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Find places

Learn how to search for places of interest, such as hotels, cafes, and gas stations using the geocoding service.

find places

Geocoding is the process of transforming an address or place name to a location on the earth's surface. A geocoding service allows you to quickly find places that meet specific criteria.

In this tutorial, you use a picklist in the user interface to select a category of places, for example, coffee shops or gas stations. You locate all the places that match this category by accessing a geocoding service. The places are displayed on the map so that you can click on them to get further information.

Prerequisites

Before starting this tutorial, you need the following:

  1. An ArcGIS Location Platform or ArcGIS Online account.

  2. A development and deployment environment that meets the system requirements.

  3. An IDE for Android development in Kotlin.

Set up authentication

To access the secure ArcGIS location services used in this tutorial, you must implement API key authentication or user authentication using an ArcGIS Location Platform or an ArcGIS Online account.

Create a new API key access token with privileges to access the secure resources used in this tutorial.

  1. Complete the Create an API key tutorial and create an API key with the following privilege(s):

    • Privileges
      • Location services > Basemaps
      • Location services > Geocoding
  2. Copy and paste the API key access token into a safe location. It will be used in a later step.

Develop or download

You have two options for completing this tutorial:

  1. Option 1: Develop the code or
  2. Option 2: Download the completed solution

Option 1: Develop the code

Open an Android Studio project

  1. Open the project you created by completing the Display a map tutorial.

  2. Continue with the following instructions to search for places of interest, such as hotels, cafes, and gas stations using the ArcGIS Geocoding service.

  3. Modify the old project for use in this new tutorial.

    1. In libs.versions.toml, add a [libraries] entry for the dependency. In the module-level build.gradle.kts (app), add the dependency for the lifecycle view model.

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      1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 [libraries] arcgis-maps-kotlin = { group = "com.esri", name = "arcgis-maps-kotlin", version.ref = "arcgisMapsKotlin" } arcgis-maps-kotlin-toolkit-bom = { group = "com.esri", name = "arcgis-maps-kotlin-toolkit-bom", version.ref = "arcgisMapsKotlin" } arcgis-maps-kotlin-toolkit-geoview-compose = { group = "com.esri", name = "arcgis-maps-kotlin-toolkit-geoview-compose" } arcgis-maps-kotlin-toolkit-authentication = { group = "com.esri", name = "arcgis-maps-kotlin-toolkit-authentication" } androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" } junit = { group = "junit", name = "junit", version.ref = "junit" } androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" } androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" } androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycleRuntimeKtx" } androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "activityCompose" }  androidx-lifecycle-viewmodel-compose = { group = "androidx.lifecycle", name = "lifecycle-viewmodel-compose", version.ref = "lifecycleRuntimeKtx" } 
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Set developer credentials

If you implemented API key authentication in the Display a map tutorial, the API key access token will only have the Basemaps privilege. The Find places tutorial requires the Geocoding privilege to find places using the LocatorTask. To create an API Key access token that has the Basemaps and Geocoding privileges, see the Set up authentication step and then follow the instructions below.

  1. In the Android view of Android Studio, open app > kotlin+java > com.example.app > MainActivity.

  2. In the onCreate() lifecycle method of the MainActivity class, set the ArcGISEnvironment.apiKey​ property by calling ApiKey.create(). Pass in your API key access token as a string and don't forget the double quotes. Do this before the setContent block.

    MainActivity.kt
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    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30  override fun onCreate(savedInstanceState: Bundle?) {  super.onCreate(savedInstanceState)   ArcGISEnvironment.apiKey = ApiKey.create("YOUR_ACCESS_TOKEN") 

Best Practice: The access token is stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

Add import statements and some Compose variables

  1. In the Android view, open app > kotlin+java > com.example.app > screens > MainScreen.kt. Replace the import statements with the imports needed for this tutorial.

