[Qt] Added QMapbox::Feature → GeoJSON conversion helper

platform/qt/app/mapwindow.cpp

@@ -258,6 +258,30 @@ void MapWindow::keyPressEvent(QKeyEvent *ev)
             }
         }
         break;
+    case Qt::Key_5: {
+            if (m_map->layerExists("circleLayer")) {
+                m_map->removeLayer("circleLayer");
+                m_map->removeSource("circleSource");
+            } else {
+                QMapbox::CoordinatesCollections geometry { { { m_map->coordinate() } } };
+                QMapbox::Feature feature { QMapbox::Feature::PointType, geometry, {}, {} };
+
+                QVariantMap circleSource;
+                circleSource["type"] = "geojson";
+                circleSource["data"] = QVariant::fromValue<QMapbox::Feature>(feature);
+                m_map->addSource("circleSource", circleSource);
+
+                QVariantMap circle;
+                circle["id"] = "circleLayer";
+                circle["type"] = "circle";
+                circle["source"] = "circleSource";
+                m_map->addLayer(circle);
+
+                m_map->setPaintProperty("circleLayer", "circle-radius", 10.0);
+                m_map->setPaintProperty("circleLayer", "circle-color", QColor("black"));
+            }
+        }
+        break;
     case Qt::Key_Tab:
         m_map->cycleDebugOptions();
         break;

platform/qt/src/qt_conversion.hpp

@@ -30,7 +30,13 @@ inline QVariant arrayMember(const QVariant& value, std::size_t i) {
 }
 
 inline bool isObject(const QVariant& value) {
-    return value.canConvert(QVariant::Map) || value.type() == QVariant::ByteArray;
+    return value.canConvert(QVariant::Map)
+        || value.type() == QVariant::ByteArray
+#if QT_VERSION >= 0x050000
+        || QString(value.typeName()) == QStringLiteral("QMapbox::Feature");
+#else
+        || QString(value.typeName()) == QString("QMapbox::Feature");
+#endif
 }
 
 inline optional<QVariant> objectMember(const QVariant& value, const char* key) {

platform/qt/src/qt_geojson.hpp

@@ -179,9 +179,20 @@ namespace mbgl {
 namespace style {
 namespace conversion {
 
+template <>
+Result<GeoJSON> convertGeoJSON(const QMapbox::Feature& feature) {
+    return Result<GeoJSON> { GeoJSON { asMapboxGLFeature(feature) } };
+}
+
 template <>
 Result<GeoJSON> convertGeoJSON(const QVariant& value) {
-    if (value.type() != QVariant::ByteArray) {
+#if QT_VERSION >= 0x050000
+    if (value.typeName() == QStringLiteral("QMapbox::Feature")) {
+#else
+    if (value.typeName() == QString("QMapbox::Feature")) {
+#endif
+        return convertGeoJSON(value.value<QMapbox::Feature>());
+    } else if (value.type() != QVariant::ByteArray) {
         return Error { "JSON data must be in QByteArray" };
     }
 
@@ -201,7 +212,7 @@ Result<GeoJSON> convertGeoJSON(const QVariant& value) {
         return Error { message.str() };
     }
 
-    conversion::Result<GeoJSON> geoJSON = conversion::convertGeoJSON<JSValue>(d);
+    Result<GeoJSON> geoJSON = convertGeoJSON<JSValue>(d);
     if (!geoJSON) {
         return Error { geoJSON.error().message };
     }