The desired location for the insertion point.
- iOS 3.2+
- Mac Catalyst 13.0+
- tvOS 9.0+
For text selections that wrap across line boundaries, this property determines whether the insertion point appears after the last character on the line or before the first character on the following line. The selection affinity is set in response to the user navigating via the keyboard (for example, command-right-arrow). The text input system checks this property when it moves the insertion point around in a document.
In the default implementation, if the selection is not at the end of the line, or if the selection is at the start of a paragraph for an empty line, a forward direction is assumed (
UIText); otherwise, a backward direction
UIText is assumed.