Getting and Setting Cursor Position of UITextField and UITextView in Swift

In my case I had to use DispatchQueue:

func textViewDidBeginEditing(_ textView: UITextView) {
   DispatchQueue.main.async {
      textField.selectedTextRange = ...
   }
}

Nothing else from this and other threads worked.

PS: I double checked which thread did textViewDidBeginEditing was running on, and it was main thread, as all UI should run on, so not sure why that little delay using main.asynch worked.

let range = field.selectedTextRange

field.text = "hello world"

field.selectedTextRange = range 

The following content applies to both UITextField and UITextView.

Useful information

The very beginning of the text field text:

let startPosition: UITextPosition = textField.beginningOfDocument

The very end of the text field text:

let endPosition: UITextPosition = textField.endOfDocument

The currently selected range:

let selectedRange: UITextRange? = textField.selectedTextRange

Get cursor position

if let selectedRange = textField.selectedTextRange {

    let cursorPosition = textField.offset(from: textField.beginningOfDocument, to: selectedRange.start)

    print("\(cursorPosition)")
}

Set cursor position

In order to set the position, all of these methods are actually setting a range with the same start and end values.

To the beginning

let newPosition = textField.beginningOfDocument
textField.selectedTextRange = textField.textRange(from: newPosition, to: newPosition)

To the end

let newPosition = textField.endOfDocument
textField.selectedTextRange = textField.textRange(from: newPosition, to: newPosition)

To one position to the left of the current cursor position

// only if there is a currently selected range
if let selectedRange = textField.selectedTextRange {

    // and only if the new position is valid
    if let newPosition = textField.position(from: selectedRange.start, offset: -1) {

        // set the new position
        textField.selectedTextRange = textField.textRange(from: newPosition, to: newPosition)
    }
}

To an arbitrary position

Start at the beginning and move 5 characters to the right.

let arbitraryValue: Int = 5
if let newPosition = textField.position(from: textField.beginningOfDocument, offset: arbitraryValue) {

    textField.selectedTextRange = textField.textRange(from: newPosition, to: newPosition)
}

Related

Select all text

textField.selectedTextRange = textField.textRange(from: textField.beginningOfDocument, to: textField.endOfDocument)

Select a range of text

// Range: 3 to 7
let startPosition = textField.position(from: textField.beginningOfDocument, offset: 3)
let endPosition = textField.position(from: textField.beginningOfDocument, offset: 7)

if startPosition != nil && endPosition != nil {
    textField.selectedTextRange = textField.textRange(from: startPosition!, to: endPosition!)
}

Insert text at the current cursor position

textField.insertText("Hello")

Notes

• Use textField.becomeFirstResponder() to give focus to the text field and make the keyboard appear.

• See this answer for how to get the text at some range.

See also

• How to Create a Range in Swift