Scroll to a certain cell on collection view before presenting the next CoachMarkView

[lmbcosta]

Question

After reading the documentation and make some tests on a sample project, I wasn't able to solve this situation:

• I have a collection view with 4 cells, for instance.
• My first CoachMarkView will be the first cell.

• My second CoachMarkView will be the third cell. I want to scroll to my third cell animated and then get the correct frame for this cell Currently I am trying to do something like

  func coachMarksController(_ coachMarksController: CoachMarksController, coachMarkAt index: Int) -> CoachMark {
  
  if index == 1 {
      collectionView.scrollToItem(at: .init(row: 3, section: 0), at: .centeredVertically, animated: true)
  }
  
  let markView = collectionView.cellForItem(at: .init(row: 3, section: 0))
  return coachMarksController.helper.makeCoachMark(for: coachMarkView,
                                                   pointOfInterest: nil,
                                                   cutoutPathMaker: { UIBezierPath(roundedRect: $0, cornerRadius: coachMarkView.frame.height / 2)
  })
  }

This only works if I pass animated argument as false: collectionView.scrollToItem(at: .init(row: 3, section: 0), at: .centeredVertically, animated: false) It will give me the previous position of the cell before the scroll, otherwise

I also tried scroll on other delegate functions like:

func coachMarksController(_ coachMarksController: CoachMarksController,
                              didHide coachMark: CoachMark,
                              at index: Int) {
        if index == 0 {
            childViewController.collectionView.scrollToItem(at: .init(row: 3, section: 0), at: .centeredVertically, animated: true)
        }
    }

and then update on delegate function

func coachMarksController(_ coachMarksController: CoachMarksController,
                              willShow coachMark: inout CoachMark,
                              beforeChanging change: ConfigurationChange,
                              at index: Int) {
        if index == 1 {
            let markView = collectionView.cellForItem(at: .init(row: 3, section: 0))
            coachMark = coachMarksController.helper.makeCoachMark(for: markView, cutoutPathMaker: { UIBezierPath(roundedRect: $0, cornerRadius: coachMarkView.frame.height / 2) })
        }

    }

and still not work.

Is there a way to handle this situation? The worst scenario: if collection view didn't dequeue a cell for certain indexPath. But let focus on the example

Thank you

[ephread]

Hey @lmbcosta, so Instructions is always a bit tacky when used will collections.

But what you can do is look into pausing and resuming the flow (also, have a look at this example)

You should be able to achieve what you want by pausing the flow in willShow, scrolling to the appropriate item and resuming the flow after the scroll completed.

[lmbcosta]

Hello, @ephread. Thank you for the reply. I was testing and, yes, I was able to make it work using pause/resume strategy. Consider this issue closed

[ephread]

I'm glad to hear that!