[all] Promote Style to public API

3 files changed, 400 insertions, 252 deletions

diff --git a/src/mbgl/style/style.cpp b/src/mbgl/style/style.cpp
index 41b4310dcf..f8dfd48b5c 100644
--- a/src/mbgl/style/style.cpp
+++ b/src/mbgl/style/style.cpp
@@ -1,308 +1,129 @@
 #include <mbgl/style/style.hpp>
-#include <mbgl/style/observer.hpp>
-#include <mbgl/style/source_impl.hpp>
-#include <mbgl/style/layers/symbol_layer.hpp>
-#include <mbgl/style/layers/custom_layer.hpp>
-#include <mbgl/style/layers/background_layer.hpp>
-#include <mbgl/style/layers/fill_layer.hpp>
-#include <mbgl/style/layers/fill_extrusion_layer.hpp>
-#include <mbgl/style/layers/line_layer.hpp>
-#include <mbgl/style/layers/circle_layer.hpp>
-#include <mbgl/style/layers/raster_layer.hpp>
-#include <mbgl/style/layer_impl.hpp>
-#include <mbgl/style/parser.hpp>
-#include <mbgl/style/transition_options.hpp>
-#include <mbgl/sprite/sprite_loader.hpp>
-#include <mbgl/util/exception.hpp>
-#include <mbgl/util/string.hpp>
-#include <mbgl/util/logging.hpp>
+#include <mbgl/style/style_impl.hpp>
+#include <mbgl/style/light.hpp>
+#include <mbgl/style/image.hpp>
+#include <mbgl/style/source.hpp>
+#include <mbgl/style/layer.hpp>
 
 namespace mbgl {
 namespace style {
 
-static Observer nullObserver;
-
-Style::Style(Scheduler& scheduler_, FileSource& fileSource_, float pixelRatio)
-    : scheduler(scheduler_),
-      fileSource(fileSource_),
-      spriteLoader(std::make_unique<SpriteLoader>(pixelRatio)),
-      light(std::make_unique<Light>()),
-      observer(&nullObserver) {
-    spriteLoader->setObserver(this);
-    light->setObserver(this);
+Style::Style(Scheduler& scheduler, FileSource& fileSource, float pixelRatio)
+    : impl(std::make_unique<Impl>(scheduler, fileSource, pixelRatio)) {
 }
 
 Style::~Style() = default;
 
