Detecting backspace in UITextField the right way

Question

Attention! This question is not a duplicate of this or this question! This is a new question to make things more clear.

So I have followed all the instructions of the posts above and I have this UITextField that becomes empty and moves to a new position every time the user hits return button. Moreover, I trace the input of the textView and I create a label of that text in the position the TextView was, like this:

- (BOOL)textFieldShouldReturn:(UITextField *)textField {

    if (textField.text.length > 5) {
        CGRect labelFrame = CGRectMake(textField.frame.origin.x, textField.frame.origin.y, 0, 0);
        UILabel *label = [[UILabel alloc] initWithFrame: labelFrame];
        label.font = [UIFont fontWithName:@"HelveticaNeue" size:14];
        [label setText:textField.text];
        [label setTextColor: [BSFunctions getColorFromHex:@"3f3f3f"]];
        label.backgroundColor =[UIColor lightGrayColor];
        [label sizeToFit];
        [labelsArray addObject:label];
        [self.view addSubview: label];

        CGRect newTextFieldFrame = CGRectMake(labelFrame.origin.x + label.frame.size.width + 5, labelFrame.origin.y, 320, 30);
        NSLog(@"Rect is %@", NSStringFromCGRect(newTextFieldFrame));
        textField.frame = newTextFieldFrame;
        textField.text = @"\u200B";
    }    
    return YES;
}

I set the text in UITextField text to be @"\u200B" and I then want to detect the backspace button on it like this:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{

    if ([string isEqualToString:@""]) {
        NSLog(@"backspace button pressed");

        if (labelsArray.count > 0) {
            UILabel *labelToDelete = [labelsArray lastObject];
            CGRect labelPosition = labelToDelete.frame;
            CGRect oldPosition = textField.frame;
            textField.frame = CGRectMake(labelPosition.origin.x, labelPosition.origin.y, oldPosition.size.width, oldPosition.size.height);
            [labelToDelete removeFromSuperview];
            [labelsArray removeLastObject];
            textField.text = @"\u200B";
        }
    }

    return YES;
}

But the problem is, it works only once and then, even with the special character added at the beginning of the textField it doesn't work. What is possibly wrong?

score 6 · Accepted Answer · answered Feb 08 '13 at 13:25

After setting

textField.text = @"\u200B";

in textField:shouldChangeCharactersInRange:replacementString:

You will have to add

return NO;

otherwise it will continue to the return YES and replace it with a @"" and then when pressing the backspace once again nothing will be changed and the delegate method will not be called.

It is possible that I misunderstood your goal here, but I hope this helps.

Detecting backspace in UITextField the right way

1 Answers1