Triangle Custom Layer
This example demonstrates adding a custom layer with CustomLayer using the Mapbox Maps SDK for Android. It includes functions for adding, swapping, and updating custom layers dynamically on the map. The custom layer consists of a triangular shape that can be customized with different colors. The activity initializes the Mapbox map with a custom layer positioned below the standard building layers and uses the ProjectionName.MERCATOR projection to display the triangle correctly on the map.
Users can interact with the custom layer by swapping it on and off the map, updating its properties, and changing its color through options available in the menu. The example uses various classes and methods such as MapboxMap, CameraOptions, CustomLayer, style, and triggerRepaint to manage custom layers and interactions on the map.
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.extension.style.layers.CustomLayer
import com.mapbox.maps.extension.style.layers.addLayerBelow
import com.mapbox.maps.extension.style.layers.customLayer
import com.mapbox.maps.extension.style.layers.properties.generated.ProjectionName
import com.mapbox.maps.extension.style.projection.generated.projection
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
*/
class TriangleCustomLayerActivity : AppCompatActivity() {
private lateinit var mapboxMap: MapboxMap
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.MAPBOX_STREETS) {
+layerAtPosition(
customLayer(
layerId = CUSTOM_LAYER_ID,
host = TriangleCustomLayer()
),
below = "building"
)
// triangle is floating when using default ProjectionName.GLOBE
+projection(ProjectionName.MERCATOR)
}
) {
mapboxMap.setCamera(CAMERA)
initFab()
}
}
private fun addCustomLayer(style: Style) {
style.addLayerBelow(
CustomLayer(CUSTOM_LAYER_ID, TriangleCustomLayer()),
below = "building"
)
binding.fab.setImageResource(R.drawable.ic_layers_clear)
}
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 {
addCustomLayer(style)
}
}
}
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 -> {
TriangleCustomLayer.color = floatArrayOf(
1.0f, 0.0f, 0.0f, 0.5f,
0.0f, 1.0f, 0.0f, 0.5f,
0.0f, 0.0f, 1.0f, 0.5f,
)
true
}
R.id.action_set_color_green -> {
TriangleCustomLayer.color = floatArrayOf(
0.0f, 1.0f, 0.0f, 0.5f,
0.0f, 0.0f, 1.0f, 0.5f,
1.0f, 0.0f, 0.0f, 0.5f,
)
true
}
R.id.action_set_color_blue -> {
TriangleCustomLayer.color = floatArrayOf(
0.0f, 0.0f, 1.0f, 0.5f,
1.0f, 0.0f, 0.0f, 0.5f,
0.0f, 1.0f, 0.0f, 0.5f,
)
true
}
else -> super.onOptionsItemSelected(item)
}
}
companion object {
private const val CUSTOM_LAYER_ID = "customId"
private val CAMERA =
CameraOptions.Builder().center(Point.fromLngLat(20.0, 58.0)).pitch(0.0).zoom(3.0).build()
}
}