-void Style::setTransitionOptions(const TransitionOptions& options) {
-    transitionOptions = options;
-}
-
-TransitionOptions Style::getTransitionOptions() const {
-    return transitionOptions;
-}
-
-void Style::setJSON(const std::string& json) {
-    sources.clear();
-    layers.clear();
-    images.clear();
-
-    transitionOptions = {};
-    transitionOptions.duration = util::DEFAULT_TRANSITION_DURATION;
-
-    Parser parser;
-    auto error = parser.parse(json);
-
-    if (error) {
-        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;
-    }
-
-    for (auto& source : parser.sources) {
-        addSource(std::move(source));
-    }
-
-    for (auto& layer : parser.layers) {
-        addLayer(std::move(layer));
-    }
-
-    name = parser.name;
-    defaultLatLng = parser.latLng;
-    defaultZoom = parser.zoom;
-    defaultBearing = parser.bearing;
-    defaultPitch = parser.pitch;
-    setLight(std::make_unique<Light>(parser.light));
-
-    spriteLoader->load(parser.spriteURL, scheduler, fileSource);
-    glyphURL = parser.glyphURL;
-
-    loaded = true;
-
-    observer->onStyleLoaded();
-}
-
-void Style::addSource(std::unique_ptr<Source> source) {
-    if (sources.get(source->getID())) {
-        std::string msg = "Source " + source->getID() + " already exists";
-        throw std::runtime_error(msg.c_str());
-    }
-
-    source->setObserver(this);
-    source->loadDescription(fileSource);
-
-    sources.add(std::move(source));
-}
-
-struct SourceIdUsageEvaluator {
-    const std::string& sourceId;
-
-    bool operator()(BackgroundLayer&) { return false; }
-    bool operator()(CustomLayer&) { return false; }
-
-    template <class LayerType>
-    bool operator()(LayerType& layer) {
-        return layer.getSourceID() == sourceId;
-    }
-};
-
-std::unique_ptr<Source> Style::removeSource(const std::string& id) {
-    // Check if source is in use
-    SourceIdUsageEvaluator sourceIdEvaluator {id};
-    auto layerIt = std::find_if(layers.begin(), layers.end(), [&](const auto& layer) {
-        return layer->accept(sourceIdEvaluator);
-    });
-
-    if (layerIt != layers.end()) {
-        Log::Warning(Event::General, "Source '%s' is in use, cannot remove", id.c_str());
-        return nullptr;
-    }
-
-    std::unique_ptr<Source> source = sources.remove(id);
-
-    if (source) {
-        source->setObserver(nullptr);
-    }
-
-    return source;
-}
-
-std::vector<Layer*> Style::getLayers() {
-    return layers.getWrappers();
-}
-
-Layer* Style::getLayer(const std::string& id) const {
-    return layers.get(id);
-}
-
-Layer* Style::addLayer(std::unique_ptr<Layer> layer, optional<std::string> before) {
-    // TODO: verify source
-
-    if (layers.get(layer->getID())) {
-        throw std::runtime_error(std::string{"Layer "} + layer->getID() + " already exists");
-    }
-
-    layer->setObserver(this);
-
-    return layers.add(std::move(layer), before);
-}
-
-std::unique_ptr<Layer> Style::removeLayer(const std::string& id) {
-    std::unique_ptr<Layer> layer = layers.remove(id);
-
-    if (layer) {
-        layer->setObserver(nullptr);
-    }
-
-    return layer;
-}
-
-void Style::setLight(std::unique_ptr<Light> light_) {
-    light = std::move(light_);
-    light->setObserver(this);
-    onLightChanged(*light);
-}
-
-Light* Style::getLight() const {
-    return light.get();
-}
-
 std::string Style::getName() const {
-    return name;
+    return impl->getName();
 }
 
 LatLng Style::getDefaultLatLng() const {
-    return defaultLatLng;
+    return impl->getDefaultLatLng();
 }
 
 double Style::getDefaultZoom() const {
-    return defaultZoom;
+    return impl->getDefaultZoom();
 }
 
 double Style::getDefaultBearing() const {
-    return defaultBearing;
+    return impl->getDefaultBearing();
 }
 
 double Style::getDefaultPitch() const {
-    return defaultPitch;
+    return impl->getDefaultPitch();
 }
 
-std::vector<Source*> Style::getSources() {
-    return sources.getWrappers();
+TransitionOptions Style::getTransitionOptions() const {
+    return impl->getTransitionOptions();
 }
 
-Source* Style::getSource(const std::string& id) const {
-    return sources.get(id);
+void Style::setTransitionOptions(const TransitionOptions& options) {
+    impl->mutated = true;
+    impl->setTransitionOptions(options);
 }
 
-bool Style::isLoaded() const {
-    if (!loaded) {
-        return false;
-    }
-
-    if (!spriteLoaded) {
-        return false;
-    }
-
-    for (const auto& source: sources) {
-        if (!source->loaded) {
-            return false;
-        }
-    }
-
-    return true;
+void Style::setLight(std::unique_ptr<Light> light) {
+    impl->setLight(std::move(light));
 }
 
-void Style::addImage(std::unique_ptr<style::Image> image) {
-    images.remove(image->getID()); // We permit using addImage to update.
-    images.add(std::move(image));
+Light* Style::getLight() {
+    impl->mutated = true;
+    return impl->getLight();
 }
 
-void Style::removeImage(const std::string& id) {
-    images.remove(id);
+const Light* Style::getLight() const {
+    return impl->getLight();
 }
 
-const style::Image* Style::getImage(const std::string& id) const {
-    return images.get(id);
+const Image* Style::getImage(const std::string& name) const {
+    return impl->getImage(name);
 }
 
