After deleteRows used, becomeFirstResponer() doesn't give focus to textField

Question

After any row is deleted by deleteRows(at:with:) from my Table View, I cannot get textfield in a reusable custom cell to get focus by becomeFirstResponder() (which is called after insertRows(at:with:) is called). becomeFirstResponder() is always called within cellForRow(at:).

This problem always starts occuring after a row is deleted from the table view by deleteRows(at:with:). Before any row is deleted there is no problem, becomeFirstResponder() can give focus to the textfield as intended.

I made some tests to understand why this problem occurs after a row is deleted... My tests showed an interesting difference:

Case 1: After any row is deleted (i.e. while becomeFirstResponder() returns false), textFieldShouldBeginEditing(_:) is called BEFORE cellForRow(at:) returns. textFieldDidBeginEditing(_:) is never called.

Case 2: On the other hand, before any row is deleted (i.e. while becomeFirstResponder() returns true), textFieldShouldBeginEditing(_:) is called AFTER cellForRow(at:) returns. textFieldDidBeginEditing(_:) is called immediately after textFieldShouldBeginEditing(_:), as expected.

The problem might be related to this difference, but I couldn't solve this mystery after trying & researching for many hours.

In a related Q&A, it is suggested not to reload tableView from within textFieldDidEndEditing(). In my case, deleteRows(at:with:) method are sometimes called from within textFieldDidEndEditing() and sometimes called from tableView(_:commit:forRowAt:) (i.e. by swiping to left). So this does not explain my problem. Another related Q&A might be this one.

getFocus() in CustomCell's class, called from cellForRow(at:) in TableViewController:

func getFocus() {
    if let itemTextField = itemTextField {
        itemTextField.delegate = self
        itemTextField.isUserInteractionEnabled = true
        itemTextField.becomeFirstResponder()
    }
}

cellForRow(at:):

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let item = items[indexPath.row]
    let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath) as! CustomCell
    cell.setCell(item: item)
    cell.delegate = self

    if insertingRow == true {
        if isTempItem(item: item, indexPath: indexPath) {
                cell.getFocus()
        } else {
            print("isTempItem returned false, no need to give focus.")
        }
    }

    return cell     
}

Don't call `getFocus` in `cellForRowAt`. The cell may not even be added to the table view yet. — rmaddy, Jul 02 '19 at 00:12
It seemed to me that is the only place where I can get access to the cell. Where else can I call it? Any suggestions please? — Luke, Jul 02 '19 at 00:15

score 0 · Accepted Answer · answered Jul 02 '19 at 01:22

0

Don't call getFocus in cellForRowAt, Insteed of when you insert new row, You can scroll to new row and call getFocus in willDisplayCell.

Hope to help you.

answered Jul 02 '19 at 01:22

Thanh Vu

1,599
10
14

This solved my problem. In fact I tried to use willDisplayCell but couldn't figure out how to use a custom cell with that method. With a little research I figured that out too. Thank you! – Luke Jul 02 '19 at 01:35

After deleteRows used, becomeFirstResponer() doesn't give focus to textField

1 Answers1