[core] Trigger repaint on source changes

Author: Asheem Mamoowala

src/mbgl/style/sources/geojson_source.cpp

@@ -33,6 +33,7 @@ void GeoJSONSource::setURL(const std::string& url_) {
 void GeoJSONSource::setGeoJSON(const mapbox::geojson::geojson& geoJSON) {
     req.reset();
     baseImpl = makeMutable<Impl>(impl(), geoJSON);
+    observer->onSourceChanged(*this);
 }
 
 optional<std::string> GeoJSONSource::getURL() const {

src/mbgl/style/sources/image_source.cpp

@@ -20,7 +20,7 @@ const ImageSource::Impl& ImageSource::impl() const {
 
 void ImageSource::setCoordinates(const std::array<LatLng, 4>& coords_) {
     baseImpl = makeMutable<Impl>(impl(), coords_);
-    observer->onSourceLoaded(*this);
+    observer->onSourceChanged(*this);
 }
 
 std::array<LatLng, 4> ImageSource::getCoordinates() const {
@@ -44,7 +44,7 @@ void ImageSource::setImage(UnassociatedImage&& image_) {
     }
     loaded = true;
     baseImpl = makeMutable<Impl>(impl(), std::move(image_));
-    observer->onSourceLoaded(*this);
+    observer->onSourceChanged(*this);
 }
 
 optional<std::string> ImageSource::getURL() const {

src/mbgl/style/style.cpp

@@ -257,6 +257,7 @@ void Style::onSourceLoaded(Source& source) {
 void Style::onSourceChanged(Source& source) {
     sources.update(source);
     observer->onSourceChanged(source);
+    observer->onUpdate(Update::Repaint);
 }
 
 void Style::onSourceError(Source& source, std::exception_ptr error) {

test/style/source.test.cpp

@@ -518,7 +518,7 @@ TEST(Source, ImageSourceImageUpdate) {
         response.data = std::make_unique<std::string>(util::read_file("test/fixtures/image/no_profile.png"));
         return response;
     };
-    test.styleObserver.sourceLoaded = [&] (Source&) {
+    test.styleObserver.sourceChanged = [&] (Source&) {
         // Should be called (test will hang if it doesn't)
         test.end();
     };