Drawing vertical text on iOS

Question

I'd like to draw an NSAttributedString (or NSString) vertically on iOS. By "vertically" I mean:

Apple's documentation says a standard attribute on an NSAttributedString is NSVerticalGlyphFormAttributeName, but unfortunately, says:

"In iOS, horizontal text is always used and specifying a different value is undefined."

The same document also mentions NSTextLayoutSectionsAttribute, which seems to support NSTextLayoutOrientation, which allows NSTextLayoutOrientationHorizontal or NSTextLayoutOrientationVertical.

None of those 4 terms get any hits on SO at the moment. Just that lonely whistling sound.

However, I don't have any idea how to set this up, whether it works with iOS, or if can be used for vertical string rendering in the style of [myAttributedString drawAtPoint: whereItOughtaGo].

Thanks.

Answer 1

If it just a single lined text as in your example you can use various workarounds. I would personally create a UILabel subclass as follows:

@implementation VerticalLabel

- (id)initWithCoder:(NSCoder *)aDecoder
{
  self = [super initWithCoder:aDecoder];

  if (self) {
    self.numberOfLines = 0;
  }

  return self;
}

- (void)setText:(NSString *)text {
  NSMutableString *newString = [NSMutableString string];

  for (int i = text.length-1; i >= 0; i--) {
    [newString appendFormat:@"%c\n", [text characterAtIndex:i]];
  }

  super.text = newString;
}

@end

Now you just have to replace:

UILabel *lbl = [[UILabel alloc] init];

with:

UILabel *lbl = [[VerticalLabel alloc] init];

to get vertical text.