Question

I’m using an existing library that wasn’t compiled with ARC and had the following line of code that I need to convert over when I upgraded my project:

CFAttributedStringSetAttribute(text, 
    CFRangeMake(position, length), 
    kCTStrokeWidthAttributeName, 
    [NSNumber numberWithFloat:[[attributes objectForKey:@"stroke"] intValue]]);

Compiling with ARC of course produced a few errors and I modified the code to make it more compliant. Is the code change below correct?

int strokeInt = [[attributes objectForKey:@"stroke"] intValue];
CFNumberRef strokeNumber = CFNumberCreate(NULL, kCFNumberSInt32Type, &strokeInt);

CFAttributedStringSetAttribute(text, 
    CFRangeMake(position, length), 
    kCTStrokeWidthAttributeName, 
    strokeNumber);

Any suggestions would be appreciated.

Answer 1

You’re leaking strokeNumber unless you are calling CFRelease on it. But CFNumber is toll-free bridged with NSNumber, so you can eliminate strokeNumber and just use a cast:

CFAttributedStringSetAttribute(text, 
    CFRangeMake(position, length), 
    kCTStrokeWidthAttributeName, 
    (__bridge CFNumberRef)[NSNumber numberWithFloat:[[attributes objectForKey:@"stroke"] intValue]]);

Furthermore, if [attributes objectForKey:@"stroke"] happens to already be an NSNumber, you can simplify to just this:

CFAttributedStringSetAttribute(text, 
    CFRangeMake(position, length), 
    kCTStrokeWidthAttributeName, 
    (__bridge CFNumberRef)[attributes objectForKey:@"stroke"]);