[camerax] Implement onCameraClosing

packages/camera/camera_android_camerax/CHANGELOG.md

@@ -23,3 +23,5 @@
 * Implements retrieval of camera information.
 * Updates README.md with plugin overview and adds contribution guide to CONTRIBUTING.md.
 * Implements video capture.
+* Implements onCameraClosing callback method for indicating the camera is closing and bumps CameraX version to 1.3.0-alpha05.
+

packages/camera/camera_android_camerax/android/build.gradle

@@ -62,7 +62,7 @@ android {
 
 dependencies {
     // CameraX core library using the camera2 implementation must use same version number.
-    def camerax_version = "1.3.0-alpha04"
+    def camerax_version = "1.3.0-alpha05"
     implementation "androidx.camera:camera-core:${camerax_version}"
     implementation "androidx.camera:camera-camera2:${camerax_version}"
     implementation "androidx.camera:camera-lifecycle:${camerax_version}"

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

@@ -26,7 +26,10 @@ public final class CameraAndroidCameraxPlugin implements FlutterPlugin, Activity
   private ImageCaptureHostApiImpl imageCaptureHostApiImpl;
   public SystemServicesHostApiImpl systemServicesHostApiImpl;
 
-  @VisibleForTesting ProcessCameraProviderHostApiImpl processCameraProviderHostApiImpl;
+  @VisibleForTesting @NonNull
+  public ProcessCameraProviderHostApiImpl processCameraProviderHostApiImpl;
+
+  @VisibleForTesting @NonNull public LiveDataHostApiImpl liveDataHostApiImpl;
 
   /**
    * Initialize this within the {@code #configureFlutterEngine} of a Flutter activity or fragment.
@@ -71,6 +74,12 @@ public void setUp(
     imageCaptureHostApiImpl =
         new ImageCaptureHostApiImpl(binaryMessenger, instanceManager, context);
     GeneratedCameraXLibrary.ImageCaptureHostApi.setup(binaryMessenger, imageCaptureHostApiImpl);
+    GeneratedCameraXLibrary.CameraHostApi.setup(
+        binaryMessenger, new CameraHostApiImpl(binaryMessenger, instanceManager));
+    liveDataHostApiImpl = new LiveDataHostApiImpl(binaryMessenger, instanceManager);
+    GeneratedCameraXLibrary.LiveDataHostApi.setup(binaryMessenger, liveDataHostApiImpl);
+    GeneratedCameraXLibrary.ObserverHostApi.setup(
+        binaryMessenger, new ObserverHostApiImpl(binaryMessenger, instanceManager));
     imageAnalysisHostApiImpl = new ImageAnalysisHostApiImpl(binaryMessenger, instanceManager);
     GeneratedCameraXLibrary.ImageAnalysisHostApi.setup(binaryMessenger, imageAnalysisHostApiImpl);
     GeneratedCameraXLibrary.AnalyzerHostApi.setup(
@@ -105,19 +114,18 @@ public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
 
   @Override
   public void onAttachedToActivity(@NonNull ActivityPluginBinding activityPluginBinding) {
-    setUp(
-        pluginBinding.getBinaryMessenger(),
-        pluginBinding.getApplicationContext(),
-        pluginBinding.getTextureRegistry());
-    updateContext(pluginBinding.getApplicationContext());
-
     Activity activity = activityPluginBinding.getActivity();
 
+    setUp(pluginBinding.getBinaryMessenger(), activity, pluginBinding.getTextureRegistry());
+    updateContext(activity);
+
     if (activity instanceof LifecycleOwner) {
       processCameraProviderHostApiImpl.setLifecycleOwner((LifecycleOwner) activity);
+      liveDataHostApiImpl.setLifecycleOwner((LifecycleOwner) activity);
     } else {
       ProxyLifecycleProvider proxyLifecycleProvider = new ProxyLifecycleProvider(activity);
       processCameraProviderHostApiImpl.setLifecycleOwner(proxyLifecycleProvider);
+      liveDataHostApiImpl.setLifecycleOwner(proxyLifecycleProvider);
     }
 
     systemServicesHostApiImpl.setActivity(activity);

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

@@ -31,10 +31,11 @@ public Long getCameraInfo(@NonNull Long identifier) {
     Camera camera = (Camera) Objects.requireNonNull(instanceManager.getInstance(identifier));
     CameraInfo cameraInfo = camera.getCameraInfo();
 