    MainScreen.kt
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    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332  @file:OptIn(ExperimentalMaterial3Api::class)  package com.example.app.screens  import android.app.Application import android.util.Log import androidx.compose.foundation.layout.PaddingValues import androidx.compose.foundation.layout.fillMaxSize import androidx.compose.foundation.layout.height import androidx.compose.foundation.layout.padding import androidx.compose.foundation.layout.widthIn import androidx.compose.foundation.layout.wrapContentSize import androidx.compose.foundation.lazy.LazyColumn import androidx.compose.material.icons.Icons import androidx.compose.material.icons.filled.MoreVert import androidx.compose.material3.DropdownMenu import androidx.compose.material3.DropdownMenuItem import androidx.compose.material3.ExperimentalMaterial3Api import androidx.compose.material3.Icon import androidx.compose.material3.IconButton import androidx.compose.material3.MaterialTheme import androidx.compose.material3.Scaffold import androidx.compose.material3.Text import androidx.compose.material3.TopAppBar import androidx.compose.runtime.Composable import androidx.compose.runtime.collectAsState import androidx.compose.runtime.getValue import androidx.compose.runtime.mutableStateOf import androidx.compose.runtime.remember import androidx.compose.runtime.setValue import androidx.compose.ui.Modifier import androidx.compose.ui.res.stringResource import androidx.compose.ui.text.font.FontStyle import androidx.compose.ui.text.style.TextAlign import androidx.compose.ui.unit.dp import androidx.lifecycle.AndroidViewModel import androidx.lifecycle.ViewModel import androidx.lifecycle.viewModelScope import androidx.lifecycle.viewmodel.compose.viewModel import com.arcgismaps.Color import com.arcgismaps.geometry.Envelope import com.arcgismaps.geometry.Point import com.arcgismaps.geometry.SpatialReference import com.arcgismaps.mapping.ArcGISMap import com.arcgismaps.mapping.BasemapStyle import com.arcgismaps.mapping.GeoElement import com.arcgismaps.mapping.Viewpoint import com.arcgismaps.mapping.symbology.SimpleLineSymbol import com.arcgismaps.mapping.symbology.SimpleLineSymbolStyle import com.arcgismaps.mapping.symbology.SimpleMarkerSymbol import com.arcgismaps.mapping.symbology.SimpleMarkerSymbolStyle import com.arcgismaps.mapping.view.Graphic import com.arcgismaps.mapping.view.GraphicsOverlay import com.arcgismaps.mapping.view.SingleTapConfirmedEvent import com.arcgismaps.tasks.geocode.GeocodeParameters import com.arcgismaps.tasks.geocode.LocatorTask import com.arcgismaps.toolkit.geoviewcompose.MapView import com.arcgismaps.toolkit.geoviewcompose.MapViewProxy import com.example.app.R import kotlinx.coroutines.Job import kotlinx.coroutines.flow.MutableStateFlow import kotlinx.coroutines.flow.StateFlow import kotlinx.coroutines.flow.asStateFlow import kotlinx.coroutines.launch 

Create a view model

Modern app architecture uses a map view model to hold the business logic and the mutable state of your app.

  1. In Android Studio: in the Android view, open app > kotlin+java > com.example.app > screens > MainScreen.kt, create a map view model that extends ViewModel.

    MainScreen.kt
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  2. In the MainScreen composable, delete the entire function body. Leave just the function declaration as shown below. Then delete the top-level code for creating a map that is part of the Display a map tutorial. In this tutorial, you will create the map within the view model.

    MainScreen.kt
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    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 @Composable fun MainScreen() {  } 
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    MainScreen.kt
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    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 fun createMap(): ArcGISMap {   return ArcGISMap(BasemapStyle.ArcGISTopographic).apply {   initialViewpoint = Viewpoint(  latitude = 34.0270,  longitude = -118.8050,   scale = 72000.0   )   }  }
  3. In the view model, create a map from a BasemapStyle and center the ArcGISMap.initialViewpoint on downtown Santa Monica, CA. Then create a MapViewProxy, which is defined in the ArcGIS Maps SDK for Kotlin Toolkit.

