From a5ef3226e6eb978307bd34444234ba9260814731 Mon Sep 17 00:00:00 2001
From: Robert Sasak <robert.sasak@gmail.com>
Date: Mon, 3 May 2021 11:35:41 +0200
Subject: [PATCH 1/2] Implement pinch to zoom

---
 example/App.js           |  2 +-
 ios/ALPRCamera.m         | 13 ++++++++++---
 ios/ALPRCameraManager.h  |  1 +
 ios/ALPRCameraManager.mm | 30 ++++++++++++++++++++++++++++++
 4 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/example/App.js b/example/App.js
index 7633b7f..ab3af8d 100644
--- a/example/App.js
+++ b/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}
diff --git a/ios/ALPRCamera.m b/ios/ALPRCamera.m
index 7dd4d1e..e343944 100644
--- a/ios/ALPRCamera.m
+++ b/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];
     }
 }
 
diff --git a/ios/ALPRCameraManager.h b/ios/ALPRCameraManager.h
index cc40ed0..7ea930f 100644
--- a/ios/ALPRCameraManager.h
+++ b/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
diff --git a/ios/ALPRCameraManager.mm b/ios/ALPRCameraManager.mm
index 26bc5e8..971973a 100644
--- a/ios/ALPRCameraManager.mm
+++ b/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)

From bb41122fb7580acabff20efbec0b16124dba9553 Mon Sep 17 00:00:00 2001
From: Robert Sasak <robert.sasak@gmail.com>
Date: Tue, 4 May 2021 11:31:12 +0200
Subject: [PATCH 2/2] Update README.md

---
 README.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/README.md b/README.md
index 6ed201c..3076998 100644
--- a/README.md
+++ b/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)