gistfile1.m

@implementation UITextView (Annex)
@dynamic visibleTextRange;

- (NSRange)visibleTextRange
{

    CGRect bounds           = self.bounds;
    CGSize textSize         = [self.text sizeWithFont:self.font constrainedToSize:bounds.size];

    UITextPosition *start   = [self characterRangeAtPoint:bounds.origin].start;
    UITextPosition *end     = [self characterRangeAtPoint:CGPointMake(textSize.width, textSize.height)].end;
    NSUInteger startPoint   = [self offsetFromPosition:self.beginningOfDocument toPosition:start];
    NSUInteger endPoint     = [self offsetFromPosition:start toPosition:end];

    return NSMakeRange(startPoint, endPoint);
    
    
}

@end