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9-patch image

Additional Developer Resources
Add 9-patch image to the style.
Android Examples App Available

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.

NinePatchImageActivity.kt
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package com.mapbox.maps.testapp.examples

import android.graphics.BitmapFactory
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.mapbox.geojson.Feature
import com.mapbox.geojson.Point
import com.mapbox.maps.CameraOptions
import com.mapbox.maps.MapView
import com.mapbox.maps.Style
import com.mapbox.maps.extension.style.image.image9Patch
import com.mapbox.maps.extension.style.layers.generated.SymbolLayer
import com.mapbox.maps.extension.style.layers.generated.symbolLayer
import com.mapbox.maps.extension.style.layers.getLayer
import com.mapbox.maps.extension.style.layers.properties.generated.IconTextFit
import com.mapbox.maps.extension.style.sources.generated.geoJsonSource
import com.mapbox.maps.extension.style.style
import com.mapbox.maps.testapp.R

/**
 * Example showcasing of adding 9-patch image to style
 * and demonstrating how it works when stretching image.
 */
class NinePatchImageActivity : AppCompatActivity() {

  private var appendTextCounter = 1
  private lateinit var style: Style
  private lateinit var mapView: MapView
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    mapView = MapView(this)
    setContentView(mapView)
    mapView.mapboxMap.loadStyle(
      styleExtension = style(Style.STANDARD) {
        +image9Patch(
          NINE_PATCH_ID,
          BitmapFactory.decodeResource(resources, R.drawable.blue_round_nine)
        )
        +geoJsonSource(SOURCE_ID) {
          feature(Feature.fromGeometry(CENTER))
        }
        +symbolLayer(LAYER_ID, SOURCE_ID) {
          iconImage(NINE_PATCH_ID)
          // make sure we stretch image both in X and Y
          iconTextFit(IconTextFit.BOTH)
          iconTextFitPadding(listOf(5.0, 5.0, 5.0, 5.0))
          textField(TEXT_BASE)
        }
      }
    ) {
      style = it
      updateIconText()
    }
    mapView.mapboxMap.setCamera(
      CameraOptions.Builder()
        .center(CENTER)
        .zoom(ZOOM)
        .build()
    )
  }

  private val runnable = {
    if (style.isValid()) {
      val layer = (style.getLayer(LAYER_ID) as SymbolLayer)
      layer.textField("${layer.textField?.getTextAsString()} $TEXT_BASE")
      appendTextCounter++
      if (appendTextCounter.rem(3) == 0) {
        layer.textField("${layer.textField?.getTextAsString()}\n")
      }
      updateIconText()
    }
  }

  // start appending text in a loop, stretching icon in both X and Y
  private fun updateIconText() {
    mapView.postDelayed(
      runnable,
      TEXT_UPDATE_TIME_MS
    )
  }

  override fun onStop() {
    super.onStop()
    mapView.removeCallbacks(runnable)
  }
  companion object {
    private const val NINE_PATCH_ID = "red"
    private const val SOURCE_ID = "source_id"
    private const val LAYER_ID = "layer_id"
    private val CENTER = Point.fromLngLat(12.554729, 55.70651)
    private const val ZOOM = 9.0
    private const val TEXT_BASE = "Hi!"
    private const val TEXT_UPDATE_TIME_MS = 1500L
  }
}
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