feat: add support for accessibility (#407)

app/src/main/AndroidManifest.xml

@@ -63,6 +63,9 @@
     <activity
         android:name=".CustomControlsActivity"
         android:exported="false"/>
+    <activity
+        android:name=".AccessibilityActivity"
+        android:exported="false"/>
 
     <!-- Used by createComponentActivity() for unit testing -->
     <activity android:name="androidx.activity.ComponentActivity" />

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

@@ -0,0 +1,79 @@
+// Copyright 2023 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 android.os.Bundle
+import android.util.Log
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import com.google.android.gms.maps.model.Marker
+
+private const val TAG = "AccessibilityActivity"
+
+
+class AccessibilityActivity : ComponentActivity() {
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContent {
+            val singaporeState = rememberMarkerState(position = singapore)
+            val cameraPositionState = rememberCameraPositionState {
+                position = defaultCameraPosition
+            }
+            val uiSettings by remember { mutableStateOf(MapUiSettings(compassEnabled = false)) }
+            val mapProperties by remember {
+                mutableStateOf(MapProperties(mapType = MapType.NORMAL))
+            }
+
+            Box(Modifier.fillMaxSize()) {
+                GoogleMap(
+                    // mergeDescendants will remove accessibility from the entire map and content inside.
+                    mergeDescendants = true,
+                    // alternatively, contentDescription will deactivate it for the maps, but not markers.
+                    contentDescription = "",
+                    cameraPositionState = cameraPositionState,
+                    properties = mapProperties,
+                    uiSettings = uiSettings,
+                    onPOIClick = {
+                        Log.d(TAG, "POI clicked: ${it.name}")
+                    }
+                ) {
+                    val markerClick: (Marker) -> Boolean = {
+                        Log.d(TAG, "${it.title} was clicked")
+                        cameraPositionState.projection?.let { projection ->
+                            Log.d(TAG, "The current projection is: $projection")
+                        }
+                        false
+                    }
+
+                    Marker(
+                        // contentDescription overrides title for TalkBack
+                        contentDescription = "Description of the marker",
+                        state = singaporeState,
+                        title = "Marker in Singapore",
+                        onClick = markerClick
+                    )
+                }
+            }
+        }
+    }
+}
+

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

@@ -44,6 +44,7 @@ import androidx.compose.material.Switch
 import androidx.compose.material.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
@@ -85,7 +86,6 @@ class BasicMapActivity : ComponentActivity() {
 
             Box(Modifier.fillMaxSize()) {
                 GoogleMapView(
-                    modifier = Modifier.matchParentSize(),
                     cameraPositionState = cameraPositionState,
                     onMapLoaded = {
                         isMapLoaded = true
@@ -129,7 +129,7 @@ fun GoogleMapView(
 
     var uiSettings by remember { mutableStateOf(MapUiSettings(compassEnabled = false)) }
     var shouldAnimateZoom by remember { mutableStateOf(true) }
-    var ticker by remember { mutableStateOf(0) }
+    var ticker by remember { mutableIntStateOf(0) }
     var mapProperties by remember {
         mutableStateOf(MapProperties(mapType = MapType.NORMAL))
     }
@@ -223,7 +223,8 @@ fun GoogleMapView(
             MapButton(
                 text = "Toggle Map",
                 onClick = { mapVisible = !mapVisible },
-                modifier = Modifier.testTag("toggleMapVisibility"),
+                modifier = Modifier
+                    .testTag("toggleMapVisibility")
             )
         }
         val coroutineScope = rememberCoroutineScope()

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

@@ -127,6 +127,13 @@ class MainActivity : ComponentActivity() {
                             }) {
                             Text(getString(R.string.custom_location_button))
                         }
+                        Spacer(modifier = Modifier.padding(5.dp))
+                        Button(
+                            onClick = {
+                                context.startActivity(Intent(context, AccessibilityActivity::class.java))
+                            }) {
+                            Text(getString(R.string.accessibility_button))
+                        }
                     }
                 }
             }

app/src/main/res/values/strings.xml

@@ -25,4 +25,5 @@
   <string name="scale_bar_activity">Scale Bar</string>
   <string name="street_view">Street View</string>
   <string name="custom_location_button">Custom Location Button</string>
+  <string name="accessibility_button">Accessibility</string>
 </resources>

