fix mem leak on ios

a closure was breaking the weekSelf reference approach
a CFTimer target was retaining self (fixed by invalidate)

Author: Tweenkie

ios/IPDFCameraViewController.h

@@ -42,7 +42,7 @@ typedef NS_ENUM(NSInteger, IPDFRectangeType)
 
 @property (nonatomic,assign) IPDFCameraViewType cameraViewType;
 
-- (void)focusAtPoint:(CGPoint)point completionHandler:(void(^)())completionHandler;
+- (void)focusAtPoint:(CGPoint)point completionHandler:(void(^)(void))completionHandler;
 
 - (void)captureImageWithCompletionHander:(void(^)(UIImage *data, UIImage *initialData, CIRectangleFeature *rectangleFeature))completionHandler;
 

ios/IPDFCameraViewController.m

@@ -8,14 +8,15 @@
 
 #import "IPDFCameraViewController.h"
 
+#import <React/RCTInvalidating.h>
 #import <AVFoundation/AVFoundation.h>
 #import <CoreMedia/CoreMedia.h>
 #import <CoreVideo/CoreVideo.h>
 #import <CoreImage/CoreImage.h>
 #import <ImageIO/ImageIO.h>
 #import <GLKit/GLKit.h>
 
-@interface IPDFCameraViewController () <AVCaptureVideoDataOutputSampleBufferDelegate>
+@interface IPDFCameraViewController () <AVCaptureVideoDataOutputSampleBufferDelegate, RCTInvalidating>
 
 @property (nonatomic,strong) AVCaptureSession *captureSession;
 @property (nonatomic,strong) AVCaptureDevice *captureDevice;
@@ -26,6 +27,9 @@ @interface IPDFCameraViewController () <AVCaptureVideoDataOutputSampleBufferDele
 @property (nonatomic, assign) BOOL forceStop;
 @property (nonatomic, assign) float lastDetectionRate;
 
+@property (atomic, assign) BOOL isCapturing;
+@property (atomic, assign) CGFloat imageDetectionConfidence;
+
 @end
 
 @implementation IPDFCameraViewController
@@ -36,12 +40,9 @@ @implementation IPDFCameraViewController
 
     BOOL _isStopped;
 
-    CGFloat _imageDedectionConfidence;
     NSTimer *_borderDetectTimeKeeper;
     BOOL _borderDetectFrame;
     CIRectangleFeature *_borderDetectLastRectangleFeature;
-
-    BOOL _isCapturing;
 }
 
 - (void)awakeFromNib
@@ -63,6 +64,11 @@ - (void)_foregroundMode
     self.forceStop = NO;
 }
 
+- (void)invalidate
+{
+  [self stop];
+}
+
 - (void)dealloc
 {
     [[NSNotificationCenter defaultCenter] removeObserver:self];
@@ -106,7 +112,7 @@ - (void)setupCameraView
     }
     if (!device) return;
 
-    _imageDedectionConfidence = 0.0;
+    self.imageDetectionConfidence = 0.0;
 
     AVCaptureSession *session = [[AVCaptureSession alloc] init];
     self.captureSession = session;
@@ -166,7 +172,7 @@ - (void)setCameraViewType:(IPDFCameraViewType)cameraViewType
 -(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection
 {
     if (self.forceStop) return;
-    if (_isStopped || _isCapturing || !CMSampleBufferIsValid(sampleBuffer)) return;
+    if (_isStopped || self.isCapturing || !CMSampleBufferIsValid(sampleBuffer)) return;
 
     CVPixelBufferRef pixelBuffer = (CVPixelBufferRef)CMSampleBufferGetImageBuffer(sampleBuffer);
 
@@ -191,13 +197,13 @@ -(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMS
 
         if (_borderDetectLastRectangleFeature)
         {
-            _imageDedectionConfidence += .5;
+            self.imageDetectionConfidence += .5;
 
             image = [self drawHighlightOverlayForPoints:image topLeft:_borderDetectLastRectangleFeature.topLeft topRight:_borderDetectLastRectangleFeature.topRight bottomLeft:_borderDetectLastRectangleFeature.bottomLeft bottomRight:_borderDetectLastRectangleFeature.bottomRight];
         }
         else
         {
-            _imageDedectionConfidence = 0.0f;
+            self.imageDetectionConfidence = 0.0f;
         }
     }
 
@@ -307,7 +313,7 @@ - (void)setDetectionRefreshRateInMS:(NSInteger)detectionRefreshRateInMS
 }
 
 
-- (void)focusAtPoint:(CGPoint)point completionHandler:(void(^)())completionHandler
+- (void)focusAtPoint:(CGPoint)point completionHandler:(void(^)(void))completionHandler
 {
     AVCaptureDevice *device = self.captureDevice;
     CGPoint pointOfInterest = CGPointZero;
@@ -341,9 +347,10 @@ - (void)focusAtPoint:(CGPoint)point completionHandler:(void(^)())completionHandl
     }
 }
 
-- (void)captureImageWithCompletionHander:(void(^)(id data, id initialData, CIRectangleFeature *rectangleFeature))completionHandler
+- (void)captureImageWithCompletionHander:(void(^)(UIImage *data, UIImage *initialData, CIRectangleFeature *rectangleFeature))completionHandler;
 {
-    if (_isCapturing) return;
+    if (self.isCapturing) return;
+    self.isCapturing = true;
 
     __weak typeof(self) weakSelf = self;
 
@@ -355,8 +362,6 @@ - (void)captureImageWithCompletionHander:(void(^)(id data, id initialData, CIRec
         }];
     }];
 
-    _isCapturing = YES;
-
     AVCaptureConnection *videoConnection = nil;
     for (AVCaptureConnection *connection in self.stillImageOutput.connections)
     {
@@ -388,7 +393,7 @@ - (void)captureImageWithCompletionHander:(void(^)(id data, id initialData, CIRec
                  enhancedImage = [self filteredImageUsingContrastFilterOnImage:enhancedImage];
              }
 
-             if (weakSelf.isBorderDetectionEnabled && rectangleDetectionConfidenceHighEnough(_imageDedectionConfidence))
+             if (weakSelf.isBorderDetectionEnabled && rectangleDetectionConfidenceHighEnough(weakSelf.imageDetectionConfidence))
              {
                  CIRectangleFeature *rectangleFeature = [self biggestRectangleInRectangles:[[self highAccuracyRectangleDetector] featuresInImage:enhancedImage]];
 
@@ -419,15 +424,15 @@ - (void)captureImageWithCompletionHander:(void(^)(id data, id initialData, CIRec
              completionHandler(initialImage, initialImage, nil);
          }
 
-         _isCapturing = NO;
+         weakSelf.isCapturing = NO;
      }];
 }
 
-- (void)hideGLKView:(BOOL)hidden completion:(void(^)())completion
+- (void)hideGLKView:(BOOL)hidden completion:(void(^)(void))completion
 {
     [UIView animateWithDuration:0.1 animations:^
     {
-        _glkView.alpha = (hidden) ? 0.0 : 1.0;
+        self->_glkView.alpha = (hidden) ? 0.0 : 1.0;
     }
     completion:^(BOOL finished)
     {