fix: Fix position changing while dragging a marker

kmp-maps/core/src/androidMain/kotlin/com/swmansion/kmpmaps/core/Extensions.kt

@@ -22,7 +22,6 @@ import com.google.maps.android.compose.ComposeMapColorScheme
 import com.google.maps.android.compose.MapProperties as GoogleMapProperties
 import com.google.maps.android.compose.MapType
 import com.google.maps.android.compose.MapUiSettings as GoogleMapUiSettings
-import com.google.maps.android.compose.MarkerState
 import com.google.maps.android.data.geojson.GeoJsonFeature
 import com.google.maps.android.data.geojson.GeoJsonLayer as GoogleGeoJsonLayer
 import com.google.maps.android.data.geojson.GeoJsonLineString
@@ -61,19 +60,18 @@ internal fun GoogleCameraPosition.toCameraPosition() =
     )
 
 /**
- * Converts MapMarker to Google Maps MarkerState.
+ * Converts Coordinates to Google Maps LatLng.
  *
- * @return MarkerState with position coordinates
+ * @return LatLng with latitude and longitude
  */
-internal fun Marker.toGoogleMapsMarkerState() =
-    MarkerState(position = LatLng(coordinates.latitude, coordinates.longitude))
+internal fun Coordinates.toGoogleMapsLatLng() = LatLng(latitude, longitude)
 
 /**
- * Converts Coordinates to Google Maps LatLng.
+ * Converts Google Maps LatLng back to [Coordinates].
  *
- * @return LatLng with latitude and longitude
+ * @return Coordinates with latitude and longitude
  */
-internal fun Coordinates.toGoogleMapsLatLng(): LatLng = LatLng(latitude, longitude)
+internal fun LatLng.toCoordinates() = Coordinates(latitude, longitude)
 
 /**
  * Converts MapTheme to native ComposeMapColorScheme.

kmp-maps/core/src/androidMain/kotlin/com/swmansion/kmpmaps/core/Map.kt

@@ -24,6 +24,7 @@ import com.google.maps.android.compose.MapEffect
 import com.google.maps.android.compose.MapsComposeExperimentalApi
 import com.google.maps.android.compose.Marker
 import com.google.maps.android.compose.MarkerComposable
+import com.google.maps.android.compose.MarkerState
 import com.google.maps.android.compose.Polygon
 import com.google.maps.android.compose.Polyline
 import com.google.maps.android.compose.clustering.Clustering
@@ -46,6 +47,7 @@ public actual fun Map(
     polylines: List<Polyline>,
     onCameraMove: ((CameraPosition) -> Unit)?,
     onMarkerClick: ((Marker) -> Unit)?,
+    onMarkerDragEnd: ((Marker) -> Unit)?,
     onCircleClick: ((Circle) -> Unit)?,
     onPolygonClick: ((Polygon) -> Unit)?,
     onPolylineClick: ((Polyline) -> Unit)?,
@@ -173,11 +175,32 @@ public actual fun Map(
         } else {
             markers.forEach { marker ->
                 key(marker.getId(), marker.contentId) {
+                    val markerState =
+                        remember(marker.getId()) {
+                            MarkerState(marker.coordinates.toGoogleMapsLatLng())
+                        }
+
+                    LaunchedEffect(marker.coordinates) {
+                        val newLatLng = marker.coordinates.toGoogleMapsLatLng()
+                        if (markerState.position != newLatLng) {
+                            markerState.position = newLatLng
+                        }
+                    }
+
                     val content = customMarkerContent[marker.contentId]
 
