Calling Objective C from C++

Hi,

Thanks for the reply.

Using just objective c++ is out of the window as this app needs to run on multiple operating systems/windowing systems.

I am getting there by setting the filetype of .cpp files in the XCode project to sourcecode.cpp.objcpp. This allows the files to be compiles the same as .mm I believe.

The main problem I have now is finding the define that is the equivalent to _OBJC_ for c++ code, my initial guess of _OBJCPP_ is wrong, any ideas?

Thanks

Andy

Maybe I should have put it better as well as I seem to be able to access what I call "Objective C" objects from c++, maybe I am using the incorrect terminology.

I have a test cpp file OSCLog.cpp:

/*
 * OSCLog.cpp
 * OSCLog
 *
 * Created by Andrew Capon on 09/04/2008.
 * Copyright 2008 CAD Ltd. All rights reserved.
 *
 */
#include "OSCLog.h"
#ifdef WIN32
void OSCLog::Start(CADTextView *pTVLog)
{
 pTVLog->AppendText("Hello World");
}
#else
void OSCLog::Start(NSTextView *pTVLog)
{
 NSString *logStr = [NSString stringWithFormat:@" hello Textview"];
 NSRange endRange;
 
 endRange.location = [[pTVLog textStorage] length];
 endRange.length = 0;
 
 [pTVLog replaceCharactersInRange:endRange withString:logStr];
 
 endRange.length = [logStr length];
 
 [pTVLog scrollRangeToVisible:endRange]; 
}
#endif

In XCode I have set this Filetype to sourcecode.cpp.ocjcpp

I have a Objective c controller class defined by OSCLogController.h:

//
// OSCLogController.h
// OSCLog
//
// Created by Andrew Capon on 04/04/2008.
// Copyright CAD Ltd All rights reserved.
//
#import <Cocoa/Cocoa.h>
#import "OSCLog.h"
@interface OSCLogController : NSObject 
{
 // controls on the form
 IBOutlet NSTextField *tfIpAddr;
 IBOutlet NSTextField *tfPort;
 IBOutlet NSTextView *tvLog;
 
 OSCLog *oscLog;
}
// Action to start the logging
-(IBAction)start:(id)sender;
@end

And implemented by OSCLogController.m:

//
// OSCLogController.m
// OSCLog
//
// Created by Andrew Capon on 04/04/2008.
// Copyright 2008 CAD Ltd All rights reserved.
//
#import "OSCLogController.h"
@implementation OSCLogController
-(id)init
{
 [super init];
 oscLog = new OSCLog();
 
 return self;
}
-(void)dealloc
{
 delete oscLog;
 [super dealloc];
}
-(IBAction)start:(id)sender
{
 oscLog->Start(tvLog);
}
@end

The NSTextView tvLog is passed to the cpp code which uses it to append some test text to the TextView.

This all works and is what I was after as the cpp code is using objective c classes (or what I call objective c classes!).


As you can see I am just using a WIN32 define to switch between WIN32 and OSX, I am really after a define like _OBJC_ for objective c++ to use as the code needs to support more than just two platforms.


Cheers

Andy

Message was edited by: AndrewCapon

Message was edited by: AndrewCapon

Code formatting seems to have been mucked up, sorry about that

Thanks for that, I have updated the post

Cheers

Andy

HI,

I tried _OBJC_ it is not defined when compiling objective c++!

I will have a look at the link, thanks for all your help on this.

Cheers

Andy

mmm, from your link:

_OBJC_
This macro is defined when you compile Objective-C .m files or Objective-C++ .mm files, or when you override the file extension with -ObjC or -ObjC++ flags.

Ill have another look tomorrow!

_OBJC_ works today, myst have mucked up yesterday!

Decided to use _APPLE_ instead anyway.

Thanks for all your help

Andy

Hi Stephan,

I'm just keeping the .cpp files and building them as Objective c++ on OSX using #ifdefs for different platforms. Saves another load of files/inheritance.

Cheers

Andy