[Qt] Allow strings as data source in the QML Item

Data values starting with ':' will be assumed to be a resource.

platform/qt/qmlapp/main.qml

@@ -323,6 +323,16 @@ ApplicationWindow {
                         source.data = ":source2.geojson"
                     }
                 }
+                RadioButton {
+                    text: "Route 3"
+                    exclusiveGroup: sourceGroup
+                    onClicked: {
+                        source.data = '{ "type": "FeatureCollection", "features": \
+                            [{ "type": "Feature", "properties": {}, "geometry": { \
+                            "type": "LineString", "coordinates": [[ 24.934938848018646, \
+                            60.16830257086771 ], [ 24.943315386772156, 60.16227776476442 ]]}}]}'
+                    }
+                }
             }
         }
 

platform/qt/src/qquickmapboxgl.cpp

@@ -290,9 +290,14 @@ bool QQuickMapboxGL::parseStyleSource(QQuickMapboxGLMapParameter *param)
         source["url"] = param->property("url");
         m_sourceChanges << source;
     } else if (sourceType == "geojson") {
-        QFile geojson(param->property("data").toString());
-        geojson.open(QIODevice::ReadOnly);
-        source["data"] = geojson.readAll();
+        auto data = param->property("data").toString();
+        if (data.startsWith(':')) {
+            QFile geojson(data);
+            geojson.open(QIODevice::ReadOnly);
+            source["data"] = geojson.readAll();
+        } else {
+            source["data"] = data.toUtf8();
+        }
         m_sourceChanges << source;
     } else {
         m_error = QGeoServiceProvider::UnknownParameterError;