[Spec] Listening for location changes in the foreground

[vividos]

Starting foreground geolocation listener

James' Geolocation plugin provides one extra feature above getting geo locations, and that is starting (and stopping) listening for geolocations and changes. I know that it's complicated when the listening should start or continue in the background, but this is not the scope for the new API. My use case is that as long as the app is open, the user wants to track where he/she is.

API

Geolocation

public static bool IsListening { get; }
public static Task<bool> StartListeningForegroundAsync(ListeningRequest request);
public static Task<bool> StopListeningForegroundAsync();
public static event EventHandler<LocationEventArgs> LocationChanged;

public class LocationEventArgs : EventArgs
{
    public Location Location { get; }
    public LocationEventArgs(Location location);
}
public class ListeningRequest
{
    public ListeningRequest();
    public ListeningRequest(GeolocationAccuracy accuracy);
    public ListeningRequest(GeolocationAccuracy accuracy, TimeSpan timeout);
    public TimeSpan MinimumTime { get; set; } = TimeSpan.FromSeconds(1);
    public GeolocationAccuracy DesiredAccuracy { get; set; } = GeolocationAccuracy.Default;
}

Scenarios

This API is purely for listening when the app is in foreground. No guarantees about what's happening when the app is in the background.

Platform Compatibility

• Target Frameworks:
  • iOS: yes
  • Android: yes
  • UWP: yes
  • MacOS: yes

Backward Compatibility

All new methods, so no backward compat issues.

Difficulty : medium

The implementation would mainly contain of the PR #1043 and parts of @jamesmontemagno 's plugin.

[vividos]

@jamesmontemagno @mattleibow @Redth what do you think? I would provide a first implementation on the base of this spec...

[vividos]

I updated the Spec, adding a new class ListeningRequest that contains MinimumTime and DesiredAccuracy, since I think that the GeolocationRequest with its default Timeout value of TimeSpan.Zero wasn't as suitable as I thought. I will also update PR #1579 with the new class.