ท่าลากและปัดด้วย Gesture Handler

React Native Gesture Handler replaces the built-in touch system with one that runs entirely on the native UI thread. The default React Native responder system processes touch events on the JavaScript thread, introducing latency when JS is busy. Gesture Handler moves recognition and response to native code, enabling the same snappy feel as native iOS and Android apps.

Gesture Handler is the standard companion to Reanimated — they are designed to work together. It provides pan, pinch, rotation, tap, long-press, and fling recognizers that feed data directly into Reanimated worklets.

Gesture Handler v2 (the modern API) uses the Gesture factory object to create gestures and the GestureDetector component to attach them to UI. This replaces the older component-based API (PanGestureHandler, TapGestureHandler) with a cleaner compositional model.

You create a gesture object (e.g., Gesture.Pan()), configure it with method chaining, and wrap your component in GestureDetector. The gesture callbacks are worklets that run on the UI thread.

The simplest pan gesture example is a draggable card. Create shared values for x and y position. In onUpdate, add the gesture's translationX/translationY to a stored start position. In onEnd, save the current position as the new start so the next drag continues from where the card stopped.

The card visually follows the finger without any JavaScript thread involvement — completely smooth even under JS load.

A common pattern is to let the user drag a card freely but snap it back to its original position when released. In the onFinalize or onEnd callback, assign a withSpring animation to the offset values, returning them to zero with a satisfying bounce.

The spring's initial velocity can be set from the gesture's final velocity (event.velocityX, event.velocityY) to create a natural-feeling throw-and-catch effect that continues the motion before bouncing back.

A swipe-to-dismiss card tracks horizontal position during the pan, and when the card is released with sufficient horizontal velocity or displacement, it animates off screen with withTiming or withDecay instead of snapping back.

Use event.velocityX to determine if the throw was intentional (fast enough), and event.translationX to check if the card was dragged far enough. If either threshold is met, fly the card off screen and call runOnJS to notify React to remove it.

Gesture.Tap() recognizes taps. Unlike Pressable or TouchableOpacity, a Gesture Handler tap runs its callback on the UI thread, enabling animated feedback without JS involvement. You can configure maxDuration and numberOfTaps for double-tap detection.

Gesture taps are especially useful when combined with Reanimated: the tap callback can directly trigger a spring animation on scale or opacity, giving zero-latency visual feedback that feels instantaneous.

Gesture Handler allows composing multiple gestures on the same component using Gesture.Simultaneous (both run at the same time) and Gesture.Exclusive (only one can be active at a time). This enables complex interactions like swipe-while-zooming on a photo viewer.

Use Gesture.Simultaneous(panGesture, pinchGesture) to allow both pan and pinch on the same element simultaneously. Use Gesture.Exclusive(swipeGesture, tapGesture) to ensure a swipe cancels a tap recognition.

Every gesture recognizer has lifecycle callbacks: onBegin fires when the gesture is recognized, onUpdate fires on every new touch event, onEnd fires when the gesture completes successfully, and onFinalize fires after end or when the gesture is cancelled.

Use onBegin to store the starting position, onUpdate to track motion, onEnd to handle successful completion, and onFinalize to clean up regardless of whether the gesture succeeded or was cancelled (e.g., interrupted by a phone call).

Gesture.LongPress() recognizes holds that exceed a minimum duration. Configure .minDuration(ms) to set the hold time. A common pattern is triggering a haptic feedback and entering an edit mode after a long press, like reordering items in a list.

Combine long press with pan for drag-to-reorder: the long press activates drag mode, and the pan moves the item while in drag mode. Gesture.Exclusive ensures a tap is ignored while dragging is active.

Gestures can be conditionally enabled with .enabled(boolean). When disabled, the gesture won't activate, allowing you to toggle interactivity based on app state. You can also call .shouldCancelWhenOutside(true) to cancel a gesture when the finger moves outside the component bounds.

The .hitSlop option expands the touch target area beyond the component's visual bounds — useful for small icon buttons that are hard to tap accurately on mobile screens.

A common challenge is a draggable card inside a ScrollView — both compete for the same touch event. Gesture Handler provides simultaneousWithExternalGesture and blocksExternalGesture to control priority. The waitFor option delays a gesture until another fails, enabling nested scroll-inside-swipe patterns.

For native scroll views, wrap them with ScrollView from Gesture Handler (import { ScrollView } from 'react-native-gesture-handler') instead of React Native's default to ensure gesture coordination works correctly.

In this lesson you learned: Gesture.Pan() creates a pan gesture recognizer that tracks finger translation in onUpdate and finishes in onEnd, withSpring on offset values creates snap-back or snap-away effects after release, and Gesture.Simultaneous composites multiple gestures so they operate at the same time. Next up we combine PinchGestureHandler and rotation for a zoomable image component.