How to animate insert sections from bottom of screen

Question

I need to do an animation in UITableView to insert sections but i need the sections to animate from the bottom of the screen.

And not like one of the default UITableViewRowAnimation animations.

This is animation i need:

Any suggestions?

Thanks

Answer 1

I figured out how to do this with a simple solution.

public func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {

    if shouldAnimate {
        cell.alpha = 0
        let transform = CATransform3DTranslate(CATransform3DIdentity, 0, UIScreen.main.bounds.height, 0)
        cell.layer.transform = transform

        UIView.animate(withDuration: 0.5, animations: {
            cell.alpha = 1
            cell.layer.transform = CATransform3DIdentity
        })
    }
}

public func tableView(_ tableView: UITableView, willDisplayHeaderView view: UIView, forSection section: Int) {
    if shouldAnimate {
        view.alpha = 0
        let transform = CATransform3DTranslate(CATransform3DIdentity, 0, UIScreen.main.bounds.height, 0)
        view.layer.transform = transform

        UIView.animate(withDuration: 0.5, animations: {
            view.alpha = 1
            view.layer.transform = CATransform3DIdentity
        })
    }
}

public func addSections(sections: IndexSet) {
    shouldAnimate = true
    CATransaction.begin()
    CATransaction.setCompletionBlock({ self.shouldAnimate = false })

    tableView.beginUpdates()
    tableView.insertSections(sections, with: .top)
    tableView.endUpdates()

    tableView.scrollToRow(at: IndexPath(row: 0, section: 1), at: .top, animated: true)

    CATransaction.commit()
}

So willDisplay cell/header handles the animation from the bottom of the screen.

shouldAnimate cancels the cells animations after finishing the insertSection