[camera] Add implementations for the torch flash mode. (flutter#3338)

* Added torch mode functionality for Android and iOS.

* Format objective c code

packages/camera/camera/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.6.3
+
+* Adds torch mode as a flash mode for Android and iOS implementations.
+
 ## 0.6.2+1
 
 * Fix the API documentation for the `CameraController.takePicture` method.

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

@@ -532,7 +532,6 @@ public void setFlashMode(@NonNull final Result result, FlashMode mode)
       return;
     }
     // Get flash
-
     this.flashMode = mode;
     initPreviewCaptureBuilder();
     this.cameraCaptureSession.setRepeatingRequest(captureRequestBuilder.build(), null, null);
@@ -553,11 +552,16 @@ private void initPreviewCaptureBuilder() {
         captureRequestBuilder.set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_OFF);
         break;
       case always:
-      default:
         captureRequestBuilder.set(
             CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_ALWAYS_FLASH);
         captureRequestBuilder.set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_OFF);
         break;
+      case torch:
+      default:
+        captureRequestBuilder.set(
+            CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON);
+        captureRequestBuilder.set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_TORCH);
+        break;
     }
   }
 

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/types/FlashMode.java

@@ -4,7 +4,8 @@
 public enum FlashMode {
   off,
   auto,
-  always;
+  always,
+  torch;
 
   public static FlashMode getValueForString(String modeStr) {
     try {

packages/camera/camera/android/src/test/java/io/flutter/plugins/camera/types/FlashModeTest.java

@@ -16,6 +16,10 @@ public void getValueForString_returns_correct_values() {
         "Returns FlashMode.always for 'always'",
         FlashMode.getValueForString("always"),
         FlashMode.always);
+    assertEquals(
+        "Returns FlashMode.torch for 'torch'",
+        FlashMode.getValueForString("torch"),
+        FlashMode.torch);
   }
 
   @Test

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

@@ -256,6 +256,15 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
               ? () => onFlashModeButtonPressed(FlashMode.always)
               : null,
         ),
+        IconButton(
+          icon: const Icon(Icons.highlight),
+          color: controller?.value?.flashMode == FlashMode.torch
+              ? Colors.orange
+              : Colors.blue,
+          onPressed: controller != null
+              ? () => onFlashModeButtonPressed(FlashMode.torch)
+              : null,
+        ),
       ],
     );
   }

packages/camera/camera/ios/Classes/CameraPlugin.m

@@ -134,13 +134,23 @@ - (UIImageOrientation)getImageRotation {
 }
 @end
 
-static AVCaptureFlashMode getFlashModeForString(NSString *mode) {
+// Mirrors FlashMode in flash_mode.dart
+typedef enum {
+  FlashModeOff,
+  FlashModeAuto,
+  FlashModeAlways,
+  FlashModeTorch,
+} FlashMode;
+
+static FlashMode getFlashModeForString(NSString *mode) {
   if ([mode isEqualToString:@"off"]) {
-    return AVCaptureFlashModeOff;
+    return FlashModeOff;
   } else if ([mode isEqualToString:@"auto"]) {
-    return AVCaptureFlashModeAuto;
+    return FlashModeAuto;
   } else if ([mode isEqualToString:@"always"]) {
-    return AVCaptureFlashModeOn;
+    return FlashModeAlways;
+  } else if ([mode isEqualToString:@"torch"]) {
+    return FlashModeTorch;
   } else {
     NSError *error = [NSError errorWithDomain:NSCocoaErrorDomain
                                          code:NSURLErrorUnknown
@@ -152,6 +162,20 @@ static AVCaptureFlashMode getFlashModeForString(NSString *mode) {
   }
 }
 
+static AVCaptureFlashMode getAVCaptureFlashModeForFlashMode(FlashMode mode) {
+  switch (mode) {
+    case FlashModeOff:
+      return AVCaptureFlashModeOff;
+    case FlashModeAuto:
+      return AVCaptureFlashModeAuto;
+    case FlashModeAlways:
+      return AVCaptureFlashModeOn;
+    case FlashModeTorch:
+    default:
+      return -1;
+  }
+}
+
 // Mirrors ResolutionPreset in camera.dart
 typedef enum {
   veryLow,
@@ -219,7 +243,7 @@ @interface FLTCam : NSObject <FlutterTexture,
 @property(assign, nonatomic) BOOL isAudioSetup;
 @property(assign, nonatomic) BOOL isStreamingImages;
 @property(assign, nonatomic) ResolutionPreset resolutionPreset;
-@property(assign, nonatomic) AVCaptureFlashMode flashMode;
+@property(assign, nonatomic) FlashMode flashMode;
 @property(assign, nonatomic) CMTime lastVideoSampleTime;
 @property(assign, nonatomic) CMTime lastAudioSampleTime;
 @property(assign, nonatomic) CMTime videoTimeOffset;
@@ -250,7 +274,7 @@ - (instancetype)initWithCameraName:(NSString *)cameraName
   _enableAudio = enableAudio;
   _dispatchQueue = dispatchQueue;
   _captureSession = [[AVCaptureSession alloc] init];
-  _flashMode = AVCaptureFlashModeAuto;
+  _flashMode = FlashModeAuto;
 