-    CameraInfoFlutterApiImpl cameraInfoFlutterApiImpl =
-        new CameraInfoFlutterApiImpl(binaryMessenger, instanceManager);
-    cameraInfoFlutterApiImpl.create(cameraInfo, reply -> {});
-
+    if (!instanceManager.containsInstance(cameraInfo)) {
+      CameraInfoFlutterApiImpl cameraInfoFlutterApiImpl =
+          new CameraInfoFlutterApiImpl(binaryMessenger, instanceManager);
+      cameraInfoFlutterApiImpl.create(cameraInfo, reply -> {});
+    }
     return instanceManager.getIdentifierForStrongReference(cameraInfo);
   }
 }

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

@@ -17,6 +17,9 @@ public CameraInfoFlutterApiImpl(
     this.instanceManager = instanceManager;
   }
 
+  /**
+   * Creates a {@link CameraInfo} instance in Dart. {@code reply} is not used so it can be empty.
+   */
   void create(CameraInfo cameraInfo, Reply<Void> reply) {
     if (!instanceManager.containsInstance(cameraInfo)) {
       create(instanceManager.addHostCreatedInstance(cameraInfo), reply);

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

@@ -5,24 +5,35 @@
 package io.flutter.plugins.camerax;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
 import androidx.camera.core.CameraInfo;
+import androidx.camera.core.CameraState;
 import androidx.camera.core.ExposureState;
 import androidx.camera.core.ZoomState;
+import androidx.lifecycle.LiveData;
 import io.flutter.plugin.common.BinaryMessenger;
 import io.flutter.plugins.camerax.GeneratedCameraXLibrary.CameraInfoHostApi;
+import io.flutter.plugins.camerax.GeneratedCameraXLibrary.LiveDataSupportedType;
 import java.util.Objects;
 
 public class CameraInfoHostApiImpl implements CameraInfoHostApi {
   private final BinaryMessenger binaryMessenger;
   private final InstanceManager instanceManager;
 
+  @VisibleForTesting public LiveDataFlutterApiWrapper liveDataFlutterApiWrapper;
+
   public CameraInfoHostApiImpl(
       @NonNull BinaryMessenger binaryMessenger, @NonNull InstanceManager instanceManager) {
     this.binaryMessenger = binaryMessenger;
     this.instanceManager = instanceManager;
+    this.liveDataFlutterApiWrapper =
+        new LiveDataFlutterApiWrapper(binaryMessenger, instanceManager);
   }
 
-  /** Retrieves the sensor rotation in degrees, relative to the device's default orientation. */
+  /**
+   * Retrieves the sensor rotation degrees of the {@link androidx.camera.core.Camera} that is
+   * represented by the {@link CameraInfo} with the specified identifier.
+   */
   @Override
   @NonNull
   public Long getSensorRotationDegrees(@NonNull Long identifier) {
@@ -31,6 +42,22 @@ public Long getSensorRotationDegrees(@NonNull Long identifier) {
     return Long.valueOf(cameraInfo.getSensorRotationDegrees());
   }
 
+  /**
+   * Retrieves the {@link LiveData} of the {@link CameraState} that is tied to the {@link
+   * androidx.camera.core.Camera} that is represented by the {@link CameraInfo} with the specified
+   * identifier.
+   */
+  @Override
+  @NonNull
+  public Long getCameraState(@NonNull Long identifier) {
+    CameraInfo cameraInfo =
+        (CameraInfo) Objects.requireNonNull(instanceManager.getInstance(identifier));
+    LiveData<CameraState> liveCameraState = cameraInfo.getCameraState();
+    liveDataFlutterApiWrapper.create(
+        liveCameraState, LiveDataSupportedType.CAMERA_STATE, reply -> {});
+    return instanceManager.getIdentifierForStrongReference(liveCameraState);
+  }
+
   /**
    * Retrieves the {@link ExposureState} of the {@link CameraInfo} with the specified identifier.
    */
@@ -49,20 +76,19 @@ public Long getExposureState(@NonNull Long identifier) {
   }
 
   /**
-   * Retrieves the current {@link ZoomState} value of the {@link CameraInfo} with the specified
-   * identifier.
+   * Retrieves the {@link LiveData} of the {@link ZoomState} of the {@link CameraInfo} with the
+   * specified identifier.
    */
   @NonNull
   @Override
   public Long getZoomState(@NonNull Long identifier) {
     CameraInfo cameraInfo =
         (CameraInfo) Objects.requireNonNull(instanceManager.getInstance(identifier));
-    // TODO(camsim99): Create/return LiveData<ZoomState> once https://github.com/flutter/packages/pull/3419 lands.
-    ZoomState zoomState = cameraInfo.getZoomState().getValue();
+    LiveData<ZoomState> zoomState = cameraInfo.getZoomState();
 
