How to draw dynamic GeoGJSON Point as a rectangle using Mapbox iOS SDK

Question

I have a map layer that has a remote GeoJSON source. I'm adding it to my Mabpox map using the MGLShapeCollectionFeature and then use the MGLCircleStyleLayer and a MGLSymbolStyleLayer to display the data along with some text.

It works as expected and the points are displayed on the map:

Data

{
  "features": [
    {
      "geometry": {
        "coordinates": [
          -120.644,
          35.238
        ],
        "type": "Point"
      },
      "properties": {
        "altim": 1019.0,
        "cover": "CLR",
        "data": "METAR",
        "dewp": 12.2,
        "fltcat": "VFR",
        "id": "KSBP",
        "obsTime": "2020-05-03T18:56:00Z",
        "prior": "5",
        "rawOb": "KSBP 031856Z 31018KT 10SM CLR 22/12 A3009 RMK AO2 SLP187 T02170122",
        "site": "San Luis Obispo/Ches",
        "slp": 1018.7,
        "temp": 21.7,
        "visib": 10.00,
        "wdir": 310,
        "wspd": 18
      },
      "type": "Feature"
    }
  ],
  "type": "FeatureCollection"
}

Result

Now the question is if it's possible to display the data as a rounded rectangle instead of just a circle. Something like this:

Answer 1

This can be done by using not a single position, but a polygon built from a position array in shape of a rounded rectangle. This rectangle can be filled with a pattern the text you would like to show.

Load fill pattern:

// Set the UIImage to be used for the fill pattern.
let fillPatternImage = UIImage(named: "stripe-pattern")!

// Add the fill pattern image to used by the style layer.
style.setImage(fillPatternImage, forName: "stripe-pattern")

With layer from a vector source (Positions Polygon array defining the rounded rectangle)

// Create a style layer using the vector source.
let layer = MGLFillStyleLayer(identifier: "drone-restrictions-style", source: source)

Add the filling pattern and set the opacity of the pattern:

layer.fillPattern = NSExpression(forConstantValue: "stripe-pattern")
layer.fillOpacity = NSExpression(forConstantValue: 0.5)

Use a separate layer to draw the text over the rounded rectangle.

Please also refer to this Mapbox example