Tap-to-focus and Pinch-to-zoom

CameraFocusSquare.h

@@ -0,0 +1,3 @@
+#import <UIKit/UIKit.h>
+@interface RCTCameraFocusSquare : UIView
+@end

CameraFocusSquare.m

@@ -0,0 +1,28 @@
+#import "CameraFocusSquare.h"
+#import <QuartzCore/QuartzCore.h>
+
+const float squareLength = 80.0f;
+@implementation RCTCameraFocusSquare
+
+- (id)initWithFrame:(CGRect)frame 
+{
+    self = [super initWithFrame:frame];
+    if (self) {
+        // Initialization code
+
+        [self setBackgroundColor:[UIColor clearColor]];
+        [self.layer setBorderWidth:2.0];
+        [self.layer setCornerRadius:4.0];
+        [self.layer setBorderColor:[UIColor whiteColor].CGColor];
+
+        CABasicAnimation* selectionAnimation = [CABasicAnimation
+                                                animationWithKeyPath:@"borderColor"];
+        selectionAnimation.toValue = (id)[UIColor blueColor].CGColor;
+        selectionAnimation.repeatCount = 8;
+        [self.layer addAnimation:selectionAnimation
+                          forKey:@"selectionAnimation"];
+
+    }
+    return self;
+}
+@end

RCTCamera.h

@@ -1,11 +1,14 @@
 #import <UIKit/UIKit.h>
 #import <AVFoundation/AVFoundation.h>
+#import "CameraFocusSquare.h"
 
 @class RCTCameraManager;
 
 @interface RCTCamera : UIView
 
 @property (nonatomic) RCTCameraManager *manager;
+@property (nonatomic) RCTCameraFocusSquare *camFocus;
+@property (nonatomic) BOOL multipleTouches;
 
 - (id)initWithManager:(RCTCameraManager*)manager;
 

RCTCamera.m

@@ -5,6 +5,7 @@
 #import "RCTUtils.h"
 
 #import <AVFoundation/AVFoundation.h>
+#import "CameraFocusSquare.h"
 
 @implementation RCTCamera
 
@@ -64,8 +65,11 @@
   
   if ((self = [super init])) {
     self.manager = manager;
+    UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinchToZoomRecognizer:)];
+    [self addGestureRecognizer:pinchGesture];
     [self.manager initializeCaptureSessionInput:AVMediaTypeVideo];
     [self.manager startSession];
+    self.multipleTouches = NO;
   }
   return self;
 }
@@ -102,4 +106,55 @@
   [self.manager changeOrientation:orientation];
 }
 
+
+- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
+{
+    // Update the touch state.
+    if ([[event touchesForView:self] count] > 1) {
+        self.multipleTouches = YES;
+    }
+
+}
+
+- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
+{
+    BOOL allTouchesEnded = ([touches count] == [[event touchesForView:self] count]);
+
+    // Do not conflict with zooming and etc.
+    if (allTouchesEnded && !self.multipleTouches) {
+        UITouch *touch = [[event allTouches] anyObject];
+        CGPoint touchPoint = [touch locationInView:touch.view];
+        // Focus camera on this point
+        [self.manager focusAtThePoint:touchPoint];
+
+        if (self.camFocus)
+        {
+            [self.camFocus removeFromSuperview];
+        }
+        // Show animated rectangle on the touched area
+        self.camFocus = [[RCTCameraFocusSquare alloc]initWithFrame:CGRectMake(touchPoint.x-40, touchPoint.y-40, 80, 80)];
+        [self.camFocus setBackgroundColor:[UIColor clearColor]];
+        [self addSubview:self.camFocus];
+        [self.camFocus setNeedsDisplay];
+
+        [UIView beginAnimations:nil context:NULL];
+        [UIView setAnimationDuration:1.0];
+        [self.camFocus setAlpha:0.0];
+        [UIView commitAnimations];
+    }
+
+    if (allTouchesEnded) {
+        self.multipleTouches = NO;
+    }
+
+}
+
+
+-(void) handlePinchToZoomRecognizer:(UIPinchGestureRecognizer*)pinchRecognizer {
+    if (pinchRecognizer.state == UIGestureRecognizerStateChanged) {
+        [self.manager zoom:pinchRecognizer.velocity];
+    }
+}
+
+
 @end

