[camera] Add support for Torch and Auto Exposure (#19845)

packages/camera/CHANGELOG.md

@@ -1,7 +1,7 @@
 ## 0.5.3
-
 * Added new quality presets.
 * Now all quality presets can be used to control image capture quality.
+* Add support for Torch and Auto Exposure
 
 ## 0.5.2+2
 

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

@@ -49,6 +49,8 @@ public class Camera {
   private final Size captureSize;
   private final Size previewSize;
   private final boolean enableAudio;
+  private final boolean enableTorch;
+  private final boolean enableAE;
 
   private CameraDevice cameraDevice;
   private CameraCaptureSession cameraCaptureSession;
@@ -76,14 +78,18 @@ public Camera(
       final FlutterView flutterView,
       final String cameraName,
       final String resolutionPreset,
-      final boolean enableAudio)
+      final boolean enableAudio,
+      final boolean enableTorch,
+      final boolean enableAE)
       throws CameraAccessException {
     if (activity == null) {
       throw new IllegalStateException("No activity available!");
     }
 
     this.cameraName = cameraName;
     this.enableAudio = enableAudio;
+    this.enableTorch = enableTorch;
+    this.enableAE = enableAE;
     this.flutterTexture = flutterView.createSurfaceTexture();
     this.cameraManager = (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);
     orientationEventListener =
@@ -319,6 +325,16 @@ private void createCaptureSession(
       }
     }
 
+    // Torch
+    captureRequestBuilder.set(
+        CaptureRequest.FLASH_MODE,
+        enableTorch ? CaptureRequest.FLASH_MODE_TORCH : CaptureRequest.FLASH_MODE_OFF);
+
+    // Auto Exposure
+    captureRequestBuilder.set(
+        CaptureRequest.CONTROL_AE_MODE,
+        enableAE ? CaptureRequest.CONTROL_AE_MODE_ON : CaptureRequest.CONTROL_AE_MODE_OFF);
+
     // Prepare the callback
     CameraCaptureSession.StateCallback callback =
         new CameraCaptureSession.StateCallback() {
@@ -332,6 +348,7 @@ public void onConfigured(@NonNull CameraCaptureSession session) {
               cameraCaptureSession = session;
               captureRequestBuilder.set(
                   CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
+
               cameraCaptureSession.setRepeatingRequest(captureRequestBuilder.build(), null, null);
               if (onSuccessCallback != null) {
                 onSuccessCallback.run();
@@ -443,6 +460,42 @@ private void setImageStreamImageAvailableListener(final EventChannel.EventSink i
         null);
   }
 
+  // Torch
+  public void setTorchMode(@NonNull final Result result, boolean enable) {
+    setTorchMode(result, enable, 1.0);
+  }
+
+  public void setTorchMode(@NonNull final Result result, boolean enable, double level) {
+    try {
+      captureRequestBuilder.set(
+          CaptureRequest.FLASH_MODE,
+          enable ? CaptureRequest.FLASH_MODE_TORCH : CaptureRequest.FLASH_MODE_OFF);
+
+      captureRequestBuilder.set(
+          CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER,
+          CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER_START);
+
+      cameraCaptureSession.setRepeatingRequest(captureRequestBuilder.build(), null, null);
+      result.success(null);
+    } catch (Exception e) {
+      result.error("cameraTorchFailed", e.getMessage(), null);
+    }
+  }
+
+  public void setAEMode(@NonNull final Result result, boolean enable) {
+    try {
+      // Auto Exposure
+      captureRequestBuilder.set(
+          CaptureRequest.CONTROL_AE_MODE,
+          enable ? CaptureRequest.CONTROL_AE_MODE_ON : CaptureRequest.CONTROL_AE_MODE_OFF);
+
+      cameraCaptureSession.setRepeatingRequest(captureRequestBuilder.build(), null, null);
+      result.success(null);
+    } catch (Exception e) {
+      result.error("cameraAEFailed", e.getMessage(), null);
+    }
+  }
+
   private void sendEvent(EventType eventType) {
     sendEvent(eventType, null);
   }

packages/camera/android/src/main/java/io/flutter/plugins/camera/CameraPlugin.java

@@ -1,5 +1,6 @@
 package io.flutter.plugins.camera;
 
+import android.content.pm.PackageManager;
 import android.hardware.camera2.CameraAccessException;
 import android.os.Build;
 import androidx.annotation.NonNull;
@@ -44,7 +45,17 @@ private void instantiateCamera(MethodCall call, Result result) throws CameraAcce
     String cameraName = call.argument("cameraName");
     String resolutionPreset = call.argument("resolutionPreset");
     boolean enableAudio = call.argument("enableAudio");
-    camera = new Camera(registrar.activity(), view, cameraName, resolutionPreset, enableAudio);
+    boolean enableTorch = call.argument("enableTorch");
+    boolean enableAE = call.argument("enableAE");
+    camera =
+        new Camera(
+            registrar.activity(),
+            view,
+            cameraName,
+            resolutionPreset,
+            enableAudio,
+            enableTorch,
+            enableAE);
 
