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# highlight(_:)

Highlights or unhighlights the scroll button the user clicked.

```
func highlight(_ flag: Bool)
```

## Discussion

The receiver invokes this method while tracking the mouse; you should not invoke it directly. If `flag` is <doc://com.apple.documentation/documentation/Swift/true>, the appropriate part is drawn highlighted; otherwise it’s drawn normally.

### Special Considerations

This method has no effect in macOS 10.7 and later.

## See Also

[`func rect(for: NSScroller.Part) -> NSRect`](/documentation/AppKit/NSScroller/rect(for:))

Returns the rectangle occupied by `aPart`, which for this method is interpreted literally rather than as an indicator of scrolling direction.


---

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