Sample exploring VoiceOver navigation among elements which are subviews of a horizontal UIScrollView.
Try navigation in Portrait and Landscape mode while VoiceOver is active, using for example flick right/left.
Upper scroll view is created by adding subviews to a standard UIScrollView.
Lower scroll view is similar, but uses a subclass of UIScrollView which implements the UIAccessibilityContainer protocol.
Summary of testing on devices with different iOS versions (mixture of iPhone, iPad, iPod Touch):
| iOS | PT-ACP | LS-ACP | PT+ACP | LS+ACP |
|---|---|---|---|---|
| 7.0.3, 7.1.1 | N | N | Y | Y |
| 8.0, 8.1 | N | Y | Y | Y |
| 8.2 | N | Y | Y | Y |
| 8.3 | N | Y | N | Y |
Key: PT=Portrait; LS=Landscape; -ACP=UIAccessibilityContainer protocol not implemented; +ACP=UIAccessibilityContainer protocol implemented; Y=Can navigate to elements which are completely off-screen; N=Cannot navigate to elements which are completely off-screen.
It appears that iOS 8 added the ability to navigate to unseen elements, but in Landscape only.
However, iOS 8.3 apparently removed the ability to navigate to unseen elements when UIAccessibilityContainer protocol is implemented.