    MapViewModel class
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  4. Create a GraphicsOverlay to display graphics that represent places of the same category, such as coffee shops.

    Then create other map view model properties as follows:

    • The current extent visible on the map view.
    • The location on the map where the user taps to obtain further information about the place represented by a graphic.
    • The selected geoelement, which is the closest geoelement to the tap location. (A graphic is a type of GeoElement.)
    • The current coroutine Job, so the job can be cancelled before launching a new coroutine.
    MapViewModel class
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    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 class MapViewModel() : ViewModel() {   // Create a map using the basemap style ArcGISTopographic.  val map = ArcGISMap(BasemapStyle.ArcGISTopographic).apply {  initialViewpoint = Viewpoint(  center = Point(  x = -118.477324,  y = 33.999390,  spatialReference = SpatialReference.wgs84()  ),  scale = 72_000.0  )  }  val mapViewProxy = MapViewProxy()   val graphicsOverlay = GraphicsOverlay()  // The current extent visible in the map view.  lateinit var geoViewExtent: Envelope   // The location on the map that the user tapped to obtain further information. (A graphic is a type of GeoElement).  private val _tapLocation = MutableStateFlow<Point?>(null)  val tapLocation: StateFlow<Point?> = _tapLocation.asStateFlow()   // The geoelement closest to the location that the user tapped.  private val _selectedGeoElement = MutableStateFlow<GeoElement?>(null)  val selectedGeoElement: StateFlow<GeoElement?> = _selectedGeoElement.asStateFlow()   private var currentIdentifyJob: Job? = null  } 
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Set up the LocatorTask

A locator task is used to search for places using a geocoding service. Results from this search contain the place location and additional information (attributes). Create the locator task along with any variables and methods needed to perform the search and display the results.

  1. In the view model, create a LocatorTask property named locator based on the Geocoding service.

    MapViewModel class
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  2. To support the geocode operation, create an enum named Category. It should have two properties: a String named "label" and a Color named "color". Each category is searched using its label and is distinguished on the map using its associated color.

    MapViewModel class
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    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332  enum class Category(val label: String, val color: Color) {  // CoffeeShop color is brown.  CoffeeShop(label = "Coffee shop", color = Color.fromRgba(r =150, g = 75, b= 0, a = 255)),  // GasStation color is orange.  GasStation(label = "Gas station", color = Color.fromRgba(r = 255, g = 165, b = 0, a =255)),  // Food color is purple.  Food(label = "Food", color = Color.fromRgba(r = 160, g = 32, b = 240, a = 255)),  // Hotel color is blue.  Hotel(label = "Hotel", color = Color.fromRgba(r = 0, g = 0, b = 255, a = 255)),  ParksOutdoors(label = "Parks and Outdoors", Color.green)  } 
  3. Create a suspend function called findPlaces() to perform the geocode search operation. The method takes a parameter of type Category that you created in the previous step to indicate which category of places to search for.

    MapViewModel class
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  4. Clear the previous results by removing all graphics from the graphics overlay. Create and configure new GeocodeParameters. Populate them with the searchArea parameter (the current map view extent) and the result attribute names.

    MapViewModel class
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    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332  suspend fun findPlaces(category: Category) {   graphicsOverlay.graphics.clear()   val geocodeParameters = GeocodeParameters().apply {  searchArea = geoViewExtent  resultAttributeNames.addAll(listOf("Place_addr", "PlaceName"))  }   } 
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  5. Perform the search query using geocode(). Pass in the category's label and the geocode parameters.

    MapViewModel class
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  6. Create graphics for each of the results and add them to the graphics overlay.

    MapViewModel class
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Identify the closest geoelement to the user's tap location

An identify operation can be used to get information about a geoelement (such as a graphic) at a location where the user has tapped on the map.

  1. Create a function called identify() that takes a SingleTapConfirmedEvent . In the function, first cancel the current identify job. Then launch a new coroutine and call MapViewProxy.identify() to identify the closest graphic(s) at the tap location.

