Show debug info for tiles that are still loading

[kkaefer]

We should show information for tiles that are still loading or processing to give the user a feel that something is happening. This could also be helpful during debugging.

@ajashton, you mentioned that you don't like the matte "grid" that other map renderers (like Apple maps) use. Do you have another suggestions?

[ajashton]

We should show information for tiles that are still loading or processing to give the user a feel that something is happening

Not sure I would agree with this, at least not for the final product - we don't do it for image tiles currently. Seems like most options would be distracting / draw more attention to the unfinished areas. Maybe just a single small spinner that shows up in the corner if things are taking longer than usual?

To me the grids Apple/Google/etc use feel like they've accidentally left on some developer/debug mode for the final user-facing product.

[incanus]

Related to perceived performance: #163

We do the top network activity spinner on iOS.

I'm a fan of the grid approach (#119) because in mobile, especially after very fast zooms or pans combined with not-great bandwidth, you don't have a sense of movement or context.

[ansis]

The matte issue #119 is still open. I think that covers everything left here. Closing