public Task<Position> GetPositionAsync( int timeout, CancellationToken cancelToken, bool includeHeading )
{
if(timeout <= 0 && timeout != Timeout.Infinite)
{
throw new ArgumentOutOfRangeException( "timeout", "timeout must be greater than or equal to 0" );
}
var tcs = new TaskCompletionSource<Position>();
if(!IsListening)
{
GeolocationSingleListener singleListener = null;
singleListener = new GeolocationSingleListener(
(float)DesiredAccuracy,
timeout,
providers.Where( manager.IsProviderEnabled ),
finishedCallback: () =>
{
for(int i = 0; i < providers.Length; ++i)
{
manager.RemoveUpdates( singleListener );
}
} );
if(cancelToken != CancellationToken.None)
{
cancelToken.Register(
() =>
{
singleListener.Cancel();
for(int i = 0; i < providers.Length; ++i)
{
manager.RemoveUpdates( singleListener );
}
},
true );
}
try
{
Looper looper = Looper.MyLooper() ?? Looper.MainLooper;
int enabled = 0;
for(int i = 0; i < providers.Length; ++i)
{
if(manager.IsProviderEnabled( providers[i] ))
{
enabled++;
}
manager.RequestLocationUpdates( providers[i], 0, 0, singleListener, looper );
}
if(enabled == 0)
{
for(int i = 0; i < providers.Length; ++i)
{
manager.RemoveUpdates( singleListener );
}
tcs.SetException( new GeolocationException( GeolocationError.PositionUnavailable ) );
return tcs.Task;
}
}
catch(SecurityException ex)
{
tcs.SetException( new GeolocationException( GeolocationError.Unauthorized, ex ) );
return tcs.Task;
}
return singleListener.Task;
}
// If we're already listening, just use the current listener
lock(positionSync)
{
if(lastPosition == null)
{
if(cancelToken != CancellationToken.None)
{
cancelToken.Register( () => tcs.TrySetCanceled() );
}
EventHandler<PositionEventArgs> gotPosition = null;
gotPosition = ( s, e ) =>
{
tcs.TrySetResult( e.Position );
PositionChanged -= gotPosition;
};
PositionChanged += gotPosition;
}
else
{
tcs.SetResult( lastPosition );
}
}
return tcs.Task;
}
public Task <Position> GetPositionAsync(int timeout, CancellationToken cancelToken, bool includeHeading)
{
if (timeout <= 0 && timeout != Timeout.Infinite)
{
throw new ArgumentOutOfRangeException("timeout", "timeout must be greater than or equal to 0");
}
var tcs = new TaskCompletionSource <Position>();
if (!IsListening)
{
GeolocationSingleListener singleListener = null;
singleListener = new GeolocationSingleListener((float)DesiredAccuracy, timeout, this.providers.Where(this.manager.IsProviderEnabled),
finishedCallback: () =>
{
for (int i = 0; i < this.providers.Length; ++i)
{
this.manager.RemoveUpdates(singleListener);
}
});
if (cancelToken != CancellationToken.None)
{
cancelToken.Register(() =>
{
singleListener.Cancel();
for (int i = 0; i < this.providers.Length; ++i)
{
this.manager.RemoveUpdates(singleListener);
}
}, true);
}
try
{
Looper looper = Looper.MyLooper() ?? Looper.MainLooper;
int enabled = 0;
for (int i = 0; i < this.providers.Length; ++i)
{
if (this.manager.IsProviderEnabled(this.providers[i]))
{
enabled++;
}
this.manager.RequestLocationUpdates(this.providers[i], 0, 0, singleListener, looper);
}
if (enabled == 0)
{
for (int i = 0; i < this.providers.Length; ++i)
{
this.manager.RemoveUpdates(singleListener);
}
tcs.SetException(new GeolocationException(GeolocationError.PositionUnavailable));
return(tcs.Task);
}
}
catch (Java.Lang.SecurityException ex)
{
tcs.SetException(new GeolocationException(GeolocationError.Unauthorized, ex));
return(tcs.Task);
}
return(singleListener.Task);
}
// If we're already listening, just use the current listener
lock (this.positionSync)
{
if (this.lastPosition == null)
{
if (cancelToken != CancellationToken.None)
{
cancelToken.Register(() => tcs.TrySetCanceled());
}
EventHandler <PositionEventArgs> gotPosition = null;
gotPosition = (s, e) =>
{
tcs.TrySetResult(e.Position);
PositionChanged -= gotPosition;
};
PositionChanged += gotPosition;
}
else
{
tcs.SetResult(this.lastPosition);
}
}
return(tcs.Task);
}