CameraX Preview Proof of Concept

packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/Camera.java

@@ -108,7 +108,7 @@ class Camera
   static {
     supportedImageFormats = new HashMap<>();
     supportedImageFormats.put("yuv420", ImageFormat.YUV_420_888);
-    supportedImageFormats.put("jpeg", ImageFormat.JPEG);
+    supportedImageFormats.put("jpeg", ImageFormat.JPEG); // may not be supported by image streaming
   }
 
   /**
@@ -399,6 +399,7 @@ private void createCaptureSession(
     // Build Flutter surface to render to.
     ResolutionFeature resolutionFeature = cameraFeatures.getResolution();
     SurfaceTexture surfaceTexture = flutterTexture.surfaceTexture();
+    // you shouldn't be able to set arbitrary size
     surfaceTexture.setDefaultBufferSize(
         resolutionFeature.getPreviewSize().getWidth(),
         resolutionFeature.getPreviewSize().getHeight());

packages/camera/camera_android/example/lib/main.dart

@@ -1090,4 +1090,4 @@ Future<void> main() async {
 /// We use this so that APIs that have become non-nullable can still be used
 /// with `!` and `?` on the stable branch.
 // TODO(ianh): Remove this once we roll stable in late 2021.
-T? _ambiguate<T>(T? value) => value;
+T? _ambiguate<T>(T? value) => value;

packages/camera/camera_android_camerax/android/src/main/AndroidManifest.xml

@@ -1,3 +1,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="io.flutter.plugins.camerax">
+  <uses-feature android:name="android.hardware.camera.any" />
+<uses-permission android:name="android.permission.CAMERA" />
+<uses-permission android:name="android.permission.RECORD_AUDIO" />
+<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
+   android:maxSdkVersion="28" />
 </manifest>

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

@@ -6,16 +6,19 @@
 
 import android.content.Context;
 import androidx.annotation.NonNull;
+import androidx.lifecycle.LifecycleOwner;
 import io.flutter.embedding.engine.plugins.FlutterPlugin;
 import io.flutter.embedding.engine.plugins.activity.ActivityAware;
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
 import io.flutter.plugin.common.BinaryMessenger;
+import io.flutter.view.TextureRegistry;
 
 /** Platform implementation of the camera_plugin implemented with the CameraX library. */
 public final class CameraAndroidCameraxPlugin implements FlutterPlugin, ActivityAware {
   private InstanceManager instanceManager;
   private FlutterPluginBinding pluginBinding;
-  private ProcessCameraProviderHostApiImpl processCameraProviderHostApi;
+  public ProcessCameraProviderHostApiImpl processCameraProviderHostApi;
+  public SystemServicesHostApiImpl systemServicesHostApi;
 
   /**
    * Initialize this within the {@code #configureFlutterEngine} of a Flutter activity or fragment.
@@ -24,7 +27,7 @@ public final class CameraAndroidCameraxPlugin implements FlutterPlugin, Activity
    */
   public CameraAndroidCameraxPlugin() {}
 
-  void setUp(BinaryMessenger binaryMessenger, Context context) {
+  void setUp(BinaryMessenger binaryMessenger, Context context, TextureRegistry textureRegistry) {
     // Set up instance manager.
     instanceManager =
         InstanceManager.open(
@@ -34,25 +37,30 @@ void setUp(BinaryMessenger binaryMessenger, Context context) {
             });
 
     // Set up Host APIs.
+    // TODO(camsim99): Alphabetize these.
     GeneratedCameraXLibrary.CameraInfoHostApi.setup(
         binaryMessenger, new CameraInfoHostApiImpl(instanceManager));
     GeneratedCameraXLibrary.JavaObjectHostApi.setup(
         binaryMessenger, new JavaObjectHostApiImpl(instanceManager));
     GeneratedCameraXLibrary.CameraSelectorHostApi.setup(
         binaryMessenger, new CameraSelectorHostApiImpl(binaryMessenger, instanceManager));
+    GeneratedCameraXLibrary.CameraHostApi.setup(
+        binaryMessenger, new CameraHostApiImpl(binaryMessenger, instanceManager));
+    GeneratedCameraXLibrary.CameraControlHostApi.setup(
+        binaryMessenger, new CameraControlHostApiImpl(binaryMessenger, instanceManager));
+    GeneratedCameraXLibrary.PreviewHostApi.setup(
+        binaryMessenger, new PreviewHostApiImpl(binaryMessenger, instanceManager, textureRegistry));
     processCameraProviderHostApi =
         new ProcessCameraProviderHostApiImpl(binaryMessenger, instanceManager, context);
     GeneratedCameraXLibrary.ProcessCameraProviderHostApi.setup(
         binaryMessenger, processCameraProviderHostApi);
+    systemServicesHostApi = new SystemServicesHostApiImpl(binaryMessenger, instanceManager);
+    GeneratedCameraXLibrary.SystemServicesHostApi.setup(binaryMessenger, systemServicesHostApi);
   }
 
