Added CMMotionActivity support

[fotiDim]

As promised this is my CMMotionActivity support contribution. I had to make a few minor changes to the way you present the dialog for the permissions to avoid a "flash" that was happening when all permissions were satisfied and the dialog shouldn't appear.

[nickoneill]

This looks good, thanks! Where was the flash being seen? Device or sim?

[felix-dumit]

Now that I'm integrating this into my app I'm also experiencing the flash issue with bluetooth.
The problem with bluetooth, and from what I saw, coremotion as well, is that to get the status you need to perform an async request. So when the show method is called the status is still .Unknown and therefore the alert is shown, but shortly afterwards (I found that for bluetooth about 10ms) the status is updated and the alert is dismissed (if previously accepted).

I've been thinking of a few different ways to solve this. Would be great to have some feedback.

• The first measure we can take is on the addPermission method, as soon as bluetooth or coremotion are added, we can trigger the status update - so there is some extra time from that point until show is called.
• Then we can either do what is already done here - delay the alert by some time in order for all statuses to update, or we can modify the statusForBluetooth (and motion) methods so they become synchronous and therefore wait for the status to be updated. <- This would involve moving a significant part of the code to a background thread and maybe making some methods require completion closures.
• We can also delay the alert while we are still waiting for either bluetooth or coremotion to complete. (instead of a fixed amount of time).

[fotiDim]

Sorry I forgot to answer about the flash issue. Indeed this was happening when the dialog should not appear (conditions met) because the motion status check was an async request. This gave the time to the dialog to appear momentarily and then disappear resulting in a flash effect.

The way I solved this was:

• The initial position of the dialog before transitioning is outside the visible window
• I set a few seconds delay before starting the transition

@felix-dumit Do you experience the flash with my pull request?

[felix-dumit]

@Navideck-fotis I did not try it, but from the changes you made I'm fairly confident it would solve it.

Edit: @Navideck-fotis It didn't work for me with bluetooth. I ended up doing a different approach, I think it would be a good idea to do something similar for motion as well.
You can see my changes at #57

[nickoneill]

I like the way this is handled in #57 versus relying on the implementation in the app (which is what I think you're suggested?). It should be simple enough to duplicate the async detection similar to bluetooth. Fix that up and we can pull this in.

[fotiDim]

@nickoneill Done!
@felix-dumit Nice implementation! It should be bullet-proof this way.

I did my testing and everything works the same for me as before.

[nickoneill]

Thanks!