GLKView gesture recognizer without a GLKViewController

Question

I have an application that uses a GLKView, with no other UI elements. I'm not using a GLKViewController, and I'm not planning to.

All of my application setup occurs in didFinishLaunchingWithOptions

My AppDelegate interface is defined as:

@interface AppDelegate : UIResponder <UIApplicationDelegate, GLKViewDelegate, UIGestureRecognizerDelegate>

As part of this setup, I'm trying to set up GestureRecognizer's (Tap, Pinch, etc) - however they appear to not be firing.

UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapFrom:)];
tapGesture.delegate = self;
tapGesture.numberOfTapsRequired = 1;
tapGesture.numberOfTouchesRequired = 1;
tapGesture.cancelsTouchesInView = NO;
[view addGestureRecognizer:tapGesture];
tapGesture.delegate = self;

My selector is defined as:

#pragma mark - GLKViewDelegate

- (void) handleTapFrom: (UITapGestureRecognizer *)recognizer
{
    // Code to respond to gesture here
    NSLog (@"tapGestureUpdated()");
}

From all the example code I can find, gesture recognisers are usually setup within the viewDidLoad method. However it seems that the GLKView does not provide this method - when I attempt to provide one, it isn't called.

Presumably, this is something that the GLKViewController provides - but as mentioned, I'm not using a GLKViewController.

Note that I am able to override the touchesBegan method (and friends), and these selectors get fired as expected.

Any idea what I'm doing wrong, or if there is a workaround?

score 0 · Accepted Answer · answered Jul 22 '15 at 21:57

So, I managed to get this working.

At the beginning of the didFinishLaunchingWithOptions I create a very simple UIViewController, along the lines of:

static UIViewController *viewController;
viewController = [[UIViewController alloc] init];

[self.window setRootViewController:viewController];

I then add the gesture to the view controller, rather than the view.

UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapFrom:)];
tapGesture.delegate = self;
tapGesture.numberOfTapsRequired = 1;
tapGesture.numberOfTouchesRequired = 1;
tapGesture.cancelsTouchesInView = NO;
//[view addGestureRecognizer:tapGesture];
[viewController.view addGestureRecognizer:tapGesture];

This seems suspect, since I've not defined what the view controller's view should be. But it seems the view controller will happily receive these events and fire on these events.

GLKView gesture recognizer without a GLKViewController

1 Answers1