Objective c - Text indentation

Question

This question is about implementing text indentation ("The placement of text farther to the right to separate it from surrounding text") in iOS.

Take for example the following text:

1. This is the first section.
2. This is the second one,
   with two lines.
3. This is the third.

Notice that the second row in section 2 begin farther to the right and just below the line above.

My code contains an array of NSString, each one should be display as a section with numeric bullet like above. for example:

NSArray *array = [NSArray arrayWithObjects:@"1. This is the first section.", @"2. This is the second one, with two lines.", @"3. This is the third.", nil];

I use UILable to display the text on screen.
To set the text from the array to the label, and to separate each string in a new line I use

myLabel.text = [array componentsJoinedByString:@"\n"];

Any ideas how to get this effect?

Answer 1

This is possible to some degree in iOS6 with - [UILabel setAttributedText:].

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.headIndent = 29;

myLabel.attributedText = [[NSAttributedString alloc] initWithString:
    @"1.\tShort line.\n2.\tLong line with content that triggers wrapping.\n3.\tShort line."
    attributes:@{NSParagraphStyleAttributeName: paragraphStyle}];

This adds indentation to the subsequent lines. It looks like iOS doesn't support tab stops in the same way as OSX so I'm not seeing a way to adjust the gap between the number and the text. This is probably possible in CoreText.

Of course, you could also just replace the label with a UIWebView and have full formatting control on all versions of iOS at the cost of performance.