gallery view: added method for modifying the content offset of the collection view

ios/lib/ReactNativeCameraKit/CKGalleryViewManager.m

@@ -568,6 +568,16 @@ RCT_EXPORT_METHOD(refreshGalleryView:(NSArray*)selectedImages
         resolve(@YES);
 }
 
+RCT_EXPORT_METHOD(modifyGalleryViewContentOffset:(NSDictionary*)params) {
+    CGPoint newOffset = self.galleryView.collectionView.contentOffset;
+    if(params[@"x"] != nil) {
+        newOffset.x += [params[@"x"] floatValue];
+    }
+    if(params[@"y"] != nil) {
+        newOffset.y += [params[@"y"] floatValue];
+    }
+    [self.galleryView.collectionView setContentOffset:newOffset];
+}
 
 #pragma mark - Static functions
 

src/CameraKitGalleryView.android.js

@@ -27,6 +27,10 @@ export default class CameraKitGalleryView extends Component {
     return true;
   }
 
+  modifyGalleryViewContentOffset (offset) {
+    //do nothing. compatability with ios
+  }
+
   render() {
     const transformedProps = {...this.props};
     transformedProps.albumName = this.props.albumName ? this.props.albumName : ALL_PHOTOS;

src/CameraKitGalleryView.ios.js

@@ -55,4 +55,8 @@ export default class CameraKitGalleryView extends Component {
     const isSuccess = await GalleryViewManager.refreshGalleryView(selectedImages);
     return isSuccess;
   }
+
+  modifyGalleryViewContentOffset (offset) {
+    GalleryViewManager.modifyGalleryViewContentOffset(offset);
+  }
 }