Emojis messing with obj-c's sizeWithFont math

Question

In a UITableView that needs to display a long list of chatlike conversations, often containing emojis, a size calculation error occurs.

My problem is, that

Answer 1

Thank you @SergiSolanellas! Here's a version that takes an attributedString, shortening the method because the text and font are already set.

//
// Given an attributed string that may have emoji characters and the width of 
// the display area, return the required display height.
//
- (CGFloat)heightForAttributedStringWithEmojis:(NSAttributedString *)attributedString forWidth:(CGFloat)width {
    CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)attributedString);
    CFRange fitRange;
    CGSize frameSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetter, CFRangeMake(0, 0), NULL, CGSizeMake(width, CGFLOAT_MAX), &fitRange);

    CFRelease(framesetter);

    return frameSize.height;
}