaded(Tile&, bool /*isNewTile*/) {}
     virtual void onTileError(Tile&, std::exception_ptr) {}
-    virtual void onNeedsRepaint() {}
+    virtual void onTileUpdated(Tile&) {}
 };
 
 } // namespace mbgl