   @Override
   public void onAttachedToEngine(@NonNull FlutterPluginBinding flutterPluginBinding) {
     pluginBinding = flutterPluginBinding;
-    (new CameraAndroidCameraxPlugin())
-        .setUp(
-            flutterPluginBinding.getBinaryMessenger(),
-            flutterPluginBinding.getApplicationContext());
   }
 
   @Override
@@ -66,7 +74,16 @@ public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
 
   @Override
   public void onAttachedToActivity(@NonNull ActivityPluginBinding activityPluginBinding) {
-    updateContext(activityPluginBinding.getActivity());
+    this.setUp(
+        pluginBinding.getBinaryMessenger(),
+        pluginBinding.getApplicationContext(),
+        pluginBinding.getTextureRegistry());
+    this.updateContext(pluginBinding.getApplicationContext());
+    this.processCameraProviderHostApi.setLifecycleOwner(
+        (LifecycleOwner) activityPluginBinding.getActivity());
+    this.systemServicesHostApi.setActivity(activityPluginBinding.getActivity());
+    this.systemServicesHostApi.setPermissionsRegistry(
+        activityPluginBinding::addRequestPermissionsResultListener);
   }
 
   @Override
@@ -89,7 +106,7 @@ public void onDetachedFromActivity() {
    * Updates context that is used to fetch the corresponding instance of a {@code
    * ProcessCameraProvider}.
    */
-  private void updateContext(Context context) {
+  public void updateContext(Context context) {
     if (processCameraProviderHostApi != null) {
       processCameraProviderHostApi.setContext(context);
     }

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

@@ -0,0 +1,23 @@
+// 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.camera.core.CameraControl;
+import io.flutter.plugin.common.BinaryMessenger;
+import io.flutter.plugins.camerax.GeneratedCameraXLibrary.CameraControlFlutterApi;
+
+public class CameraControlFlutterApiImpl extends CameraControlFlutterApi {
+  private final InstanceManager instanceManager;
+
+  public CameraControlFlutterApiImpl(
+      BinaryMessenger binaryMessenger, InstanceManager instanceManager) {
+    super(binaryMessenger);
+    this.instanceManager = instanceManager;
+  }
+
+  void create(CameraControl cameraControl, Reply<Void> reply) {
+    create(instanceManager.addHostCreatedInstance(cameraControl), reply);
+  }
+}

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

@@ -0,0 +1,27 @@
+// 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.camera.core.CameraControl;
+import io.flutter.plugin.common.BinaryMessenger;
+import io.flutter.plugins.camerax.GeneratedCameraXLibrary.CameraControlHostApi;
+
+public class CameraControlHostApiImpl implements CameraControlHostApi {
+  private final BinaryMessenger binaryMessenger;
+  private final InstanceManager instanceManager;
+
+  public CameraControlHostApiImpl(
+      BinaryMessenger binaryMessenger, InstanceManager instanceManager) {
+    this.binaryMessenger = binaryMessenger;
+    this.instanceManager = instanceManager;
+  }
+
+  @Override
+  public void setZoomRatio(@NonNull Long identifier, @NonNull Long ratio) {
+    CameraControl cameraControl = (CameraControl) instanceManager.getInstance(identifier);
+    cameraControl.setZoomRatio(ratio);
+  }
+}

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

@@ -0,0 +1,22 @@
+// 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.camera.core.Camera;
+import io.flutter.plugin.common.BinaryMessenger;
+import io.flutter.plugins.camerax.GeneratedCameraXLibrary.CameraFlutterApi;
+
+public class CameraFlutterApiImpl extends CameraFlutterApi {
+  private final InstanceManager instanceManager;
+
+  public CameraFlutterApiImpl(BinaryMessenger binaryMessenger, InstanceManager instanceManager) {
+    super(binaryMessenger);
+    this.instanceManager = instanceManager;
+  }
+
+  void create(Camera camera, Reply<Void> reply) {
+    create(instanceManager.addHostCreatedInstance(camera), reply);
+  }
+}

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

@@ -0,0 +1,32 @@
+// 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.camera.core.Camera;
+import androidx.camera.core.CameraControl;
+import io.flutter.plugin.common.BinaryMessenger;
+import io.flutter.plugins.camerax.GeneratedCameraXLibrary.CameraHostApi;
+
+public class CameraHostApiImpl implements CameraHostApi {
+  private final BinaryMessenger binaryMessenger;
+  private final InstanceManager instanceManager;
+
+  public CameraHostApiImpl(BinaryMessenger binaryMessenger, InstanceManager instanceManager) {
+    this.binaryMessenger = binaryMessenger;
+    this.instanceManager = instanceManager;
+  }
+
+  @Override
+  public Long getCameraControl(@NonNull Long identifier) {
+    Camera camera = (Camera) instanceManager.getInstance(identifier);
+    CameraControl cameraControl = camera.getCameraControl();
+
+    final CameraControlFlutterApiImpl cameraControlFlutterApiImpl =
+        new CameraControlFlutterApiImpl(binaryMessenger, instanceManager);
+    cameraControlFlutterApiImpl.create(cameraControl, result -> {});
+    return instanceManager.getIdentifierForStrongReference(cameraControl);
+  }
+}

