topic Re: Command AddVertex in .NET Maps SDK Questions

Command AddVertex

JonasLeksell — Wed, 12 Nov 2014 08:41:19 GMT

Hi All,

We are trying to use the
command AddVertex to edit existing polygons and like to add this using XAML
code: e.g. <Button Content="Add Vertex" Command="{Binding
AddVertex}" CommandParameter="{Binding GPSPosition}" … /> where
GPSPosition is a function in the code behind. However using the command
parameter with the gps function or not we seem not to be able to get this
button to activate when editing.

Has anyone looked at this
Before and have a solution on this? Or know if we are addressing this the wrong way?

Re: Command AddVertex

AnttiKajanus1 — Wed, 12 Nov 2014 09:52:25 GMT

What DataContext you are using here? Are you using Editor.AddVertex command?

If you have map in the same view, try to use elementName binding to the myMapView.Editor.AddVertex and then bind normally to your command parameter that is coming from DataContext.

Re: Command AddVertex

JonasLeksell — Wed, 12 Nov 2014 10:23:05 GMT

Hi Antti,

Thx, for checking in to this question. Yes I am using the ICommand AddVertex from MapView.Editor and
are using the following DataContext:

DataContext="{Binding ElementName=mapView, Path=Editor}"

I am also using command as Undo, Redo and Cancel, and those are activated when I editing my map.

By some reason the button connected to the AddVertex command never gets in a valid state because it
will not become clickable.

Do you have a sample showing how this should work?

Regards,

Jonas

Re: Command AddVertex

AnttiKajanus1 — Wed, 12 Nov 2014 11:52:33 GMT

You can do it something like this, not very nice sample but you get the point

View : Notice binding

 <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
     <esri:MapView x:Name="MyMapView"
        LayerLoaded="MyMapView_LayerLoaded">
        <esri:Map>
        <layers:ArcGISTiledMapServiceLayer ID="Basemap"
            ServiceUri="http://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer"/>
        </esri:Map>
    </esri:MapView>
        
    <Button Command="{Binding ElementName=MyMapView, Path=Editor.AddVertex}" CommandParameter="{Binding GPSLocation}"
                Background="Green"
                Width="100" Height="100" HorizontalAlignment="Right" VerticalAlignment="Top"
                >add vertex</Button>
</Grid>

ViewModel

public class MainPageViewModel : INotifyPropertyChanged
    {
        DispatcherTimer timer;

        public MainPageViewModel()
        {
            timer = new DispatcherTimer()
            {
                Interval = new TimeSpan(0, 0, 3)
            };
            timer.Tick += timer_Tick;
            timer.Start();


            GPSLocation = new MapPoint(0, 0, SpatialReferences.WebMercator);
        }


        void timer_Tick(object sender, object e)
        {
            var random = new Random(DateTime.Now.Millisecond);


            GPSLocation = new MapPoint(random.Next(-10000000, 10000000), random.Next(-1000000,1000000), GPSLocation.SpatialReference);
        }


        private MapPoint _gpsLocation;
        public MapPoint GPSLocation
        {
            get { return _gpsLocation; }
            set { _gpsLocation = value; RaisePropertyChanged("GPSLocation"); }
        }


        public event PropertyChangedEventHandler PropertyChanged;
        protected void RaisePropertyChanged(string name)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(name));
            }
        }
    }

And set DataContext to new MainPageViewModel and activate editor. For example like this

public MainPage()
{
    this.InitializeComponent();
  DataContext = new MainPageViewModel();
  MyMapView.NavigationCompleted += MyMapView_NavigationCompleted;
}


private async void MyMapView_NavigationCompleted(object sender, EventArgs e)
{
    MyMapView.NavigationCompleted -= MyMapView_NavigationCompleted;


    try
  {
  var geom = await MyMapView.Editor.RequestShapeAsync(DrawShape.Polygon);
  }
  catch (Exception)
  {
  // todo
  }
}

Hope this helps.

Re: Command AddVertex

JonasLeksell — Thu, 13 Nov 2014 08:30:50 GMT

Hi Antti,

Thx, great sample I could get it to work, and I tried to modify the code I have to use DataContext="{Binding
ElementName=mapView, Path=Editor.AddVertex}" instead of calling on Command=”AddVertex”.

What I the saw was that the AddVertex button is always active, meaning it does not check if it is an
edit session as I get with the other commands.

Thanks for the help, we will do some more testing on this,

Regards,
Jonas

Re: Command AddVertex

AnttiKajanus1 — Thu, 13 Nov 2014 10:31:58 GMT

Hmm, it should check it. Are you able to create a repro for me to look at?

Re: Command AddVertex

JonasLeksell — Fri, 14 Nov 2014 10:01:49 GMT

Hi Antti,

Forget it...