RCTCamera.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		0314E39D1B661A460092D183 /* CameraFocusSquare.m in Sources */ = {isa = PBXBuildFile; fileRef = 0314E39C1B661A460092D183 /* CameraFocusSquare.m */; };
 		4107014D1ACB732B00C6AA39 /* RCTCamera.m in Sources */ = {isa = PBXBuildFile; fileRef = 410701481ACB732B00C6AA39 /* RCTCamera.m */; };
 		4107014E1ACB732B00C6AA39 /* RCTCameraManager.m in Sources */ = {isa = PBXBuildFile; fileRef = 4107014A1ACB732B00C6AA39 /* RCTCameraManager.m */; };
 		454EBCF41B5082DC00AD0F86 /* NSMutableDictionary+ImageMetadata.m in Sources */ = {isa = PBXBuildFile; fileRef = 454EBCF31B5082DC00AD0F86 /* NSMutableDictionary+ImageMetadata.m */; };
@@ -25,6 +26,8 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		0314E39B1B661A0C0092D183 /* CameraFocusSquare.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = CameraFocusSquare.h; sourceTree = "<group>"; };
+		0314E39C1B661A460092D183 /* CameraFocusSquare.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = CameraFocusSquare.m; sourceTree = "<group>"; };
 		4107012F1ACB723B00C6AA39 /* libRCTCamera.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = libRCTCamera.a; sourceTree = BUILT_PRODUCTS_DIR; };
 		410701471ACB732B00C6AA39 /* RCTCamera.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = RCTCamera.h; sourceTree = "<group>"; };
 		410701481ACB732B00C6AA39 /* RCTCamera.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = RCTCamera.m; sourceTree = "<group>"; };
@@ -47,6 +50,8 @@
 		410701241ACB719800C6AA39 = {
 			isa = PBXGroup;
 			children = (
+				0314E39C1B661A460092D183 /* CameraFocusSquare.m */,
+				0314E39B1B661A0C0092D183 /* CameraFocusSquare.h */,
 				454EBCF31B5082DC00AD0F86 /* NSMutableDictionary+ImageMetadata.m */,
 				410701471ACB732B00C6AA39 /* RCTCamera.h */,
 				410701481ACB732B00C6AA39 /* RCTCamera.m */,
@@ -119,6 +124,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				0314E39D1B661A460092D183 /* CameraFocusSquare.m in Sources */,
 				454EBCF41B5082DC00AD0F86 /* NSMutableDictionary+ImageMetadata.m in Sources */,
 				4107014E1ACB732B00C6AA39 /* RCTCameraManager.m in Sources */,
 				4107014D1ACB732B00C6AA39 /* RCTCamera.m in Sources */,

RCTCameraManager.h

@@ -60,6 +60,7 @@ typedef NS_ENUM(NSInteger, RCTCameraTorchMode) {
 @property (nonatomic) NSInteger videoTarget;
 @property (nonatomic, strong) RCTResponseSenderBlock videoCallback;
 
+
 - (void)changeAspect:(NSString *)aspect;
 - (void)changeCamera:(NSInteger)camera;
 - (void)changeOrientation:(NSInteger)orientation;
@@ -71,5 +72,8 @@ typedef NS_ENUM(NSInteger, RCTCameraTorchMode) {
 - (void)stopCapture;
 - (void)startSession;
 - (void)stopSession;
+- (void)focusAtThePoint:(CGPoint) atPoint;
+- (void)zoom:(CGFloat)velocity;
+
 
 @end

RCTCameraManager.m

@@ -105,6 +105,7 @@ RCT_EXPORT_VIEW_PROPERTY(torchMode, NSInteger);
 
     self.sessionQueue = dispatch_queue_create("cameraManagerQueue", DISPATCH_QUEUE_SERIAL);
 
+
   }
   return self;
 }
@@ -661,5 +662,46 @@ didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL
   });
 }
 
+- (void) focusAtThePoint:(CGPoint) atPoint;
+{
+    Class captureDeviceClass = NSClassFromString(@"AVCaptureDevice");
+    if (captureDeviceClass != nil) {
+        dispatch_async([self sessionQueue], ^{
+            AVCaptureDevice *device = [[self videoCaptureDeviceInput] device];
+            if([device isFocusPointOfInterestSupported] &&
+               [device isFocusModeSupported:AVCaptureFocusModeAutoFocus]) {
+                CGRect screenRect = [[UIScreen mainScreen] bounds];
+                double screenWidth = screenRect.size.width;
+                double screenHeight = screenRect.size.height;
+                double focus_x = atPoint.x/screenWidth;
+                double focus_y = atPoint.y/screenHeight;
+                if([device lockForConfiguration:nil]) {
+                    [device setFocusPointOfInterest:CGPointMake(focus_x,focus_y)];
+                    [device setFocusMode:AVCaptureFocusModeAutoFocus];
+                    if ([device isExposureModeSupported:AVCaptureExposureModeAutoExpose]){
+                        [device setExposureMode:AVCaptureExposureModeAutoExpose];
+                    }
+                    [device unlockForConfiguration];
+                }
+            }
+        });
+    }
+}
+
+- (void) zoom:(CGFloat)velocity {
+    const CGFloat pinchVelocityDividerFactor = 20.0f; // TODO: calibrate or make this component's property
+    NSError *error = nil;
+    AVCaptureDevice *device = [[self videoCaptureDeviceInput] device];
+    if ([device lockForConfiguration:&error]) {
+        CGFloat zoomFactor = device.videoZoomFactor + atan(velocity / pinchVelocityDividerFactor);
+        device.videoZoomFactor = zoomFactor >= 1.0f ? zoomFactor : 1.0f;
+        [device unlockForConfiguration];
+    } else {
+        NSLog(@"error: %@", error);
+    }
+}
+
+
+
 
 @end