Allows the delegate for
sender to constrain the maximum coordinate limit of a divider when the user drags it.
- macOS 10.0+
The split view that sent the message.
The proposed maximum coordinate limit of the subview, in the split view’s flipped coordinate system.
Specifies the divider the user is moving, with the first divider being 0 and increasing from top to bottom (or left to right).
The maximum coordinate limit of the divider.
This method is invoked before the split view begins tracking the mouse to position a divider. You may further constrain the limits that have been already set, but you cannot extend the divider limits.
If the split bars are horizontal (views are one on top of the other),
proposed is the bottom limit. If the split bars are vertical (views are side by side),
proposed is the right limit. The initial value of
proposed is the bottom (or right side) of the subview after the divider.