How to make a UITextView scroll while typing/editing

I used the following code in the textViewDidChange: method and it seemed to work well.

- (void)textViewDidChange:(UITextView *)textView {
    CGPoint bottomOffset = CGPointMake(0, self.theTextView.contentSize.height - self.theTextView.bounds.size.height);
    [self.theTextView setContentOffset:bottomOffset animated:YES];
}

This seems to scroll the UITextView slightly further so that your cursor isn't cut off.


I tried to put in your textViewDidChange: a snippet like:

if([textView.text hasSuffix:@"\n"])
    [self.textView setContentOffset:CGPointMake(0,INT_MAX) animated:YES];

It's not really clean, I'm working toward finding some better stuff, but for now it works :D

UPDATE: Since this is a bug that only happens on iOS 7 (Beta 5, for now), you can do a workaround with this code:

if([textView.text hasSuffix:@"\n"]) { 
    double delayInSeconds = 0.2; 
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC)); 
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){ 
        CGPoint bottomOffset = CGPointMake(0, self.textView.contentSize.height - self.textView.bounds.size.height); 
        [self.textView setContentOffset:bottomOffset animated:YES]; 
    }); 
}

Then, on iOS 6 you can choose either to set the delay to 0.0 or to use just the content of the block.


Problems with other answers:

  • when only scanning for "\n", if you type a line of text that exceeds the width of the text view, then scrolling will not occur.
  • when always setting contentOffset in textViewDidChange:, if you edit the middle of the text you do not want to scroll to the bottom.

The solution is to add this to the text view delegate:

- (void)textViewDidChange:(UITextView *)textView {
    CGRect line = [textView caretRectForPosition:
        textView.selectedTextRange.start];
    CGFloat overflow = line.origin.y + line.size.height
        - ( textView.contentOffset.y + textView.bounds.size.height
        - textView.contentInset.bottom - textView.contentInset.top );
    if ( overflow > 0 ) {
        // We are at the bottom of the visible text and introduced a line feed, scroll down (iOS 7 does not do it)
        // Scroll caret to visible area
        CGPoint offset = textView.contentOffset;
        offset.y += overflow + 7; // leave 7 pixels margin
        // Cannot animate with setContentOffset:animated: or caret will not appear
        [UIView animateWithDuration:.2 animations:^{
            [textView setContentOffset:offset];
        }];
    }
}