0Pricing
React Native Academy · レッスン

Gesture Handlerによるパン・スワイプジェスチャー

React Native Gesture Handlerをインストールし、PanGestureHandlerとuseAnimatedGestureHandlerを使ってドラッグ可能なカードを作成します。リリース時には元の位置へ戻します。

「Gesture Handlerによるパン・スワイプジェスチャー」はCoddyKit上の無料React Native Academyレッスンです。 これはレッスン3/4です。 下記で完全なレッスンを無料で読むことができます。その後、ブラウザ内の組み込みコードエディタと24時間対応のAIチューターでハンズオン演習できます。 これはReact Native Academy学習パスの一部であり、ウェブとCoddyKitアプリ全体で進捗が同期されます。 React Native Academyコースには全4レッスンが含まれています。

このレッスンの一部はまだ翻訳されておらず、英語で表示されています。

What Is React Native 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.

// Install:
// npx expo install react-native-gesture-handler

// Wrap your app root with GestureHandlerRootView:
import { GestureHandlerRootView } from 'react-native-gesture-handler';

export default function App() {
  return (
    <GestureHandlerRootView style={{ flex: 1 }}>
      <YourApp />
    </GestureHandlerRootView>
  );
}

The Gesture API (v2)

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.

import { Gesture, GestureDetector } from 'react-native-gesture-handler';

const panGesture = Gesture.Pan()
  .onUpdate((event) => {
    'worklet';
    // event.translationX, event.translationY available
  });

return (
  <GestureDetector gesture={panGesture}>
    <Animated.View style={animatedStyle} />
  </GestureDetector>
);

Building a Draggable Card

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.

import { Gesture, GestureDetector } from 'react-native-gesture-handler';
import Animated, { useSharedValue, useAnimatedStyle } from 'react-native-reanimated';

const offsetX = useSharedValue(0);
const offsetY = useSharedValue(0);
const startX = useSharedValue(0);
const startY = useSharedValue(0);

const pan = Gesture.Pan()
  .onBegin(() => {
    startX.value = offsetX.value;
    startY.value = offsetY.value;
  })
  .onUpdate((e) => {
    offsetX.value = startX.value + e.translationX;
    offsetY.value = startY.value + e.translationY;
  });

const style = useAnimatedStyle(() => ({
  transform: [
    { translateX: offsetX.value },
    { translateY: offsetY.value },
  ],
}));

Snapping Back to Origin on Release

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.

import { withSpring } from 'react-native-reanimated';

const pan = Gesture.Pan()
  .onUpdate((e) => {
    offsetX.value = startX.value + e.translationX;
    offsetY.value = startY.value + e.translationY;
  })
  .onEnd((e) => {
    offsetX.value = withSpring(0, { velocity: e.velocityX });
    offsetY.value = withSpring(0, { velocity: e.velocityY });
  });

Swipe to Dismiss Pattern

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.

const DISMISS_VELOCITY = 800;
const DISMISS_DISTANCE = 150;

const pan = Gesture.Pan()
  .onUpdate((e) => { offsetX.value = e.translationX; })
  .onEnd((e) => {
    const shouldDismiss =
      Math.abs(e.velocityX) > DISMISS_VELOCITY ||
      Math.abs(e.translationX) > DISMISS_DISTANCE;

    if (shouldDismiss) {
      const direction = e.translationX > 0 ? 1 : -1;
      offsetX.value = withTiming(direction * 400, { duration: 200 },
        () => runOnJS(onDismiss)()
      );
    } else {
      offsetX.value = withSpring(0);
    }
  });

Tap Gesture for Press Interactions

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.

const scale = useSharedValue(1);

const tap = Gesture.Tap()
  .onBegin(() => {
    scale.value = withSpring(0.95);
  })
  .onFinalize(() => {
    scale.value = withSpring(1);
  });

const style = useAnimatedStyle(() => ({
  transform: [{ scale: scale.value }],
}));

return (
  <GestureDetector gesture={tap}>
    <Animated.View style={[styles.button, style]} />
  </GestureDetector>
);

Composing Gestures: Simultaneous and Exclusive

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.

const pan = Gesture.Pan().onUpdate(...);
const pinch = Gesture.Pinch().onUpdate(...);

// Both work at the same time (e.g. photo viewer):
const composedGesture = Gesture.Simultaneous(pan, pinch);

