Display multiple icon images in a symbol layer

package com.mapbox.maps.testapp.examples
 
import android.graphics.BitmapFactory
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.mapbox.maps.Style
import com.mapbox.maps.extension.style.expressions.dsl.generated.switchCase
import com.mapbox.maps.extension.style.image.image
import com.mapbox.maps.extension.style.layers.generated.symbolLayer
import com.mapbox.maps.extension.style.layers.properties.generated.IconAnchor
import com.mapbox.maps.extension.style.sources.generated.vectorSource
import com.mapbox.maps.extension.style.style
import com.mapbox.maps.testapp.R
import com.mapbox.maps.testapp.databinding.ActivityIconPropertyBinding
 
/**
* Add point data and several images to a style and use the switchCase and
* get expressions to choose which image to display at each point in a SymbolLayer
* based on a data property.
*/
class IconPropertyActivity : AppCompatActivity() {
 
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val binding = ActivityIconPropertyBinding.inflate(layoutInflater)
setContentView(binding.root)
 
binding.mapView.getMapboxMap().loadStyle(
styleExtension = style(Style.OUTDOORS) {
// Add icons from the U.S. National Parks Service to the map's style.
+image(RESTROOMS) {
bitmap(BitmapFactory.decodeResource(resources, R.drawable.nps_restrooms))
}
+image(TRAIL_HEAD) {
bitmap(BitmapFactory.decodeResource(resources, R.drawable.nps_trailhead))
}
+image(PICNIC_AREA) {
bitmap(BitmapFactory.decodeResource(resources, R.drawable.nps_picnic_area))
}
// Access a vector tileset that contains places of interest at Yosemite National Park.
// This tileset was created by uploading NPS shape files to Mapbox Studio.
+vectorSource(SOURCE_ID) {
url(SOURCE_URI)
}
// Create a symbol layer and access the layer contained.
+symbolLayer(LAYER_ID, SOURCE_ID) {
// Access the layer that contains the Point of Interest (POI) data.
// The source layer property is a unique identifier for a layer within a vector tile source.
sourceLayer(SOURCE_LAYER_ID)
// Expression that adds conditions to the source to determine styling.
// `POITYPE` refers to a key in the data source. The values tell us which icon to use from the sprite sheet
iconImage(
switchCase {
eq {
get {
literal(ICON_KEY)
}
literal(KEY_PICNIC_AREA)
}
literal(PICNIC_AREA)
eq {
get {
literal(ICON_KEY)
}
literal(KEY_RESTROOMS)
}
literal(RESTROOMS)
eq {
get {
literal(ICON_KEY)
}
literal(KEY_TRAIL_HEAD)
}
literal(TRAIL_HEAD)
// default case is to return an empty string so no icon will be loaded
literal("")
}
)
iconAllowOverlap(true)
iconAnchor(IconAnchor.BOTTOM)
}
}
)
}
 
companion object {
private const val SOURCE_URI = "mapbox://examples.ciuz0vpc"
private const val SOURCE_LAYER_ID = "Yosemite_POI-38jhes"
private const val RESTROOMS = "restrooms"
private const val TRAIL_HEAD = "trailhead"
private const val PICNIC_AREA = "picnic-area"
private const val KEY_PICNIC_AREA = "Picnic Area"
private const val KEY_RESTROOMS = "Restroom"
private const val KEY_TRAIL_HEAD = "Trailhead"
private const val SOURCE_ID = "source_id"
private const val LAYER_ID = "layer_id"
private const val ICON_KEY = "POITYPE"
}
}