I did set it in DataContext instead of Command. That´s why I got that behavior.

Regards,

Jonas

Re: Command AddVertex

AnttiKajanus1 — Fri, 14 Nov 2014 11:01:34 GMT

Cheers. Remember to mark topic answered.

Re: Command AddVertex

MartinBrzezinka — Mon, 01 Dec 2014 08:06:35 GMT

Dear Antti

I'm the reason for Jonas' question.
We have found you answer very helpful and I want to thank you for that.

However, it worked for us in your stand-alone application but not in our big project.
It turns out the difference was that you were always drawing new polygons
while we have been trying to edit present ones...

After some more digging, we have found out that the AddVertex button won't get enabled
if MapView.Editor.EditorMode == EditGeometry. It works only for EditorMode == Draw.

Could you please confirm this and accept as a bug?

Another question regarding AddVertex
The newly added point ends up at the end of the vertex list (last in a line)
regadless of what has been highlighted by the user.
Is there any way of telling to the Editor that the point should be added after marked VertexPosition?
If not, I think it should be very high on your todo - list.

Best regards,
Martin Brzezinka
Sweden

Re: Command AddVertex

AnttiKajanus1 — Sun, 12 Dec 2021 08:09:59 GMT

Hey Martin,

Editor is designed to perform edits on a map. This means that when EditorMode is set to Draw, it enables Editors functionality and in this case enables AddVertex. If you are editing geometry without performing it on the map, then Editor most likely isn't correct way to do it. If you're making changes to the geometry outside of the map, you should be modifying geometry directly using builders like PolygonBuilder Class ‌

Here is small example how to modify existing polygon

PolygonBuilder builder = new PolygonBuilder(polygon); // Create builder from existing polygon
builder.AddPoint(new MapPoint(x, y)); // Add point to end
builder.Parts[0].InsertPoint(index, new MapPoint(x, y)); // Insert point into specific location
graphic.Geometry = builder.ToGeometry(); // Create geometry and assign it back to the graphic / feature

I noticed that we haven't documented using Builders very well but we are going to improve that part.

About the second part, can you define a bit more detail the use case behind it and what is the workflow that you are looking from the editor?

Re: Command AddVertex

MartinBrzezinka — Mon, 01 Dec 2014 11:35:07 GMT

Thank you for your answer.

Yes, the geometry is being edited on the map. The workflow in both cases is as follows:

User has a map in one layer, user drawn lines and polygons in another.

User selects a line or polygon to INTERACTIVELLY edit it with mouse or touch.

This triggers a call to async MapView.Editor.EditGeometryAsync(geometry);
Buttons connected to MapView.Editor's ICommands are being enabled and disabled automatically.

This works fine for all graphics and all buttons (ICommands),
EXCEPT for just AddVertex on existing lines/polygons being edited.

Our editing is done by calling an asyncronous method EditGeometryAsync

so I don't really see how do we jack in the PolygonBuilder there?

Our AddVertex button adds a GPS position which is just a regular MapPoint.

And as I said, it's working fine when drawing a new line or polygon.

But when editing an existing one, the AddVertex button won't ever get enabled.

This seems to be due to a limitation inside the Editor
depending on which EditorMode is on, Draw or EditGraphic.

Second question remains:

how do we tell the Editor where to add the new point when editing interactivelly?
User selects a node in a line or polygon.
User needs to INTERACTIVELLY (by clicking on AddVertex button)

add the new point after that selected node,
not at the end of the line as it is by default.

I can see that here we could use the PolygonBuilder to add a point where we want to.
The trouble is that property Editor.VertexPosition which I understand holds the highlighted node, is private.
Problem #2 is that at the same time, user needs to be able to

interactivelly edit the line, i.e. drag nodes with mouse

so we must use the asynchronous method and leave control over to the Editor, don't we?

Re: Command AddVertex

AnttiKajanus1 — Sun, 12 Dec 2021 08:10:01 GMT

I had finally time to check this today.

In case one, it's true that AddVertex is not available on when editing existing geometry. Currently there is no easy way to say for the editor that add new vertex after selected one while Editor is active so I created new issue for that.

If you are doing editing, you can get vertex position reported back from the editor using following code but I'm not sure if that helps in this case.

Progress<GeometryEditStatus> progress = new Progress<GeometryEditStatus>();
progress.ProgressChanged += progress_ProgressChanged;
...
var geometry = await MyMapView.Editor.EditGeometryAsync(feature.Geometry, null, progress);

private void progress_ProgressChanged(object sender, GeometryEditStatus e)
{
     // do stuff
}

Re: Command AddVertex

MartinBrzezinka — Mon, 08 Dec 2014 19:18:58 GMT

Thank you Antti,

I look forward to get this fixed in the next release.