Fixed Camera Switching Bug (#9671)

Fixed camera switching issue where phones with multiple back cameras could not correctly switch to some other chosen camera. Fixed by specifying a camera via its CameraInfo instead of its direction.

Fixes flutter/flutter#164963

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Author: jesswrd

packages/camera/camera_android_camerax/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.6.19+1
+
+* Fixes incorrect camera switching by selecting a camera via its CameraInfo.
+
 ## 0.6.19
 
 * Changes target rotation of captured images to current default display rotation to fix captured

packages/camera/camera_android_camerax/android/src/main/java/io/flutter/plugins/camerax/CameraSelectorProxyApi.java

@@ -9,6 +9,7 @@
 import androidx.camera.core.CameraInfo;
 import androidx.camera.core.CameraSelector;
 import androidx.camera.core.ExperimentalLensFacing;
+import java.util.Collections;
 import java.util.List;
 
 /**
@@ -24,7 +25,8 @@ class CameraSelectorProxyApi extends PigeonApiCameraSelector {
   @ExperimentalLensFacing
   @NonNull
   @Override
-  public CameraSelector pigeon_defaultConstructor(@Nullable LensFacing requireLensFacing) {
+  public CameraSelector pigeon_defaultConstructor(
+      @Nullable LensFacing requireLensFacing, @Nullable CameraInfo cameraInfoForFilter) {
     final CameraSelector.Builder builder = new CameraSelector.Builder();
     if (requireLensFacing != null) {
       switch (requireLensFacing) {
@@ -42,6 +44,9 @@ public CameraSelector pigeon_defaultConstructor(@Nullable LensFacing requireLens
           break;
       }
     }
+    if (cameraInfoForFilter != null) {
+      builder.addCameraFilter(cameraInfos -> Collections.singletonList(cameraInfoForFilter));
+    }
     return builder.build();
   }
 

packages/camera/camera_android_camerax/android/src/main/java/io/flutter/plugins/camerax/CameraXLibrary.g.kt

@@ -2027,7 +2027,8 @@ abstract class PigeonApiCameraSelector(
     open val pigeonRegistrar: CameraXLibraryPigeonProxyApiRegistrar
 ) {
   abstract fun pigeon_defaultConstructor(
-      requireLensFacing: LensFacing?
+      requireLensFacing: LensFacing?,
+      cameraInfoForFilter: androidx.camera.core.CameraInfo?
   ): androidx.camera.core.CameraSelector
 
   /** A static `CameraSelector` that selects the default back facing camera. */
@@ -2057,10 +2058,12 @@ abstract class PigeonApiCameraSelector(
             val args = message as List<Any?>
             val pigeon_identifierArg = args[0] as Long
             val requireLensFacingArg = args[1] as LensFacing?
+            val cameraInfoForFilterArg = args[2] as androidx.camera.core.CameraInfo?
             val wrapped: List<Any?> =
                 try {
                   api.pigeonRegistrar.instanceManager.addDartCreatedInstance(
-                      api.pigeon_defaultConstructor(requireLensFacingArg), pigeon_identifierArg)
+                      api.pigeon_defaultConstructor(requireLensFacingArg, cameraInfoForFilterArg),
+                      pigeon_identifierArg)
                   listOf(null)
                 } catch (exception: Throwable) {
                   CameraXLibraryPigeonUtils.wrapError(exception)

packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/CameraSelectorTest.java

@@ -10,6 +10,7 @@
 
 import androidx.camera.core.CameraInfo;
 import androidx.camera.core.CameraSelector;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import org.junit.Test;
@@ -18,13 +19,30 @@ public class CameraSelectorTest {
   @Test
   public void pigeon_defaultConstructor_createsCameraSelectorInstanceWithLensFacing() {
     final PigeonApiCameraSelector api = new TestProxyApiRegistrar().getPigeonApiCameraSelector();
-
     final CameraSelector selector =
-        api.pigeon_defaultConstructor(io.flutter.plugins.camerax.LensFacing.FRONT);
+        api.pigeon_defaultConstructor(io.flutter.plugins.camerax.LensFacing.FRONT, null);
 
     assertEquals(selector.getLensFacing(), (Integer) CameraSelector.LENS_FACING_FRONT);
   }
 
