Native Custom Layer
This example demonstrates the Custom Layer API in the Mapbox Maps SDK for Android by implementing custom layers and painting them with different colors.
The code below instantiates a map containing a custom layer with a specific layerId and provides options to interact with the custom layer, such as swapping its position, updating the layer appearance, and changing the color dynamically. Users can trigger layer updates, set the color to red, green, or blue using corresponding menu options, and swap the custom layer position between the middle and bottom slots using a floating action button.
This example code is part of the Maps SDK for Android Examples App, a working Android project available on GitHub. Android developers are encouraged to run the examples app locally to interact with this example in an emulator and explore other features of the Maps SDK.
See our Run the Maps SDK for Android Examples App tutorial for step-by-step instructions.
package com.mapbox.maps.testapp.examples.customlayer
import android.os.Bundle
import android.view.Menu
import android.view.MenuItem
import androidx.appcompat.app.AppCompatActivity
import com.mapbox.geojson.Point
import com.mapbox.maps.*
import com.mapbox.maps.dsl.cameraOptions
import com.mapbox.maps.extension.style.layers.CustomLayer
import com.mapbox.maps.extension.style.layers.addLayer
import com.mapbox.maps.extension.style.layers.customLayer
import com.mapbox.maps.extension.style.style
import com.mapbox.maps.testapp.R
import com.mapbox.maps.testapp.databinding.ActivityCustomLayerBinding
/**
* Test activity showcasing the Custom Layer API where [CustomLayerHost] is implemented in C++.
*
* Additionally we make use of `slot` here initially placing custom layer in the "middle"
* and placing it in the "bottom" when turning it on / off.
*/
class NativeCustomLayerActivity : AppCompatActivity() {
private lateinit var mapboxMap: MapboxMap
private val nativeCustomLayer = NativeExampleCustomLayer()
private lateinit var binding: ActivityCustomLayerBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityCustomLayerBinding.inflate(layoutInflater)
setContentView(binding.root)
mapboxMap = binding.mapView.mapboxMap
mapboxMap.loadStyle(
style(Style.STANDARD) {
+customLayer(
layerId = CUSTOM_LAYER_ID,
host = nativeCustomLayer
) {
slot("middle")
}
}
) {
mapboxMap.setCamera(
cameraOptions {
center(Point.fromLngLat(116.39053, 39.91448))
pitch(0.0)
bearing(0.0)
zoom(10.0)
}
)
initFab()
}
}
private fun initFab() {
binding.fab.setOnClickListener {
swapCustomLayer()
}
}
private fun swapCustomLayer() {
mapboxMap.style?.let { style ->
if (style.styleLayerExists(CUSTOM_LAYER_ID)) {
style.removeStyleLayer(CUSTOM_LAYER_ID)
binding.fab.setImageResource(R.drawable.ic_layers)
} else {
style.addLayer(
CustomLayer(CUSTOM_LAYER_ID, nativeCustomLayer).apply { slot("bottom") },
)
binding.fab.setImageResource(R.drawable.ic_layers_clear)
}
}
}
private fun updateLayer() {
mapboxMap.triggerRepaint()
}
override fun onCreateOptionsMenu(menu: Menu): Boolean {
menuInflater.inflate(R.menu.menu_custom_layer, menu)
return true
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
return when (item.itemId) {
R.id.action_update_layer -> {
updateLayer()
true
}
R.id.action_set_color_red -> {
nativeCustomLayer.setColor(1.0f, 0.0f, 0.0f, 1.0f)
true
}
R.id.action_set_color_green -> {
nativeCustomLayer.setColor(0.0f, 1.0f, 0.0f, 1.0f)
true
}
R.id.action_set_color_blue -> {
nativeCustomLayer.setColor(0.0f, 0.0f, 1.0f, 1.0f)
true
}
else -> super.onOptionsItemSelected(item)
}
}
companion object {
private const val CUSTOM_LAYER_ID = "customId"
}
}