macOS C-call and Obj-C function

[DennisBlah]

Hi all,

I'm trying to hit: [myTableView reloadData] from a C function.

Is there anyone who can help me here?

————
I just made a static variable of the tableview within the class and defined it in viewdidload
it works now just like the obj-c wrapper call

 

[Senor Cuete]

Hi all,

I'm trying to hit: [myTableView reloadData] from a C function.

Is there anyone who can help me here?

————
I just made a static variable of the tableview within the class and defined it in viewdidload
it works now just like the obj-c wrapper call

Objective C is a superset of C. A compiler that can compile Objective C also compiles C. I wonder if you could put your code in a .m file and run it. The compiler would understand the [myTableView reloadData] statement.You would need to #import <Cocoa/Cocoa.h>.

 

[DennisBlah]

Objective C is a superset of C. A compiler that can compile Objective C also compiles C. I wonder if you could put your code in a .m file and run it. The compiler would understand the [myTableView reloadData] statement.You would need to #import <Cocoa/Cocoa.h>.

Hi Senor Cuete,

Thanks for your response!
I did try it just now, as I found a little time.
Basically my code is a usb monitor, and is called from didFinishLoading.

The trigger DeviceAdded (which is a C function) can't do [myTableView reloadData];
Even when I imported Cocoa.h to the project. It shows "Use of undeclared identifier 'myTableView'"
The tableView is declared in .h file and synthesized in .m

Nevertheless in case I need more functions and as lazy as I am (I also have some obj-c functions I need to call from C now...) I now implemented as following
"static AppDelegate *myDelegate"
And I call [[myDelegate myTableView] reloadData]; and works fine

//Start usb monitor below
    CFMutableDictionaryRef  matchingDict;
    CFRunLoopSourceRef      runLoopSource;
    kern_return_t           kr;

    matchingDict = IOServiceMatching(kIOUSBDeviceClassName);
    if (matchingDict == NULL) {
        fprintf(stderr, "IOServiceMatching returned NULL.\n");
    }
    gNotifyPort = IONotificationPortCreate(kIOMasterPortDefault);
    runLoopSource = IONotificationPortGetRunLoopSource(gNotifyPort);
    gRunLoop = CFRunLoopGetCurrent();
    CFRunLoopAddSource(gRunLoop, runLoopSource, kCFRunLoopDefaultMode);
    kr = IOServiceAddMatchingNotification(gNotifyPort,
                                          kIOFirstMatchNotification,
                                          matchingDict,
                                          DeviceAdded,
                                          NULL,
                                          &gAddedIter
                                          );

 

[Krevnik]

As a sort of "for the future" response, you can also do something slightly different if you want to keep some code using the C/C++ compiler instead of using the Obj-C compiler:

//----- MyObjCType.h
#ifdef __OBJC__
@interface MyObjCType : NSObject
{
    - (void)reloadData;
}

typedef MyObjCType *MyObjCTypeRef;
#else
typedef void *MyObjCTypeRef;
#endif

void ReloadDataForMyObjCType(MyObjCTypeRef targetObject);

//----- MyObjCType.m
// <Insert ObjC Code Somewhere Here>
void ReloadDataForMyObjCType(MyObjCTypeRef targetObject)
{
    [targetObject reloadData];
}

//----- MyCCode.c

void MyFunctionDoesAThing()
{
    MyObjCTypeRef targetObject = GetSomeTypeRef();
    ReloadDataForMyObjCType(targetObject);
}

This pattern will hide the Obj-C code away from the C code and still make it callable from C code by using the typedef trickery.

 

[DennisBlah]

As a sort of "for the future" response, you can also do something slightly different if you want to keep some code using the C/C++ compiler instead of using the Obj-C compiler:

//----- MyObjCType.h
#ifdef __OBJC__
@interface MyObjCType : NSObject
{
    - (void)reloadData;
}

typedef MyObjCType *MyObjCTypeRef;
#else
typedef void *MyObjCTypeRef;
#endif

void ReloadDataForMyObjCType(MyObjCTypeRef targetObject);

//----- MyObjCType.m
// <Insert ObjC Code Somewhere Here>
void ReloadDataForMyObjCType(MyObjCTypeRef targetObject)
{
    [targetObject reloadData];
}

//----- MyCCode.c

void MyFunctionDoesAThing()
{
    MyObjCTypeRef targetObject = GetSomeTypeRef();
    ReloadDataForMyObjCType(targetObject);
}

This pattern will hide the Obj-C code away from the C code and still make it callable from C code by using the typedef trickery.

I did not try it, but will definitely do so in future!
Thats awesome thank you very much