Mac OS UserNotificationCenter in Qt

Question

The goal is to display notifications (popup+notification center) in Mac Os.

Attemp #1. Create myclass.h + myclass.mm files (using OBJECTIVE_SOURCES). I was able to add notifications to notification center. But in order to create popups I should implement NSUserNotificationCenterDelegate:shouldPresentNotification. Naive implementation of the method and passing class as delegate raises compile-time exception: this is of *MyClass type, whereas setDelegate method requires id

Attempt #2. Define myclass using objective-c style with @interface directive and so on. Unfortunatly, compiler could not compile NSObject.h. Looks like class objective-c is not supported in Qt, and we forced to use C++ class declaration.

Any ideas, how to implement given mac-os protocol in C++ class?

Working example

MyClass.h

class MyClass
{
public:
    void test();
}

MyClass.mm

void MyClass::test()
{
  NSUserNotification *userNotification = [[[NSUserNotification alloc] init] autorelease];
  userNotification.title = @"Title";
  userNotification.informativeText = @"Test message";
  [[NSUserNotificationCenter defaultUserNotificationCenter] deliverNotification:userNotification];
}

Trying to add popups. Raises exception in setDelegate method

MyClass.h

class MyClass
{
public:
    explicit MyClass();
    void test();
    BOOL shouldPresentNotification(NSUserNotificationCenter *center, NSUserNotification *notification);
}

MyClass.mm

MyClass::MyClass()
{
    [[NSUserNotificationCenter defaultUserNotificationCenter] setDelegate:this];
}

BOOL MyClass::shouldPresentNotification(NSUserNotificationCenter *center, NSUserNotification *notification)
{
    return YES;
}

void MyClass::test()
{
  NSUserNotification *userNotification = [[[NSUserNotification alloc] init] autorelease];
  userNotification.title = @"Title";
  userNotification.informativeText = @"Test message";
  [[NSUserNotificationCenter defaultUserNotificationCenter] deliverNotification:userNotification];
}

Can you provide some of the code please? – trojanfoe Mar 03 '14 at 09:14 — trojanfoe, Mar 03 '14 at 09:14
added to post some samples – developer Mar 03 '14 at 09:24 — developer, Mar 03 '14 at 09:24

score 0 · Answer 1 · answered Mar 03 '14 at 09:47

0

Solution turned out to be easy: you should just cast this to required protocol

MyClass::MyClass()
{
    id<NSUserNotificationCenterDelegate> self = (id<NSUserNotificationCenterDelegate>)this;
    [[NSUserNotificationCenter defaultUserNotificationCenter] setDelegate:self]; 
}

BOOL MyClass::shouldPresentNotification(NSUserNotificationCenter *center, NSUserNotification *notification)
{
    return YES;
}

void MyClass::test()
{
  NSUserNotification *userNotification = [[[NSUserNotification alloc] init] autorelease];
  userNotification.title = @"Title";
  userNotification.informativeText = @"Test message";
  [[NSUserNotificationCenter defaultUserNotificationCenter] deliverNotification:userNotification];
}

answered Mar 03 '14 at 09:47

developer

319
2
13

Interesting. So each C++ object instance is also an Objective-C object? – trojanfoe Mar 03 '14 at 09:50
As far as I understood Qt C++ classes are somehow compiled into Objective-C. Though, maybe I'm wrong – developer Mar 03 '14 at 10:19
No, that's certainly not true. Qt classes are pure C++ and don't have anything to do with Objective-C. I am surprised your code works. – trojanfoe Mar 03 '14 at 10:58
It is not pure Qt class. Moreover, it should be Objective-C++ class – developer Mar 03 '14 at 11:11

Mac OS UserNotificationCenter in Qt

1 Answers1

Linked