Fixing plugin

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

@@ -4,6 +4,8 @@
 
 package io.flutter.plugins.camerax;
 
+import javax.annotation.processing.Generated;
+
 import android.app.Activity;
 import android.content.Context;
 import androidx.annotation.NonNull;
@@ -19,8 +21,10 @@ public final class CameraAndroidCameraxPlugin implements FlutterPlugin, Activity
   private InstanceManager instanceManager;
   private FlutterPluginBinding pluginBinding;
   private LiveCameraStateHostApiImpl liveCameraStateHostApiImpl;
-  private ProcessCameraProviderHostApiImpl processCameraProviderHostApi;
-  private ImageCaptureHostApiImpl imageCaptureHostApi;
+  private ProcessCameraProviderHostApiImpl processCameraProviderHostApiImpl;
+  private ImageCaptureHostApiImpl imageCaptureHostApiImpl;
+  private LiveDataHostApiImpl liveDataHostApiImpl;
+
   public SystemServicesHostApiImpl systemServicesHostApi;
 
   /**
@@ -48,21 +52,22 @@ void setUp(BinaryMessenger binaryMessenger, Context context, TextureRegistry tex
         binaryMessenger, new CameraSelectorHostApiImpl(binaryMessenger, instanceManager));
     GeneratedCameraXLibrary.JavaObjectHostApi.setup(
         binaryMessenger, new JavaObjectHostApiImpl(instanceManager));
-    processCameraProviderHostApi =
+    processCameraProviderHostApiImpl =
         new ProcessCameraProviderHostApiImpl(binaryMessenger, instanceManager, context);
     GeneratedCameraXLibrary.ProcessCameraProviderHostApi.setup(
-        binaryMessenger, processCameraProviderHostApi);
+        binaryMessenger, processCameraProviderHostApiImpl);
     systemServicesHostApi = new SystemServicesHostApiImpl(binaryMessenger, instanceManager);
     GeneratedCameraXLibrary.SystemServicesHostApi.setup(binaryMessenger, systemServicesHostApi);
     GeneratedCameraXLibrary.PreviewHostApi.setup(
         binaryMessenger, new PreviewHostApiImpl(binaryMessenger, instanceManager, textureRegistry));
-    imageCaptureHostApi = new ImageCaptureHostApiImpl(binaryMessenger, instanceManager, context);
-    GeneratedCameraXLibrary.ImageCaptureHostApi.setup(binaryMessenger, imageCaptureHostApi);
+    imageCaptureHostApiImpl = new ImageCaptureHostApiImpl(binaryMessenger, instanceManager, context);
+    GeneratedCameraXLibrary.ImageCaptureHostApi.setup(binaryMessenger, imageCaptureHostApiImpl);
     GeneratedCameraXLibrary.CameraHostApi.setup(
         binaryMessenger, new CameraHostApiImpl(binaryMessenger, instanceManager));
-    liveCameraStateHostApiImpl = new LiveCameraStateHostApiImpl(binaryMessenger, instanceManager);
-    GeneratedCameraXLibrary.LiveCameraStateHostApi.setup(
-        binaryMessenger, liveCameraStateHostApiImpl);
+    liveDataHostApiImpl = new LiveDataHostApiImpl(binaryMessenger, instanceManager);
+    GeneratedCameraXLibrary.LiveDataHostApi.setup(binaryMessenger, liveDataHostApiImpl);
+    GeneratedCameraXLibrary.ObserverHostApi.setup(
+        binaryMessenger, new ObserverHostApiImpl(binaryMessenger, instanceManager));
   }
 
   @Override
@@ -88,8 +93,8 @@ public void onAttachedToActivity(@NonNull ActivityPluginBinding activityPluginBi
     updateContext(pluginBinding.getApplicationContext());
 
     Activity activity = activityPluginBinding.getActivity();
-    processCameraProviderHostApi.setLifecycleOwner((LifecycleOwner) activity);
-    liveCameraStateHostApiImpl.setLifecycleOwner((LifecycleOwner) activity);
+    processCameraProviderHostApiImpl.setLifecycleOwner((LifecycleOwner) activity);
+    liveDataHostApiImpl.setLifecycleOwner((LifecycleOwner) activity);
     systemServicesHostApi.setActivity(activity);
     systemServicesHostApi.setPermissionsRegistry(
         activityPluginBinding::addRequestPermissionsResultListener);
@@ -116,11 +121,11 @@ public void onDetachedFromActivity() {
    * ProcessCameraProvider}.
    */
   public void updateContext(Context context) {
-    if (processCameraProviderHostApi != null) {
-      processCameraProviderHostApi.setContext(context);
+    if (processCameraProviderHostApiImpl != null) {
+      processCameraProviderHostApiImpl.setContext(context);
     }
-    if (imageCaptureHostApi != null) {
-      processCameraProviderHostApi.setContext(context);
+    if (imageCaptureHostApiImpl != null) {
+      processCameraProviderHostApiImpl.setContext(context);
     }
   }
 }

