I'm trying to integrate the GCController framework into my project. I'm not so familiar with Objective-C, so please excuse my ignorance around how this is supposed to work.
I have a class that extends NSOpenGLView, which registers observer methods for the various controller notifications, like so:
-(void)awakeFromNib
{
// Do some stuff
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(controllerStateChanged) name:GCControllerDidConnectNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(controllerStateChanged) name:GCControllerDidDisconnectNotification object:nil];
}
and I've defined a super simple handler as such:
- (void)controllerStateChanged {
NSLog (#"something happened, let's check it out\n");
}
Problem is, these events/notifications never seem to fire - and when I inspect [GCController controllers], it's entirely empty.
Of course, it stands to reason that if there are no controllers, there will be no events - so maybe I'm doing something wrong?
Or perhaps, for whatever reason - my controller simply fails to generate the required events (I'm using a PS4 controller which is registered with the OS, be it wirelessly or via USB, so I'm not sure what I'm missing here).
Is there some other place I need to enable these notifications? Do I need to somehow initialise the GCController framework?
So it turns out that the GCController framework only supports MFi (Made For iPod, Made For iPhone, Made For iPad) controller products.
For anyone looking to support non-MFi controllers, you'll need to interface with the HID via IOKit. Or use the rather excellent DDHIDLib instead
Related
I am developing an iOS application where need to do some stuff when I have Internet connection and other, when I haven't. If I haven't at some point I will show a message to the user to give me internet and come back. The question it is how to detect the following situation:
the user press the Home button twice, goes to multitasking , Settings and will connect to internet
the user comes back with multitasking to my app, but doesn't press anything
I know I will get callbacks to the AppDelegate:
- (void)applicationDidEnterBackground:(UIApplication *)application
- (void) applicationDidBecomeActive:(UIApplication *)application
but the code ( it is not started by me) it is very big, and I don't want to handle there the UIViewController needs, if there is any alternative.
My UIViewController's - (void)viewDidAppear:(BOOL)animated it isn't called when the user came back.
The breakpoint it is not hited for sure!
Any usable ideas, except in AppDelegate?
You can use the notification center to listen to applicationDidEnterBackground within the view controller:
[[NSNotificationCenter defaultCenter] addObserver: self
selector: #selector(handleEnteredBackground:)
name: UIApplicationDidEnterBackgroundNotification
object: nil];
Do this in viewDidLoad. Similarily for applicationDidBecomeActive.
Don't forget to remove yourself as an observer in viewDidUnload.
The application delegate is the correct place to be handling application state changes, but just because that is the case, it doesn't mean you must put all the logic that is triggered by the application state change in there.
Put the logic where it belongs. If it's networking code, that's not in the application delegate and it's not in the view controller, it's in a separate class. Then look into ways of tying the different parts of your application together. In most cases, notifications, KVO and the shared instance pattern are good approaches to take.
I use sharekit with mail/twitter/facebook and I am really new to objective-c. sharekit works well and sends my images like it should.
in my app I have a screenshot function. I want the app to 'freeze' when a screenshot is taken, stopping to send any shake- or touch-event to the scene behind the sharekit-action.
in my screenshot-layer I have three buttons which call the shareItem-methods of their specified service, like
[SHKTwitter shareItem:item];
vereything works fine 'till here. but now when the sending is finished (or canceled or errored) I need the app to 'unfreeze', sharekit should tell my app that it is allowed to listen to any touch- or shake-action again.
I am sorry but I think I don't understand the concept of using the delegate here. I mean, is 'sendDidFinish' meant to be inside a delegate? and if so, how could I tell sharekit who is its delegate? or do I have to edit the send-service classes (like SHKItem or SHKFacebook) itself?
please don't downrate me for this question. I really want to get behind this mystery...
SHKTwitter inherit from SHKOAuthSharer, who inherit from SHKSharer. SHKSharer has a delegate protocol called "SharerDelegate".
So you can use an instance of SHKTwitter, then set it's delegate as :
shkTwitterInstance.shareDelegate = yourDelegateObject.
And implement the delegate method
- (void)sharerFinishedSending:(SHKSharer *)sharer;.
Try that.
EDIT (OTHER, AND MORE POPULAR, SOLUTION)
Also, you can suscribe your object to "SHKSendDidFinish" notification from SHKTwitter object.
[[NSNotificationCenter defaultCenter] addObserver:yourObject selector:#selector(theMethodthatYouWantToExecuteWhenTheNotificationIsRaised:) name:#"SHKSendDidFinish" object:shkTwitterObject];
I'd like my controller to subscribe to notifications from view. However, before doing that, I'd like to confirm if it is OK for a view to know the instance of its controller?
Let me offer you a more specific example of what I have in mind.
My controller creates the view and informs it that it is its controller
self.gameView = [[GameView alloc] initWithController:self];
Once done, it subscribes for notifications from this view
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(saySomething:)
name:#"SaySomethingClever" object:nil];
Meanwhile the view does its thing, but when the right time comes, it posts a notification
[[NSNotificationCenter defaultCenter] postNotificationName:
#"SaySomethingClever" object:gvc];
In order for it to do it, the view needs to know the recipient of the notification (gvc).
