Disable UIScrollView scrolling when UITextField becomes first responder

When a UITextField embedded in a UIScrollView becomes the first responder (for example, by the user typing in some character), the UIScrollView scrolls to that Field automatically. Is there any way to disable that?

Duplicate rdar://16538222

Solution 1:

Building on Moshe's answer... Subclass UIScrollView and override the following method:

- (void)scrollRectToVisible:(CGRect)rect animated:(BOOL)animated

Leave it empty. Job done!

In Swift:

class CustomScrollView: UIScrollView {
    override func scrollRectToVisible(_ rect: CGRect, animated: Bool) { }
}

Solution 2:

I've been struggling with the same problem, and at last I've found a solution.

I've investigated how the auto-scroll is done by tracking the call-trace, and found that an internal [UIFieldEditor scrollSelectionToVisible] is called when a letter is typed into the UITextField. This method seems to act on the UIScrollView of the nearest ancestor of the UITextField.

So, on textFieldDidBeginEditing, by wrapping the UITextField with a new UIScrollView with the same size of it (that is, inserting the view in between the UITextField and it's superview), this will block the auto-scroll. Finally remove this wrapper on textFieldDidEndEditing.

The code goes like:

- (void)textFieldDidBeginEditing:(UITextField*)textField {  
    UIScrollView *wrap = [[[UIScrollView alloc] initWithFrame:textField.frame] autorelease];  
    [textField.superview addSubview:wrap];  
    [textField setFrame:CGRectMake(0, 0, textField.frame.size.width, textField.frame.size.height)]; 
    [wrap addSubview: textField];  
}  

- (void)textFieldDidEndEditing:(UITextField*)textField {  
  UIScrollView *wrap = (UIScrollView *)textField.superview;  
  [textField setFrame:CGRectMake(wrap.frame.origin.x, wrap.frame.origin.y, wrap.frame.size.width, textField.frame.size.height)];
  [wrap.superview addSubview:textField];  
  [wrap removeFromSuperview];  
}  

hope this helps!