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

@@ -57,15 +57,27 @@ public void create(
       @Nullable CameraState.StateError error,
       @NonNull CameraStateFlutterApi.Reply<Void> callback) {
 
-    // TODO(camsim99): actually fix this
     CameraStateType cameraStateType;
     switch (type) {
-      default:
-      cameraStateType = CameraStateType.CLOSED;
+      case CameraState.Type.CLOSED:
+        cameraStateType = CameraState.Type.CLOSED;
+        break;
+      case CameraState.Type.CLOSING:
+        cameraStateType = CameraState.Type.CLOSING;
+        break;
+      case CameraState.Type.OPEN:
+        cameraStateType = CameraState.Type.CLOSED;
+        break;
+      case CameraState.Type.OPENING:
+        cameraStateType = CameraState.Type.CLOSED;
+        break;
+      case CameraState.Type.PENDING_OPEN:
+        cameraStateType = CameraState.Type.CLOSED;
+        break;
     }
 
     if (error != null) {
-      new CameraStateErrorFlutterApiWrapper(binaryMessenger, instanceManager).create(error, Long.valueOf(error.getCode()), "TODO(camsim99)", reply -> {});
+      new CameraStateErrorFlutterApiWrapper(binaryMessenger, instanceManager).create(error, Long.valueOf(error.getCode()), getCameraStateErrorDescription(error), reply -> {});
     }
 
     if (!instanceManager.containsInstance(instance)) {
@@ -77,6 +89,41 @@ public void create(
     }
   }
 
+  /**
+   * Returns an error message corresponding to the specified {@link CameraState.StateError}.
+   *
+   * <p>See https://developer.android.com/reference/androidx/camera/core/CameraState#constants_1 for
+   * more information on the different {@link CameraState.StateError} types.
+   */
+  private String getCameraStateErrorDescription(@NonNull CameraState.StateError cameraStateError) {
+    final int cameraStateErrorCode = cameraStateError.getCode();
+    final String cameraStateErrorDescription = cameraStateErrorCode + ": ";
+    switch (cameraStateErrorCode) {
+      case CameraState.ERROR_CAMERA_IN_USE:
+        return cameraStateErrorDescription
+            + "The camera was already in use, possibly by a higher-priority camera client.";
+      case CameraState.ERROR_MAX_CAMERAS_IN_USE:
+        return cameraStateErrorDescription
+            + "The limit number of open cameras has been reached, and more cameras cannot be opened until other instances are closed.";
+      case CameraState.ERROR_OTHER_RECOVERABLE_ERROR:
+        return cameraStateErrorDescription
+            + "The camera device has encountered a recoverable error. CameraX will attempt to recover from the error.";
+      case CameraState.ERROR_STREAM_CONFIG:
+        return cameraStateErrorDescription + "Configuring the camera has failed.";
+      case CameraState.ERROR_CAMERA_DISABLED:
+        return cameraStateErrorDescription
+            + "The camera device could not be opened due to a device policy. Thia may be caused by a client from a background process attempting to open the camera.";
+      case CameraState.ERROR_CAMERA_FATAL_ERROR:
+        return cameraStateErrorDescription
+            + "The camera was closed due to a fatal error. This may require the Android device be shut down and restarted to restore camera function or may indicate a persistent camera hardware problem.";
+      case CameraState.ERROR_DO_NOT_DISTURB_MODE_ENABLED:
+        return cameraStateErrorDescription
+            + "The camera could not be opened because 'Do Not Disturb' mode is enabled. Please disable this mode, and try opening the camera again.";
+      default:
+        return "There was an undefined issue with the camera state.";
+    }
+  }
+
   /**
    * Sets the Flutter API used to send messages to Dart.
    *

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

@@ -26,10 +26,8 @@ public class LiveDataHostApiImpl implements LiveDataHostApi {
   // To ease adding additional methods, this value is added prematurely.
   @SuppressWarnings({"unused", "FieldCanBeLocal"})
   private final BinaryMessenger binaryMessenger;
-
   private final InstanceManager instanceManager;
-
-  public LifecycleOwner fakeLifecycleOwner;
+  private LifecycleOwner lifecycleOwner;
 
