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Version: 2.x

Upgrading to the new API introduced in Gesture Handler 2

Make sure to migrate off the RNGestureHandlerEnabledRootView (Android only)

Gesture Handler 1 required you to override createRootView to return an instance of RNGestureHandlerEnabledRootView. This class has been the cause of many hard to debug and fix crashed and was deprecated in version 2.0, and subsequently removed in version 2.4. If you are still using it, check out migrating off RNGHEnabledRootView guide.

Upgrading to the new API

The most important change brought by the Gesture Handler 2 is the new Gesture API, along with the GestureDetector component. It makes declaring gesture easier, as it handles much of the work under the hood and reduces the amount of necessary boilerplate code. Instead of a separate component for every type of gesture, the GestureDetector component is used to attach gestures to the underlying view based on the configuration object passed to it. The configuration objects are created using the Gesture object, here is a simple example:

const tapGesture = Gesture.Tap().onStart(() => {
console.log('Tap!');
});
...
return (
<GestureDetector gesture={tapGesture}>
<View />
</GestureDetector>
);

As you can see, there are no onGestureEvent and onHandlerStateChange callbacks, instead the state machine is handled under the hood and relevant callbacks are called for specific transitions or events:

  • onBegin - called when the gesture transitions to the BEGAN state, which in most cases is when the gesture starts processing the touch stream - when the finger first touches the view
  • onStart - called when the activation criteria for the gesture are met and it transitions from BEGAN to ACTIVE state
  • onUpdate - replaces onGestureEvent, called every time the gesture sends a new event while it's in the ACTIVE state
  • onChange - if defined, called just after onUpdate, the events passed to it are the same as the ones passed to onUpdate but they also contain change values which hold the change in value they represent since the last event (i.e. in case of the Pan gesture, the event will also contain changeX and changeY properties)
  • onEnd - called when the gesture transitions from the ACTIVE state to either of END, FAILED or CANCELLED - you can tell whether the gesture finished due to user interaction or because of other reason (like getting cancelled by the system, or failure criteria) using the second value passed to the onEnd callback alongside the event
  • onFinalize called when the gesture transitions into either of END, FAILED or CANCELLED state, if the gesture was ACTIVE, onEnd will be called first (similarily to onEnd you can determine the reason for finishing using the second argument)

The difference between onEnd and onFinalize is that the onEnd will be called only if the gesture was ACTIVE, while onFinalize will be called if the gesture has BEGAN. This means that you can use onEnd to clean up after onStart, and onFinalize to clean up after onBegin (or both onBegin and onStart).

Configuring the gestures

The new gesture objects are configured in the builder-like pattern. Instead of properties, each gesture provides methods that allow for its customization. In most cases the names of the methods are the same as the relevant props, ot at least very similar. For example:

return (
<TapGestureHandler
numberOfTaps={2}
maxDurationMs={500}
maxDelayMs={500}
maxDist={10}
onHandlerStateChange={({ nativeEvent }) => {
if (nativeEvent.state === State.ACTIVE) {
console.log('Tap!');
}
}}>
<View />
</TapGestureHandler>
);

Would have the same effect as:

const tapGesture = Gesture.Tap()
.numberOfTaps(2)
.maxDuration(500)
.maxDelay(500)
.maxDistance(10)
.onStart(() => {
console.log('Tap!');
});

return (
<GestureDetector gesture={tapGesture}>
<View />
</GestureDetector>
);

You can check the modifiers available to specific gestures in the API Reference under Gestures.

Using multiple gestures on the same view

Using the gesture handler components, if you wanted to have multiple gestures on one view, you would have to stack them on top of each other and, in case you wanted to use animations, add an Animated.View after each handler, resulting in a deep component tree, for example:

return (
<TapGestureHandler ... >
<Animated.View>
<PanGestureHandler ... >
<Animated.View>
<PinchGestureHandler ... >
<YourView />
</PinchGestureHandler>
</Animated.View>
</PanGestureHandler>
</Animated.View>
</TapGestureHandler>
);

With the GestureDetector you can use the Gesture Composition API to stack the gestures onto one view:

const tapGesture = Gesture.Tap();
const panGesture = Gesture.Pan();
const pinchGesture = Gesture.Pinch();

return (
<GestureDetector gesture={Gesture.Race(tapGesture, panGesture, pinchGesture)}>
<YourView />
</GestureDetector>
);

Similarily, you can use Gesture.Simultaneous to replace stacked gesture handlers that should be able to recognize gestures simultaneously, and Gesture.Exclusive to replace stacked gesture handlers that require failure of others.

Replacing waitFor and simultaneousHandlers

If you want to make relations between the gestures attached to the same view, you should use the Gesture Composition API described above. However, if you want to make a relation between gestures attached to different views, or between gesture and an old gesture handler, you should use simultaneousWithExternalGesture instead of simultaneousHandlers, and requireExternalGestureToFail instead of waitFor. In case you need a ref object to pass to an old gesture handler, you can set it to the gesture using .withRef(refObject) modifier.