I have a NSTextAttachment subclass with overridden
attachmentBoundsForTextContainer:proposedLineFragment:glyphPosition:characterIndex:
imageForBounds:textContainer:characterIndex:.
I need to redraw the attachment(s) at some point. Calling setNeedsDisplay on the UITextView doesn't work.
Any ideas? I'd like to avoid recreating attachments and/or the attributed string.
You'll want to use one of textView.layoutManager's methods.
invalidateDisplayCharacterRange:
imageForBounds:textContainer:characterIndex: will be called again.attachmentBoundsForTextContainer:[...]Index: will not be called again.image has been changed with another one of the same size.invalidateLayoutForCharacterRange:actualCharacterRange:
imageForBounds:textContainer:characterIndex: will be called again.attachmentBoundsForTextContainer:[...]Index: will be called again.image has been changed with another one of a different size.If you just want to update a single attachment, you may find this helper method I wrote helpful:
- (NSRange)rangeOfAttachment:(NSTextAttachment *)attachment {
__block NSRange ret;
[self.textStorage enumerateAttribute:NSAttachmentAttributeName
inRange:NSMakeRange(0, self.textStorage.length)
options:0
usingBlock:^(id value, NSRange range, BOOL *stop) {
if (attachment == value) {
ret = range;
*stop = YES;
}
}];
return ret;
}
You can pass the resulting NSRange of this method to the first argument of either of those invalidate methods. For the actualCharacterRange: argument of the second method, I've been passing in NULL without any problems.
Well, after some digging, that can done by invalidating the layout manager:
[textView.layoutManager invalidate....]
If you just want to change the NSTextAttachment which is init by a image, I suggest you to use
setAttachmentSize:size forGlyphRange:range
