How can you intercept pasting into a NSTextView to remove unsupported formatting?
问题 I'm trying to create a simple NSTextView-based window for simple WYSIWYG editing. However, I only want to allow certain types of formatting (e.g. Bold, Italic, Underline and a single heading type but no colors or different fonts.) The issue is if I simply use NSTextView, someone can create or copy formatted text in another program, then simply paste it into that view and all that formatting goes with it, allowing things I'm not allowing, such as different fonts, colors, etc. At best, I want