Who can help with UIPanGestureRecognizer?

Question

iOS

I set myself a goal to write a side menu without frames. Almost did it, but the problem with moving to the right side, how to completely disable the opening to the right side? CenterViewController.swift

import UIKit

class CenterViewController: UIViewController {

    override func viewDidLoad() {
        
        super.viewDidLoad()

        let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(CenterViewController.handlePanGesture(_:)))
        self.view.addGestureRecognizer(panGestureRecognizer)
        
    }

    enum SideMenuControllerPresentationStyle {
        
        case None
        case Started
        case Ended
 
    }
    
    var presentationStyle: SideMenuControllerPresentationStyle = .None

    func handlePanGesture(recognizer: UIPanGestureRecognizer) {
        
        let gestureIsDraggingFromLeftToRight = (recognizer.velocityInView(view).x > 0)

        switch(recognizer.state) {
            
            case .Began:
                
                if gestureIsDraggingFromLeftToRight {
                
                    self.view.layer.shadowColor = UIColor.lightGrayColor().CGColor
                    self.view.layer.shadowOpacity = 1
                    self.view.layer.shadowOffset = CGSizeZero
                    self.view.layer.shadowRadius = 10
                    
                    presentationStyle = .Started
                    
                }
            
                if presentationStyle == .Ended {
                    
                    presentationStyle = .Started
                    
                }
            
            case .Changed:

                if presentationStyle == .Started {
 
                    recognizer.view!.center.x = recognizer.view!.center.x + recognizer.translationInView(view).x
                    recognizer.setTranslation(CGPointZero, inView: view)

                    
                }

            case .Ended:
            
                if self.view.frame.origin.x > 125 {
                    
                
                    UIView.animateWithDuration(0.2, delay: 0, options: [], animations: {
                    
                    self.view.frame.origin.x = 250
                    
                        }, completion: { (Bool) -> Void in
 
                    })
                    
                    self.presentationStyle = .Ended
            
                } else {
                    
                    UIView.animateWithDuration(0.2, delay: 0, options: [], animations: {
                        
                        self.view.frame.origin.x = 0
                        
                        }, completion: { (Bool) -> Void in
                            
                        
                            
                    })
                    
                    self.presentationStyle = .None
                    
                }
            
            default:
                
                break
            
            
        }
        
    }

}

ViewController.swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let centerController = self.storyboard?.instantiateViewControllerWithIdentifier("CenterViewController") as! CenterViewController
        
        centerController.view.frame = self.view.frame
        
        addChildViewController(centerController)
        
        self.view.addSubview(centerController.view)
        
    }

}

Answer 1

You can see how this is already implemented - for example, in JASidePanel a) and b)

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
             shouldReceiveTouch touch: UITouch) -> Bool

You can try to use this delegate method and limit the perception of the corresponding gestures based on points, if I understand correctly