When I display a GsdkStreamView, the view is filled in black when no stream is set, so when there’s no drone connection. I would like to display instead a stream that makes the user understand there’s no connection, much like how it is done in FreeFlight 7 on iOS:
FreeFlight does this by displaying another view on top of the GsdkStreamView when no drone is connected. This is the easiest way to achieve what you want.
The textureLoader feature is more complex, and was mostly intended for use-cases where the application needs to modify the streamed picture before rendering (as an example, this is the feature used by FreeFlight 6 to apply the color palette for thermal imaging streaming on Anafi Thermal or Anafi USA drones). While it should be possible to do what you want to do with this feature, it is probably not the “good” solution.