topic Re: MapView toScreen returns wrong screenpoint in ArcGIS JavaScript Maps SDK Questions

MapView toScreen returns wrong screenpoint

EemeliP — Sun, 12 Dec 2021 07:49:06 GMT

Hi,

I have an application that loads a Webmap from portal using ArcGIS JS version 4.12. Then I navigate to certain point with MapView goTo function. That works fine. Then I need to convert the Point into ScreenPoint in order to do a hittest. When I do the "toScreen" conversion it returns a point on screen that is not on the right place.

Am I missing something here, or should somehow take the spatial reference of the map into account. The Point I create from x and y coordinates points into the right place. Why does the "toScreen" point into a wrong place even though the goto leads into right place? I have tried to change or set different spatial references for the point before "toScreen" but it does not seem to help.

Example:

var point = new Point();
point.longitude = "-2.12953405978807";
point.latitude = "50.6877745154717";

// screenPt is x: 1210, y: 416 although it should be something like x: 959  & y: 528.
var screenPt = _view.basemapView.view.toScreen( point );‍‍‍‍‍‍‍‍‍‍‍‍

Re: MapView toScreen returns wrong screenpoint

RobertScheitlin__GISP — Wed, 11 Sep 2019 13:00:21 GMT

Eemeli,

Why are you using the basmapView and not just the _view to get the screen point?

var screenPt = _view.toScreen(point);‍‍

Re: MapView toScreen returns wrong screenpoint

EemeliP — Thu, 12 Sep 2019 04:35:31 GMT

Hi Robert,

Actually using "basemapView.view" was just the last experiment I had and accidentally left it there as an example. I have the same result when using "_view": the generated screen point is out of screen.

var screenPt = _view.toScreen( point );

Re: MapView toScreen returns wrong screenpoint

EemeliP — Sun, 12 Dec 2021 07:49:09 GMT

Hi,

I think I was able to resolve this. It was about timing as there was on-going "pan" and therefore the original point was "moving on the screen" and the resulted screenpoint was more or less random.

I fixed this by waiting that the view animation is done:

_view.watch( "animation",function( response ) {

     if( response && response.state !== "running" ) {

           var screenPt = _view.toScreen( point );
     }
}‍‍‍‍‍‍‍


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