[camerax] Update Activity references when ActivityAware lifecycle methods called

packages/camera/camera_android_camerax/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.5.0+27
+
+* Removes or updates any references to an `ActivityPluginBinding` when the plugin is detached
+  or attached/re-attached, respectively, to an `Activity.`
+
 ## 0.5.0+26
 
 * Fixes new lint warnings.

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

@@ -20,13 +20,15 @@
 public final class CameraAndroidCameraxPlugin implements FlutterPlugin, ActivityAware {
   private InstanceManager instanceManager;
   private FlutterPluginBinding pluginBinding;
-  private PendingRecordingHostApiImpl pendingRecordingHostApiImpl;
-  private RecorderHostApiImpl recorderHostApiImpl;
-  private VideoCaptureHostApiImpl videoCaptureHostApiImpl;
-  private ImageAnalysisHostApiImpl imageAnalysisHostApiImpl;
-  private ImageCaptureHostApiImpl imageCaptureHostApiImpl;
-  private CameraControlHostApiImpl cameraControlHostApiImpl;
-  public @Nullable SystemServicesHostApiImpl systemServicesHostApiImpl;
+  @VisibleForTesting @Nullable public PendingRecordingHostApiImpl pendingRecordingHostApiImpl;
+  @VisibleForTesting @Nullable public RecorderHostApiImpl recorderHostApiImpl;
+  @VisibleForTesting @Nullable public VideoCaptureHostApiImpl videoCaptureHostApiImpl;
+  @VisibleForTesting @Nullable public ImageAnalysisHostApiImpl imageAnalysisHostApiImpl;
+  @VisibleForTesting @Nullable public ImageCaptureHostApiImpl imageCaptureHostApiImpl;
+  @VisibleForTesting @Nullable public CameraControlHostApiImpl cameraControlHostApiImpl;
+  @VisibleForTesting @Nullable public SystemServicesHostApiImpl systemServicesHostApiImpl;
+
+  @VisibleForTesting
   public @Nullable DeviceOrientationManagerHostApiImpl deviceOrientationManagerHostApiImpl;
 
   @VisibleForTesting
@@ -136,42 +138,54 @@ public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
   public void onAttachedToActivity(@NonNull ActivityPluginBinding activityPluginBinding) {
     Activity activity = activityPluginBinding.getActivity();
 
+    // Set up Host API implementations based on the context that `activity` provides.
     setUp(pluginBinding.getBinaryMessenger(), activity, pluginBinding.getTextureRegistry());
 
-    if (activity instanceof LifecycleOwner) {
-      processCameraProviderHostApiImpl.setLifecycleOwner((LifecycleOwner) activity);
-      liveDataHostApiImpl.setLifecycleOwner((LifecycleOwner) activity);
-    } else {
-      ProxyLifecycleProvider proxyLifecycleProvider = new ProxyLifecycleProvider(activity);
-      processCameraProviderHostApiImpl.setLifecycleOwner(proxyLifecycleProvider);
-      liveDataHostApiImpl.setLifecycleOwner(proxyLifecycleProvider);
-    }
+    // Set any needed references to `activity` itself.
+    updateLifecycleOwner(activity);
+    updateActivity(activity);
 
-    systemServicesHostApiImpl.setActivity(activity);
+    // Set permissions registry reference.
     systemServicesHostApiImpl.setPermissionsRegistry(
         activityPluginBinding::addRequestPermissionsResultListener);
-    deviceOrientationManagerHostApiImpl.setActivity(activity);
   }
 
   @Override
   public void onDetachedFromActivityForConfigChanges() {
+    // Clear any references to previously attached `ActivityPluginBinding`/`Activity`.
     updateContext(pluginBinding.getApplicationContext());
+    updateLifecycleOwner(null);
+    updateActivity(null);
+    systemServicesHostApiImpl.setPermissionsRegistry(null);
   }
 
   @Override
   public void onReattachedToActivityForConfigChanges(
       @NonNull ActivityPluginBinding activityPluginBinding) {
-    updateContext(activityPluginBinding.getActivity());
+    Activity activity = activityPluginBinding.getActivity();
+
+    // Set any needed references to `activity` itself or its context.
+    updateContext(activity);
+    updateLifecycleOwner(activity);
+    updateActivity(activity);
+
+    // Set permissions registry reference.
+    systemServicesHostApiImpl.setPermissionsRegistry(
+        activityPluginBinding::addRequestPermissionsResultListener);
   }
 
