Core Text's CTFramesetterSuggestFrameSizeWithConstraints() returns incorrect size everytime
- by nsapplication
According to the docs, CTFramesetterSuggestFrameSizeWithConstraints () "determines the frame size needed for a string range".
Unfortunately the size returned by this function is never accurate. Here is what I am doing:
NSAttributedString *string = [[[NSAttributedString alloc] initWithString:@"lorem ipsum" attributes:nil] autorelease];
CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef) string);
CGSize textSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetter, CFRangeMake(0,0), NULL, CGSizeMake(rect.size.width, CGFLOAT_MAX), NULL);
The returned size always has the correct width calculated, however the height is always slightly shorter than what is expected.
Is this the correct way to use this method?
Is there any other way to layout Core Text?
Seems I am not the only one to run into problems with this method. See https://devforums.apple.com/message/181450.
