Add the android-maps-utils library and use the Cluster functionality to display a nice item amount when the markers are too close.

app/build.gradle

@@ -66,6 +66,7 @@ dependencies {
     implementation 'com.google.code.gson:gson:2.8.5'
     implementation 'com.google.android.material:material:1.0.0'
     implementation 'com.google.android.gms:play-services-maps:16.0.0'
+    implementation 'com.google.maps.android:android-maps-utils:0.5+'
     // AAC Lifecycle
     implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"
     kapt "androidx.lifecycle:lifecycle-compiler:$lifecycle_version"

app/src/main/java/cy/agorise/bitsybitshareswallet/database/entities/Merchant.kt

@@ -3,6 +3,8 @@ package cy.agorise.bitsybitshareswallet.database.entities
 import androidx.room.ColumnInfo
 import androidx.room.Entity
 import androidx.room.PrimaryKey
+import com.google.android.gms.maps.model.LatLng
+import com.google.maps.android.clustering.ClusterItem
 
 @Entity(tableName = "merchants")
 data class Merchant(
@@ -10,9 +12,22 @@ data class Merchant(
     @ColumnInfo(name = "id") val _id: String,
     @ColumnInfo(name = "name") val name: String,
     @ColumnInfo(name = "address") val address: String?,
-    @ColumnInfo(name = "lat") val lat: Float,
-    @ColumnInfo(name = "lon") val lon: Float,
+    @ColumnInfo(name = "lat") val lat: Double,
+    @ColumnInfo(name = "lon") val lon: Double,
     @ColumnInfo(name = "phone") val phone: String?,
     @ColumnInfo(name = "telegram") val telegram: String?,
     @ColumnInfo(name = "website") val website: String?
-)
+) : ClusterItem {
+    override fun getSnippet(): String {
+        return address ?: ""
+    }
+
+    override fun getTitle(): String {
+        return name
+    }
+
+    override fun getPosition(): LatLng {
+        return LatLng(lat, lon)
+    }
+
+}

app/src/main/java/cy/agorise/bitsybitshareswallet/fragments/MerchantsFragment.kt

@@ -21,13 +21,13 @@ import retrofit2.Call
 import retrofit2.Response
 import retrofit2.Retrofit
 import retrofit2.converter.gson.GsonConverterFactory
-import java.io.IOException
 import android.graphics.Bitmap
 import android.graphics.Canvas
 import android.graphics.drawable.Drawable
 import android.preference.PreferenceManager
 import androidx.core.content.ContextCompat
 import com.google.android.gms.maps.model.*
+import com.google.maps.android.clustering.ClusterManager
 import cy.agorise.bitsybitshareswallet.database.entities.Merchant
 import cy.agorise.bitsybitshareswallet.utils.Constants
 import cy.agorise.bitsybitshareswallet.utils.toast
@@ -44,7 +44,7 @@ class MerchantsFragment : Fragment(), OnMapReadyCallback, retrofit2.Callback<Fea
 
     private lateinit var mMap: GoogleMap
 
-    private var merchants: List<Merchant>? = null
+    private var mClusterManager: ClusterManager<Merchant>? = null
 
     private lateinit var merchantIcon: BitmapDescriptor
 
@@ -107,6 +107,13 @@ class MerchantsFragment : Fragment(), OnMapReadyCallback, retrofit2.Callback<Fea
 
         verifyLocationPermission()
 
+        // Setup clusters to group markers when possible
+        mClusterManager = ClusterManager(context, mMap)
+
+        // Point the map's listeners at the listeners implemented by the cluster manager.
+        mMap.setOnCameraIdleListener(mClusterManager)
+        mMap.setOnMarkerClickListener(mClusterManager)
+
         val gson = GsonBuilder()
             .setLenient()
             .create()
@@ -142,26 +149,14 @@ class MerchantsFragment : Fragment(), OnMapReadyCallback, retrofit2.Callback<Fea
     override fun onResponse(call: Call<FeathersResponse<Merchant>>, response: Response<FeathersResponse<Merchant>>) {
         if (response.isSuccessful) {
             val res: FeathersResponse<Merchant>? = response.body()
-            merchants = res!!.data
-            for (mer in merchants!!) {
-                val location = LatLng(mer.lat.toDouble(), mer.lon.toDouble())
-                mMap.addMarker(
-                    MarkerOptions().position(location).title(mer.name).snippet(mer.address).icon(merchantIcon)
-                )
-            }
+            val merchants = res?.data ?: return
+            mClusterManager?.addItems(merchants)
         } else {
-            try {
-                Log.e("error_bitsy", response.errorBody()?.string())
-            } catch (e: IOException) {
-                e.printStackTrace()
-            }
-
+            Log.e("error_bitsy", response.errorBody()?.string())
         }
     }
 
-    override fun onFailure(call: Call<FeathersResponse<Merchant>>, t: Throwable) {
-
-    }
+    override fun onFailure(call: Call<FeathersResponse<Merchant>>, t: Throwable) { /* Do nothing */ }
 
     private fun getMarkerIconFromDrawable(drawable: Drawable): BitmapDescriptor {
         val canvas = Canvas()