   /**
    * Constructs a {@link LiveDataHostApiImpl}.
@@ -44,20 +42,21 @@ public LiveDataHostApiImpl(
     this.instanceManager = instanceManager;
   }
 
+  /** Sets {@link LifecycleOwner} used to observe the camera state if so requested. */
+  public void setLifecycleOwner(LifecycleOwner lifecycleOwner) {
+    this.lifecycleOwner = lifecycleOwner;
+  }
+
   @Override
   @SuppressWarnings("unchecked")
   public void observe(@NonNull Long identifier, @NonNull Long observerIdentifier) {
-
-    // tODO(camsim99): get lifecycleowner
     getLiveDataInstance(identifier)
-        .observe(fakeLifecycleOwner, Objects.requireNonNull(instanceManager.getInstance(observerIdentifier)));
+        .observe(lifecycleOwner, Objects.requireNonNull(instanceManager.getInstance(observerIdentifier)));
   }
 
   @Override
   public void removeObservers(@NonNull Long identifier) {
-
-        // tODO(camsim99): get lifecycleowner
-    getLiveDataInstance(identifier).removeObservers(fakeLifecycleOwner);
+    getLiveDataInstance(identifier).removeObservers(lifecycleOwner);
   }
 
   private LiveData<?> getLiveDataInstance(@NonNull Long identifier) {

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

@@ -57,8 +57,7 @@ public void onChanged(
       CameraState state = (CameraState) value;
       new CameraStateFlutterApiWrapper(binaryMessenger, instanceManager).create(state, state.getType(), state.getError(), reply -> {});
     } else {
-      // TODO(camsim99): make this more specific
-      throw new UnsupportedOperationException();
+      throw new UnsupportedOperationException("The type of value in observance is not wrapped by this plugin.");
     }
 
     api.onChanged(

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

@@ -65,7 +65,7 @@ public void observe() {
         new LiveDataHostApiImpl(mockBinaryMessenger, instanceManager);
 
     LifecycleOwner fakeLifecycleOwner = mock(LifecycleOwner.class);
-    hostApi.fakeLifecycleOwner = fakeLifecycleOwner;
+    hostApi.setLifecycleOwner(fakeLifecycleOwner);
 
     hostApi.observe(instanceIdentifier, observerIdentifier);
 
@@ -82,7 +82,7 @@ public void removeObservers() {
         new LiveDataHostApiImpl(mockBinaryMessenger, instanceManager);
 
         LifecycleOwner fakeLifecycleOwner = mock(LifecycleOwner.class);
-        hostApi.fakeLifecycleOwner = fakeLifecycleOwner;
+        hostApi.setLifecycleOwner(fakeLifecycleOwner);
 
     hostApi.removeObservers(instanceIdentifier);
 

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

@@ -4,16 +4,20 @@
 
 import 'dart:async';
 
+import 'package:async/async.dart';
 import 'package:camera_platform_interface/camera_platform_interface.dart';
 import 'package:flutter/widgets.dart';
 import 'package:stream_transform/stream_transform.dart';
 
 import 'camera.dart';
 import 'camera_info.dart';
 import 'camera_selector.dart';
+import 'camera_state.dart';
+import 'camera_state_error.dart';
 import 'camerax_library.g.dart';
 import 'image_capture.dart';
-import 'live_camera_state.dart';
+import 'live_data.dart';
+import 'observer.dart';
 import 'preview.dart';
 import 'process_camera_provider.dart';
 import 'surface.dart';
@@ -37,7 +41,7 @@ class AndroidCameraCameraX extends CameraPlatform {
   Camera? camera;
 
   /// The [LiveCameraState] that represents the state of the [camera] instance.
-  LiveCameraState? liveCameraState;
+  LiveData<CameraState>? liveCameraState;
 
   /// The [Preview] instance that can be configured to present a live camera preview.
   @visibleForTesting
@@ -167,7 +171,7 @@ class AndroidCameraCameraX extends CameraPlatform {
     // instance as bound but not paused.
     camera = await processCameraProvider!
         .bindToLifecycle(cameraSelector!, <UseCase>[preview!, imageCapture!]);
-    _updateLiveCameraState();
+    _updateLiveCameraState(flutterSurfaceTextureId);
     _previewIsPaused = false;
 
     return flutterSurfaceTextureId;
@@ -228,6 +232,7 @@ class AndroidCameraCameraX extends CameraPlatform {
   @override
   Future<void> dispose(int cameraId) async {
     preview?.releaseFlutterSurfaceTexture();
+    liveCameraState?.removeObservers();
     processCameraProvider?.unbindAll();
   }
 