     EventChannel cameraEventChannel =
         new EventChannel(
@@ -128,6 +139,31 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull final Result result)
           }
           break;
         }
+      case "torchOn":
+        {
+          camera.setTorchMode(result, true, call.argument("level"));
+          break;
+        }
+      case "torchOff":
+        {
+          camera.setTorchMode(result, false);
+          break;
+        }
+      case "hasTorch":
+        {
+          result.success(hasTorch());
+          break;
+        }
+      case "aeOn":
+        {
+          camera.setAEMode(result, true);
+          break;
+        }
+      case "aeOff":
+        {
+          camera.setAEMode(result, false);
+          break;
+        }
       case "dispose":
         {
           if (camera != null) {
@@ -142,6 +178,14 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull final Result result)
     }
   }
 
+  private boolean hasTorch() {
+    return registrar
+        .context()
+        .getApplicationContext()
+        .getPackageManager()
+        .hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
+  }
+
   // We move catching CameraAccessException out of onMethodCall because it causes a crash
   // on plugin registration for sdks incompatible with Camera2 (< 21). We want this plugin to
   // to be able to compile with <21 sdks for apps that want the camera and support earlier version.

packages/camera/example/lib/main.dart

@@ -37,6 +37,7 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
   VideoPlayerController videoController;
   VoidCallback videoPlayerListener;
   bool enableAudio = true;
+  bool enableTorch = false;
 
   @override
   void initState() {
@@ -96,7 +97,12 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
             ),
           ),
           _captureControlRowWidget(),
-          _toggleAudioWidget(),
+          Row(
+            children: <Widget>[
+              _toggleAudioWidget(),
+              _toggleTorchWidget(),
+            ],
+          ),
           Padding(
             padding: const EdgeInsets.all(5.0),
             child: Row(
@@ -152,6 +158,39 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
     );
   }
 
+  /// Display the Torch Switch
+  Widget _toggleTorchWidget() {
+    return Padding(
+      padding: const EdgeInsets.only(left: 25),
+      child: Row(
+        children: <Widget>[
+          const Text('Enable Torch:'),
+          Switch(value: enableTorch, onChanged: _toggleTorch),
+        ],
+      ),
+    );
+  }
+
+  /// Toggle Torch
+  Future<void> _toggleTorch(bool value) async {
+    bool hasTorch = false;
+
+    if (controller != null) {
+      hasTorch = await controller.hasTorch;
+    }
+
+    if (hasTorch) {
+      enableTorch = value;
+      if (enableTorch) {
+        controller.torchOn();
+      } else {
+        controller.torchOff();
+      }
+    }
+
+    setState(() {});
+  }
+
   /// Display the thumbnail of the captured image or video.
   Widget _thumbnailWidget() {
     return Expanded(

packages/camera/ios/Classes/CameraPlugin.m

@@ -158,6 +158,8 @@ @interface FLTCam : NSObject <FlutterTexture,
 @property(readonly, nonatomic) int64_t textureId;
 @property(nonatomic, copy) void (^onFrameAvailable)();
 @property BOOL enableAudio;
+@property BOOL enableTorch;
+@property BOOL enableAE;
 @property(nonatomic) FlutterEventChannel *eventChannel;
 @property(nonatomic) FLTImageStreamHandler *imageStreamHandler;
 @property(nonatomic) FlutterEventSink eventSink;
@@ -183,6 +185,8 @@ @interface FLTCam : NSObject <FlutterTexture,
 - (instancetype)initWithCameraName:(NSString *)cameraName
                   resolutionPreset:(NSString *)resolutionPreset
                        enableAudio:(BOOL)enableAudio
+                       enableTorch:(BOOL)enableTorch
+                          enableAE:(BOOL)enableAE
                      dispatchQueue:(dispatch_queue_t)dispatchQueue
                              error:(NSError **)error;
 
@@ -193,6 +197,9 @@ - (void)stopVideoRecordingWithResult:(FlutterResult)result;
 - (void)startImageStreamWithMessenger:(NSObject<FlutterBinaryMessenger> *)messenger;
 - (void)stopImageStream;
 - (void)captureToFile:(NSString *)filename result:(FlutterResult)result;
+- (void)setTorchMode:(BOOL)enable level:(float)level;
+- (void)setTorchMode:(BOOL)enable;
+- (void)setAEMode:(BOOL)enable;
 @end
 