+                    if (marker.androidMarkerOptions.draggable) {
+                        LaunchedEffect(markerState.isDragging) {
+                            if (!markerState.isDragging) {
+                                marker.coordinates = markerState.position.toCoordinates()
+                                onMarkerDragEnd?.invoke(marker)
+                            }
+                        }
+                    }
+
                     if (content != null) {
                         MarkerComposable(
-                            state = marker.toGoogleMapsMarkerState(),
+                            state = markerState,
                             title = marker.title,
                             anchor = marker.androidMarkerOptions.anchor.toOffset(),
                             draggable = marker.androidMarkerOptions.draggable,
@@ -191,7 +214,7 @@ public actual fun Map(
                         )
                     } else {
                         Marker(
-                            state = marker.toGoogleMapsMarkerState(),
+                            state = markerState,
                             title = marker.title,
                             anchor = marker.androidMarkerOptions.anchor.toOffset(),
                             draggable = marker.androidMarkerOptions.draggable,

kmp-maps/core/src/commonMain/kotlin/com/swmansion/kmpmaps/core/AndroidMapTypes.kt

@@ -41,6 +41,9 @@ public data class AndroidUISettings(
  * @property draggable Whether the marker can be dragged by the user
  * @property snippet Additional text displayed below the title
  * @property zIndex The z-index for layering markers
+ *
+ * Note: In the current Android implementation, draggability is only supported when
+ * [ClusterSettings.enabled] is set to `false`.
  */
 @Serializable
 public data class AndroidMarkerOptions(

kmp-maps/core/src/commonMain/kotlin/com/swmansion/kmpmaps/core/Map.kt

@@ -95,6 +95,7 @@ import androidx.compose.ui.Modifier
  * @param polylines List of polylines to display on the map
  * @param onCameraMove Callback invoked when the map camera position changes due to user interaction
  * @param onMarkerClick Callback invoked when a marker is clicked
+ * @param onMarkerDragEnd Callback invoked when dragging a marker completes (drag operation ends)
  * @param onCircleClick Callback invoked when a circle is clicked
  * @param onPolygonClick Callback invoked when a polygon is clicked
  * @param onPolylineClick Callback invoked when a polyline is clicked
@@ -103,8 +104,8 @@ import androidx.compose.ui.Modifier
  * @param onPOIClick Callback invoked when the user clicks on a Point of Interest
  * @param onMapLoaded Callback invoked when the map has finished loading
  * @param geoJsonLayers List of GeoJSON layers to display on the map
- * @param customMarkerContent Map of content IDs to Composable functions for custom marker content.
- * @param webCustomMarkerContent Map of content IDs to a function returning an HTML string.
+ * @param customMarkerContent Map of content IDs to Composable functions for custom marker content
+ * @param webCustomMarkerContent Map of content IDs to a function returning an HTML string
  */
 @Composable
 public expect fun Map(
@@ -119,6 +120,7 @@ public expect fun Map(
     polylines: List<Polyline> = emptyList(),
     onCameraMove: ((CameraPosition) -> Unit)? = null,
     onMarkerClick: ((Marker) -> Unit)? = null,
+    onMarkerDragEnd: ((Marker) -> Unit)? = null,
     onCircleClick: ((Circle) -> Unit)? = null,
     onPolygonClick: ((Polygon) -> Unit)? = null,
     onPolylineClick: ((Polyline) -> Unit)? = null,

kmp-maps/core/src/commonMain/kotlin/com/swmansion/kmpmaps/core/MapTypes.kt

@@ -79,7 +79,14 @@ public data class MapUISettings(
 /**
  * Represents a marker on the map.
  *
- * @property coordinates The geographical coordinates where the marker should be placed
+ * @property coordinates The geographical coordinates where the marker should be placed.
+ *
+ * Note on Mutability: Although this is a `var` to allow the library to update positions during
+ * dragging, you should treat it as immutable. To move the marker programmatically, pass a new
+ * [Marker] instance to the map.
+ *
+ * Directly mutating this field may not trigger UI updates, especially on iOS.
+ *
  * @property title The title text displayed when the marker is tapped
  * @property androidMarkerOptions Android-specific options for customizing a marker
  * @property iosMarkerOptions iOS-specific options for customizing a marker
@@ -92,7 +99,7 @@ public data class MapUISettings(
 @JsonIgnoreUnknownKeys
 @OptIn(ExperimentalSerializationApi::class)
 public data class Marker(
-    val coordinates: Coordinates,
+    var coordinates: Coordinates,
     val title: String? = "No title was provided",
     val androidMarkerOptions: AndroidMarkerOptions = AndroidMarkerOptions(),
     val iosMarkerOptions: IosMarkerOptions? = null,

