Custom Vector graphics for current location

[decay]

I am trying to replace the blue dot for the current location with a custom vector graphic.  I know you can replace the image with a .png or some other fixed image.

It would appear that AGSVectorMarkerSymbolElement might fit the situation, but I am having a problem constructing the object based on this statement

To create a red square, for example, construct an instance AGSVectorMarkerSymbolElement with a AGSMultilayerPolygonSymbol that contains a red AGSSolidFillSymbolLayer and a square geometry.

This appears to use layers instead of overlays, and I am not sure if layers can be animated (or converted to an overlay somehow).  It also appears that the functionality I am looking for (animated vector graphics on the map), is more of a ArcGIS pro thing where the element is created as a JSON object, but I can't be sure based on the documentation.

Thanks.

[MarkDostal]

Hello and thank you for your question.  Creating a multi-layer symbol requires several steps.  Below is code to create a square polygon symbol using custom points and using that as the default location display symbol.

// The array of points for our shape (polygon), a 1 x 1 square
// The size is set on the final symbol, below.
let points = [
    AGSPoint(x: 0, y: 0, spatialReference: nil),
    AGSPoint(x: 0, y: 1, spatialReference: nil),
    AGSPoint(x: 1, y: 1, spatialReference: nil),
    AGSPoint(x: 1, y: 0, spatialReference: nil)
]
// Create the polygon from our points.
let polygon = AGSPolygon(points: points)
// Create a red solid fill symbol layer.
let redFill = AGSSolidFillSymbolLayer(color: .red)
// Create a multi-layer polygons ymbol from the solid fill layer.
let multiLayerPolygonSymbol = AGSMultilayerPolygonSymbol(symbolLayers: [redFill])
// Create a vector marker element using our polygon geometry and multi-layer symbol.
let vectorElement = AGSVectorMarkerSymbolElement(geometry: polygon, multilayerSymbol: multiLayerPolygonSymbol)
// Create a vector marker symbol layer from our element.
let vectorMarker = AGSVectorMarkerSymbolLayer(vectorMarkerSymbolElements: [vectorElement])
// Create the multi-layer point symbol.
let symbol = AGSMultilayerPointSymbol(symbolLayers: [vectorMarker])
// Set the size of our symbol.
symbol.size = 24.0
// Set our symbol as the location display symbol.
mapView.locationDisplay.defaultSymbol = symbol

You can modify the "points" array to get any geometry you'd like.

Regarding animation, there is no built-in animation capabilities with the Runtime as relates to the location display or graphics.  However it is possible to programmatically modify the symbol/geometry to get animation.

You can see some code to animate a graphics overlay graphic in an Esri Community response here:

https://community.esri.com/t5/arcgis-runtime-sdk-for-ios-questions/make-a-pulse-animation-in-agspict...

Let us know if you have more questions!

Mark

[decay]

Thanks Mark.

I did add your code in, and I am not seeing the red polygon on the map.  I still see the blue dot for current position, or nothing if I turn it off with showLocation = false.

[MarkDostal]

When are you setting the symbol on the mapView.locationDisplay?

mapView.locationDisplay.defaultSymbol = symbol

In my test code, I put it in the `viewDidLoad()` method to ensure that the mapView was visible on the screen. 

Mark

[decay]

It's in a function that gets called at as the last line in viewDidLoad()

[decay]

Mark,

The issue appeared to be using the AGSSimulatedLocationDataSource for location updates.  When I turned that off, the red square appeared.  The location indicator is totally different.  Is there any way to change the indicator for a simulated data source?

[MarkDostal · Accepted solution]

That's good (that it's called in `viewDidLoad()`).  Can you check what `autoPanMode`, the location display is in (some modes use different symbols)?  Or you can try setting all the `locationDisplay` symbols:

 mapView.locationDisplay.accuracySymbol = symbol
 mapView.locationDisplay.acquiringSymbol = symbol
 mapView.locationDisplay.headingSymbol = symbol
 mapView.locationDisplay.courseSymbol = symbol

Also, you can try setting the symbol to a basic symbol, to see if the issue is with the multi-layer symbol or not:

mapView.locationDisplay.defaultSymbol = AGSSimpleMarkerSymbol(style: .diamond, color: .green, size: 24.0)

 Mark

[decay]

Setting the courseSymbol property with the AGSSimulatedLocationDataSource did the trick.  Thanks.

Is there any way to coerce an AGSModelSceneSymbol to be used as the location indicator?

[MarkDostal]

Unfortunately, the location display is only available in 2D and the `AGSModelSceneSymbol` is a 3D symbol, so that won't be possible.

If you can get the list of points out from the model, you should be able to create an `AGSPolygon` to display it as in the example above.

Mark