Layout.swift: Fatal error: Attempted to read an unowned reference but the object was already deallocated

[mschonvogel]

Sometimes when dismissing the panel with a swipe gesture, it crashes in Layout.swift, line 307.

I'm using version 2.2.0

This is how create the panel:

    static func createPanel(userId: String) -> FloatingPanelController {
        let panelViewController = FloatingPanelController()
        let viewController = ProfileViewController(userId: userId)
        viewController.panelController = panelViewController
        panelViewController.layout = IntrinsicFloatingPanelLayout()
        let behavior = FloatingPanelDefaultBehavior()
        behavior.removalInteractionVelocityThreshold = 2.5
        panelViewController.behavior = behavior
        panelViewController.set(contentViewController: viewController)
        panelViewController.isRemovalInteractionEnabled = true
        panelViewController.surfaceView.appearance.cornerRadius = Metrics.Panel.cornerRadius
        panelViewController.surfaceView.backgroundColor = UIColor.defaultBackground
        panelViewController.backdropView.dismissalTapGestureRecognizer.isEnabled = true
        panelViewController.surfaceView.grabberHandle.isHidden = true
        return panelViewController
    }

And this is the layout I'm using:

class IntrinsicFloatingPanelLayout: FloatingPanelLayout {
    let position: FloatingPanelPosition = .bottom
    let initialState: FloatingPanelState = .full
    var anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] {
        [
            .full: FloatingPanelIntrinsicLayoutAnchor(absoluteOffset: 0, referenceGuide: .superview),
        ]
    }
}

[scenee]

Thank you for your report. I've been wondering about a possibility of a memory leak in updateScrollView() since before but I've had no evidence. But now I'm convinced the inner function must be change thanks to your report. I will take care of this crash this weekend.

[scenee]

Hello, @mschonvogel. I've created a branch to attempt to fix this issue(PR #441). Could you please check whether this branch fixes your reporting issue or not?

[mschonvogel]

Yes, will do. As I am not really able to reproduce the bug, I'd say I'll just use the app and let you know in 2-3 days if it crashed again or not?

[mschonvogel]

Looking good, no crash so far @scenee 👍

[scenee]

Thank you so much, @mschonvogel 🎉 I will merge PR #441 and release the new version in a week.