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NSGestureRecognizerRepresentable

A wrapper for an NSGestureRecognizer that you use to integrate that gesture recognizer into your SwiftUI hierarchy.

Declaration

@MainActor @preconcurrency protocol NSGestureRecognizerRepresentable

Overview

Use an NSGestureRecognizerRepresentable instance to create and manage an NSGestureRecognizer object in your SwiftUI interface.

To add your gesture recognizer to a SwiftUI view, create an instance of NSGestureRecognizerRepresentable and use the gesture(_:) modifier to attach it. The system calls the methods of your representable instance at appropriate times to create and update the gesture recognizer.

The following example shows the inclusion of a custom MyGestureRecognizer structure in the view hierarchy.

struct ContentView: View {
   var body: some View {
      VStack {
         Image("Mountain")
             .gesture(MyGestureRecognizer())
      }
   }
}

NSGestureRecognizerRepresentable types can use the environment and have data dependencies, similar to views and view representables. The system will call the appropriate methods on your instance to propagate the latest data.

Handling Gesture Recognizer Actions

SwiftUI automatically installs a target to handle the gesture recognizer’s action on your behalf. Implement the handleNSGestureRecognizerAction method to react to the gesture recognizing its action.

You can optionally include a coordinator object to forward delegate messages from your gesture recognizer or add additional targets.

Coordinate Space Conversions

The gesture recognizer you create may not be attached to an NSView in the hierarchy, or it may return a view with different geometry than your SwiftUI view.

To handle this, use the converter on the context to perform coordinate space conversions from the global coordinate space. You can pass the gesture recognizer and a SwiftUI coordinate space to the converter to retrieve a final converted point. Passing the local coordinate space (the default) will provide the point in the SwiftUI view the gesture recognizer is attached to.

Topics

Associated Types

Instance Methods

Type Aliases

See Also

Adding AppKit gesture recognizers into SwiftUI view hierarchies