    MapViewModel class
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Add functions to clear the selected geoelement and log errors

  1. Add a function that clears the currently selected geoelement. Then add a function to log errors.

    MapViewModel class
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Add a Scaffold with a top bar and a dropdown menu

The MainScreen composable needs some variables to hold state for a dropdown menu, a view model, and the currently selected geoelement. It also needs a Scaffold composable to display a dropdown menu, the map view, and a callout.

  1. In the MainScreen composable function add the following:

    • A mutable state boolean to hold whether a dropdown menu, which you'll create in a later step, is expanded.
    • An instance of your MapViewModel class, using the Jetpack Compose viewModel() function.
    • A selectedGeoElement variable that collects the mapViewModel.selectedGeoElement, which was defined as a StateFlow<GeoElement>.
    MainScreen()
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  2. Add a Scaffold that has a top bar. Add an empty content lambda to the Scaffold. That lambda is where you will add MapView in a later step.

    MainScreen()
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  3. Add an actions lambda as a parameter to the TopAppBar. The lambda will first display a More options icon (the three vertical dots), which the user taps to display a dropdown menu of place categories.

    MainScreen()
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  4. The actions lambda then defines a DropdownMenu that has a DropdownMenuItem for each of the categories you created in the map view model.

    MainScreen()
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Add MapView to display the map and interact with the map view model

Add the MapView composable and pass the parameters that do the following:

  • Display the current extent of the map when the extent (visible area) changes.

  • Define a MapViewProxy

  • Attach the graphics overlay to display the graphics that represent places matching the category selected in the dropdown menu.

  • Call the identify() function when the user taps on the map. You created this function in the map view model.

    MapView()
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Define CalloutContent to display name and address for the found place

When a user taps on a graphic, a callout displays showing the name and address of the geoelement closest to the tapped location on the map.

  1. Define a composable function named CalloutContent that displays the name of the place in larger font size and the address of the place in a smaller size.

    CalloutContent()
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Display information for the found place

The MapView needs one more parameter so the callout content displays on top of the map view.

  1. Go back to MapView in your code and add the content parameter, which is a lambda that calls the Callout composable defined in the ArcGIS Maps SDK for Kotlin Toolkit. The Callout function has its own content lambda parameter, which in turn calls your CalloutContent function with the attributes (Place_addr, PlaceName) you specified in the map view model .

    MapView()
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  2. Click Run > Run > app to run the app.

When the app opens, tap the More options icon in the upper right and select a place category. Then tap one of the places and see its name and address. If you zoom or pan to another area, tap the More options icon again and select a category to display places in the new extent.

Alternatively, you can download the tutorial solution, as follows.

Option 2: Download the solution

  1. Click the Download solution link in the right-hand side of this page.

  2. Unzip the file to a location on your machine.

  3. Run Android Studio.

  4. Go to File > Open.... Navigate to the solution folder and click Open.

    On Windows: If you are in the Welcome to Android Studio dialog, click Open and navigate to the solution folder. Then click Open.

Since the downloaded solution does not contain authentication credentials, you must add the developer credentials that you created in the Set up authentication section.

Set developer credentials in the solution

To allow your app users to access ArcGIS location services, use the developer credentials that you created in the Set up authentication step to authenticate requests for resources.

  1. In the Android view of Android Studio, open app > kotlin+java > com.example.app > MainActivity. Set the AuthenticationMode to .API_KEY.

    MainActivity.kt
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  2. Set the apiKey property with your API key access token.

    MainActivity.kt
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Best Practice: The access token is stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

Run the app

Click Run > Run > app to run the app.

When the app opens, tap the More options icon in the upper right and select a place category. Then tap one of the places and see its name and address. If you zoom or pan to another area, tap the More options icon again and select a category to display places in the new extent.

What's next?

Learn how to use additional API features, ArcGIS location services, and ArcGIS tools in these tutorials:

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