<!--
{
  "availability" : [
    "iOS: 7.0.0 -",
    "iPadOS: 7.0.0 -",
    "macCatalyst: 13.1.0 -",
    "macOS: 10.9.0 -",
    "tvOS: 9.0.0 -",
    "visionOS: 1.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "GameController",
  "identifier" : "/documentation/GameController/GCControllerButtonValueChangedHandler",
  "metadataVersion" : "0.1.0",
  "role" : "Type Alias",
  "symbol" : {
    "kind" : "Type Alias",
    "modules" : [
      "Game Controller"
    ],
    "preciseIdentifier" : "c:@T@GCControllerButtonValueChangedHandler"
  },
  "title" : "GCControllerButtonValueChangedHandler"
}
-->

# GCControllerButtonValueChangedHandler

The signature for the block that executes when a button’s state changes.

```
typealias GCControllerButtonValueChangedHandler = (GCControllerButtonInput, Float, Bool) -> Void
```

## Parameters

`button`

The button element whose state changed.

`value`

A normalized number between `0.0` (minimum) and `1.0` (maximum) that represents the amount of physical or simulated pressure that the user applies to the button.

`pressed`

A Boolean value that indicates whether the user is pressing the button. If <doc://com.apple.documentation/documentation/Swift/true>, the user is pressing the button and the `value` parameter contains the amount of pressure. If <doc://com.apple.documentation/documentation/Swift/false>, the user isn’t applying any pressure and the `value` parameter is `0.0`.

## Discussion

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)