Default page not working properly when lazy loading three pages?

[thomaaam]

Expected behavior and actual behavior
I expect that when using defaultPage that the corresponding page always loads first without the interference of neighbouring pages (on either left or right side). The current behaviour (when loading page index 2 of 3) is that the fourth page (with index 3) is first loaded and then it jumps back to the page with index 2; it should always stay on index 2.

Steps to reproduce the problem
Create a PagingMenuController with four pagingControllers that loads some data into their views, then set defaultPage=2. If you see that the menu item which corresponds to the fourth page is shown before the menu item of the third page, you have reproduced it.

Specifications like the version of the project, library, or Swift
PagingMenuController version 2.2 and Swift version 3.0.2
EDIT: I use the following PagingMenuControllerCustomizable properties:

   var componentType: ComponentType {
      return .all(menuOptions: MenuOptions(menuItems: menuItems,
            infinite: false, width: 180.0, widthMode: .flexible),
            pagingControllers: pagingControllers)
   }
   var lazyLoadingPage: LazyLoadingPage {
      return .three
   }
   var defaultPage: Int {
      return 2
   }

I have tried to "hack" some custom solution for it, but I always seem to end up very briefly showing the fourth page.

[thomaaam]

I managed to work around this by adding a protocol for hiding the pagingControllers until the defaultPage controller was done loading and being shown on screen. This (partly) works, but I still have to wait briefly before the defaultPage controller is being shown at all, leaving me with this void for a short duration. I want the behaviour to equal the behaviour I get when lazyLoadingPage=.one, only that I can swipe sideways as soon as my left and/or right "pagingControllers" are done loading.

[thomaaam]

This seemed to be a life cycle issue. Calling the setup of the PagingMenuController instance below super's viewDidLoad rather than super's viewWillAppear fixed this issue.

[biajoeknee]

@kitasuke I have the same issue and am also using four view controllers, except I left the defaultPage var at 1. @thomaaam's fix didn't work for me.

The problem is the PagingMenuController always shows the last view controller first, however, the text that's displayed, underlined in the center of the menu is the defaultPage's menu title , but the view controller that's actually shown is the fourth view controller.

When I swipe to the right during this inconsistency, the menu item changes to the fourth view controller's title, but the view controller itself doesn't move at all, so afterwards, the fourth view controller is shown with its menu title, and it continues to work properly after that.

But if I instead swipe to the left, then the opposite happens, the view controller changes to the first view controller, and the menu item doesn't change at all, so afterwards, the first view controller is shown with its menu title, and it continues to work properly after that.

[biajoeknee]

@kitasuke I'm also finding that no matter what I set the defaultPage to, when the PagingMenuController loads, the current menu item title correctly displays the defaultPage's title, but the view controller that's shown with it is always the view controller that's to the left of the defaultPage. The PagingMenuController always begins working properly after a single swipe is made to either the left or the right.

[biajoeknee]

I'm finding the issue is in this method:

class PagingViewController: UIViewController {
    internal func positionMenuController() {
        if let currentViewController = currentViewController, let currentView = currentViewController.view {
            contentScrollView.contentOffset.x = currentView.frame.minX
        }
    }
}

The frame of the currentViewController is all zeroes. How I'm creating the PagingMenuController is through interface builder. I have a view controller with a corresponding .xib file, I add the PagingMenuController to the view controller's .xib file, create an outlet for the PagingMenuController in the view controller's swift file, and link the PagingMenuController to it.

Doesn't matter whether I setup the PagingMenuController in my controller's viewDidLoad, viewWillAppear, or viewDidAppear, the issue persists.