topic How test my draw before drawing? in .NET Maps SDK Questions

How test my draw before drawing?

KilianBahuaud — Wed, 26 Feb 2020 09:08:47 GMT

Hi everyone,

I've a problem with drawing on map on ArcGIS SDK 100.7 for .NET.

I'm using SketchEditor and I need to configure visibility of a button with SketchEditor.CompleteCommand.CanExecute.

My problem is that the execution of my test is always done before the drawing.

Sequence step by step :

- //Step 1

- Geometry g = await MapView.SketchEditor.StartAsync(SketchCreationMode.Point, true); //Async method

- MapView.SketchEditor.CompleteCommand.CanExecute(null); //Return false

- //Step 2 : Click on the map

- MapView.SketchEditor.CompleteCommand.CanExecute(null); //Return false

- //The 1st drawing appears on the map

- //Step 3 : Click on the map

- MapView.SketchEditor.CompleteCommand.CanExecute(null); //Return true but detect only 1st point instead of 1st & 2nd.

- //The 2nd drawing appears on the map

My goal is to detect the first point into my first control.

The difficult is my initialisation are asynchrone, but my control is synchrone.

I tried to pass the 2 asynchronously but the error is still present.

Currently, my button appears when creating the 2nd point. I have the same problem for polylines and polygons. My button appears at the 3rd point for my polyline, and at my 4th point for my polygon. There is always a point of delay.

Have you got any idea?

Thank you

Re: How test my draw before drawing?

JoeHershman — Wed, 26 Feb 2020 16:07:25 GMT

The CompleteCommand is managed by the API and cannot be used in the ways you are describing.

When you use the SketchEditor you basically give control of the map to device input. Once you call

geometry = await SketchEditor.StartAsync(sketchCreationMode, false);‍

The Map is now waiting for input, (i.e., a mouse-click or tap). The API basically controls things until the correct input is received.

I am not sure I understand the goal you are trying to achieve. Do you want the use to be able to accept the placement of the geometry?

-Joe

Re: How test my draw before drawing?

KilianBahuaud — Thu, 27 Feb 2020 08:26:30 GMT

Thanks for your answer.

My real problem is the order of event execution.

After a click, the MapView Tapped event is detected before the geometry creation.

So, I don't know how control future geometry because it doesn't yet exist.

Do you know how to reverse the order of execution of events?

Re: How test my draw before drawing?

JoeHershman — Thu, 27 Feb 2020 17:28:17 GMT

I'm not sure what you mean by 'control future geometry.' The geometry is created by the SketchEditor. In the method you are calling

mapPoint = (MapPoint)await SketchEditor.StartAsync(SketchCreationMode.Point, false);

The next line of code will have the geometry after the MapView is tapped. You really don't need to do anything in the MapView.Tapped event handler.

What do you want your button to be doing? I am not clear what your workflow is. You will need some kind of Command to initiate the call above to the SketchEditor. In the esri provided sample they have a button that when invoked Starts the sketch editor.

Re: How test my draw before drawing?

KilianBahuaud — Fri, 28 Feb 2020 13:29:28 GMT

What I want to do is very simple.

If any geometry is created, then my button is visible.

My button is here to validate the draw. I need to detect that the drawing can be completed.

-If SketchEditor initialized but no drawing, then button "Validate" hidden

-If SketchEditor.Command.canComplete then button "Validate" visible

Re: How test my draw before drawing?

dotMorten_esri — Mon, 02 Mar 2020 17:09:22 GMT

The easiest is to just bind the command to the button, and it'll automatically enable/disable. That's actually the main reason it's a command.

If you want to do it programmatically, use the CanExecuteChanged event on the ICommand interface to detect when the state of the command might have changed.

Re: How test my draw before drawing?

JoeHershman — Sun, 12 Dec 2021 08:16:16 GMT

Yup I'll have to eat a little crow here, I have set the SketchCreationMode to false in our standard configuration which behaves differently and just triggers on the click. Although I don't think binding directly to SketchEditor.CompleteCommand does what is being asked.

