#6

@objc private func handlePanGesture(_ recognizer: UIPanGestureRecognizer) {
        switch recognizer.state {
        case .began:
            panStartPoint = recognizer.translation(in: subContentView)
            startingLeftConstraingConstant = subContentLeftConstraint.constant
        case .changed:
            let currentPoint = recognizer.translation(in: subContentView)
            let deltaX = currentPoint.x - panStartPoint.x

            let panningLeft = currentPoint.x < panStartPoint.x

            if startingLeftConstraingConstant == 0 {
                //была закрыта, сейчас открывается
                if panningLeft {
                    subContentLeftConstraint.constant = max(deltaX, -sideMenuWidth)
                } else {
                    subContentLeftConstraint.constant = min(deltaX, 0)
                }
            } else {
                //хотя бы частично была открыта
                let adjustment = startingLeftConstraingConstant + deltaX
                if panningLeft {
                    subContentLeftConstraint.constant = max(adjustment, -sideMenuWidth)
                } else {
                    subContentLeftConstraint.constant = min(adjustment, 0)
                }
            }
        case .ended:
            if startingLeftConstraingConstant == 0 {
                let neededConstantToOpen = -sideMenuWidth / 6
                if subContentLeftConstraint.constant <= neededConstantToOpen {
                    _setSideMenuHidden(false, animated: true, notifyDelegate: true)
                } else {
                    _setSideMenuHidden(true, animated: true, notifyDelegate: false)
                }
            } else {
                let neededConstantToClose = -sideMenuWidth * 5 / 6
                if subContentLeftConstraint.constant >= neededConstantToClose {
                    _setSideMenuHidden(true, animated: true, notifyDelegate: true)
                } else {
                    _setSideMenuHidden(false, animated: true, notifyDelegate: false)
                }
            }
        case .cancelled:
            //delegate?.messageItemCellDidEndPan(self)
            if startingLeftConstraingConstant == 0 {
                _setSideMenuHidden(true, animated: true, notifyDelegate: false)
            } else {
                _setSideMenuHidden(false, animated: true, notifyDelegate: false)
            }
        default:
            break
        }
    }