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# tableView(_:validateDrop:proposedRow:proposedDropOperation:)

Used by `aTableView` to determine a valid drop target.

```
@MainActor optional func tableView(_ tableView: NSTableView, validateDrop info: any NSDraggingInfo, proposedRow row: Int, proposedDropOperation dropOperation: NSTableView.DropOperation) -> NSDragOperation
```

## Parameters

`tableView`

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.

`dropOperation`

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:)`](/documentation/AppKit/NSTableView/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`.

---

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