In Xaml:

<Button Command="{Binding CompleteCommand}" Text="Yo Dude" Height="30" IsVisible="{Binding YoVisible}"/>‍‍

In ViewModel (I have SketchEditor initialized in ViewModels through an event, so this would be slightly different in the MapView's ViewModel):

EventAggregator.GetEvent<SketchEditorInitializedEvent>().Subscribe(se =>
{
	SketchEditor = se;
	SketchEditor.CompleteCommand.CanExecuteChanged += CompleteCommandOnCanExecuteChanged;
	
}));

private void CompleteCommandOnCanExecuteChanged(object sender, EventArgs e)
{
	var x = SketchEditor.Geometry;
	if ( x != null )
	{
		YoVisible = true;
	}
	Console.WriteLine("Here");
}

public bool YoVisible
{
	get => _yoVisible;
	set => SetProperty(ref _yoVisible, value);
}

public ICommand CompleteCommand => new DelegateCommand<object>(ExecuteComplete);

private void ExecuteComplete(object obj)
{
	if ( SketchEditor.CompleteCommand.CanExecute(null) )
	{
		SketchEditor.CompleteCommand.Execute(null);
	}
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Although you really don't need the if statement in the ExecuteComplete as the button is only visible if the CanExecute is True

I don't see any way that you could actually know what CanExecute is besides there being a geometry associated to the SketchEditor

Re: How test my draw before drawing?

KilianBahuaud — Sun, 12 Dec 2021 08:16:19 GMT

Thanks for your answers, but it's not exactly that.
You'll find my code below to better understand.

In Xaml :

<AppBarButton Margin="0,0,-15,0"
              Command="{Binding ValiderTraceCommand}"
              Icon="Accept"
              Label="Valider le tracé"
              Style="{StaticResource DefaultAppBarButtonStyle}"
              Visibility="{Binding ValiderTraceCommandIsVisible, Converter={StaticResource BoolToVisibilityConverter}, Mode=OneWay}" 
              Width="100"  
              FontSize="10"/>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

<Border Grid.Column="1"
        BorderBrush="Gray"
        BorderThickness="1,0,0,0">
    <esriControls:MapView x:Name="mapView"
                          Map="{Binding Map}" Loaded="mapView_Loaded">
        <interactivity:Interaction.Behaviors>
            <core:EventTriggerBehavior EventName="GeoViewTapped">
                <core:InvokeCommandAction Command="{Binding OnMapViewTappedCommand}" />
            </core:EventTriggerBehavior>
        </interactivity:Interaction.Behaviors>
    </esriControls:MapView>
</Border>‍‍‍‍‍‍‍‍‍‍‍‍

In View :

public bool ValiderTraceCommandIsVisible
{
    get
    {
        return ValiderTraceCommand.CanExecute(null);
    }
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍

‍‍‍‍‍‍‍public RelayCommand ValiderTraceCommand
{
    get
    {
        return _validerTraceCommand ?? (_validerTraceCommand = new RelayCommand(async () => await ValiderTrace(), CanValiderTrace));
    }
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

private async Task ValiderTrace()
{
    if (MapView.SketchEditor.CompleteCommand.CanExecute(null))
    {
        MapView.SketchEditor.CompleteCommand.Execute(null);
    }
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

private Boolean CanValiderTrace()
{
    return MapView.SketchEditor.CompleteCommand.CanExecute(null) && otherVariable;
}

public RelayCommand<object> OnMapViewTappedCommand
{
    get
    {
        return _onMapViewTappedCommand ??
                       (_onMapViewTappedCommand =
                           new RelayCommand<object>(async mapView => await OnMapViewTapped(mapView)));
    }
}
private async Task OnMapViewTapped(object mapViewInputEventArgs)
{
    ValiderTraceCommand.RaiseCanExecuteChanged();
    ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍RaisePropertyChanged(() => ValiderTraceCommandIsVisible);
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

SketchEditor is initialized by :

Geometry g = await MapView.SketchEditor.StartAsync(SketchCreationMode.Polygon, true);‍

Here's the problem, when I click on the map, OnMapViewTapped runs before drawing.

Therefore, during the third point creation, my test detect only two point. Always one point behind.

How can I launch this test after the drawing ?

Re: How test my draw before drawing?

JoeHershman — Thu, 05 Mar 2020 16:53:49 GMT

I am not clear where this part is in your code, what triggers the SketchEditor to Start?

Geometry g = await MapView.SketchEditor.StartAsync(SketchCreationMode.Polygon, true);

Using the SketchEditor you don't need to be handling GeoViewTapped. It will move past the above line of code when the shape is complete. Once it moves past the geometry is drawn on the MapView and the CompleteCommand.CanExecute will be true

Re: How test my draw before drawing?

KilianBahuaud — Fri, 06 Mar 2020 09:04:23 GMT

Yes, the line after the initialisation runs when the drawing is complete but I want to run drawing test before the end of the drawing. That is why I use GeoViewTapped.

I want to check that the drawing can be completed before it is complete.

Re: How test my draw before drawing?

JoeHershman — Fri, 06 Mar 2020 14:45:27 GMT

I'm sorry but I am missing something, I don't understand how a point would not be valid to complete the polygon and why one would want to confirm.