+  @Test
+  public void pigeon_defaultConstructor_createsCameraSelectorInstanceWithCameraInfo() {
+    final PigeonApiCameraSelector api = new TestProxyApiRegistrar().getPigeonApiCameraSelector();
+    final androidx.camera.core.CameraInfo cameraInfo = mock(CameraInfo.class);
+    final androidx.camera.core.CameraInfo cameraInfoToSelect = mock(CameraInfo.class);
+
+    final CameraSelector selector = api.pigeon_defaultConstructor(null, cameraInfoToSelect);
+
+    final List<androidx.camera.core.CameraInfo> cameraInfosList = new ArrayList<>();
+    cameraInfosList.add(cameraInfo);
+    cameraInfosList.add(cameraInfoToSelect);
+
+    final List<androidx.camera.core.CameraInfo> filteredCameraInfosList =
+        selector.filter(new ArrayList<>(cameraInfosList));
+    assertEquals(1, filteredCameraInfosList.size());
+    assertEquals(cameraInfoToSelect, filteredCameraInfosList.get(0));
+  }
+
   @Test
   public void filter_callsFilterWithMethodParameters() {
     final PigeonApiCameraSelector api = new TestProxyApiRegistrar().getPigeonApiCameraSelector();

packages/camera/camera_android_camerax/lib/src/android_camera_camerax.dart

@@ -266,6 +266,9 @@ class AndroidCameraCameraX extends CameraPlatform {
   @visibleForTesting
   late bool enableRecordingAudio;
 
+  /// A map to associate a [CameraInfo] with its camera name.
+  final Map<String, CameraInfo> _savedCameras = <String, CameraInfo>{};
+
   /// Returns list of all available cameras and their descriptions.
   @override
   Future<List<CameraDescription>> availableCameras() async {
@@ -302,6 +305,8 @@ class AndroidCameraCameraX extends CameraPlatform {
       cameraName = 'Camera $cameraCount';
       cameraCount++;
 
+      _savedCameras[cameraName] = cameraInfo;
+
       // TODO(camsim99): Use camera ID retrieved from Camera2CameraInfo as
       // camera name: https://github.com/flutter/flutter/issues/147545.
       cameraDescriptions.add(
@@ -357,13 +362,15 @@ class AndroidCameraCameraX extends CameraPlatform {
     if (error != null) {
       throw CameraException(error.errorCode, error.description);
     }
+    // Choose CameraInfo to create CameraSelector by name associated with desired camera.
+    final CameraInfo? chosenCameraInfo = _savedCameras[cameraDescription.name];
 
     // Save CameraSelector that matches cameraDescription.
     final LensFacing cameraSelectorLensDirection =
         _getCameraSelectorLensDirection(cameraDescription.lensDirection);
     cameraIsFrontFacing = cameraSelectorLensDirection == LensFacing.front;
     cameraSelector = proxy.newCameraSelector(
-      requireLensFacing: cameraSelectorLensDirection,
+      cameraInfoForFilter: chosenCameraInfo,
     );
     // Start listening for device orientation changes preceding camera creation.
     unawaited(

packages/camera/camera_android_camerax/lib/src/camerax_library.g.dart

@@ -1964,6 +1964,7 @@ class CameraSelector extends PigeonInternalProxyApiBaseClass {
     super.pigeon_binaryMessenger,
     super.pigeon_instanceManager,
     LensFacing? requireLensFacing,
+    CameraInfo? cameraInfoForFilter,
   }) {
     final int pigeonVar_instanceIdentifier = pigeon_instanceManager
         .addDartCreatedInstance(this);
@@ -1979,7 +1980,11 @@ class CameraSelector extends PigeonInternalProxyApiBaseClass {
           binaryMessenger: pigeonVar_binaryMessenger,
         );
     final Future<Object?> pigeonVar_sendFuture = pigeonVar_channel.send(
-      <Object?>[pigeonVar_instanceIdentifier, requireLensFacing],
+      <Object?>[
+        pigeonVar_instanceIdentifier,
+        requireLensFacing,
+        cameraInfoForFilter,
+      ],
     );
     () async {
       final List<Object?>? pigeonVar_replyList =

packages/camera/camera_android_camerax/lib/src/camerax_proxy.dart

@@ -108,6 +108,7 @@ class CameraXProxy {
   /// Constructs [CameraSelector].
   final CameraSelector Function({
     LensFacing? requireLensFacing,
+    CameraInfo? cameraInfoForFilter,
     BinaryMessenger? pigeon_binaryMessenger,
     PigeonInstanceManager? pigeon_instanceManager,
   })

packages/camera/camera_android_camerax/pigeons/camerax_library.dart

@@ -290,7 +290,10 @@ enum LensFacing {
   ),
 )
 abstract class CameraSelector {
-  CameraSelector(LensFacing? requireLensFacing);
+  CameraSelector(
+    LensFacing? requireLensFacing,
+    CameraInfo? cameraInfoForFilter,
+  );
 
   /// A static `CameraSelector` that selects the default back facing camera.
   @static

packages/camera/camera_android_camerax/pubspec.yaml

@@ -2,7 +2,7 @@ name: camera_android_camerax
 description: Android implementation of the camera plugin using the CameraX library.
 repository: https://github.com/flutter/packages/tree/main/packages/camera/camera_android_camerax
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+camera%22
-version: 0.6.19
+version: 0.6.19+1
 
 environment:
   sdk: ^3.7.0