-void Style::setObserver(style::Observer* observer_) {
-    observer = observer_;
+void Style::addImage(std::unique_ptr<Image> image) {
+    impl->mutated = true;
+    impl->addImage(std::move(image));
 }
 
-void Style::onSourceLoaded(Source& source) {
-    sources.update(source);
-    observer->onSourceLoaded(source);
-    observer->onUpdate(Update::Repaint);
+void Style::removeImage(const std::string& name) {
+    impl->mutated = true;
+    impl->removeImage(name);
 }
 
-void Style::onSourceChanged(Source& source) {
-    sources.update(source);
-    observer->onSourceChanged(source);
-    observer->onUpdate(Update::Repaint);
+std::vector<Source*> Style::getSources() {
+    impl->mutated = true;
+    return impl->getSources();
 }
 
-void Style::onSourceError(Source& source, std::exception_ptr error) {
-    lastError = error;
-    Log::Error(Event::Style, "Failed to load source %s: %s",
-               source.getID().c_str(), util::toString(error).c_str());
-    observer->onSourceError(source, error);
-    observer->onResourceError(error);
+std::vector<const Source*> Style::getSources() const {
+    return const_cast<const Impl&>(*impl).getSources();
 }
 
-void Style::onSourceDescriptionChanged(Source& source) {
-    sources.update(source);
-    observer->onSourceDescriptionChanged(source);
-    if (!source.loaded) {
-        source.loadDescription(fileSource);
-    }
+Source* Style::getSource(const std::string& id) {
+    impl->mutated = true;
+    return impl->getSource(id);
 }
 
-void Style::onSpriteLoaded(std::vector<std::unique_ptr<Image>>&& images_) {
-    for (auto& image : images_) {
-        addImage(std::move(image));
-    }
-    spriteLoaded = true;
-    observer->onUpdate(Update::Repaint); // For *-pattern properties.
+const Source* Style::getSource(const std::string& id) const {
+    return impl->getSource(id);
 }
 
-void Style::onSpriteError(std::exception_ptr error) {
-    lastError = error;
-    Log::Error(Event::Style, "Failed to load sprite: %s", util::toString(error).c_str());
-    observer->onResourceError(error);
+void Style::addSource(std::unique_ptr<Source> source) {
+    impl->mutated = true;
+    impl->addSource(std::move(source));
 }
 
-void Style::onLayerChanged(Layer& layer) {
-    layers.update(layer);
-    observer->onUpdate(Update::Repaint);
+std::unique_ptr<Source> Style::removeSource(const std::string& sourceID) {
+    impl->mutated = true;
+    return impl->removeSource(sourceID);
 }
 
-void Style::onLightChanged(const Light&) {
-    observer->onUpdate(Update::Repaint);
+std::vector<Layer*> Style::getLayers() {
+    impl->mutated = true;
+    return impl->getLayers();
 }
 
-void Style::dumpDebugLogs() const {
-    for (const auto& source : sources) {
-        source->dumpDebugLogs();
-    }
+std::vector<const Layer*> Style::getLayers() const {
+    return const_cast<const Impl&>(*impl).getLayers();
 }
 
-const std::string& Style::getGlyphURL() const {
-    return glyphURL;
+Layer* Style::getLayer(const std::string& layerID) {
+    impl->mutated = true;
+    return impl->getLayer(layerID);
 }
 
-Immutable<std::vector<Immutable<Image::Impl>>> Style::getImageImpls() const {
-    return images.getImpls();
+const Layer* Style::getLayer(const std::string& layerID) const {
+    return impl->getLayer(layerID);
 }
 
-Immutable<std::vector<Immutable<Source::Impl>>> Style::getSourceImpls() const {
-    return sources.getImpls();
+void Style::addLayer(std::unique_ptr<Layer> layer, const optional<std::string>& before) {
+    impl->mutated = true;
+    impl->addLayer(std::move(layer), before);
 }
 
-Immutable<std::vector<Immutable<Layer::Impl>>> Style::getLayerImpls() const {
-    return layers.getImpls();
+std::unique_ptr<Layer> Style::removeLayer(const std::string& id) {
+    impl->mutated = true;
+    return impl->removeLayer(id);
 }
 