kmp-maps/core/src/iosMain/kotlin/com/swmansion/kmpmaps/core/Map.kt

@@ -41,6 +41,7 @@ public actual fun Map(
     polylines: List<Polyline>,
     onCameraMove: ((CameraPosition) -> Unit)?,
     onMarkerClick: ((Marker) -> Unit)?,
+    onMarkerDragEnd: ((Marker) -> Unit)?,
     onCircleClick: ((Circle) -> Unit)?,
     onPolygonClick: ((Polygon) -> Unit)?,
     onPolylineClick: ((Polyline) -> Unit)?,

kmp-maps/core/src/jvmMain/kotlin/com/swmansion/kmpmaps/core/Map.kt

@@ -30,6 +30,7 @@ public actual fun Map(
     polylines: List<Polyline>,
     onCameraMove: ((CameraPosition) -> Unit)?,
     onMarkerClick: ((Marker) -> Unit)?,
+    onMarkerDragEnd: ((Marker) -> Unit)?,
     onCircleClick: ((Circle) -> Unit)?,
     onPolygonClick: ((Polygon) -> Unit)?,
     onPolylineClick: ((Polyline) -> Unit)?,

kmp-maps/google-maps/src/androidMain/kotlin/com/swmansion/kmpmaps/googlemaps/Map.kt

@@ -28,6 +28,7 @@ public actual fun Map(
     polylines: List<Polyline>,
     onCameraMove: ((CameraPosition) -> Unit)?,
     onMarkerClick: ((Marker) -> Unit)?,
+    onMarkerDragEnd: ((Marker) -> Unit)?,
     onCircleClick: ((Circle) -> Unit)?,
     onPolygonClick: ((Polygon) -> Unit)?,
     onPolylineClick: ((Polyline) -> Unit)?,
@@ -51,6 +52,7 @@ public actual fun Map(
         polylines,
         onCameraMove,
         onMarkerClick,
+        onMarkerDragEnd,
         onCircleClick,
         onPolygonClick,
         onPolylineClick,

kmp-maps/google-maps/src/commonMain/kotlin/com/swmansion/kmpmaps/googlemaps/Map.kt

@@ -34,6 +34,7 @@ import com.swmansion.kmpmaps.core.Polyline
  * @param polylines List of polylines to display on the map
  * @param onCameraMove Callback invoked when the map camera position changes due to user interaction
  * @param onMarkerClick Callback invoked when a marker is clicked
+ * @param onMarkerDragEnd Callback invoked when a marker drag operation ends
  * @param onCircleClick Callback invoked when a circle is clicked
  * @param onPolygonClick Callback invoked when a polygon is clicked
  * @param onPolylineClick Callback invoked when a polyline is clicked
@@ -58,6 +59,7 @@ public expect fun Map(
     polylines: List<Polyline> = emptyList(),
     onCameraMove: ((CameraPosition) -> Unit)? = null,
     onMarkerClick: ((Marker) -> Unit)? = null,
+    onMarkerDragEnd: ((Marker) -> Unit)? = null,
     onCircleClick: ((Circle) -> Unit)? = null,
     onPolygonClick: ((Polygon) -> Unit)? = null,
     onPolylineClick: ((Polyline) -> Unit)? = null,

kmp-maps/google-maps/src/iosMain/kotlin/com/swmansion/kmpmaps/googlemaps/Map.kt

@@ -56,6 +56,7 @@ public actual fun Map(
     polylines: List<Polyline>,
     onCameraMove: ((CameraPosition) -> Unit)?,
     onMarkerClick: ((Marker) -> Unit)?,
+    onMarkerDragEnd: ((Marker) -> Unit)?,
     onCircleClick: ((Circle) -> Unit)?,
     onPolygonClick: ((Polygon) -> Unit)?,
     onPolylineClick: ((Polyline) -> Unit)?,

