如何在NSTextView中的NSString周围添加框

Question

I'm working on a OS X application and I'm pretty much stuck at this. I have some text inside NSTextView and I would like to put box around some strings (I have ranges for those substrings).

Any ideas?

Also, perfect solution would be to create something similar that Xcode has, when you type for example [NSString stringWithFormat: (NSString *), ..)]; Screenshot:

I'm interested in that blue box which suggests what type is expected. Any help would be really appreciated!

This question is not entirely related to possible duplicate question, since they are working on iOS application with slightly different approach.

Answer 1

I'm pretty sure that Xcode achieves these effects using NSTextAttachment objects embedded within NSAttributedString instances. (The same sort of effect can be seen in their NSTokenField control, which definitely uses this approach).

It's a pretty big topic though: you need to be proficient with attributed strings, text attachments, the NSTextAttachmentCell class and a few other bits and pieces from Cocoa's text architecture. The job is made all the more difficult by the fact that there's very little documentation (official or unoffical) for doing this sort of thing.