macOS: how to get access to the NSApplicationDelegate?

davecotter

Qt must, under the hood, have an appDelegate? How do i get access to that, if i say want to add a virtual method to it, and pass it to a library that needs access to it?

i saw this:
https://wiki.qt.io/Application_Start-up_Patterns

but that talks about replacing QApplication, which i can't do because that's.. well, my entire app is in there already.

I just want to get access to the existing (?) one. there must be one, right?

davecotter

okay here:

id	appDelegate = [[NSApplication sharedApplication] delegate];

note that that "id" is actually of type QCocoaApplicationDelegate, but that's a private type so you can't use it :(

some other info here too

SGaist

Hi,

You can take some inspiration from QTBUG-38184 which ask a similar question for iOS.

Hope it helps

mpergand

I used a custom delegate in the past (Qt 4 i think)

static AppDelegate *sAppDelegate;

 void  CocoaBridge::installDelegate(MPQt::Application *app)
 {
	sAppDelegate=[AppDelegate new];
	sAppDelegate->qtApp=app;
	[NSApp setDelegate:sAppDelegate];
 }

The drawback is that you need to deal events like openFiles or applicationShouldTerminate by yourself:

-(NSApplicationTerminateReply) applicationShouldTerminate:(NSApplication*) sender
{ Q_UNUSED(sender)
	Log("NSApp should terminate")
	QEvent ev(QEvent::Close);
	qtApp->sendEvent(qtApp,&ev);

	if(ev.isAccepted())
		{
		qtApp->quit();
		return NSTerminateNow;
		}

	return NSTerminateCancel;
}

davecotter

okay here:

id	appDelegate = [[NSApplication sharedApplication] delegate];

note that that "id" is actually of type QCocoaApplicationDelegate, but that's a private type so you can't use it :(

some other info here too