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

@@ -0,0 +1,118 @@
+// 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 android.Manifest;
+import android.Manifest.permission;
+import android.app.Activity;
+import android.content.pm.PackageManager;
+import androidx.annotation.VisibleForTesting;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+
+final class CameraPermissions {
+  interface PermissionsRegistry {
+    @SuppressWarnings("deprecation")
+    void addListener(
+        io.flutter.plugin.common.PluginRegistry.RequestPermissionsResultListener handler);
+  }
+
+  interface ResultCallback {
+    void onResult(String errorCode, String errorDescription);
+  }
+
+  /**
+   * Camera access permission errors handled when camera is created. See {@code MethodChannelCamera}
+   * in {@code camera/camera_platform_interface} for details.
+   */
+  private static final String CAMERA_PERMISSIONS_REQUEST_ONGOING =
+      "CameraPermissionsRequestOngoing";
+
+  private static final String CAMERA_PERMISSIONS_REQUEST_ONGOING_MESSAGE =
+      "Another request is ongoing and multiple requests cannot be handled at once.";
+  private static final String CAMERA_ACCESS_DENIED = "CameraAccessDenied";
+  private static final String CAMERA_ACCESS_DENIED_MESSAGE = "Camera access permission was denied.";
+  private static final String AUDIO_ACCESS_DENIED = "AudioAccessDenied";
+  private static final String AUDIO_ACCESS_DENIED_MESSAGE = "Audio access permission was denied.";
+
+  private static final int CAMERA_REQUEST_ID = 9796;
+  @VisibleForTesting boolean ongoing = false;
+
+  void requestPermissions(
+      Activity activity,
+      PermissionsRegistry permissionsRegistry,
+      boolean enableAudio,
+      ResultCallback callback) {
+    if (ongoing) {
+      callback.onResult(
+          CAMERA_PERMISSIONS_REQUEST_ONGOING, CAMERA_PERMISSIONS_REQUEST_ONGOING_MESSAGE);
+      return;
+    }
+    if (!hasCameraPermission(activity) || (enableAudio && !hasAudioPermission(activity))) {
+      permissionsRegistry.addListener(
+          new CameraRequestPermissionsListener(
+              (String errorCode, String errorDescription) -> {
+                ongoing = false;
+                callback.onResult(errorCode, errorDescription);
+              }));
+      ongoing = true;
+      ActivityCompat.requestPermissions(
+          activity,
+          enableAudio
+              ? new String[] {Manifest.permission.CAMERA, Manifest.permission.RECORD_AUDIO}
+              : new String[] {Manifest.permission.CAMERA},
+          CAMERA_REQUEST_ID);
+    } else {
+      // Permissions already exist. Call the callback with success.
+      callback.onResult(null, null);
+    }
+  }
+
+  private boolean hasCameraPermission(Activity activity) {
+    return ContextCompat.checkSelfPermission(activity, permission.CAMERA)
+        == PackageManager.PERMISSION_GRANTED;
+  }
+
+  private boolean hasAudioPermission(Activity activity) {
+    return ContextCompat.checkSelfPermission(activity, permission.RECORD_AUDIO)
+        == PackageManager.PERMISSION_GRANTED;
+  }
+
+  @VisibleForTesting
+  @SuppressWarnings("deprecation")
+  static final class CameraRequestPermissionsListener
+      implements io.flutter.plugin.common.PluginRegistry.RequestPermissionsResultListener {
+
+    // There's no way to unregister permission listeners in the v1 embedding, so we'll be called
+    // duplicate times in cases where the user denies and then grants a permission. Keep track of if
+    // we've responded before and bail out of handling the callback manually if this is a repeat
+    // call.
+    boolean alreadyCalled = false;
+
+    final ResultCallback callback;
+
+    @VisibleForTesting
+    CameraRequestPermissionsListener(ResultCallback callback) {
+      this.callback = callback;
+    }
+
+    @Override
+    public boolean onRequestPermissionsResult(int id, String[] permissions, int[] grantResults) {
+      if (alreadyCalled || id != CAMERA_REQUEST_ID) {
+        return false;
+      }
+
+      alreadyCalled = true;
+      if (grantResults[0] != PackageManager.PERMISSION_GRANTED) {
+        callback.onResult(CAMERA_ACCESS_DENIED, CAMERA_ACCESS_DENIED_MESSAGE);
+      } else if (grantResults.length > 1 && grantResults[1] != PackageManager.PERMISSION_GRANTED) {
+        callback.onResult(AUDIO_ACCESS_DENIED, AUDIO_ACCESS_DENIED_MESSAGE);
+      } else {
+        callback.onResult(null, null);
+      }
+      return true;
+    }
+  }
+}