   _captureDevice = [AVCaptureDevice deviceWithUniqueID:cameraName];
   NSError *localError = nil;
@@ -303,7 +327,10 @@ - (void)captureToFile:(FlutterResult)result API_AVAILABLE(ios(10)) {
   if (_resolutionPreset == max) {
     [settings setHighResolutionPhotoEnabled:YES];
   }
-  [settings setFlashMode:_flashMode];
+  AVCaptureFlashMode avFlashMode = getAVCaptureFlashModeForFlashMode(_flashMode);
+  if (avFlashMode != -1) {
+    [settings setFlashMode:avFlashMode];
+  }
   NSError *error;
   NSString *path = [self getTemporaryFilePathWithExtension:@"jpg"
                                                  subfolder:@"pictures"
@@ -694,25 +721,51 @@ - (void)resumeVideoRecordingWithResult:(FlutterResult)result {
 }
 
 - (void)setFlashModeWithResult:(FlutterResult)result mode:(NSString *)modeStr {
-  AVCaptureFlashMode mode;
+  FlashMode mode;
   @try {
     mode = getFlashModeForString(modeStr);
   } @catch (NSError *e) {
     result(getFlutterError(e));
     return;
   }
-  if (!_captureDevice.hasFlash) {
-    result([FlutterError errorWithCode:@"setFlashModeFailed"
-                               message:@"Device does not have flash capabilities"
-                               details:nil]);
-    return;
-  }
-  if (![_capturePhotoOutput.supportedFlashModes
-          containsObject:[NSNumber numberWithInt:((int)mode)]]) {
-    result([FlutterError errorWithCode:@"setFlashModeFailed"
-                               message:@"Device does not support this specific flash mode"
-                               details:nil]);
-    return;
+  if (mode == FlashModeTorch) {
+    if (!_captureDevice.hasTorch) {
+      result([FlutterError errorWithCode:@"setFlashModeFailed"
+                                 message:@"Device does not support torch mode"
+                                 details:nil]);
+      return;
+    }
+    if (!_captureDevice.isTorchAvailable) {
+      result([FlutterError errorWithCode:@"setFlashModeFailed"
+                                 message:@"Torch mode is currently not available"
+                                 details:nil]);
+      return;
+    }
+    if (_captureDevice.torchMode != AVCaptureTorchModeOn) {
+      [_captureDevice lockForConfiguration:nil];
+      [_captureDevice setTorchMode:AVCaptureTorchModeOn];
+      [_captureDevice unlockForConfiguration];
+    }
+  } else {
+    if (!_captureDevice.hasFlash) {
+      result([FlutterError errorWithCode:@"setFlashModeFailed"
+                                 message:@"Device does not have flash capabilities"
+                                 details:nil]);
+      return;
+    }
+    AVCaptureFlashMode avFlashMode = getAVCaptureFlashModeForFlashMode(mode);
+    if (![_capturePhotoOutput.supportedFlashModes
+            containsObject:[NSNumber numberWithInt:((int)avFlashMode)]]) {
+      result([FlutterError errorWithCode:@"setFlashModeFailed"
+                                 message:@"Device does not support this specific flash mode"
+                                 details:nil]);
+      return;
+    }
+    if (_captureDevice.torchMode != AVCaptureTorchModeOff) {
+      [_captureDevice lockForConfiguration:nil];
+      [_captureDevice setTorchMode:AVCaptureTorchModeOff];
+      [_captureDevice unlockForConfiguration];
+    }
   }
   _flashMode = mode;
   result(nil);
@@ -854,6 +907,12 @@ - (BOOL)setupWriterForPath:(NSString *)path {
     [_audioOutput setSampleBufferDelegate:self queue:_dispatchQueue];
   }
 
+  if (_flashMode == FlashModeTorch) {
+    [self.captureDevice lockForConfiguration:nil];
+    [self.captureDevice setTorchMode:AVCaptureTorchModeOn];
+    [self.captureDevice unlockForConfiguration];
+  }
+
   [_videoWriter addInput:_videoWriterInput];
   [_captureVideoOutput setSampleBufferDelegate:self queue:_dispatchQueue];
 

packages/camera/camera/pubspec.yaml

@@ -2,7 +2,7 @@ name: camera
 description: A Flutter plugin for getting information about and controlling the
   camera on Android and iOS. Supports previewing the camera feed, capturing images, capturing video,
   and streaming image buffers to dart.
-version: 0.6.2+1
+version: 0.6.3
 homepage: https://github.com/flutter/plugins/tree/master/packages/camera/camera
 
 dependencies:

packages/camera/camera_platform_interface/test/method_channel/method_channel_camera_test.dart

@@ -478,12 +478,15 @@ void main() {
         );
 
         // Act
+        await camera.setFlashMode(cameraId, FlashMode.torch);
         await camera.setFlashMode(cameraId, FlashMode.always);
         await camera.setFlashMode(cameraId, FlashMode.auto);
         await camera.setFlashMode(cameraId, FlashMode.off);
 
         // Assert
         expect(channel.log, <Matcher>[
+          isMethodCall('setFlashMode',
+              arguments: {'cameraId': cameraId, 'mode': 'torch'}),
           isMethodCall('setFlashMode',
               arguments: {'cameraId': cameraId, 'mode': 'always'}),
           isMethodCall('setFlashMode',