protected override void OnElementChanged(ElementChangedEventArgs <View> e)
{
base.OnElementChanged(e);
// For XAML Previewer or FormsGoogleMaps.Init not called.
if (!FormsGoogleMaps.IsInitialized)
{
var label = new UILabel()
{
Text = "Xamarin.Forms.GoogleMaps",
BackgroundColor = Color.Teal.ToUIColor(),
TextColor = Color.Black.ToUIColor(),
TextAlignment = UITextAlignment.Center
};
SetNativeControl(label);
return;
}
var oldMapView = (MapView)Control;
if (e.OldElement != null)
{
_cameraLogic.Unregister();
}
if (e.NewElement != null)
{
var mapModel = (Map)e.NewElement;
if (Control == null)
{
SetNativeControl(new MapView(RectangleF.Empty));
var mkMapView = (MapView)Control;
mkMapView.CameraPositionChanged += CameraPositionChanged;
mkMapView.CoordinateTapped += CoordinateTapped;
mkMapView.CoordinateLongPressed += CoordinateLongPressed;
mkMapView.DidTapMyLocationButton = DidTapMyLocation;
}
_cameraLogic.Register(Map, NativeMap);
if (mapModel.LastMoveToRegion != null)
{
_cameraLogic.MoveToRegion(mapModel.LastMoveToRegion, false);
}
UpdateMapType();
UpdateIsShowingUser();
UpdateHasScrollEnabled();
UpdateHasZoomEnabled();
UpdateIsTrafficEnabled();
foreach (var logic in _logics)
{
logic.Register(oldMapView, (Map)e.OldElement, NativeMap, Map);
logic.RestoreItems();
logic.OnMapPropertyChanged(new PropertyChangedEventArgs(Map.SelectedPinProperty.PropertyName));
}
}
}
async Task UpdateVisibleRegion()
{
if (Control == null || Element == null)
{
return;
}
if (!_firstZoomLevelChangeFired)
{
await _cameraLogic.MoveToRegion(Element.LastMoveToRegion, MapAnimationKind.None);
_firstZoomLevelChangeFired = true;
return;
}
Geopoint nw, se = null;
try
{
Control.GetLocationFromOffset(new Windows.Foundation.Point(0, 0), out nw);
Control.GetLocationFromOffset(new Windows.Foundation.Point(Control.ActualWidth, Control.ActualHeight), out se);
}
catch (Exception)
{
return;
}
if (nw != null && se != null)
{
var boundingBox = new GeoboundingBox(nw.Position, se.Position);
var center = new Position(boundingBox.Center.Latitude, boundingBox.Center.Longitude);
var latitudeDelta = Math.Abs(center.Latitude - boundingBox.NorthwestCorner.Latitude);
var longitudeDelta = Math.Abs(center.Longitude - boundingBox.NorthwestCorner.Longitude);
Element.VisibleRegion = new MapSpan(center, latitudeDelta, longitudeDelta);
}
}
void InitializeLogic()
{
_cameraLogic.MoveToRegion(((Map)Element).LastMoveToRegion, false);
foreach (var logic in _logics)
{
if (logic.Map != null)
{
logic.RestoreItems();
logic.OnMapPropertyChanged(new PropertyChangedEventArgs(Map.SelectedPinProperty.PropertyName));
}
}
_ready = false;
_onLayout = false;
}