Func<Rect> The calculated frame of the accessibility node, in screen coordinates.
Delegate that calculates the frame of the accessibility node, automatically keeping it up-to-date.
The node's frame can be set either through this delegate or through the
AccessibilityNode.frame property. Using this delegate should simplify the update of the node's
frame by automatically keeping it in sync with the coordinates of the visual element represented by the
node.
If the AccessibilityNode.frame is not set, it gets its value from this delegate.
If this delegate is not set, calling AccessibilityHierarchy.RefreshNodeFrames sets the
AccessibilityNode.frame to Rect.zero.