/// <summary>
/// Updates the UI to account for the user's current position, if available,
/// resetting the MapControl bounds and refreshing the travel info.
/// </summary>
/// <param name="isGeolocatorReady">false if the Geolocator is known to be unavailable; otherwise, true.</param>
/// <returns></returns>
private async Task ResetViewAsync(bool isGeolocatorReady = true)
{
LocationData currentLocation = null;
if (isGeolocatorReady)
{
currentLocation = await GetCurrentLocationAsync();
}
if (currentLocation != null)
{
if (MappedLocations.Count > 0 && MappedLocations[0].IsCurrentLocation)
{
MappedLocations.RemoveAt(0);
}
await LocationHelper.TryUpdateMissingLocationInfoAsync(currentLocation, "Current Location");
MappedLocations.Insert(0, new LocationData {
Name = "Current Location", Position = currentLocation.Position, IsCurrentLocation = true
});
RouteWaypoints.Insert(0, currentLocation);
}
// Set the current view of the map control.
var positions = Locations.Select(loc => loc.Position).ToList();
if (currentLocation != null)
{
positions.Insert(0, currentLocation.Position);
}
if (positions.Count > 0)
{
bool isSuccessful = await SetViewBoundsAsync(positions);
if (isSuccessful && positions.Count < 2)
{
MyMap.ZoomLevel = 15;
}
else if (!isSuccessful && positions.Count > 0)
{
MyMap.Center = new Geopoint(positions[0]);
MyMap.ZoomLevel = 15;
}
}
}
public MainViewModel()
{
Restaurants.CollectionChanged += async(s, e) =>
{
if (e.NewItems != null)
{
foreach (Restaurant restaurant in e.NewItems)
{
MappedLocations.Add(
new MappedLocation
{
Restaurant = restaurant,
Index = Restaurants.IndexOf(restaurant) + 1,
Position = new BasicGeoposition
{
Latitude = restaurant.Latitude,
Longitude = restaurant.Longitude
}
});
if (restaurant.Distance == 0)
{
await SetDistanceAsync(restaurant);
}
}
}
if (e.OldItems != null)
{
foreach (Restaurant restaurant in e.OldItems)
{
MappedLocations.Remove(MappedLocations.First(location => location.Restaurant == restaurant));
}
foreach (var location in MappedLocations)
{
location.Index = Restaurants.IndexOf(location.Restaurant) + 1;
}
}
};
}