   @Override
   public void onDetachedFromActivity() {
+    // Clear any references to previously attached `ActivityPluginBinding`/`Activity`.
     updateContext(pluginBinding.getApplicationContext());
+    updateLifecycleOwner(null);
+    updateActivity(null);
+    systemServicesHostApiImpl.setPermissionsRegistry(null);
   }
 
   /**
    * Updates context that is used to fetch the corresponding instance of a {@code
-   * ProcessCameraProvider}.
+   * ProcessCameraProvider} to each of the relevant camera controls.
    */
   public void updateContext(@NonNull Context context) {
     if (processCameraProviderHostApiImpl != null) {
@@ -196,4 +210,32 @@ public void updateContext(@NonNull Context context) {
       cameraControlHostApiImpl.setContext(context);
     }
   }
+
+  /** Sets {@code LifecycleOwner} that is used to control the lifecycle of the camera by CameraX. */
+  public void updateLifecycleOwner(@Nullable Activity activity) {
+    if (activity == null) {
+      processCameraProviderHostApiImpl.setLifecycleOwner(null);
+      liveDataHostApiImpl.setLifecycleOwner(null);
+    } else if (activity instanceof LifecycleOwner) {
+      processCameraProviderHostApiImpl.setLifecycleOwner((LifecycleOwner) activity);
+      liveDataHostApiImpl.setLifecycleOwner((LifecycleOwner) activity);
+    } else {
+      ProxyLifecycleProvider proxyLifecycleProvider = new ProxyLifecycleProvider(activity);
+      processCameraProviderHostApiImpl.setLifecycleOwner(proxyLifecycleProvider);
+      liveDataHostApiImpl.setLifecycleOwner(proxyLifecycleProvider);
+    }
+  }
+
+  /**
+   * Updates {@code Activity} that is used for requesting camera permissions and tracking the
+   * orientation of the device.
+   */
+  public void updateActivity(@Nullable Activity activity) {
+    if (systemServicesHostApiImpl != null) {
+      systemServicesHostApiImpl.setActivity(activity);
+    }
+    if (deviceOrientationManagerHostApiImpl != null) {
+      deviceOrientationManagerHostApiImpl.setActivity(activity);
+    }
+  }
 }

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

@@ -36,6 +36,10 @@ public void enableTorch(
         @NonNull CameraControl cameraControl,
         @NonNull Boolean torch,
         @NonNull GeneratedCameraXLibrary.Result<Void> result) {
+      if (context == null) {
+        throw new IllegalStateException("Context must be set to enable the torch.");
+      }
+
       ListenableFuture<Void> enableTorchFuture = cameraControl.enableTorch(torch);
 
       Futures.addCallback(
@@ -58,6 +62,10 @@ public void setZoomRatio(
         @NonNull CameraControl cameraControl,
         @NonNull Double ratio,
         @NonNull GeneratedCameraXLibrary.Result<Void> result) {
+      if (context == null) {
+        throw new IllegalStateException("Context must be set to set zoom ratio.");
+      }
+
       float ratioAsFloat = ratio.floatValue();
       ListenableFuture<Void> setZoomRatioFuture = cameraControl.setZoomRatio(ratioAsFloat);
 

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

@@ -48,6 +48,11 @@ public void setActivity(@NonNull Activity activity) {
   @Override
   public void startListeningForDeviceOrientationChange(
       @NonNull Boolean isFrontFacing, @NonNull Long sensorOrientation) {
+    if (activity == null) {
+      throw new IllegalStateException(
+          "Activity must be set to start listening for device orientation changes.");
+    }
+
     deviceOrientationManager =
         cameraXProxy.createDeviceOrientationManager(
             activity,

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

@@ -19,7 +19,7 @@ public class ImageAnalysisHostApiImpl implements ImageAnalysisHostApi {
 
   private InstanceManager instanceManager;
   private BinaryMessenger binaryMessenger;
-  private Context context;
+  @Nullable private Context context;
 
   @VisibleForTesting @NonNull public CameraXProxy cameraXProxy = new CameraXProxy();
 
@@ -65,6 +65,10 @@ public void create(
    */
   @Override
   public void setAnalyzer(@NonNull Long identifier, @NonNull Long analyzerIdentifier) {
+    if (context == null) {
+      throw new IllegalStateException("Context must be set to set an Analyzer.");
+    }
+
     getImageAnalysisInstance(identifier)
         .setAnalyzer(
             ContextCompat.getMainExecutor(context),

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

@@ -22,7 +22,7 @@ public class ImageCaptureHostApiImpl implements ImageCaptureHostApi {
   private final BinaryMessenger binaryMessenger;
   private final InstanceManager instanceManager;
 
