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# browser(_:selectionIndexesForProposedSelection:inColumn:)

Asks the delegate for a set of indexes to select when the user changes the selection in the browser with the keyboard or mouse.

```
@MainActor optional func browser(_ browser: NSBrowser, selectionIndexesForProposedSelection proposedSelectionIndexes: IndexSet, inColumn column: Int) -> IndexSet
```

## Parameters

`browser`

The browser.

`proposedSelectionIndexes`

The set of indexes of the items in the proposed selection.

`column`

The column index of the column containing the selection.

## Return Value

The set of indexes of the items that should be selected.

## Discussion

This method may be called multiple times, with one new index added to the previous selection, to see whether a particular index can be selected when the user is extending the selection with the keyboard or mouse. The `proposedSelectionIndexes` parameter contains the entire selection, and you can return the existing selection if you do not want to change it. This method works only for item-based browsers.

---

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