Slide Gesture moving from right to left when not called

Question

I'm having trouble making it only slide from left to right. When I try to get to the side bar menu from swiping left to right it opens but when I slide from right to left it leaves a black space unoccupied. I want it to just work for the slide guesture from left to right to open my side bar menu. Let me know if you need more information. Anything will help thanks!

import UIKit import QuartzCore

enum SlideOutState { case LeftCollapsed case LeftPanelExpanded }

class ContainerViewController: UIViewController, CenterViewControllerDelegate, UIGestureRecognizerDelegate {

var centerNavigationController: UINavigationController!
var centerViewController: CenterViewController!
var currentState: SlideOutState = .LeftCollapsed {
    didSet {
        let shouldShowShadow = currentState != .LeftCollapsed
        showShadowForCenterViewController(shouldShowShadow)
    }
}
var leftViewController: SidePanelViewController?

let centerPanelExpandedOffset: CGFloat = 60

override init() {
    super.init(nibName: nil, bundle: nil)
}

required init(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

override func viewDidLoad() {
    super.viewDidLoad()

    centerViewController = UIStoryboard.centerViewController()
    centerViewController.delegate = self

    // wrap the centerViewController in a navigation controller, so we can push views to it
    // and display bar button items in the navigation bar
    centerNavigationController = UINavigationController(rootViewController: centerViewController)
    view.addSubview(centerNavigationController.view)
    addChildViewController(centerNavigationController)

    centerNavigationController.didMoveToParentViewController(self)

    let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: "handlePanGesture:")
    centerNavigationController.view.addGestureRecognizer(panGestureRecognizer)
}

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

    switch(recognizer.state) {
    case .Began:
        if (currentState == .LefCollapsed) {
            if (gestureIsDraggingFromLeftToRight) {
                addLeftPanelViewController()
            }

            showShadowForCenterViewController(true)
        }
    case .Changed:
        recognizer.view!.center.x = recognizer.view!.center.x + recognizer.translationInView(view).x
        recognizer.setTranslation(CGPointZero, inView: view)
    case .Ended:
        if (leftViewController != nil) {
            // animate the side panel open or closed based on whether the view has moved more or less than halfway
            let hasMovedGreaterThanHalfway = recognizer.view!.center.x > view.bounds.size.width
            animateLeftPanel(shouldExpand: hasMovedGreaterThanHalfway)
        }
    default:
        break
    }
}

}

Answer 1

Add in the Began case an else-Statement where u disable the recognizer.
Enable it again before break.

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

        switch(recognizer.state) {
        case .Began:
            if (currentState == .BothCollapsed) {
                if (gestureIsDraggingFromLeftToRight) {
                    addLeftPanelViewController()
                } else {
                    recognizer.enabled = false
                }
                showShadowForCenterViewController(true)
            }
        case .Changed:
            recognizer.view!.center.x = recognizer.view!.center.x + recognizer.translationInView(view).x
            recognizer.setTranslation(CGPointZero, inView: view)
        case .Ended:
            if (leftViewController != nil) {
                // animate the side panel open or closed based on whether the view has moved more or less than halfway
                let hasMovedGreaterThanHalfway = recognizer.view!.center.x > view.bounds.size.width
                animateLeftPanel(shouldExpand: hasMovedGreaterThanHalfway)
            }
        default:
            recognizer.enabled = true
            break
        }
    }