-  private Context context;
+  @Nullable private Context context;
   private SystemServicesFlutterApiImpl systemServicesFlutterApiImpl;
 
   public static final String TEMPORARY_FILE_NAME = "CAP";
@@ -87,6 +87,10 @@ public void setFlashMode(@NonNull Long identifier, @NonNull Long flashMode) {
   @Override
   public void takePicture(
       @NonNull Long identifier, @NonNull GeneratedCameraXLibrary.Result<String> result) {
+    if (context == null) {
+      throw new IllegalStateException("Context must be set to take picture.");
+    }
+
     ImageCapture imageCapture = getImageCaptureInstance(identifier);
     final File outputDir = context.getCacheDir();
     File temporaryCaptureFile;

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

@@ -25,7 +25,7 @@
 public class LiveDataHostApiImpl implements LiveDataHostApi {
   private final BinaryMessenger binaryMessenger;
   private final InstanceManager instanceManager;
-  private LifecycleOwner lifecycleOwner;
+  @Nullable private LifecycleOwner lifecycleOwner;
 
   /**
    * Constructs a {@link LiveDataHostApiImpl}.
@@ -40,7 +40,7 @@ public LiveDataHostApiImpl(
   }
 
   /** Sets {@link LifecycleOwner} used to observe the camera state if so requested. */
-  public void setLifecycleOwner(@NonNull LifecycleOwner lifecycleOwner) {
+  public void setLifecycleOwner(@Nullable LifecycleOwner lifecycleOwner) {
     this.lifecycleOwner = lifecycleOwner;
   }
 
@@ -51,6 +51,10 @@ public void setLifecycleOwner(@NonNull LifecycleOwner lifecycleOwner) {
   @Override
   @SuppressWarnings("unchecked")
   public void observe(@NonNull Long identifier, @NonNull Long observerIdentifier) {
+    if (lifecycleOwner == null) {
+      throw new IllegalStateException("LifecycleOwner must be set to observe a LiveData instance.");
+    }
+
     getLiveDataInstance(identifier)
         .observe(
             lifecycleOwner,
@@ -60,6 +64,10 @@ public void observe(@NonNull Long identifier, @NonNull Long observerIdentifier)
   /** Removes all observers of this instance that are tied to the {@link lifecycleOwner}. */
   @Override
   public void removeObservers(@NonNull Long identifier) {
+    if (lifecycleOwner == null) {
+      throw new IllegalStateException("LifecycleOwner must be set to remove LiveData observers.");
+    }
+
     getLiveDataInstance(identifier).removeObservers(lifecycleOwner);
   }
 

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

@@ -20,7 +20,7 @@
 public class PendingRecordingHostApiImpl implements PendingRecordingHostApi {
   private final BinaryMessenger binaryMessenger;
   private final InstanceManager instanceManager;
-  private Context context;
+  @Nullable private Context context;
 
   @VisibleForTesting @NonNull public CameraXProxy cameraXProxy = new CameraXProxy();
 
@@ -63,6 +63,10 @@ public Long start(@NonNull Long identifier) {
   @Nullable
   @VisibleForTesting
   public Executor getExecutor() {
+    if (context == null) {
+      throw new IllegalStateException("Context must be set to get an executor to start recording.");
+    }
+
     return ContextCompat.getMainExecutor(context);
   }
 

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

@@ -6,6 +6,7 @@
 
 import android.content.Context;
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.camera.core.Camera;
 import androidx.camera.core.CameraInfo;
 import androidx.camera.core.CameraSelector;
@@ -24,8 +25,8 @@ public class ProcessCameraProviderHostApiImpl implements ProcessCameraProviderHo
   private final BinaryMessenger binaryMessenger;
   private final InstanceManager instanceManager;
 
-  private Context context;
-  private LifecycleOwner lifecycleOwner;
+  @Nullable private Context context;
+  @Nullable private LifecycleOwner lifecycleOwner;
 
   public ProcessCameraProviderHostApiImpl(
       @NonNull BinaryMessenger binaryMessenger,
@@ -36,7 +37,7 @@ public ProcessCameraProviderHostApiImpl(
     this.context = context;
   }
 
-  public void setLifecycleOwner(@NonNull LifecycleOwner lifecycleOwner) {
+  public void setLifecycleOwner(@Nullable LifecycleOwner lifecycleOwner) {
     this.lifecycleOwner = lifecycleOwner;
   }
 
