Open Radar

 
31-Oct-2012 10:23 AM alexis gallagher:
Summary:
UIPageViewController class documentation says that the readonly property gestureRecognizers will return an NSArray of of the class's gestureRecognizers. But when you set the transition style to UIPageViewControllerTransitionStyleScroll (newly supported on iOS6), the gestureRecognizers property always returns an empty array.


Steps to Reproduce:
1. in Xcode 4.5.1, create a new project using the iOS Page-Based Application template.
2. In the template-created file RootViewController.m, at the end of the implementation of viewDidLoad:, add the following NSLog statement:

NSLog(@"gestureRecognizers = %@",self.pageViewController.gestureRecognizers);

3. Run the app and observe that, as expected, the NSLog statement prints to the console the array of gesture recognizers setup by the UIPageViewController.

4. Now in the same file, go to line 28, and change UIPageViewControllerTransitionStylePageCurl to   UIPageViewControllerTransitionStyleScroll.

5. Run the app again, and observe that in the console the UIPageViewController now reports having no gesture recognizers.

Expected Results:
I would expect the -[UIPageViewController gestureRecognizers] to expose its gesture recognizers even when the UIPageViewControllerTransitionStyle is UIPageViewControllerTransitionStyleScroll.

Actual Results:
It returns an empty NSArray

Regression:
As near as I can tell, this happens always.

Notes:
Traffic on stack overflow suggests I'm not the only one to observe this.