Re: [v1 1/1] dinput: Sort virtual joysticks by name on the Mac

[DavidL]

Hi Ken,

So I wanted to try to hew as close to the behavior of debugstr_cf as
possible since that is the output that the user sees already in trace logs.
Here's how I decided handle each case:

static CFStringRef copy_device_name(IOHIDDeviceRef device)
> {
>     CFTypeRef ref;
>     CFStringRef name = NULL;
> if(device)
> {
>     assert(IOHIDDeviceGetTypeID() == CFGetTypeID(device));
>     ref = IOHIDDeviceGetProperty(device, CFSTR(kIOHIDProductKey));
>     if (ref && CFStringGetTypeID() == CFGetTypeID(ref))
>         name = CFStringCreateCopy(kCFAllocatorDefault,ref);
>     else if (ref)
>         name = CFCopyDescription(ref);
>     else
>         name = CFStringCreateCopy(kCFAllocatorDefault,CFSTR("(null)"));
> }
> else
>     ERR("Invalid Device requested %p\n",device);
>
> return name;
>
> }
> static CFComparisonResult device_name_comparator(IOHIDDeviceRef device1,
> IOHIDDeviceRef device2)
> {
>     CFStringRef name1 = copy_device_name(device1), name2 =
> copy_device_name(device2);
>     CFComparisonResult result = CFStringCompare(name1, name2,
> (kCFCompareForcedOrdering | kCFCompareNumerically));
>     if(name1)
>         CFRelease(name1);
>     if(name2)
>         CFRelease(name2);
>     return  result;
> }

What do you think?

Cheers,
David

On Sun, Jul 17, 2016 at 8:20 PM, DavidL  wrote:
> Right-o! I was wondering what the CFRelease was doing in the debugstr_cf
> function. :)
>
> Cheers,
> David
>
> On Sun, Jul 17, 2016 at 2:11 PM, Ken Thomases  wrote:
> > On Jul 17, 2016, at 4:08 PM, Ken Thomases  wrote:
> > > On Jul 16, 2016, at 3:15 AM, David Lawrie
> >
> > wrote:
> > > > +static CFStringRef get_device_name(IOHIDDeviceRef device)
> > > > +{
> > > > - CFTypeRef ref;
> > > > - CFStringRef name = CFSTR("Default Name");
> > >
> > > You can probably do better for a fallback.  For example, you can format
> >
> > the vendor ID and product ID into a string.  For an extreme take on this,
> > see the Copy_DeviceName() function in Apple's HID Calibrator sample code:
> > >
> >
> > https://developer.apple.com/library/mac/samplecode/HID_Calibrator/Listings/H...
> >
> > Oh, and for the case where device is NULL, it's fine to return NULL.  It
> > should never happen and, if it does, we want a crash to figure out why and
> > fix things in a better manner, rather than papering over it with a bogus
> > value.
> >
> > -Ken