@@ -57,6 +58,10 @@ public void setContext(@NonNull Context context) {
    */
   @Override
   public void getInstance(@NonNull GeneratedCameraXLibrary.Result<Long> result) {
+    if (context == null) {
+      throw new IllegalStateException("Context must be set to get ProcessCameraProvider instance.");
+    }
+
     ListenableFuture<ProcessCameraProvider> processCameraProviderFuture =
         ProcessCameraProvider.getInstance(context);
 
@@ -110,6 +115,11 @@ public List<Long> getAvailableCameraInfos(@NonNull Long identifier) {
       @NonNull Long identifier,
       @NonNull Long cameraSelectorIdentifier,
       @NonNull List<Long> useCaseIds) {
+    if (lifecycleOwner == null) {
+      throw new IllegalStateException(
+          "LifecycleOwner must be set to get ProcessCameraProvider instance.");
+    }
+
     ProcessCameraProvider processCameraProvider =
         (ProcessCameraProvider) Objects.requireNonNull(instanceManager.getInstance(identifier));
     CameraSelector cameraSelector =

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

@@ -23,7 +23,7 @@
 public class RecorderHostApiImpl implements RecorderHostApi {
   private final BinaryMessenger binaryMessenger;
   private final InstanceManager instanceManager;
-  private Context context;
+  @Nullable private Context context;
 
   @NonNull @VisibleForTesting public CameraXProxy cameraXProxy = new CameraXProxy();
 
@@ -46,6 +46,10 @@ public void create(
       @Nullable Long aspectRatio,
       @Nullable Long bitRate,
       @Nullable Long qualitySelector) {
+    if (context == null) {
+      throw new IllegalStateException("Context must be set to create Recorder instance.");
+    }
+
     Recorder.Builder recorderBuilder = cameraXProxy.createRecorderBuilder();
     if (aspectRatio != null) {
       recorderBuilder.setAspectRatio(aspectRatio.intValue());
@@ -89,6 +93,10 @@ public Long getTargetVideoEncodingBitRate(@NonNull Long identifier) {
   @NonNull
   @Override
   public Long prepareRecording(@NonNull Long identifier, @NonNull String path) {
+    if (context == null) {
+      throw new IllegalStateException("Context must be set to prepare recording.");
+    }
+
     Recorder recorder = getRecorderFromInstanceId(identifier);
     File temporaryCaptureFile = openTempFile(path);
     FileOutputOptions fileOutputOptions =

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

@@ -7,6 +7,7 @@
 import android.app.Activity;
 import android.content.Context;
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
 import io.flutter.plugin.common.BinaryMessenger;
 import io.flutter.plugins.camerax.CameraPermissionsManager.PermissionsRegistry;
@@ -19,7 +20,7 @@
 public class SystemServicesHostApiImpl implements SystemServicesHostApi {
   private final BinaryMessenger binaryMessenger;
   private final InstanceManager instanceManager;
-  private Context context;
+  @Nullable private Context context;
 
   @VisibleForTesting public @NonNull CameraXProxy cameraXProxy = new CameraXProxy();
   @VisibleForTesting public @NonNull SystemServicesFlutterApiImpl systemServicesFlutterApi;
@@ -46,7 +47,7 @@ public void setActivity(@NonNull Activity activity) {
     this.activity = activity;
   }
 
-  public void setPermissionsRegistry(@NonNull PermissionsRegistry permissionsRegistry) {
+  public void setPermissionsRegistry(@Nullable PermissionsRegistry permissionsRegistry) {
     this.permissionsRegistry = permissionsRegistry;
   }
 
@@ -59,6 +60,10 @@ public void setPermissionsRegistry(@NonNull PermissionsRegistry permissionsRegis
   @Override
   public void requestCameraPermissions(
       @NonNull Boolean enableAudio, @NonNull Result<CameraPermissionsErrorData> result) {
+    if (activity == null) {
+      throw new IllegalStateException("Activity must be set to request camera permissions.");
+    }
+
     CameraPermissionsManager cameraPermissionsManager =
         cameraXProxy.createCameraPermissionsManager();
     cameraPermissionsManager.requestPermissions(
@@ -84,6 +89,10 @@ public void requestCameraPermissions(
   @Override
   @NonNull
   public String getTempFilePath(@NonNull String prefix, @NonNull String suffix) {
+    if (context == null) {
+      throw new IllegalStateException("Context must be set to create a temporary file.");
+    }
+
     try {
       File path = File.createTempFile(prefix, suffix, context.getCacheDir());
       return path.toString();