Create Mojave Cocoa window programmatically in Objective-C

Question

I'm trying to create a minimal application in order for me to start a game engine from scratch. Here is the code:

#import <Cocoa/Cocoa.h>

int main (int argc, const char * argv[]){
    NSWindow *window = [[NSWindow alloc] init];
    [window makeKeyAndOrderFront:nil];
    CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0, false)
    while (1);
    return 0;
}

I would how to display a window without calling CFRunLoopRunInMode().

Xcode 10.1

MacOS 10.14.3

Answer 1

I think I have found the answer myself. The window does not appear unless it receives the nextEventMatchingMask: message. This is probably what triggers the window in a CFRunLoop and is what I wanted to know, although it would be nice if I could dig deeper. For now, I'm happy with the following solution.

#import <Cocoa/Cocoa.h>
int main (int argc, const char * argv[]){
@autoreleasepool {
    // Create a default window
    NSWindow *window = [[NSWindow alloc] init];
    // Make it blue just for better visibility
    [window setBackgroundColor:[NSColor blueColor]];
    // Bring to front and make it key
    [window makeKeyAndOrderFront:nil];
    // Custom run loop
    NSEvent* event;
    while(1) {
        do {
            event = [window nextEventMatchingMask:NSEventMaskAny]; //window shows now
            if ([event type] == NSEventTypeLeftMouseDown) {
                NSLog(@"Mouse down");
            }
            else {
                NSLog(@"Something happened");
            }
        } while (event != nil);
    }
}
return 0;
}

I don't have a reference for that. I can only refer to this article: Handmade Hero for mac in which the window appears due to a similar method. That was not good enough for me because such a method involves NSApp, which I would like to avoid, if possible.