-    ZoomStateFlutterApiImpl zoomStateFlutterApiImpl =
-        new ZoomStateFlutterApiImpl(binaryMessenger, instanceManager);
-    zoomStateFlutterApiImpl.create(zoomState, result -> {});
+    LiveDataFlutterApiWrapper liveDataFlutterApiWrapper =
+        new LiveDataFlutterApiWrapper(binaryMessenger, instanceManager);
+    liveDataFlutterApiWrapper.create(zoomState, LiveDataSupportedType.ZOOM_STATE, reply -> {});
 
     return instanceManager.getIdentifierForStrongReference(zoomState);
   }

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

@@ -0,0 +1,57 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package io.flutter.plugins.camerax;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
+import androidx.camera.core.CameraState;
+import io.flutter.plugin.common.BinaryMessenger;
+import io.flutter.plugins.camerax.GeneratedCameraXLibrary.CameraStateErrorFlutterApi;
+
+/**
+ * Flutter API implementation for {@link CameraStateError}.
+ *
+ * <p>This class may handle adding native instances that are attached to a Dart instance or passing
+ * arguments of callbacks methods to a Dart instance.
+ */
+public class CameraStateErrorFlutterApiWrapper {
+  private final BinaryMessenger binaryMessenger;
+  private final InstanceManager instanceManager;
+  private CameraStateErrorFlutterApi cameraStateErrorFlutterApi;
+
+  /**
+   * Constructs a {@link CameraStateErrorFlutterApiWrapper}.
+   *
+   * @param binaryMessenger used to communicate with Dart over asynchronous messages
+   * @param instanceManager maintains instances stored to communicate with attached Dart objects
+   */
+  public CameraStateErrorFlutterApiWrapper(
+      @NonNull BinaryMessenger binaryMessenger, @NonNull InstanceManager instanceManager) {
+    this.binaryMessenger = binaryMessenger;
+    this.instanceManager = instanceManager;
+    cameraStateErrorFlutterApi = new CameraStateErrorFlutterApi(binaryMessenger);
+  }
+
+  /**
+   * Stores the {@link CameraStateError} instance and notifies Dart to create and store a new {@link
+   * CameraStateError} instance that is attached to this one. If {@code instance} has already been
+   * added, this method does nothing.
+   */
+  public void create(
+      @NonNull CameraState.StateError instance,
+      @NonNull Long code,
+      @NonNull CameraStateErrorFlutterApi.Reply<Void> callback) {
+    if (!instanceManager.containsInstance(instance)) {
+      cameraStateErrorFlutterApi.create(
+          instanceManager.addHostCreatedInstance(instance), code, callback);
+    }
+  }
+
+  /** Sets the Flutter API used to send messages to Dart. */
+  @VisibleForTesting
+  void setApi(@NonNull CameraStateErrorFlutterApi api) {
+    this.cameraStateErrorFlutterApi = api;
+  }
+}

