[core] Pass std::exception_ptr in style::Observer::onStyleError

include/mbgl/util/exception.hpp

@@ -20,5 +20,20 @@ struct MisuseException : Exception {
     MisuseException(const std::string &msg) : Exception(msg) {}
 };
 
+struct StyleParseException : Exception {
+    StyleParseException(const char *msg) : Exception(msg) {}
+    StyleParseException(const std::string &msg) : Exception(msg) {}
+};
+
+struct StyleLoadException : Exception {
+    StyleLoadException(const char *msg) : Exception(msg) {}
+    StyleLoadException(const std::string &msg) : Exception(msg) {}
+};
+
+struct NotFoundException : Exception {
+    NotFoundException(const char *msg) : Exception(msg) {}
+    NotFoundException(const std::string &msg) : Exception(msg) {}
+};
+
 } // namespace util
 } // namespace mbgl

src/mbgl/map/map.cpp

@@ -16,6 +16,7 @@
 #include <mbgl/storage/file_source.hpp>
 #include <mbgl/storage/resource.hpp>
 #include <mbgl/storage/response.hpp>
+#include <mbgl/util/exception.hpp>
 #include <mbgl/util/projection.hpp>
 #include <mbgl/util/math.hpp>
 #include <mbgl/util/exception.hpp>
@@ -61,7 +62,7 @@ public:
     void onSourceAttributionChanged(style::Source&, const std::string&) override;
     void onUpdate(Update) override;
     void onStyleLoaded() override;
-    void onStyleError() override;
+    void onStyleError(std::exception_ptr) override;
     void onResourceError(std::exception_ptr) override;
 
     void render(View&);
@@ -364,11 +365,14 @@ void Map::setStyleURL(const std::string& url) {
         if (res.error) {
             if (res.error->reason == Response::Error::Reason::NotFound &&
                 util::mapbox::isMapboxURL(impl->styleURL)) {
-                Log::Error(Event::Setup, "style %s could not be found or is an incompatible legacy map or style", impl->styleURL.c_str());
+                const std::string message = "style " + impl->styleURL + " could not be found or is an incompatible legacy map or style";
+                Log::Error(Event::Setup, message.c_str());
+                impl->onStyleError(std::make_exception_ptr(util::NotFoundException(message)));
             } else {
-                Log::Error(Event::Setup, "loading style failed: %s", res.error->message.c_str());
+                const std::string message = "loading style failed: " + res.error->message;
+                Log::Error(Event::Setup, message.c_str());
+                impl->onStyleError(std::make_exception_ptr(util::StyleLoadException(message)));
             }
-            impl->onStyleError();
             impl->onResourceError(std::make_exception_ptr(std::runtime_error(res.error->message)));
         } else if (res.notModified || res.noContent) {
             return;
@@ -1098,7 +1102,7 @@ void Map::Impl::onStyleLoaded() {
     observer.onDidFinishLoadingStyle();
 }
 
-void Map::Impl::onStyleError() {
+void Map::Impl::onStyleError(std::exception_ptr) {
     observer.onDidFailLoadingMap();
 }
 

src/mbgl/style/observer.hpp

@@ -5,6 +5,8 @@
 #include <mbgl/style/source_observer.hpp>
 #include <mbgl/map/update.hpp>
 
+#include <exception>
+
 namespace mbgl {
 namespace style {
 
@@ -13,7 +15,7 @@ class Observer : public GlyphAtlasObserver,
                  public SourceObserver {
 public:
     virtual void onUpdate(Update) {}
-    virtual void onStyleError() {}
+    virtual void onStyleError(std::exception_ptr) {}
     virtual void onStyleLoaded() {}
     virtual void onResourceError(std::exception_ptr) {}
 };

src/mbgl/style/style.cpp

@@ -25,6 +25,7 @@
 #include <mbgl/renderer/render_item.hpp>
 #include <mbgl/renderer/render_tile.hpp>
 #include <mbgl/util/constants.hpp>
+#include <mbgl/util/exception.hpp>
 #include <mbgl/util/geometry.hpp>
 #include <mbgl/util/string.hpp>
 #include <mbgl/util/logging.hpp>
@@ -110,8 +111,9 @@ void Style::setJSON(const std::string& json) {
     auto error = parser.parse(json);
 
     if (error) {
-        Log::Error(Event::ParseStyle, "Failed to parse style: %s", util::toString(error).c_str());
-        observer->onStyleError();
+        std::string message = "Failed to parse style: " + util::toString(error);
+        Log::Error(Event::ParseStyle, message.c_str());
+        observer->onStyleError(std::make_exception_ptr(util::StyleParseException(message)));
         observer->onResourceError(error);
         return;
     }