fix a bug about compute string size

[xiaou]

In NSAttributedString+Attributes.m, I find a bug about '-(CGSize)sizeConstrainedToSize:(CGSize)maxSize fitRange:(NSRange*)fitRange' function.

1. how to find this bug: my text is @"2 3"; and max size is (width=255.5, height=3.40282e+38); (other attribute like font, you can try it~). then invoke this function, the return value's width is bigger than maxSize.width.

2. what I do to fix it: -(CGSize)sizeConstrainedToSize:(CGSize)maxSize fitRange:(NSRange)fitRange { CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)self); CFRange fitCFRange = CFRangeMake(0,0); CGSize sz = CTFramesetterSuggestFrameSizeWithConstraints(framesetter,CFRangeMake(0,0),NULL,maxSize,&fitCFRange); if (framesetter) CFRelease(framesetter); if (fitRange) fitRange = NSMakeRange(fitCFRange.location, fitCFRange.length);

   CGSize res = CGSizeMake( floorf(sz.width+1) , floorf(sz.height+1) );

   // now I fixed the result(It made a bug). -add by U. if(res.width > maxSize.width) res.width = maxSize.width; if(res.height > maxSize.height) res.height = maxSize.height;

   return res; }

——that's what I do, maybe not the best resolution. ——xiaou_is_me@163.com

[AliSoftware]

Hi, and thanks for filing an issue for this. But I won't change and merge this because:

• This is an Apple bug in CTFramesetterSuggestFrameSizeWithConstraints. You should really file a bug to Apple (bugreport.apple.com) instead so that Apple fixes it in next iOS releases
• Changing this will change the behavior of OHAttributedLabel as sizeToFit/sizeThatFits: methods of OHAttributedLabel are based on this method, and if you call e.g. [label sizeThatFits:CGSizeMake(10,10)] with a font which lineHeight is greater than 10, with your patch it will return a height of 10 for the label whereas it should return the font's lineHeight (as it does for now), exactly the same way as UILabel does. As stated in the sizeThatFits: documentation, this method may return a size greater than the maxSize in some cases that make sense, like when the maxSize.height is smaller than even one line of text, etc
• Trimming the value to a maximum won't correctly fix the issue neither, as if the CTFramesetterSuggestFrameSizeWithConstraints methods tells you that it needs a size of 260x100 whereas you asked for a maxSize of 255x200, your fix will return 255x100 which is probably totally wrong, as reducing the width for the text rendering will likely provoke text wrapping, leading to some text going to the next line and probably add one extra line and takes not 100 but something like 120 in height. So instead of returning a size that is greater than your maxSize but makes sense and is the real size the string would take when drawn, you instead return a totally wrong size with your fix.

So changing this will totally break the behavior and moreover won't return values that make sense and reflect a real size, that's why I have to dismiss your fix. Please file a bugreport to Apple instead. (You can still tweak the size returned by this method by yourself in your own app code if you really need to alter it for your specific purpose, but still take into account the last bullet I wrote above)

Note: for the next time please create a pull request instead of pasting the code (without formatting) in the issue, I can merge much more easily if you do that (so your fix would have been included eariler in the master branch)