feat: add rotation support to cluster item API

maps-app/src/androidTest/java/com/google/maps/android/compose/GoogleMapViewClusteringTests.kt

@@ -0,0 +1,170 @@
+/*
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.maps.android.compose
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.size
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.mutableFloatStateOf
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.unit.dp
+import com.google.android.gms.maps.model.CameraPosition
+import com.google.android.gms.maps.model.LatLng
+import com.google.android.gms.maps.model.Marker
+import com.google.common.truth.Truth.assertThat
+import com.google.maps.android.clustering.ClusterManager
+import com.google.maps.android.compose.clustering.Clustering
+import com.google.maps.android.compose.clustering.ClusteringMarkerProperties
+import com.google.maps.android.compose.markerexamples.MyItem
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.TimeUnit
+
+class GoogleMapViewClusteringTests {
+    @get:Rule
+    val composeTestRule = createComposeRule()
+
+    private val startingPosition = LatLng(1.23, 4.56)
+    private lateinit var cameraPositionState: CameraPositionState
+
+    @Before
+    fun setUp() {
+        cameraPositionState = CameraPositionState(
+            position = CameraPosition.fromLatLngZoom(startingPosition, 12f)
+        )
+    }
+
+    private fun initMapAndGetMarker(
+        clusterManagerHolder: Array<ClusterManager<MyItem>?>,
+        content: @Composable () -> Unit
+    ): Marker {
+        check(hasValidApiKey) { "Maps API key not specified" }
+        val countDownLatch = CountDownLatch(1)
+
+        composeTestRule.setContent {
+            GoogleMapView(
+                modifier = Modifier.fillMaxSize(),
+                cameraPositionState = cameraPositionState,
+                onMapLoaded = {
+                    countDownLatch.countDown()
+                }
+            ) {
+                content()
+            }
+        }
+
+        val mapLoaded = countDownLatch.await(MAP_LOAD_TIMEOUT_SECONDS, TimeUnit.SECONDS)
+        assertThat(mapLoaded).isTrue()
+
+        composeTestRule.waitUntil(timeoutMillis = 10_000) {
+            composeTestRule.runOnUiThread {
+                val cm = clusterManagerHolder[0]
+                cm != null && cm.markerCollection.markers.isNotEmpty()
+            }
+        }
+
+        return composeTestRule.runOnUiThread {
+            clusterManagerHolder[0]!!.markerCollection.markers.first()
+        }
+    }
+
+    @OptIn(MapsComposeExperimentalApi::class)
+    @Test
+    fun testClusteringParametersRotationUpdatesMarker() {
+        val rotationState = mutableFloatStateOf(45f)
+        val clusterManagerHolder = arrayOfNulls<ClusterManager<MyItem>>(1)
+        val items = listOf(MyItem(startingPosition, "Item", "Snippet", 0f))
+
+        val marker = initMapAndGetMarker(clusterManagerHolder) {
+            Clustering(
+                items = items,
+                clusterItemContentRotation = rotationState.floatValue,
+                clusterItemContentAnchor = Offset(0.5f, 0.5f),
+                clusterItemContent = {
+                    Surface(modifier = Modifier.size(20.dp)) {
+                        Text("X")
+                    }
+                },
+                onClusterManager = { cm ->
+                    clusterManagerHolder[0] = cm
+                }
+            )
+        }
+
+        composeTestRule.runOnUiThread {
+            assertThat(marker.rotation).isEqualTo(45f)
+        }
+
+        rotationState.floatValue = 180f
+        composeTestRule.waitForIdle()
+        composeTestRule.waitUntil(timeoutMillis = 5_000) {
+            composeTestRule.runOnUiThread { marker.rotation == 180f }
+        }
+
+        composeTestRule.runOnUiThread {
+            assertThat(marker.rotation).isEqualTo(180f)
+        }
+    }
+
+    @OptIn(MapsComposeExperimentalApi::class)
+    @Test
+    fun testClusteringMarkerPropertiesRotationUpdatesMarker() {
+        val rotationState = mutableFloatStateOf(45f)
+        val clusterManagerHolder = arrayOfNulls<ClusterManager<MyItem>>(1)
+        val items = listOf(MyItem(startingPosition, "Item", "Snippet", 0f))
+
+        val marker = initMapAndGetMarker(clusterManagerHolder) {
+            Clustering(
+                items = items,
+                clusterItemContentAnchor = Offset(0.5f, 0.5f),
+                clusterItemContent = {
+                    ClusteringMarkerProperties(
+                        rotation = rotationState.floatValue,
+                        anchor = Offset(0.5f, 0.5f)
+                    )
+                    Surface(modifier = Modifier.size(20.dp)) {
+                        Text("X")
+                    }
+                },
+                onClusterManager = { cm ->
+                    clusterManagerHolder[0] = cm
+                }
+            )
+        }
+
+        composeTestRule.runOnUiThread {
+            assertThat(marker.rotation).isEqualTo(45f)
+        }
+
+        rotationState.floatValue = 180f
+        composeTestRule.waitForIdle()
+        composeTestRule.waitUntil(timeoutMillis = 5_000) {
+            composeTestRule.runOnUiThread { marker.rotation == 180f }
+        }
+
+        composeTestRule.runOnUiThread {
+            assertThat(marker.rotation).isEqualTo(180f)
+        }
+    }
+}

maps-app/src/main/AndroidManifest.xml

@@ -70,6 +70,9 @@
         <activity
             android:name=".markerexamples.MarkerClusteringActivity"
             android:exported="true" />
+        <activity
+            android:name=".markerexamples.MarkerClusteringRotationActivity"
+            android:exported="true" />
         <activity
             android:name=".LocationTrackingActivity"
             android:exported="true" />

maps-app/src/main/java/com/google/maps/android/compose/Demo.kt

@@ -44,6 +44,7 @@ import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import com.google.maps.android.compose.markerexamples.AdvancedMarkersActivity
 import com.google.maps.android.compose.markerexamples.MarkerClusteringActivity
+import com.google.maps.android.compose.markerexamples.MarkerClusteringRotationActivity
 import com.google.maps.android.compose.markerexamples.draggablemarkerscollectionwithpolygon.DraggableMarkersCollectionWithPolygonActivity
 import com.google.maps.android.compose.markerexamples.markerdragevents.MarkerDragEventsActivity
 import com.google.maps.android.compose.markerexamples.markerscollection.MarkersCollectionActivity
@@ -142,6 +143,11 @@ sealed class ActivityGroup(
                 R.string.marker_clustering_activity_description,
                 MarkerClusteringActivity::class
             ),
+            Activity(
+                R.string.marker_clustering_rotation_activity,
+                R.string.marker_clustering_rotation_activity_description,
+                MarkerClusteringRotationActivity::class
+            ),
             Activity(
                 R.string.marker_drag_events_activity,
                 R.string.marker_drag_events_activity_description,