ios - Toolbar with "Previous" and "Next" for Keyboard inputAccessoryView

Question

I've been trying to implement this toolbar, where only the 'Next' button is enabled when the top textField is the firstResponder and only the 'Previous' button is enabled when the bottom textField is the firstResponder.

It kind of works, but what keeps happening is I need to tap the 'Previous'/'Next' buttons twice each time to enable/disable the opposing button.

Am I missing something in the responder chain that's making this happen?

Here's my code:

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self.topText becomeFirstResponder];
}


- (UIToolbar *)keyboardToolBar {

    UIToolbar *toolbar = [[UIToolbar alloc] init];
    [toolbar setBarStyle:UIBarStyleBlackTranslucent];
    [toolbar sizeToFit];

    UISegmentedControl *segControl = [[UISegmentedControl alloc] initWithItems:@[@"Previous", @"Next"]];
    [segControl setSegmentedControlStyle:UISegmentedControlStyleBar];
    segControl.momentary = YES;
    segControl.highlighted = YES;

    [segControl addTarget:self action:@selector(changeRow:) forControlEvents:(UIControlEventValueChanged)];
    [segControl setEnabled:NO forSegmentAtIndex:0];

    UIBarButtonItem *nextButton = [[UIBarButtonItem alloc] initWithCustomView:segControl];

    NSArray *itemsArray = @[nextButton];

    [toolbar setItems:itemsArray];

    return toolbar;
}

- (void)changeRow:(id)sender {

    int idx = [sender selectedSegmentIndex];

    if (idx == 1) {
        [sender setEnabled:NO forSegmentAtIndex:1];
        [sender setEnabled:YES forSegmentAtIndex:0];
        self.topText.text = @"Top one";
        [self.bottomText becomeFirstResponder];
    }
    else {
        [sender setEnabled:NO forSegmentAtIndex:0];
        [sender setEnabled:YES forSegmentAtIndex:1];
        self.bottomText.text =@"Bottom one";
        [self.topText becomeFirstResponder];
    }
}


-(void)textFieldDidBeginEditing:(UITextField *)textField {
    if (!textField.inputAccessoryView) {
        textField.inputAccessoryView = [self keyboardToolBar];
    }
}

Answer 1

Here is a UIViewController extension that I use whenever I need a group of UITextFields to provide navigation via input accessory. No need to use UITextField delegation with this approach, and adding the behavior to multiple forms becomes a single-liner. Also supports the 'Done' button to dismiss.

extension UIViewController {
  func addInputAccessoryForTextFields(textFields: [UITextField], dismissable: Bool = true, previousNextable: Bool = false) {
    for (index, textField) in textFields.enumerated() {
      let toolbar: UIToolbar = UIToolbar()
      toolbar.sizeToFit()

      var items = [UIBarButtonItem]()
      if previousNextable {
        let previousButton = UIBarButtonItem(image: UIImage(named: "Backward Arrow"), style: .plain, target: nil, action: nil)
        previousButton.width = 30
        if textField == textFields.first {
          previousButton.isEnabled = false
        } else {
          previousButton.target = textFields[index - 1]
          previousButton.action = #selector(UITextField.becomeFirstResponder)
        }

        let nextButton = UIBarButtonItem(image: UIImage(named: "Forward Arrow"), style: .plain, target: nil, action: nil)
        nextButton.width = 30
        if textField == textFields.last {
          nextButton.isEnabled = false
        } else {
          nextButton.target = textFields[index + 1]
          nextButton.action = #selector(UITextField.becomeFirstResponder)
        }
        items.append(contentsOf: [previousButton, nextButton])
      }

      let spacer = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
      let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: view, action: #selector(UIView.endEditing))
      items.append(contentsOf: [spacer, doneButton])


      toolbar.setItems(items, animated: false)
      textField.inputAccessoryView = toolbar
    }
  }
}

example:

let field1 = UITextField()
let field2 = UITextField()
addInputAccessoryForTextFields([field1, field2], dismissable: true, previousNextable: true)

Here's a reasonable arrow icon.