 } // namespace style
diff --git a/src/mbgl/style/style_impl.cpp b/src/mbgl/style/style_impl.cpp
new file mode 100644
index 0000000000..7235226f84
--- /dev/null
+++ b/src/mbgl/style/style_impl.cpp
@@ -0,0 +1,321 @@
+#include <mbgl/style/style_impl.hpp>
+#include <mbgl/style/observer.hpp>
+#include <mbgl/style/source_impl.hpp>
+#include <mbgl/style/layers/symbol_layer.hpp>
+#include <mbgl/style/layers/custom_layer.hpp>
+#include <mbgl/style/layers/background_layer.hpp>
+#include <mbgl/style/layers/fill_layer.hpp>
+#include <mbgl/style/layers/fill_extrusion_layer.hpp>
+#include <mbgl/style/layers/line_layer.hpp>
+#include <mbgl/style/layers/circle_layer.hpp>
+#include <mbgl/style/layers/raster_layer.hpp>
+#include <mbgl/style/layer_impl.hpp>
+#include <mbgl/style/parser.hpp>
+#include <mbgl/style/transition_options.hpp>
+#include <mbgl/sprite/sprite_loader.hpp>
+#include <mbgl/util/exception.hpp>
+#include <mbgl/util/string.hpp>
+#include <mbgl/util/logging.hpp>
+
+namespace mbgl {
+namespace style {
+
+static Observer nullObserver;
+
+Style::Impl::Impl(Scheduler& scheduler_, FileSource& fileSource_, float pixelRatio)
+    : scheduler(scheduler_),
+      fileSource(fileSource_),
+      spriteLoader(std::make_unique<SpriteLoader>(pixelRatio)),
+      light(std::make_unique<Light>()),
+      observer(&nullObserver) {
+    spriteLoader->setObserver(this);
+    light->setObserver(this);
+}
+
+Style::Impl::~Impl() = default;
+
+void Style::Impl::setTransitionOptions(const TransitionOptions& options) {
+    transitionOptions = options;
+}
+
+TransitionOptions Style::Impl::getTransitionOptions() const {
+    return transitionOptions;
+}
+
+void Style::Impl::setJSON(const std::string& json) {
+    sources.clear();
+    layers.clear();
+    images.clear();
+
+    transitionOptions = {};
+    transitionOptions.duration = util::DEFAULT_TRANSITION_DURATION;
+
+    Parser parser;
+    auto error = parser.parse(json);
+
+    if (error) {
+        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;
+    }
+
+    for (auto& source : parser.sources) {
+        addSource(std::move(source));
+    }
+
+    for (auto& layer : parser.layers) {
+        addLayer(std::move(layer));
+    }
+
+    name = parser.name;
+    defaultLatLng = parser.latLng;
+    defaultZoom = parser.zoom;
+    defaultBearing = parser.bearing;
+    defaultPitch = parser.pitch;
+    setLight(std::make_unique<Light>(parser.light));
+
+    spriteLoader->load(parser.spriteURL, scheduler, fileSource);
+    glyphURL = parser.glyphURL;
+
+    loaded = true;
+
+    observer->onStyleLoaded();
+}
+
+void Style::Impl::addSource(std::unique_ptr<Source> source) {
+    if (sources.get(source->getID())) {
+        std::string msg = "Source " + source->getID() + " already exists";
+        throw std::runtime_error(msg.c_str());
+    }
+
+    source->setObserver(this);
+    source->loadDescription(fileSource);
+
+    sources.add(std::move(source));
+}
+
+struct SourceIdUsageEvaluator {
+    const std::string& sourceId;
+
+    bool operator()(BackgroundLayer&) { return false; }
+    bool operator()(CustomLayer&) { return false; }
+
+    template <class LayerType>
+    bool operator()(LayerType& layer) {
+        return layer.getSourceID() == sourceId;
+    }
+};
+
+std::unique_ptr<Source> Style::Impl::removeSource(const std::string& id) {
+    // Check if source is in use
+    SourceIdUsageEvaluator sourceIdEvaluator {id};
+    auto layerIt = std::find_if(layers.begin(), layers.end(), [&](const auto& layer) {
+        return layer->accept(sourceIdEvaluator);
+    });
+
+    if (layerIt != layers.end()) {
+        Log::Warning(Event::General, "Source '%s' is in use, cannot remove", id.c_str());
+        return nullptr;
+    }
+
+    std::unique_ptr<Source> source = sources.remove(id);
+
+    if (source) {
+        source->setObserver(nullptr);
+    }
+
+    return source;
+}
+
+std::vector<Layer*> Style::Impl::getLayers() {
+    return layers.getWrappers();
+}
+
+std::vector<const Layer*> Style::Impl::getLayers() const {
+    auto wrappers = layers.getWrappers();
+    return std::vector<const Layer*>(wrappers.begin(), wrappers.end());
+}
+
+Layer* Style::Impl::getLayer(const std::string& id) const {
+    return layers.get(id);
+}
+
+Layer* Style::Impl::addLayer(std::unique_ptr<Layer> layer, optional<std::string> before) {
+    // TODO: verify source
+
+    if (layers.get(layer->getID())) {
+        throw std::runtime_error(std::string{"Layer "} + layer->getID() + " already exists");
+    }
+
+    layer->setObserver(this);
+    observer->onUpdate(Update::Repaint);
+
+    return layers.add(std::move(layer), before);