@@ -240,20 +245,20 @@ class AndroidCameraCameraX extends CameraPlatform {
   /// The camera started to close.
   @override
   Stream<CameraClosingEvent> onCameraClosing(int cameraId) {
-    return LiveCameraState.cameraClosingStreamController.stream
-        .map<CameraClosingEvent>((bool isCameraClosing) {
-      assert(isCameraClosing);
-      return CameraClosingEvent(cameraId);
-    });
+    return _cameraEvents(cameraId).whereType<CameraClosingEvent>();
   }
 
   /// The camera experienced an error.
   @override
   Stream<CameraErrorEvent> onCameraError(int cameraId) {
-    return SystemServices.cameraErrorStreamController.stream
-        .map<CameraErrorEvent>((String errorDescription) {
-      return CameraErrorEvent(cameraId, errorDescription);
-    });
+    return StreamGroup.mergeBroadcast<
+        CameraErrorEvent>(<Stream<CameraErrorEvent>>[
+      SystemServices.cameraErrorStreamController.stream
+          .map<CameraErrorEvent>((String errorDescription) {
+        return CameraErrorEvent(cameraId, errorDescription);
+      }),
+      _cameraEvents(cameraId).whereType<CameraErrorEvent>()
+    ]);
   }
 
   /// The ui orientation changed.
@@ -276,15 +281,15 @@ class AndroidCameraCameraX extends CameraPlatform {
   /// [cameraId] not used.
   @override
   Future<void> resumePreview(int cameraId) async {
-    await _bindPreviewToLifecycle();
+    await _bindPreviewToLifecycle(cameraId);
     _previewIsPaused = false;
   }
 
   /// Returns a widget showing a live camera preview.
   @override
   Widget buildPreview(int cameraId) {
     return FutureBuilder<void>(
-        future: _bindPreviewToLifecycle(),
+        future: _bindPreviewToLifecycle(cameraId),
         builder: (BuildContext context, AsyncSnapshot<void> snapshot) {
           switch (snapshot.connectionState) {
             case ConnectionState.none:
@@ -319,7 +324,7 @@ class AndroidCameraCameraX extends CameraPlatform {
 
   /// Binds [preview] instance to the camera lifecycle controlled by the
   /// [processCameraProvider].
-  Future<void> _bindPreviewToLifecycle() async {
+  Future<void> _bindPreviewToLifecycle(int cameraId) async {
     assert(processCameraProvider != null);
     assert(cameraSelector != null);
     assert(preview != null);
@@ -332,7 +337,7 @@ class AndroidCameraCameraX extends CameraPlatform {
 
     camera = await processCameraProvider!
         .bindToLifecycle(cameraSelector!, <UseCase>[preview!]);
-    _updateLiveCameraState();
+    _updateLiveCameraState(cameraId);
   }
 
   /// Unbinds [preview] instance to camera lifecycle controlled by the
@@ -350,12 +355,26 @@ class AndroidCameraCameraX extends CameraPlatform {
 
   // Methods concerning camera information:
 
-  /// Adds fresh observers to the [LiveCameraState] of the current [camera].
-  Future<void> _updateLiveCameraState() async {
+  /// Adds fresh observers to the [LiveData] of the [CameraState] of the
+  /// current [camera].
+  Future<void> _updateLiveCameraState(int cameraId) async {
     final CameraInfo cameraInfo = await camera!.getCameraInfo();
     liveCameraState?.removeObservers();
     liveCameraState = await cameraInfo.getLiveCameraState();
-    liveCameraState!.addObserver();
+    liveCameraState!.observe(_createCameraClosingObserver(cameraId));
+  }
+
+  Observer<CameraState> _createCameraClosingObserver(int cameraId) {
+    return Observer<CameraState>(onChanged: (CameraState state) {
+      if (state.type == CameraStateType.closing) {
+        cameraEventStreamController.add(CameraClosingEvent(cameraId));
+      }
+
+      if (state.error != null) {
+        cameraEventStreamController
+            .add(CameraErrorEvent(cameraId, state.error!.description));
+      }
+    });
   }
 
   // Methods for mapping Flutter camera constants to CameraX constants: