The accessibility frame is used by VoiceOver for hit testing touches, drawing the VoiceOver cursor, and calculating where in the focused element to simulate a tap when the user double-taps the screen. Note that the frame is in screen coordinates!
myElement.accessibilityFrame = frameInScreenCoordinates;
If your elements or screen layouts change often, consider overriding -accessibilityFrame
to always provide an up-to-date rect.
Calculating the screen-relative frame of scroll view subviews can be error-prone and tedious. iOS 10 introduces a new API to make this easier: accessibilityFrameInContainerSpace
.