+}
+
+std::unique_ptr<Layer> Style::Impl::removeLayer(const std::string& id) {
+    std::unique_ptr<Layer> layer = layers.remove(id);
+
+    if (layer) {
+        layer->setObserver(nullptr);
+        observer->onUpdate(Update::Repaint);
+    }
+
+    return layer;
+}
+
+void Style::Impl::setLight(std::unique_ptr<Light> light_) {
+    light = std::move(light_);
+    light->setObserver(this);
+    onLightChanged(*light);
+}
+
+Light* Style::Impl::getLight() const {
+    return light.get();
+}
+
+std::string Style::Impl::getName() const {
+    return name;
+}
+
+LatLng Style::Impl::getDefaultLatLng() const {
+    return defaultLatLng;
+}
+
+double Style::Impl::getDefaultZoom() const {
+    return defaultZoom;
+}
+
+double Style::Impl::getDefaultBearing() const {
+    return defaultBearing;
+}
+
+double Style::Impl::getDefaultPitch() const {
+    return defaultPitch;
+}
+
+std::vector<Source*> Style::Impl::getSources() {
+    return sources.getWrappers();
+}
+
+std::vector<const Source*> Style::Impl::getSources() const {
+    auto wrappers = sources.getWrappers();
+    return std::vector<const Source*>(wrappers.begin(), wrappers.end());
+}
+
+Source* Style::Impl::getSource(const std::string& id) const {
+    return sources.get(id);
+}
+
+bool Style::Impl::isLoaded() const {
+    if (!loaded) {
+        return false;
+    }
+
+    if (!spriteLoaded) {
+        return false;
+    }
+
+    for (const auto& source: sources) {
+        if (!source->loaded) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+void Style::Impl::addImage(std::unique_ptr<style::Image> image) {
+    images.remove(image->getID()); // We permit using addImage to update.
+    images.add(std::move(image));
+}
+
+void Style::Impl::removeImage(const std::string& id) {
+    images.remove(id);
+}
+
+const style::Image* Style::Impl::getImage(const std::string& id) const {
+    return images.get(id);
+}
+
+void Style::Impl::setObserver(style::Observer* observer_) {
+    observer = observer_;
+}
+
+void Style::Impl::onSourceLoaded(Source& source) {
+    sources.update(source);
+    observer->onSourceLoaded(source);
+    observer->onUpdate(Update::Repaint);
+}
+
+void Style::Impl::onSourceChanged(Source& source) {
+    sources.update(source);
+    observer->onSourceChanged(source);
+    observer->onUpdate(Update::Repaint);
+}
+
+void Style::Impl::onSourceError(Source& source, std::exception_ptr error) {
+    lastError = error;
+    Log::Error(Event::Style, "Failed to load source %s: %s",
+               source.getID().c_str(), util::toString(error).c_str());
+    observer->onSourceError(source, error);
+    observer->onResourceError(error);
+}
+
+void Style::Impl::onSourceDescriptionChanged(Source& source) {
+    sources.update(source);
+    observer->onSourceDescriptionChanged(source);
+    if (!source.loaded) {
+        source.loadDescription(fileSource);
+    }
+}
+
+void Style::Impl::onSpriteLoaded(std::vector<std::unique_ptr<Image>>&& images_) {
+    for (auto& image : images_) {
+        addImage(std::move(image));
+    }
+    spriteLoaded = true;
+    observer->onUpdate(Update::Repaint); // For *-pattern properties.
+}
+
+void Style::Impl::onSpriteError(std::exception_ptr error) {
+    lastError = error;
+    Log::Error(Event::Style, "Failed to load sprite: %s", util::toString(error).c_str());
+    observer->onResourceError(error);
+}
+
+void Style::Impl::onLayerChanged(Layer& layer) {
+    layers.update(layer);
+    observer->onUpdate(Update::Repaint);
+}
+
+void Style::Impl::onLightChanged(const Light&) {
+    observer->onUpdate(Update::Repaint);
+}
+
+void Style::Impl::dumpDebugLogs() const {
+    for (const auto& source : sources) {
+        source->dumpDebugLogs();
+    }
+}
+
+const std::string& Style::Impl::getGlyphURL() const {
+    return glyphURL;
+}
+
+Immutable<std::vector<Immutable<Image::Impl>>> Style::Impl::getImageImpls() const {
+    return images.getImpls();
+}
+
+Immutable<std::vector<Immutable<Source::Impl>>> Style::Impl::getSourceImpls() const {
+    return sources.getImpls();
+}
+
+Immutable<std::vector<Immutable<Layer::Impl>>> Style::Impl::getLayerImpls() const {
+    return layers.getImpls();
+}
+
+} // namespace style
+} // namespace mbgl
diff --git a/src/mbgl/style/style.hpp b/src/mbgl/style/style_impl.hpp
index 7e8f6f640b..2bdb51a26c 100644
--- a/src/mbgl/style/style.hpp
+++ b/src/mbgl/style/style_impl.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mbgl/style/style.hpp>
 #include <mbgl/style/transition_options.hpp>
 #include <mbgl/style/observer.hpp>
 #include <mbgl/style/source_observer.hpp>
@@ -28,14 +29,14 @@ class SpriteLoader;
 
