/// <summary>
/// Validate whether the new (temp) geometry can be saved - is it valid?
/// </summary>
/// <returns>valid/not valid</returns>
private bool CanSaveNewGeom()
{
if (GeometryType == "Punkt")
{
return(TempCoordinates.Count > 0);
}
else if (GeometryType == "Linie")
{
return(TempCoordinates.Count > 1);
}
else
{
var isValid = MapModel.CheckValidityOfPolygon(TempCoordinates);
if (TempCoordinates.Count <= 3)
{
CurrentPolygonSelfIntersecting = false;
}
if (TempCoordinates.Count > 3 && isValid)
{
CurrentPolygonSelfIntersecting = false;
return(true);
}
else
{
if (TempCoordinates.Count > 3)
{
if (!CurrentPolygonSelfIntersecting) //Polyon was not previously self-intersecting
{
CurrentPolygonSelfIntersecting = true;
Device.BeginInvokeOnMainThread(async() =>
{
bool ok = await App.Current.MainPage.DisplayAlert("Das aktuelle Polygon schneidet sich selbst", "Solange es eine ungültige Geometrie hat kann es nicht gespeichert werden", "Weiter zeichnen", "Rückgängig machen");
if (!ok)
{
try
{
TempCoordinates.RemoveAt(TempCoordinates.Count - 2);
CurrentPolygonSelfIntersecting = false;
MessagingCenter.Send <MapPageVM>(this, "ShapeDrawingUndone");
SaveGeomCommand.ChangeCanExecute();
}
catch (Exception e)
{
Console.WriteLine("Had a problem undoing the shape: " + e.Message);
}
}
});
}
}
return(false);
}
}
}
/// <summary>
/// Add a temporary geometry to the map
/// </summary>
/// <param name="screenPt"></param>
public void AddTempPoint(Mapsui.UI.Forms.Position screenPt)
{
if (CanAddMapGeometry)
{
if (TempCoordinates.Count == 0)
{
MessagingCenter.Send <MapPageVM>(this, "SelectGeometryType");
}
if (Map.Layers[Map.Layers.Count - 1] == TempLayer)
{
Map.Layers.Remove(TempLayer);
}
var mapPt = new Mapsui.Geometries.Point(Convert.ToDouble(screenPt.Longitude), Convert.ToDouble(screenPt.Latitude));
if (GeometryType == "Punkt")
{
TempCoordinates = new List <Mapsui.Geometries.Point>()
{
mapPt
};
}
else if (GeometryType == "Polygon" && TempCoordinates.Count > 0)
{
var prevCoords = new List <Mapsui.Geometries.Point>(TempCoordinates);
if (TempCoordinates.Count == 1)
{
//Complete the polygon
TempCoordinates.Add(TempCoordinates[0]);
}
TempCoordinates.Insert(TempCoordinates.Count - 1, mapPt);
}
else
{
TempCoordinates.Add(mapPt);
}
TempLayer = MapModel.CreateTempLayer(TempCoordinates);
Map.Layers.Insert(Map.Layers.Count, TempLayer);
(SaveGeomCommand as Command).ChangeCanExecute();
}
}