CompleteCommand can only be executed when you have a geometry already. It allows you to accept (finalize) that geometry. As opposed to moving a vertex before finishing. If you want the level of control you seem to desire and validate each point then you pretty much would need to just create your own editor and use the passed in point to draw a graphic on a graphics layer.

Again, I may just not understand what you are really trying to accomplish and apologize if that is the case

Re: How test my draw before drawing?

KilianBahuaud — Mon, 09 Mar 2020 08:12:07 GMT

Sorry, I d'on't see how explain.

I have a hidden button and I want to alter his visibility.

At begin, button are hidden.

Next, we start drawing.

When at least one point is drawn, I want the button to appear.

The visibility depends on the drawing but also on another variable, so a "Binding" is not enough.

The real problem is the order of execution, when we clicked on the map, the GeoViewTapped event runs before the new point of the drawing.

Since I check the visibility in this event, I'm always one point behind. When I draw the 2nd point, my check only detects the first point. Same with more points.

Re: How test my draw before drawing?

dotMorten_esri — Mon, 09 Mar 2020 20:29:44 GMT

The ICommand interface should deal with automatically enabling/disabling the button, so if you don't want to hide the button this will work exactly like you want just by binding the Command to the button.

If you do want to hide the button, you would override the visual state of the button to instead collapse it, instead of disabling it. See: wpf - how to hide a button that is bound to a command that cannot execute? - Stack Overflow

Re: How test my draw before drawing?

KilianBahuaud — Sun, 12 Dec 2021 08:16:22 GMT

I tried your method but the order of runs don't change.

With breakpoint, I see the Icommand runs before drawing modify.

It's the same problem.

Here is my updated code:

<AppBarButton Margin="0,0,-15,0"
              Command="{Binding ValiderTraceCommand}"
              Icon="Accept"
              Label="Valider le tracé"
              Style="{StaticResource DefaultAppBarButtonStyle}"
              Visibility="{Binding ValiderTraceCommandIsVisible, Converter={StaticResource BoolToVisibilityConverter}, Mode=OneWay}" Width="100"  FontSize="10"/>‍‍‍‍‍‍

public bool ValiderTraceCommandIsVisible
{
    get
    {
        return MapView.SketchEditor.CompleteCommand.CanExecute(null);
    }
}‍‍‍‍‍‍‍

Re: How test my draw before drawing?

dotMorten_esri — Tue, 10 Mar 2020 15:45:55 GMT

I think I'm at a point where I just don't understand what you're trying to achieve. I don't get what you mean by the order of commands. Commands don't execute until you press the button they are bound to. Perhaps there's just a misunderstanding of what these commands are used for. Also you don't have to use the commands, but can just execute methods on the SketchEditor yourself.

Re: How test my draw before drawing?

KilianBahuaud — Tue, 10 Mar 2020 16:04:30 GMT

When we clicked, they are many action that take in place. These actions are not launched simultaneously.

So there is an order of execution. This order is :

- ICommand (Visibility)

- GeoViewTapped

- The point is drawn

The point is drawn after all the other actions. That's the problem.

Re: How test my draw before drawing?

dotMorten_esri — Tue, 10 Mar 2020 16:40:35 GMT

Is this the code you have?

- //Step 1

- Geometry g = await MapView.SketchEditor.StartAsync(SketchCreationMode.Point, true); //Async method

- MapView.SketchEditor.CompleteCommand.CanExecute(null); //Return false

If so, the second line of code won't run until the draw has completed, because you're awaiting the draw to complete. Remove the await if that's what you want.

Task<Geometry> drawTask = MapView.SketchEditor.StartAsync(SketchCreationMode.Point, true);
[...run other core... ]
Geometry g = await drawTask;

Re: How test my draw before drawing?

KilianBahuaud — Tue, 10 Mar 2020 16:53:50 GMT

Sorry, I understand my mistake, I misspoke.

SketchEditor.CompleteCommand.CanExecute runs in an other method.

When CanExecute runs, StartAsync isn't finished.

I want to detect when CanExecute is true before the end of StartAsync.

Re: How test my draw before drawing?

dotMorten_esri — Tue, 10 Mar 2020 19:03:59 GMT

> I want to detect when CanExecute is true before the end of StartAsync.

You'll need to listen to the CompleteCommand.CanExecuteChanged event to be notified if the command's CanExecute has potentially changed, then call CanExecute(...) each time it fires to check the status.

Ie something along the lines of:

SketchEditor.CompleteCommand.CanExecuteChanged += (s,e) => { if(SketchEditor.CompleteCommand.CanExecute(null)) { DoSomething(); } };
Geometry g = await MapView.SketchEditor.StartAsync(SketchCreationMode.Point, true);

I'm just now realizing you're drawing a point. Point geometry completes immediately when you click.