Setting vertical align of truncated tails for NSAttributedString with NSTextAttachment

Question

I'm using the following code to generate a NSAttributedString for UILabel in iOS 8.

// a long long Chinese title 
NSString *title = @"这是一个很长很长很长很长很长很长的中文标题";
// setup icon attachment
NSTextAttachment *iconAttachment = [[NSTextAttachment alloc] init];
iconAttachment.image = [UIImage imageNamed:imageName];
iconAttachment.bounds = bounds;
NSAttributedString *ycardImageString = [NSAttributedString attributedStringWithAttachment:iconAttachment];

// setup attributed text
NSMutableAttributedString *attributedText = [[NSMutableAttributedString alloc] initWithString:title];
if (shouldShowYcard) {
    [attributedText insertAttributedString:ycardImageString atIndex:0];
    [attributedText insertAttributedString:[[NSAttributedString alloc] initWithString:@" "] atIndex:1];
    [attributedText addAttribute:NSBaselineOffsetAttributeName value:@(offset) range:NSMakeRange(0, 1)];
}
NSRange titleRange = NSMakeRange(shouldShowYcard ? 2 : 0, title.length);
[attributedText addAttribute:NSFontAttributeName value:font range:titleRange];
[attributedText addAttribute:NSForegroundColorAttributeName value:color range:titleRange];

However it seems that the NSTextAttachment will effect the vertical position of truncated tails, just like the following pictures.

Is there a way to set the vertical aignment for the truncated tails?

My goal is to have bottom align tails in Chinese language.

This is an icon for test.

Answer 1

OK, finally I choose a ugly way to fix this problem by setting NSBaselineOffsetAttributeName for truncate tail.

Here is a way to calculate the truncate part. But in my case, my label width is fixed so that I can directly set the range for control.

if (title.length > 10 && ([[[UIDevice currentDevice] systemVersion] floatValue] < 9.0)) {
    [attributedText addAttribute:NSBaselineOffsetAttributeName value:@(-4) range:NSMakeRange(9, 1)];
}