Fix #3590: Added compass and distance overlay to map views

[kgraefe]

This fixes #3590 which is marked as a duplicate of #1382.

[samueltardieu]

Also, please use present tense ("Add compass and distance overlay to map views") in commit messages.

Thanks for your contribution. I have done a quick read of the change and made a few comments. Could you please address them and submit an updated version?

[SammysHP]

Without looking at the code, I found two issues:

• Orientation consistency: The arrow points to the cache relative to the orientation of the phone while the arrow on the map (your position) is relative to the map.
• You don't know the target for which the arrow indicates the direction. IMHO this UI needs the often requested line from your current position to the target.

[Lineflyer]

Any news/feedback regarding the comments?

[kgraefe]

Yes. I agree with SammyHP that the meaning of the arrow is not obvious to the user. I will discard the compass arrow and will instead implement the line from the current position to the target as soon as find some spare time (being at home because programming is no fun on my netbook...). Since that would introduce another overlay layer (which should be below all the other layers) I plan to refactor cgeo.geocaching.maps.mapsforge.MapsforgeOverlay beforehand to reduce duplicated code.

[SammysHP]

Don't invest too much time into the refactoring of any map related code as we will replace it anyway soon.

[Lineflyer]

@kgraefe

Reading your last comment I think that we can close this PR?
Anyway another approach with a heading line would be really cool.