Implement pinch to zoom

README.md

@@ -284,3 +284,7 @@ Note: If you are getting errors, double check that you have completed all of the
 
 - OpenALPR built from [OpenALPR-iOS](https://github.com/twelve17/openalpr-ios)
 - Project scaffold based on [react-native-camera](https://github.com/lwansbrough/react-native-camera)
+
+## Sponsors
+
+- [repocoin.io](https://repocoin.io)

example/App.js

@@ -317,7 +317,7 @@ export default class App extends Component {
  </TouchableOpacity>
  <Text style={styles.plateText}>{plate}</Text>
  <Text style={styles.confidenceText}>
- {confidence ? confidence + '%' : ''}
+ {confidence ? (+confidence).toFixed(1) + '%' : ''}
  </Text>
  <TouchableOpacity
  style={styles.takePicture}

ios/ALPRCamera.m

@@ -163,6 +163,14 @@ - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
  {
  [self.camFocus removeFromSuperview];
  }
+ NSDictionary *event = @{
+ @"target": self.reactTag,
+ @"touchPoint": @{
+ @"x": [NSNumber numberWithDouble:touchPoint.x],
+ @"y": [NSNumber numberWithDouble:touchPoint.y]
+ }
+ };
+ [self.bridge.eventDispatcher sendAppEventWithName:@"focusChanged" body:event];
 
  // Show animated rectangle on the touched area
  if (_touchToFocus) {
@@ -181,13 +189,12 @@ - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
  if (allTouchesEnded) {
  _multipleTouches = NO;
  }
- 
+
 }
 
 -(void) handlePinchToZoomRecognizer:(UIPinchGestureRecognizer*)pinchRecognizer {
-
  if (pinchRecognizer.state == UIGestureRecognizerStateChanged) {
- return;
+ [self.manager zoom:pinchRecognizer.velocity reactTag:self.reactTag];
  }
 }
 

ios/ALPRCameraManager.h

@@ -54,5 +54,6 @@ typedef NS_ENUM(NSInteger, ALPRCameraTorchMode) {
 - (void)startSession;
 - (void)stopSession;
 - (void)focusAtThePoint:(CGPoint) atPoint;
+- (void)zoom:(CGFloat)velocity reactTag:(NSNumber *)reactTag;
 
 @end

ios/ALPRCameraManager.mm

@@ -563,6 +563,36 @@ - (void)focusAtThePoint:(CGPoint) atPoint;
  }
 }
 
+- (void)zoom:(CGFloat)velocity reactTag:(NSNumber *)reactTag{
+ if (isnan(velocity)) {
+ return;
+ }
+ 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);
+ if (zoomFactor > device.activeFormat.videoMaxZoomFactor) {
+ zoomFactor = device.activeFormat.videoMaxZoomFactor;
+ } else if (zoomFactor < 1) {
+ zoomFactor = 1.0f;
+ }
+
+ NSDictionary *event = @{
+ @"target": reactTag,
+ @"zoomFactor": [NSNumber numberWithDouble:zoomFactor],
+ @"velocity": [NSNumber numberWithDouble:velocity]
+ };
+
+ [self.bridge.eventDispatcher sendAppEventWithName:@"zoomChanged" body:event];
+
+ device.videoZoomFactor = zoomFactor;
+ [device unlockForConfiguration];
+ } else {
+ NSLog(@"error: %@", error);
+ }
+}
+
 - (void)setCaptureQuality:(NSString *)quality
 {
 #if !(TARGET_IPHONE_SIMULATOR)