Loading Indicator for Rain Tiles

[Nebukadneza]

Hi There,

often, the map loads quickly or is already cached, but the meteonowcast "rain"-tiles take very long to load. Especially when switching on the animation, it is not clear to the user when loading has finished. This is especially true if zoomed in, and it is not clear whether there is no rain, or it merely has not loaded yet. Then, the user either has to wait for a long time to be certain, zoom out until encountering a bit of rain "somewhere", and/or jog the time-slider back and forth to see up "until when" it already finished loading.

The users certainty and ease of use could be improved by providing a simple loading indicator that shows when the meteonowcast-"rain"-tiles have finished loading successfully.

I have also opened this issue on the core side, since both web and android suffer from the same problem: meteocool/core#154

I also want to take the opportunity for thanking you for this great project! I use it daily, and back before corona when cycling into an office was still a thing it was my daily safety measure against getting very wet :-).