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

@@ -1,4 +1,4 @@
-// Copyright 2021 Google LLC
+// Copyright 2023 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -36,6 +36,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalInspectionMode
 import androidx.compose.ui.platform.LocalLifecycleOwner
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.viewinterop.AndroidView
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleEventObserver
@@ -50,6 +51,7 @@ import kotlinx.coroutines.awaitCancellation
 /**
  * A compose container for a [MapView].
  *
+ * @param mergeDescendants deactivates the map for accessibility purposes
  * @param modifier Modifier to be applied to the GoogleMap
  * @param cameraPositionState the [CameraPositionState] to be used to control or observe the map's
  * camera state
@@ -72,6 +74,7 @@ import kotlinx.coroutines.awaitCancellation
  */
 @Composable
 public fun GoogleMap(
+    mergeDescendants: Boolean = false,
     modifier: Modifier = Modifier,
     cameraPositionState: CameraPositionState = rememberCameraPositionState(),
     contentDescription: String? = null,
@@ -115,18 +118,16 @@ public fun GoogleMap(
     val currentLocationSource by rememberUpdatedState(locationSource)
     val currentCameraPositionState by rememberUpdatedState(cameraPositionState)
     val currentContentPadding by rememberUpdatedState(contentPadding)
-
-    // If we pass a custom location button, the native one is deactivated.
     val currentUiSettings by rememberUpdatedState(uiSettings)
     val currentMapProperties by rememberUpdatedState(properties)
 
     val parentComposition = rememberCompositionContext()
     val currentContent by rememberUpdatedState(content)
-
     LaunchedEffect(Unit) {
         disposingComposition {
             mapView.newComposition(parentComposition) {
                 MapUpdater(
+                    mergeDescendants = mergeDescendants,
                     contentDescription = contentDescription,
                     cameraPositionState = currentCameraPositionState,
                     clickListeners = mapClickListeners,
@@ -206,13 +207,15 @@ private fun MapView.lifecycleObserver(previousState: MutableState<Lifecycle.Even
                     this.onCreate(Bundle())
                 }
             }
+
             Lifecycle.Event.ON_START -> this.onStart()
             Lifecycle.Event.ON_RESUME -> this.onResume()
             Lifecycle.Event.ON_PAUSE -> this.onPause()
             Lifecycle.Event.ON_STOP -> this.onStop()
             Lifecycle.Event.ON_DESTROY -> {
                 //handled in onDispose
             }
+
             else -> throw IllegalStateException()
         }
         previousState.value = event

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

@@ -15,6 +15,7 @@
 package com.google.maps.android.compose
 
 import android.annotation.SuppressLint
+import android.view.View.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.ComposeNode
@@ -112,6 +113,7 @@ internal val NoPadding = PaddingValues()
 @Suppress("NOTHING_TO_INLINE")
 @Composable
 internal inline fun MapUpdater(
+    mergeDescendants: Boolean = false,
     contentDescription: String?,
     cameraPositionState: CameraPositionState,
     clickListeners: MapClickListeners,
@@ -121,6 +123,10 @@ internal inline fun MapUpdater(
     mapUiSettings: MapUiSettings,
 ) {
     val map = (currentComposer.applier as MapApplier).map
+    val mapView = (currentComposer.applier as MapApplier).mapView
+    if (mergeDescendants) {
+        mapView.importantForAccessibility = IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS
+    }
     val density = LocalDensity.current
     val layoutDirection = LocalLayoutDirection.current
     ComposeNode<MapPropertiesNode, MapApplier>(

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

@@ -133,7 +133,7 @@ public fun rememberMarkerState(
 
 /**
  * A composable for a marker on the map.
- *
+ * @param contentDescription the content description for accessibility purposes
  * @param state the [MarkerState] to be used to control or observe the marker
  * state such as its position and info window
  * @param alpha the alpha (opacity) of the marker
@@ -156,6 +156,7 @@ public fun rememberMarkerState(
 @Composable
 @GoogleMapComposable
 public fun Marker(
+    contentDescription: String? = "",
     state: MarkerState = rememberMarkerState(),
     alpha: Float = 1.0f,
     anchor: Offset = Offset(0.5f, 1.0f),
@@ -175,6 +176,7 @@ public fun Marker(
     onInfoWindowLongClick: (Marker) -> Unit = {},
 ) {
     MarkerImpl(
+        contentDescription = contentDescription,
         state = state,
         alpha = alpha,
         anchor = anchor,
@@ -434,6 +436,7 @@ public fun MarkerInfoWindowContent(
 @Composable
 @GoogleMapComposable
 private fun MarkerImpl(
+    contentDescription: String? = "",
     state: MarkerState = rememberMarkerState(),
     alpha: Float = 1.0f,
     anchor: Offset = Offset(0.5f, 1.0f),
@@ -459,6 +462,7 @@ private fun MarkerImpl(
     ComposeNode<MarkerNode, MapApplier>(
         factory = {
             val marker = mapApplier?.map?.addMarker {
+                contentDescription(contentDescription)
                 alpha(alpha)
                 anchor(anchor.x, anchor.y)
                 draggable(draggable)