https://developer.apple.com/documentation/uikit/uigesturerecognizerdelegate/1624229-gesturerecognizer

3:31 AM

(これは逆もある)

3:33 AM

あとは、https://developer.apple.com/documentation/uikit/uiscrollview/1619418-touchesshouldbegin とか、あと https://developer.apple.com/documentation/uikit/uiscrollview/1619390-isdirectionallockenabled あたりも必要かも。