Instance Method

tableView(_:validateDrop:proposedRow:proposedDropOperation:)

Used by aTableView to determine a valid drop target.

Declaration

optional func tableView(_ tableView: NSTableView, validateDrop info: NSDraggingInfo, proposedRow row: Int, proposedDropOperation dropOperation: NSTableViewDropOperation) -> NSDragOperation

Parameters

aTableView

The table view that sent the message.

info

An object that contains more information about this dragging operation.

row

The index of the proposed target row.

operation

The type of dragging operation proposed.

Return Value

The dragging operation the data source will perform.

Discussion

The data source may retarget a drop by calling setDropRow(_:dropOperation:) and returning something other than NSDragOperationNone. A data source might retarget for various reasons, such as to provide better visual feedback when inserting into a sorted position.

To propose a drop on the second row, row would be 2 and operation would be NSTableViewDropOn. To propose a drop below the last row, row would be [aTableView numberOfRows] and operation would be NSTableViewDropAbove.