CODEWITHSUNDEEP
iosswiftuitableviewscroll
Elphaba
Elphaba

Reputation: 89

Make the last row in UITableView appear at top

I have a UITableView with a random number of custom cells. It's working fine.

I am moving the selected cell to the top of the UITableView with:

tableView.scrollTo(index path animated)

However, when the selected cell is on the last full 'page' of cells, this doesn't work - obviously.

Can I make this work by somehow 'padding' out the table with empty space, dependent on the Y position of the selected cell, so that even selecting the last row, it would animate and move to the top of the table view?

I thought:

let point = CGPoint(x: 0, y: 200)
tableView.setContentOffset(point, animated: false)

would work, but it didn't (the 200) was a test amount.

I'm sure this is possible, could I please get a pointer?

Upvotes: 4

Views: 1450

Answers (2)

Elphaba
Elphaba

Reputation: 89

rMaddy gave the right answer. Thanks so much! I'd never have thought of using the footer!

Just for those that might be interested here was the working code:

NOTE, that it's just a prototype, so I'm hard coding number of cells and how many can be visible on screen at once.

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)
{
    let maxNumberOfRows        = 24
    let maxNumberOfVisibleRows = 10
    let safeArea: CGFloat      = 20

    let cell = tableView.cellForRow(at: indexPath)

    if indexPath.row >= maxNumberOfRows - maxNumberOfVisibleRows
    {
        let numberOfSpacesRequired = ( maxNumberOfRows - indexPath.row ) * Int((cell?.bounds.height)!)

        let spaceView = UIView()

        spaceView.bounds = CGRect(x: 0, y: 0, width: Int(tableView.bounds.width), height: ( Int(tableView.bounds.height - safeArea) - numberOfSpacesRequired) )

        tableView.tableFooterView = spaceView
    }

    tableView.scrollToRow(at: indexPath, at: UITableViewScrollPosition.top, animated: true)
}

Upvotes: 1

rmaddy
rmaddy

Reputation: 318774

If you want to allow a table view to be scrolled far enough for the last row to reach the top of the screen, set a view as the table view's tableFooterView.

Make it an empty UIView with a height that is equal to the visible height of the table view minus the height of one row.

Upvotes: 2

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