I'd like to use this opportunity and as you whether the following is ok:
When initWithController is called, the view
-(id) initWithController: (GameViewController* )g {
gvc = g;
return [self initWithFrame:CGRectMake(0, 0, 480, 300)];
}
where initWithFrame:CGRectMake is a private method that handles specific view stuff.
Everything works fine, however, i wonder whether this approach is morally acceptable
It's not strictly a problem if the view has a reference to its controller, but it looks like your real problem is a misunderstanding of the notification posting method.
The object argument isn't the receiver. Indeed, if it were -- if the poster of a notification had to know the object that was going to get the notification -- that would defeat the entire purpose of the notification. You could just call the appropriate method! The point of notifications is that the poster doesn't need to know the other objects which are listening.
The object argument is actually used by the receiver to distinguish which notifications it should care about. Most frequently, the argument is the poster itself:
[[NSNotificationCenter defaultCenter] postNotificationName:IDidSomethingInteresting
object:self];
but it can in fact be any object.
When registering for notifications, you can specify a particular instance whose notifications you're interested in. This is the object argument to addObserver:... The notification center will then only pass on those notifications whose name and object match what was specified.
Even if you pass nil for the object in addObserver:..., you can check the object of a received notification and only act if the poster was one that you are interested in.
For example, there might be several windows in you application, and you may be interested in knowing when one of them is resized, but you don't care what happens to the rest of them. You would pass just that window instance as the object for addObserver:...
To sum up, your view in this case doesn't need that reference to its controller in order to for the controller to receive notifications posted by the view.
See also: "Posting Notifications"
While the concept is OK, it's not needed in your case:
[[NSNotificationCenter defaultCenter] postNotificationName:#"SaySomethingClever"
object:self];
The object referenced by an NSNotification is usually the object which posts a notification. The whole notification idea is that posters don't need to know about observers.
I would focus on controllers calling other controllers (or ideally model methods).
Allow each view to work with it's main resource and allow the controller for that view to make additional calls.
I am trying to handle device orientation changes on a viewcontroller for one of my views.
Here is my code:
- (void)viewDidLoad {
[super viewDidLoad];
NSLog(#"viewDidLoad");
// Tell the UIDevice to send notifications when the orientation changes
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(orientationChanged:) name:UIDeviceOrientationDidChangeNotification object:nil];
}
// tell the director that the orientation has changed
- (void) orientationChanged:(NSNotification *)notification
{
NSLog(#"orientationChanged");
}
When I first launch the App, the orientationChanged selector gets called, but then after that it does not get called again no matter how much I rotate the iPad. Does anyone have any idea what I might be doing wrong? When I put similar code in the app delegate, it works fine, but in this particular view controller, it is not behaiving properly.
I know this question is a bit old, but just thought I'd add a link to a tutorial I found when I was in the same situation you were (wanting to get notifications for device rotation, regardless of what the interface orientation was).
This tutorial gives a nice and simple overview of how to handle device rotation using UIDeviceOrientationDidChangeNotification.
I also had issues with UIDeviceOrientationDidChangeNotification not firing (it worked fine in the simulator, but not on my device). After a bit of debugging I realised that I had Portrait Orientation Locked on the device, and this was causing the UIDeviceOrientationDidChangeNotification not to fire. Not sure if that's your issue, but it's something that's easy to overlook and worth checking.
the problem is that the orientation will not change unless you specify that it can do so. when you rotate the device/simulator, the framework calls
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation;
where interface orientation is the orientation the system wants to use, however you have to return YES or it will not change.
if you are not returning YES then your orientation is not changing and therefore you cannot get notified for an orientation change (because it did not happen)
I've been thinking about this and have read through another stackoverflow question regarding the best recommended way to communicate between view controllers. However, the question/answer for that doesn't seem to address the best approach for the reverse behavior.
i.e. to pass data from ParentController to its ModalController, we could initialize ModalController like initWithDataToProcess:.
But what if we want to do the reverse? How would I notify the previous controller about a new data?
e.g. User clicks on 'new person' button on the ParentController. I initiate a new ModalController and present the user with a person editor view via presentModalViewController:. User clicks on 'done' to add a new person. I dismissModalViewController: and UI returns to the ParentController's view.
Using a global field reference in a singleton object (app delegate or other) is bad. delegation (via formal protocol) and notifications (via NSNotificationCenter) seems overkill. Any suggestions?
It is generally cleaner to use notifications. Just add your observer like this....
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(somethingHappened:) name:#"MyNotification" object:nil];
and elsewhere in your code you'd post the notification whenever you need to.
[[NSNotificationCenter defaultCenter] postNotificationName:#"MyNotification" object:self];
In the example I'm passing self but you can pass any object you wish really and it will be fed to your somethingHappened: function
The important thing is to keep the #"MyNotification" very descriptive and unique. Adding your project name to the beginning is a good way to keep things unique...eg. #"ProjAXViewHasGotData"
A delegate is pretty much the minimum you can do. If you think it is too much of a hassle to declare a new protocol for this, just pass in the parent view controller and have the modal one call a method on it.