---
title: "toolPickerIsRulerActiveDidChange(_:)"
framework: pencilkit
role: symbol
role_heading: Instance Method
path: "pencilkit/pktoolpickerobserver/toolpickerisruleractivedidchange(_:)"
---

# toolPickerIsRulerActiveDidChange(_:)

Tells the observer when a person shows or hides the ruler.

## Declaration

```swift
optional func toolPickerIsRulerActiveDidChange(_ toolPicker: PKToolPicker)
```

## Parameters

- `toolPicker`: The tool picker whose configuration changed.

## See Also

### Detecting tool configuration changes

- [toolPickerSelectedToolItemDidChange(_:)](pencilkit/pktoolpickerobserver/toolpickerselectedtoolitemdidchange(_:).md)