Question

When applying the kCTParagraphStyleSpecifierParagraphSpacing style, it has no visual effect to the rendered text. The other attributes, such as line spacing and text alignment work perfectly. What could I be doing wrong?

CTTextAlignment theAlignment = kCTRightTextAlignment;
CGFloat paragraphSpacingFloat = 150.0;
CGFloat paragraphSpacingBeforeFloat = 150.0;
CGFloat lineSpacing = CTFontGetLeading(baseFont)*5.0;

CFIndex theNumberOfSettings = 4;
CTParagraphStyleSetting theSettings[4] = {
  { kCTParagraphStyleSpecifierParagraphSpacing, sizeof(CGFloat), &paragraphSpacingFloat },
  { kCTParagraphStyleSpecifierParagraphSpacingBefore, sizeof(CGFloat), &paragraphSpacingBeforeFloat },
  { kCTParagraphStyleSpecifierAlignment, sizeof(CTTextAlignment), &theAlignment },
  { kCTParagraphStyleSpecifierLineSpacing, sizeof(CGFloat), &lineSpacing }
};

CTParagraphStyleRef theParagraphRef = CTParagraphStyleCreate(theSettings, theNumberOfSettings);
[attr addAttribute:(id)kCTParagraphStyleAttributeName value:(id)theParagraphRef range:r];
[attr addAttribute:(id)kCTFontAttributeName value:(id)baseFont range:r];
CFRelease(theParagraphRef);

I render the text using

CTFrameSetter frameSetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)attr);
CTFrameRef frame = CTFramesetterCreateFrame(frameSetter, CFRangeMake([[attr string] length], 0), the_drawing_cgrect, NULL);
CTFrameDraw(frame, context);

Answer 1

Are you sure your string has paragraph separators? kCTParagraphStyleSpecifierParagraphSpacing doesn’t work on new lines. It requires actual \u2029.

Try this code to replace all newlines with paragraph separators:

NSArray *paragraphs = [string componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]];
NSString *text = [items componentsJoinedByString:@"\u2029"];