 namespace style {
 
-class Style : public SpriteLoaderObserver,
-              public SourceObserver,
-              public LayerObserver,
-              public LightObserver,
-              public util::noncopyable {
+class Style::Impl : public SpriteLoaderObserver,
+                    public SourceObserver,
+                    public LayerObserver,
+                    public LightObserver,
+                    public util::noncopyable {
 public:
-    Style(Scheduler&, FileSource&, float pixelRatio);
-    ~Style() override;
+    Impl(Scheduler&, FileSource&, float pixelRatio);
+    ~Impl() override;
 
     void setJSON(const std::string&);
 
@@ -47,13 +48,17 @@ public:
         return lastError;
     }
 
-    std::vector<Source*> getSources();
+    std::vector<      Source*> getSources();
+    std::vector<const Source*> getSources() const;
     Source* getSource(const std::string& id) const;
+
     void addSource(std::unique_ptr<Source>);
     std::unique_ptr<Source> removeSource(const std::string& sourceID);
 
-    std::vector<Layer*> getLayers();
+    std::vector<      Layer*> getLayers();
+    std::vector<const Layer*> getLayers() const;
     Layer* getLayer(const std::string& id) const;
+
     Layer* addLayer(std::unique_ptr<Layer>,
                     optional<std::string> beforeLayerID = {});
     std::unique_ptr<Layer> removeLayer(const std::string& layerID);
@@ -82,6 +87,7 @@ public:
 
     void dumpDebugLogs() const;
 
+    bool mutated = false;
     bool loaded = false;
     bool spriteLoaded = false;