---
title: NSView.TrackingRectTag
framework: appkit
role: symbol
role_heading: Type Alias
path: appkit/nsview/trackingrecttag
---

# NSView.TrackingRectTag

This type describes the rectangle used to track the mouse.

## Declaration

```swift
typealias TrackingRectTag = Int
```

## Discussion

Discussion If the value of this type is 0, it is invalid. See the methods addTrackingRect(_:owner:userData:assumeInside:) and removeTrackingRect(_:).

## See Also

### Managing Tracking Rectangles

- [addTrackingRect(_:owner:userData:assumeInside:)](appkit/nsview/addtrackingrect(_:owner:userdata:assumeinside:).md)
- [removeTrackingRect(_:)](appkit/nsview/removetrackingrect(_:).md)