[camerax] Add system services to plugin

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

@@ -11,12 +11,14 @@
 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;
-  public ProcessCameraProviderHostApiImpl processCameraProviderHostApi;
+  private ProcessCameraProviderHostApiImpl processCameraProviderHostApi;
+  public SystemServicesHostApiImpl systemServicesHostApi;
 
   /**
    * Initialize this within the {@code #configureFlutterEngine} of a Flutter activity or fragment.
@@ -25,7 +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(
@@ -45,6 +47,8 @@ void setUp(BinaryMessenger binaryMessenger, Context context) {
         new ProcessCameraProviderHostApiImpl(binaryMessenger, instanceManager, context);
     GeneratedCameraXLibrary.ProcessCameraProviderHostApi.setup(
         binaryMessenger, processCameraProviderHostApi);
+    systemServicesHostApi = new SystemServicesHostApiImpl(binaryMessenger, instanceManager);
+    GeneratedCameraXLibrary.SystemServicesHostApi.setup(binaryMessenger, systemServicesHostApi);
   }
 
   @Override
@@ -63,10 +67,16 @@ public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
 
   @Override
   public void onAttachedToActivity(@NonNull ActivityPluginBinding activityPluginBinding) {
-    setUp(pluginBinding.getBinaryMessenger(), pluginBinding.getApplicationContext());
+    setUp(
+        pluginBinding.getBinaryMessenger(),
+        pluginBinding.getApplicationContext(),
+        pluginBinding.getTextureRegistry());
     updateContext(pluginBinding.getApplicationContext());
     processCameraProviderHostApi.setLifecycleOwner(
         (LifecycleOwner) activityPluginBinding.getActivity());
+    systemServicesHostApi.setActivity(activityPluginBinding.getActivity());
+    systemServicesHostApi.setPermissionsRegistry(
+        activityPluginBinding::addRequestPermissionsResultListener);
   }
 
   @Override

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

@@ -0,0 +1,120 @@
+// 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 CameraPermissionsManager {
+  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;
+      // grantResults could be empty if the permissions request with the user is interrupted
+      // https://developer.android.com/reference/android/app/Activity#onRequestPermissionsResult(int,%20java.lang.String[],%20int[])
+      if (grantResults.length == 0 || 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;
+    }
+  }
+}

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

@@ -4,10 +4,23 @@
 
 package io.flutter.plugins.camerax;
 
+import android.app.Activity;
 import androidx.camera.core.CameraSelector;
 
 public class CameraXProxy {
   public CameraSelector.Builder createCameraSelectorBuilder() {
     return new CameraSelector.Builder();
   }
+
+  public CameraPermissionsManager createCameraPermissionsManager() {
+    return new CameraPermissionsManager();
+  }
+
+  public DeviceOrientationManager createDeviceOrientationManager(
+      Activity activity,
+      Boolean isFrontFacing,
+      int sensorOrientation,
+      DeviceOrientationManager.DeviceOrientationChangeCallback callback) {
+    return new DeviceOrientationManager(activity, isFrontFacing, sensorOrientation, callback);
+  }
 }