I am using ArcGIS Runtime 100.2.1 for Qt. Few days back i have gone through some sample runtime application for WPF. In that i saw many useful and easy API's for creating geometries and identifying graphics layers
// Wait for user to draw
var geom = await MyMapView.Editor.RequestShapeAsync(DrawShape.Polygon);
//Hit test whlie mouse hovering
var graphic = await _graphicsLayer.HitTestAsync(MyMapView, screenPoint);
Is there any similar kind of API's available in Runtime sdk for Qt?