 @implementation FLTCam {
@@ -204,6 +211,8 @@ @implementation FLTCam {
 - (instancetype)initWithCameraName:(NSString *)cameraName
                   resolutionPreset:(NSString *)resolutionPreset
                        enableAudio:(BOOL)enableAudio
+                       enableTorch:(BOOL)enableTorch
+                          enableAE:(BOOL)enableAE
                      dispatchQueue:(dispatch_queue_t)dispatchQueue
                              error:(NSError **)error {
   self = [super init];
@@ -249,6 +258,15 @@ - (instancetype)initWithCameraName:(NSString *)cameraName
   [_motionManager startAccelerometerUpdates];
 
   [self setCaptureSessionPreset:_resolutionPreset];
+
+  if (enableTorch) {
+    [self setTorchMode:enableTorch];
+  }
+
+  if (enableAE) {
+    [self setAEMode:enableAE];
+  }
+
   return self;
 }
 
@@ -578,6 +596,44 @@ - (void)stopImageStream {
   }
 }
 
+- (bool)hasTorch {
+  AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
+  return ([device hasTorch] && [device hasFlash]);
+}
+
+- (void)setTorchMode:(BOOL)enable {
+  [self setTorchMode:enable level:1.0];
+}
+
+- (void)setTorchMode:(BOOL)enable level:(float)level {
+  AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
+  if ([device hasTorch] && [device hasFlash]) {
+    [device lockForConfiguration:nil];
+    if (enable) {
+      NSError *error = nil;
+      float acceptedLevel =
+          (level < AVCaptureMaxAvailableTorchLevel ? level : AVCaptureMaxAvailableTorchLevel);
+      NSLog(@"FLash level: %f", acceptedLevel);
+      [device setTorchModeOnWithLevel:acceptedLevel error:&error];
+    } else {
+      [device setTorchMode:AVCaptureTorchModeOff];
+    }
+    [device unlockForConfiguration];
+  }
+}
+
+- (void)setAEMode:(BOOL)enable {
+  AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
+  [device lockForConfiguration:nil];
+  if (enable) {
+    int exposure = AVCaptureExposureModeContinuousAutoExposure;
+    if (exposure && [device isExposureModeSupported:exposure]) device.exposureMode = exposure;
+  } else {
+    device.exposureMode = AVCaptureExposureModeAutoExpose;
+  }
+  [device unlockForConfiguration];
+}
+
 - (BOOL)setupWriterForPath:(NSString *)path {
   NSError *error = nil;
   NSURL *outputURL;
@@ -734,10 +790,14 @@ - (void)handleMethodCallAsync:(FlutterMethodCall *)call result:(FlutterResult)re
     NSString *cameraName = call.arguments[@"cameraName"];
     NSString *resolutionPreset = call.arguments[@"resolutionPreset"];
     NSNumber *enableAudio = call.arguments[@"enableAudio"];
+    NSNumber *enableTorch = call.arguments[@"enableTorch"];
+    NSNumber *enableAE = call.arguments[@"enableAE"];
     NSError *error;
     FLTCam *cam = [[FLTCam alloc] initWithCameraName:cameraName
                                     resolutionPreset:resolutionPreset
                                          enableAudio:[enableAudio boolValue]
+                                         enableTorch:[enableTorch boolValue]
+                                            enableAE:[enableAE boolValue]
                                        dispatchQueue:_dispatchQueue
                                                error:&error];
     if (error) {
@@ -773,6 +833,21 @@ - (void)handleMethodCallAsync:(FlutterMethodCall *)call result:(FlutterResult)re
   } else if ([@"stopImageStream" isEqualToString:call.method]) {
     [_camera stopImageStream];
     result(nil);
+  } else if ([@"hasTorch" isEqualToString:call.method]) {
+    result([NSNumber numberWithBool:[_camera hasTorch]]);
+  } else if ([@"torchOn" isEqualToString:call.method]) {
+    NSNumber *level = call.arguments[@"level"];
+    [_camera setTorchMode:true level:[level floatValue]];
+    result(nil);
+  } else if ([@"torchOff" isEqualToString:call.method]) {
+    [_camera setTorchMode:false];
+    result(nil);
+  } else if ([@"aeOn" isEqualToString:call.method]) {
+    [_camera setAEMode:true];
+    result(nil);
+  } else if ([@"aeOff" isEqualToString:call.method]) {
+    [_camera setAEMode:false];
+    result(nil);
   } else {
     NSDictionary *argsMap = call.arguments;
     NSUInteger textureId = ((NSNumber *)argsMap[@"textureId"]).unsignedIntegerValue;