CODEWITHSUNDEEP
objective-cmacosfocusevent-loop
BlueskyMed
BlueskyMed

Reputation: 1305

OSX 10.10 App doesn't get focus or event loop

Restarting app development after a 15 year hiatus. Current project is conversion of old windows-type command line utility into interactive OS X windowed app. I created a view delegate inside main window and can draw and update NSTable view. The updates are generated in the App's main loop which takes a UDP/TCP stream, parses and updates view via appropriate delegation.

Here's the problem: When I run the app, the main window does not apparently get focus (window control buttons on upper left are grey), the Menu created from my .xib is inert, and the window itself does not respond to resizing or to mouse hits inside the table view scroll bars. Also, the mouse pointer is the spinning beachball when over the App's window.

My guess is that I am not providing time to the Objective C run loop for event processing. I do send a "display" to my window on every iteration of my app loop, but I guess it is not sufficient (Apple is not very clear about what objects get what messages when sending this kind of update message). Am I on the right track?

Is there a way to let the system Event loop run an iteration each time through my app main loop?

Thanks!

Update: I tried explicitly providing event loop time in my app's main loop with: [[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.1]];

There was no apparent change in app behavior.

Upvotes: 0

Views: 101

Answers (2)

BlueskyMed
BlueskyMed

Reputation: 1305

Despite comparing the nibs and connections between my code and a freshly created .xib prototype, i could find no reason for my code to not get focus.

The fix was to move my code guts into the project with a new .xib. This works but is unsatisfying

Upvotes: 0

TheDarkKnight
TheDarkKnight

Reputation: 27611

My guess is that I am not providing time to the Objective C run loop for event processing.

In this case, I recommend you read about Grand Central Dispatch, which provides concurrency, allowing the GUI to remain responsive.

There's a good explanation of GCD here and whilst it looks like a large and complicated subject, you'll probably only need a few lines of code to make use of GCD. For example: -

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{  
    // do some work    
});

Upvotes: 0

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