Mac Forum / Programming / Mac Programming / July 2005

Hi everybody

I am using the carbon library in my application to display a native
file choose dialog. Works fine so far, but when the dialog displays it
prints a lot of warnings to the console like:

_NSAutoreleaseNoPool(): Object 0x136b320 of class NSImage autoreleased
with no pool in place - just leaking

Searching around the web, I found out that I need to create a
NSAutoreleasePool object, but I could just find the Objective C
bindings (I'm writing in c++). Even worse, on several apple documents
they claimed, that if you want to combine Objective C and C functions
you must add an NSAutoreleasePool to your Objective C functions (that
sounds to me like there isn't a possibility to create a
NSAutoreleasePool in C).

Does anybody has an idea on how to get rid of this warning?

Here is my code:

string OpenDialog::runCarbon()
{
#ifdef HAVE_CARBON
    NavDialogCreationOptions dlgOptions;
    NavGetDefaultDialogCreationOptions(&dlgOptions);
    dlgOptions.location.v=dlgOptions.location.h=-1;
    dlgOptions.windowTitle=CFStringCreateWithCString(0, title.c_str(),
        CFStringGetSystemEncoding());
    dlgOptions.modality=kWindowModalityAppModal;

    NavDialogRef dialogRef;
    NavCreateChooseFileDialog(&dlgOptions, 0, 0, 0, 0, 0, &dialogRef);
    NavDialogRun(dialogRef);

    NavUserAction result = NavDialogGetUserAction(dialogRef);
    if (result == kNavUserActionChoose)
    {
        NavReplyRecord reply;
        memset(&reply, '\0', sizeof(reply));
        NavDialogGetReply(dialogRef, &reply);

        if (reply.validRecord)
        {
            AEKeyword keyword;
            FSRef ref;

            AEGetNthPtr(&reply.selection, 1, typeFSRef, &keyword,
                NULL, &ref, sizeof(ref), NULL);
            CFURLRef url=CFURLCreateFromFSRef(NULL, &ref);
            CFStringRef urlString=CFURLCopyFileSystemPath(url,
                kCFURLPOSIXPathStyle);
            CFRelease(url);
            return string(CFStringGetCStringPtr(urlString,
                kCFStringEncodingMacRoman));
        }
        NavDisposeReply(&reply);
    }
    NavDialogDispose(dialogRef);
#endif
    return "";
}