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];
}];
}
}