Allows the delegate for
sender to constrain the divider to certain positions.
- macOS 10.0+
The split view that sent the message.
The cursor’s current position, and the proposed position of the divider.
Specifies the divider the user is moving, with the first divider being 0 and increasing from top to bottom (or left to right).
The position at which to constrain the divider.
If the delegate implements this method, the split view calls it repeatedly as the user moves the divider.
For example, if a subview’s height must be a multiple of a certain number, use this method to return the multiple nearest to