kmp-maps/google-maps/src/jvmMain/kotlin/com/swmansion/kmpmaps/googlemaps/Map.kt

@@ -28,6 +28,7 @@ public actual fun Map(
     polylines: List<Polyline>,
     onCameraMove: ((CameraPosition) -> Unit)?,
     onMarkerClick: ((Marker) -> Unit)?,
+    onMarkerDragEnd: ((Marker) -> Unit)?,
     onCircleClick: ((Circle) -> Unit)?,
     onPolygonClick: ((Polygon) -> Unit)?,
     onPolylineClick: ((Polyline) -> Unit)?,
@@ -51,6 +52,7 @@ public actual fun Map(
         polylines,
         onCameraMove,
         onMarkerClick,
+        onMarkerDragEnd,
         onCircleClick,
         onPolygonClick,
         onPolylineClick,

sample/src/commonMain/kotlin/com/swmansion/kmpmaps/sample/Examples.kt

@@ -49,7 +49,8 @@ val exampleMarkers =
         Marker(
             coordinates = softwareMansionPin,
             title = "Software Mansion",
-            androidMarkerOptions = AndroidMarkerOptions(snippet = "Software house"),
+            androidMarkerOptions =
+                AndroidMarkerOptions(snippet = "Software house", draggable = true),
             contentId = "swmansion_marker",
         ),
         Marker(

sample/src/commonMain/kotlin/com/swmansion/kmpmaps/sample/MapWrapper.kt

@@ -27,14 +27,14 @@ internal data class MapOptions(
     val cameraPosition: CameraPosition =
         CameraPosition(
             coordinates = Coordinates(latitude = 50.0619, longitude = 19.9373),
-            zoom = 10f,
+            zoom = 14f,
         ),
     val showAllComponents: Boolean = true,
     val useGoogleMapsMapView: Boolean = true,
     val showPointGeoJson: Boolean = false,
     val showPolygonGeoJson: Boolean = false,
     val showLineGeoJson: Boolean = false,
-    val clusteringEnabled: Boolean = true,
+    val clusteringEnabled: Boolean = false,
 )
 
 @Composable
@@ -91,7 +91,9 @@ internal fun MapWrapper(
         onPOIClick = { println("POI clicked: $it") },
         onMapLoaded = { println("Map loaded") },
         onMapLongClick = { println("Map long clicked: $it") },
-        onMarkerClick = { marker -> println("Marker clicked: ${marker.title}") },
+        onMarkerClick = { marker ->
+            println("Marker clicked: ${marker.title} ${marker.coordinates}")
+        },
         onMapClick = { coordinates -> println("Map clicked at: $coordinates") },
         geoJsonLayers = geoJsonLayers,
         customMarkerContent = customMarkerContent,
@@ -118,6 +120,7 @@ private fun Map(
     polylines: List<Polyline> = emptyList(),
     onCameraMove: ((CameraPosition) -> Unit)? = null,
     onMarkerClick: ((Marker) -> Unit)? = null,
+    onMarkerDragEnd: ((Marker) -> Unit)? = null,
     onCircleClick: ((Circle) -> Unit)? = null,
     onPolygonClick: ((Polygon) -> Unit)? = null,
     onPolylineClick: ((Polyline) -> Unit)? = null,
@@ -143,6 +146,7 @@ private fun Map(
                 polylines = polylines,
                 onCameraMove = onCameraMove,
                 onMarkerClick = onMarkerClick,
+                onMarkerDragEnd = onMarkerDragEnd,
                 onCircleClick = onCircleClick,
                 onPolygonClick = onPolygonClick,
                 onPolylineClick = onPolylineClick,
@@ -167,6 +171,7 @@ private fun Map(
                 polylines = polylines,
                 onCameraMove = onCameraMove,
                 onMarkerClick = onMarkerClick,
+                onMarkerDragEnd = onMarkerDragEnd,
                 onCircleClick = onCircleClick,
                 onPolygonClick = onPolygonClick,
                 onPolylineClick = onPolylineClick,