[core] Replace MapChange enum with MapObserver

3 files changed, 41 insertions, 5 deletions

diff --git a/include/mbgl/map/backend.hpp b/include/mbgl/map/backend.hpp
index 4a43921c0b..cd756abe43 100644
--- a/include/mbgl/map/backend.hpp
+++ b/include/mbgl/map/backend.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#include <mbgl/map/change.hpp>
+#include <mbgl/map/map_observer.hpp>
 
 #include <memory>
 
@@ -12,7 +12,7 @@ class Context;
 
 class BackendScope;
 
-class Backend {
+class Backend : public MapObserver {
 public:
     Backend();
     virtual ~Backend();
@@ -24,9 +24,6 @@ public:
     // in the near future. (Not called for Map::renderStill() mode.)
     virtual void invalidate() = 0;
 
-    // Notifies a watcher of map x/y/scale/rotation changes.
-    virtual void notifyMapChange(MapChange change);
-
 protected:
     // Called when the backend's GL context needs to be made active or inactive. These are called,
     // as a matched pair, in four situations:
diff --git a/include/mbgl/map/map.hpp b/include/mbgl/map/map.hpp
index 02e14bea4e..79fcd34d9b 100644
--- a/include/mbgl/map/map.hpp
+++ b/include/mbgl/map/map.hpp
@@ -2,6 +2,7 @@
 
 #include <mbgl/util/optional.hpp>
 #include <mbgl/util/chrono.hpp>
+#include <mbgl/map/map_observer.hpp>
 #include <mbgl/map/mode.hpp>
 #include <mbgl/util/geo.hpp>
 #include <mbgl/util/feature.hpp>
diff --git a/include/mbgl/map/map_observer.hpp b/include/mbgl/map/map_observer.hpp
new file mode 100644
index 0000000000..e0a734cf5b
--- /dev/null
+++ b/include/mbgl/map/map_observer.hpp
@@ -0,0 +1,38 @@
+#pragma once
+
+#include <cstdint>
+
+namespace mbgl {
+
+class MapObserver {
+public:
+    static MapObserver& nullObserver() {
+        static MapObserver mapObserver;
+        return mapObserver;
+    }
+
+    enum class CameraChangeMode : uint32_t {
+        Immediate,
+        Animated
+    };
+
+    enum class RenderMode : uint32_t {
+        Partial,
+        Full
+    };
+
+    virtual void onCameraWillChange(CameraChangeMode) {}
+    virtual void onCameraIsChanging() {}
+    virtual void onCameraDidChange(CameraChangeMode) {}
+    virtual void onWillStartLoadingMap() {}
+    virtual void onDidFinishLoadingMap() {}
+    virtual void onDidFailLoadingMap() {}
+    virtual void onWillStartRenderingFrame() {}
+    virtual void onDidFinishRenderingFrame(RenderMode) {}
+    virtual void onWillStartRenderingMap() {}
+    virtual void onDidFinishRenderingMap(RenderMode) {}
+    virtual void onDidFinishLoadingStyle() {}
+    virtual void onSourceDidChange() {}
+};
+
+} // namespace mbgl