// Only one wins (e.g. swipe OR tap):
const exclusiveGesture = Gesture.Exclusive(
  Gesture.Fling().direction(Directions.LEFT).onEnd(onSwipe),
  Gesture.Tap().onEnd(onTap)
);

Gesture Lifecycle: Begin, Update, End, Finalize

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).

const pan = Gesture.Pan()
  .onBegin(() => { startPos.value = offsetX.value; })
  .onUpdate((e) => { offsetX.value = startPos.value + e.translationX; })
  .onEnd((e) => {
    // Gesture completed successfully
    if (Math.abs(e.translationX) > 100) runOnJS(onSwipeAway)();
    else offsetX.value = withSpring(0);
  })
  .onFinalize(() => {
    // Always runs — reset any temporary state
  });

Long Press Gesture

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.

import * as Haptics from 'expo-haptics';

const [isDragging, setIsDragging] = React.useState(false);

const longPress = Gesture.LongPress()
  .minDuration(400)
  .onStart(() => {
    scale.value = withSpring(1.05);
    runOnJS(Haptics.selectionAsync)();
    runOnJS(setIsDragging)(true);
  });

const pan = Gesture.Pan()
  .enabled(isDragging)
  .onUpdate((e) => {
    offsetY.value = e.translationY;
  });

Gesture State and Enabling/Disabling

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.

const [isEnabled, setIsEnabled] = React.useState(true);

const tap = Gesture.Tap()
  .enabled(isEnabled)
  .hitSlop({ top: 10, bottom: 10, left: 10, right: 10 })
  .shouldCancelWhenOutside(true)
  .onEnd(() => {
    runOnJS(handleTap)();
  });

// Disable temporarily:
setIsEnabled(false); // tap won't fire

Handling Gesture Conflicts with ScrollView

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.

import { ScrollView } from 'react-native-gesture-handler';

// Use GH's ScrollView to allow gesture coordination:
<ScrollView>
  <GestureDetector gesture={pan}>
    <Animated.View style={style}>
      {/* Draggable card inside scroll */}
    </Animated.View>
  </GestureDetector>
</ScrollView>

Quick Check

Test your understanding of React Native Mobile Development concepts from this lesson.

Lesson Recap

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.

よくある質問

「Gesture Handlerによるパン・スワイプジェスチャー」レッスンは無料ですか？

はい。「Gesture Handlerによるパン・スワイプジェスチャー」の完全なテキストはこのウェブで無料で読めます。インタラクティブに演習し（組み込みコードエディタと24時間対応のAIチューター）、React Native Academyコースの残りをアンロックするには、CoddyKit PROにアップグレードしてください。 React Native Academyコースには全4レッスンが含まれています。

「Gesture Handlerによるパン・スワイプジェスチャー」で何を学びますか？

React Native Gesture Handlerをインストールし、PanGestureHandlerとuseAnimatedGestureHandlerを使ってドラッグ可能なカードを作成します。リリース時には元の位置へ戻します。 ブラウザで直接実行するハンズオンコードでReact Native Academyを演習し、24時間対応のAIチューターがレッスンを進める中での質問に答えます。

React Native Academyを始めるのに経験は必要ですか？

事前経験は必要ありません。CoddyKitのReact Native Academyは初級者から上級者向けに構成されているため、ここから始めるか最初から始めて、自分のペースで進むことができます。 これはレッスン3/4です。

「Gesture Handlerによるパン・スワイプジェスチャー」レッスンにはどのくらい時間がかかりますか？

ほとんどのCoddyKitレッスンは約5～10分かかります。各レッスンはコンパクトでインタラクティブなので、着実に進歩し、ウェブとアプリ全体で正確に前回の場所から再開できます。

このReact Native Academyレッスンでコードを書いて実行できますか？

はい。すべてのReact Native Academyレッスンに組み込みコードエディタが含まれているため、ブラウザでリアルコードを書いて実行し、即座のAIフィードバックを取得できます。ローカル設定は不要です。

このコースのすべてのレッスン

  1. ReanimatedとShared Valuesのインストール
  2. WorkletとUIスレッドでのコード実行
  3. Gesture Handlerによるパン・スワイプジェスチャー
  4. ピンチズームと回転
← React Native Academyに戻る