---
title: "onPencilDoubleTap(perform:)"
framework: swiftui
role: symbol
role_heading: Instance Method
path: "swiftui/view/onpencildoubletap(perform:)"
---

# onPencilDoubleTap(perform:)

Adds an action to perform after the user double-taps their Apple Pencil.

## Declaration

```swift
nonisolated func onPencilDoubleTap(perform action: @escaping (PencilDoubleTapGestureValue) -> Void) -> some View

```

## Parameters

- `action`: The action to perform after the user double-taps their Apple Pencil.

## Return Value

Return Value A view that performs action after the user double-taps their Apple Pencil.

## Discussion

Discussion You should respect people’s setting for the double-tap gesture by reading the preferredPencilDoubleTapAction environment value, if the setting makes sense in your app. If it doesn’t, consider giving people a way to specify custom behavior in your app instead. In the example below, double-tapping an Apple Pencil will… do nothing if this is what the user selected in the Settings app, switch the tool to ”Lasso” if this is the action they have configured in the app, switch the tool to ”Eraser” if they haven’t configured a custom action in the app and this is what they selected in the Settings app, switch the tool to the last used one otherwise. enum MyDrawingTool: Equatable {     case brush     case lasso     case eraser     ... }

enum MyPencilAction: String {     case switchLasso     ... }

@State private var currentTool = MyDrawingTool.brush @State private var lastTool: MyDrawingTool?

@Environment(\.preferredPencilDoubleTapAction) private var globalAction @AppStorage("customPencilDoubleTapAction") private var customAction: MyPencilAction?

var body: some View {     MyDrawingCanvas()         .onPencilDoubleTap { _ in             guard globalAction != .ignore else {                 // Respect the user’s preference to ignore the double-tap gesture.                 return             }             if let customAction {                 // If a custom action is configured, respect it.                 if customAction == .switchLasso, currentTool != .lasso {                      (currentTool, lastTool) = (.lasso, currentTool)                 }             } else if globalAction == .switchEraser, currentTool != .eraser {                 // Switch to eraser if the user prefers it otherwise.                 (currentTool, lastTool) = (.eraser, currentTool)             } else if let lastTool {                 // Switch to the last used tool by default.                 (currentTool, lastTool) = (lastTool, currentTool)             }         } } For more information about Apple Pencil double-tap gestures, see Human Interface Guidelines. note: If multiple views with the onPencilDoubleTap view modifier are visible, all their action closures will be performed after the user double-taps their Apple Pencil.

## See Also

### Recognizing Apple Pencil gestures

- [onPencilSqueeze(perform:)](swiftui/view/onpencilsqueeze(perform:).md)
- [preferredPencilDoubleTapAction](swiftui/environmentvalues/preferredpencildoubletapaction.md)
- [preferredPencilSqueezeAction](swiftui/environmentvalues/preferredpencilsqueezeaction.md)
- [PencilPreferredAction](swiftui/pencilpreferredaction.md)
- [PencilDoubleTapGestureValue](swiftui/pencildoubletapgesturevalue.md)
- [PencilSqueezeGestureValue](swiftui/pencilsqueezegesturevalue.md)
- [PencilSqueezeGesturePhase](swiftui/pencilsqueezegesturephase.md)
- [PencilHoverPose](swiftui/pencilhoverpose.md)