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

@@ -0,0 +1,102 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package io.flutter.plugins.camerax;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+import androidx.camera.core.CameraState;
+import io.flutter.plugin.common.BinaryMessenger;
+import io.flutter.plugins.camerax.GeneratedCameraXLibrary.CameraStateFlutterApi;
+import io.flutter.plugins.camerax.GeneratedCameraXLibrary.CameraStateType;
+import io.flutter.plugins.camerax.GeneratedCameraXLibrary.CameraStateTypeData;
+
+/**
+ * Flutter API implementation for {@link CameraState}.
+ *
+ * <p>This class may handle adding native instances that are attached to a Dart instance or passing
+ * arguments of callbacks methods to a Dart instance.
+ */
+public class CameraStateFlutterApiWrapper {
+  private final BinaryMessenger binaryMessenger;
+  private final InstanceManager instanceManager;
+  private CameraStateFlutterApi cameraStateFlutterApi;
+
+  /**
+   * Constructs a {@link CameraStateFlutterApiWrapper}.
+   *
+   * @param binaryMessenger used to communicate with Dart over asynchronous messages
+   * @param instanceManager maintains instances stored to communicate with attached Dart objects
+   */
+  public CameraStateFlutterApiWrapper(
+      @NonNull BinaryMessenger binaryMessenger, @NonNull InstanceManager instanceManager) {
+    this.binaryMessenger = binaryMessenger;
+    this.instanceManager = instanceManager;
+    cameraStateFlutterApi = new CameraStateFlutterApi(binaryMessenger);
+  }
+
+  /**
+   * Stores the {@link CameraState} instance and notifies Dart to create and store a new {@link
+   * CameraState} instance that is attached to this one. If {@code instance} has already been added,
+   * this method does nothing.
+   */
+  public void create(
+      @NonNull CameraState instance,
+      @NonNull CameraStateType type,
+      @Nullable CameraState.StateError error,
+      @NonNull CameraStateFlutterApi.Reply<Void> callback) {
+    if (instanceManager.containsInstance(instance)) {
+      return;
+    }
+
+    if (error != null) {
+      // if there is a problem with the current camera state, we need to create a CameraStateError
+      // to send to the Dart side.
+      new CameraStateErrorFlutterApiWrapper(binaryMessenger, instanceManager)
+          .create(error, Long.valueOf(error.getCode()), reply -> {});
+    }
+
+    cameraStateFlutterApi.create(
+        instanceManager.addHostCreatedInstance(instance),
+        new CameraStateTypeData.Builder().setValue(type).build(),
+        instanceManager.getIdentifierForStrongReference(error),
+        callback);
+  }
+
+  /** Converts CameraX CameraState.Type to CameraStateType that the Dart side understands. */
+  @NonNull
+  public static CameraStateType getCameraStateType(@NonNull CameraState.Type type) {
+    CameraStateType cameraStateType = null;
+    switch (type) {
+      case CLOSED:
+        cameraStateType = CameraStateType.CLOSED;
+        break;
+      case CLOSING:
+        cameraStateType = CameraStateType.CLOSING;
+        break;
+      case OPEN:
+        cameraStateType = CameraStateType.OPEN;
+        break;
+      case OPENING:
+        cameraStateType = CameraStateType.OPENING;
+        break;
+      case PENDING_OPEN:
+        cameraStateType = CameraStateType.PENDING_OPEN;
+        break;
+    }
+
+    if (cameraStateType == null) {
+      throw new IllegalArgumentException(
+          "The CameraState.Type passed to this method was not recognized.");
+    }
+    return cameraStateType;
+  }
+
+  /** Sets the Flutter API used to send messages to Dart. */
+  @VisibleForTesting
+  void setApi(@NonNull CameraStateFlutterApi api) {
+    this.cameraStateFlutterApi = api;
+  }
+}

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

@@ -32,10 +32,12 @@ public CameraSelector.Builder createCameraSelectorBuilder() {
     return new CameraSelector.Builder();
   }
 
+  /** Creates an instance of {@link CameraPermissionsManager}. */
   public CameraPermissionsManager createCameraPermissionsManager() {
     return new CameraPermissionsManager();
   }
 
+  /** Creates an instance of the {@link DeviceOrientationManager}. */
   public DeviceOrientationManager createDeviceOrientationManager(
       @NonNull Activity activity,
       @NonNull Boolean isFrontFacing,
@@ -44,16 +46,18 @@ public DeviceOrientationManager createDeviceOrientationManager(
     return new DeviceOrientationManager(activity, isFrontFacing, sensorOrientation, callback);
   }
 
+  /** Creates a builder for an instance of the {@link Preview} use case. */
   public Preview.Builder createPreviewBuilder() {
     return new Preview.Builder();
   }
 
+  /** Creates a {@link Surface} instance from the specified {@link SurfaceTexture}. */
   public Surface createSurface(@NonNull SurfaceTexture surfaceTexture) {
     return new Surface(surfaceTexture);
   }
 
   /**
-   * Creates an instance of the {@code SystemServicesFlutterApiImpl}.
+   * Creates an instance of the {@link SystemServicesFlutterApiImpl}.
    *
    * <p>Included in this class to utilize the callback methods it provides, e.g. {@code
    * onCameraError(String)}.
@@ -69,6 +73,7 @@ public Recorder.Builder createRecorderBuilder() {
     return new Recorder.Builder();
   }
 
+  /** Creates a builder for an instance of the {@link ImageCapture} use case. */
   @NonNull
   public ImageCapture.Builder createImageCaptureBuilder() {
     return new ImageCapture.Builder();