Question

My app implements a custom spell checker with its own window and a different workflow from the built-in spell checker in iOS. Therefore I have switched off correction in the main text input view. This disables the built-in suggestions, but also the highlighting of misspelled words.

Is there a way to keep the highlighting, but disable the suggestions?

Answer 1

You will have to roll your own. Here’s a rough (iOS 5 and later):

Drop a view with transparent background on top of the text view.

Find the visible range of text like so:

- (NSRange)visibleRangeOfTextView:(UITextView *)textView {
    CGRect bounds = textView.bounds;
    UITextPosition *start = [textView characterRangeAtPoint:bounds.origin].start;
    UITextPosition *end = [textView characterRangeAtPoint:CGPointMake(CGRectGetMaxX(bounds), CGRectGetMaxY(bounds))].end;
    return NSMakeRange([textView offsetFromPosition:textView.beginningOfDocument toPosition:start],
                   [textView offsetFromPosition:start toPosition:end]);
}

Search for misspelled words in that range.

Find their on-screen coordinates using UITextView firstRectForRange method.

Highlight any way you want.

Deciding when to do this is left as an exercise for the eager student 🙂