nsoperation

I am trying to monitor a stream of video output from a FireWire camera. I have created an Interface Builder interface with buttons and an NSImageView . While image monitoring is occurring within an endless loop, I want to: change some camera parameters on the fly (gain, gamma, etc.) tell the monitoring to stop so I can save an image to a file (set a flag that stops the while loop) Using the button features, I have been unable to loop the video frame monitor, while still looking for a button press (much like using the keypressed feature from C.) Two options present themselves: Initiate a new

I watched with a great attention the WWDC 2015 sessions about Advanced NSOperations and I played a little bit with the example code . The provided abstraction are really great, but there is something I may did not really good understand. I would like to pass result data between two consequent Operation subclasses without using a MOC. Imagine I have a APIQueryOperation which has a NSData? property and a second operation ParseJSONOperation consuming this property. How do I provide this NSData? intance to the second operation ? I tried something like this : queryOperation = APIQueryOperation

I need to use a thread in order to retrieve an image from the web and assign it into an image view. I have subclassed NSOperation and called it from my view controller like: NSOperation *operation = [[[GetImage alloc] init] autorelease]; [queue addOperation:operation]; I get the image fine but how do I go about assigning that image that is in my NSOperation class? I have the image stored in a UIImage called RetrievedImage: NSData *imageData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:url]]; retrievedImage = [[UIImage alloc] initWithData:imageData]; [imageData release]; How do

My question is related to the "Delta Download" thing as it was named in WWDC 2014 Advanced CloudKit. I'm trying to make syncronization for my Core Data app, which is iPhone only for now (think: there is only one device active). So, basically the app will store user records in the cloud from one same device, for the most cases for now. I have trouble with understanding custom zone feature which is based on CKFetchRecordChangesOperation aka Delta Download. As I got it right, we have CKServerChangeToken 's to maintain sync operations (I mean download only those records which was added/modified