[iOS] Fix manualActivation being ignored after a config update mid-gesture

[m-bert]

Description

On iOS a handler with manualActivation: true activates on its own if its config is updated mid-gesture. Any re-render during the gesture triggers that, since the config is re-sent on every render.

setConfig: runs resetConfig before updateConfig:, and resetConfig went through the manualActivation setter, which removed the RNManualActivationRecognizer from the view. UIKit cancels a recognizer removed mid-touch, so the failure requirement it imposed on the handler was lost and the new blocker created by updateConfig: never saw the touch.

resetConfig now only clears the flag and the blocker is reconciled once after the config is applied, only when its presence no longer matches the flag. Android and web already reset values only.

Test plan

Repro

import React, { useRef, useState } from 'react';
import { StyleSheet, Text, View } from 'react-native';
import {
  GestureDetector,
  GestureStateManager,
  usePanGesture,
} from 'react-native-gesture-handler';

const ACTIVATION_THRESHOLD = 20;

type Phase = 'idle' | 'began' | 'active';

const color = (phase: Phase) =>
  phase === 'active' ? '#21a37c' : phase === 'began' ? '#f6b914' : '#9b59b6';

export default function EmptyExample() {
  const [phaseA, setPhaseA] = useState<Phase>('idle');
  const [phaseB, setPhaseB] = useState<Phase>('idle');

  const neverActivatePan = usePanGesture({
    manualActivation: true,
    runOnJS: true,
    onBegin: () => {
      console.log('[A never-activate] onBegin');
      setPhaseA('began');
    },
    onActivate: () => {
      console.log('[A never-activate] onActivate (SHOULD NOT HAPPEN)');
      setPhaseA('active');
    },
    onFinalize: (e) => {
      console.log(`[A never-activate] onFinalize canceled=${e.canceled}`);
      setPhaseA('idle');
    },
  });

  const start = useRef({ x: 0, y: 0 });
  const requested = useRef(false);

  const selfActivatePan = usePanGesture({
    manualActivation: true,
    runOnJS: true,
    onTouchesDown: (e) => {
      const t = e.allTouches[0];
      start.current = { x: t.x, y: t.y };
      requested.current = false;
    },
    onTouchesMove: (e) => {
      if (requested.current) {
        return;
      }
      const t = e.allTouches[0];
      const dx = t.x - start.current.x;
      const dy = t.y - start.current.y;
      if (Math.hypot(dx, dy) > ACTIVATION_THRESHOLD) {
        requested.current = true;
        GestureStateManager.activate(e.handlerTag);
      }
    },
    onBegin: () => {
      console.log('[B self-activate] onBegin');
      setPhaseB('began');
    },
    onActivate: () => {
      console.log('[B self-activate] onActivate');
      setPhaseB('active');
    },
    onFinalize: (e) => {
      console.log(`[B self-activate] onFinalize canceled=${e.canceled}`);
      setPhaseB('idle');
    },
  });

  return (
    <View style={styles.container}>
      <Text style={styles.label}>A: manualActivation, never activated</Text>
      <GestureDetector gesture={neverActivatePan}>
        <View style={[styles.box, { backgroundColor: color(phaseA) }]} />
      </GestureDetector>

      <Text style={styles.label}>
        B: manualActivation, activate() after {ACTIVATION_THRESHOLD}px
      </Text>
      <GestureDetector gesture={selfActivatePan}>
        <View style={[styles.box, { backgroundColor: color(phaseB) }]} />
      </GestureDetector>

      <Text style={styles.hint}>
        Purple = idle, orange = BEGAN, green = ACTIVE. Drag each box. A must
        never turn green.
      </Text>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    gap: 8,
  },
  label: { marginTop: 16, fontSize: 15, opacity: 0.6 },
  hint: { marginTop: 24, fontSize: 13, opacity: 0.5, textAlign: 'center' },
  box: { width: 150, height: 150, borderRadius: 12 },
});

[coderabbitai]

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• packages/react-native-gesture-handler/apple/RNGestureHandler.mm

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📝 Summary

Summary by CodeRabbit

• Bug Fixes
  • Improved synchronization of manual activation settings when gesture handler configuration changes.
  • Prevented unnecessary recognizer updates when the manual activation state is already correct.
  • Ensured resetting configuration consistently disables manual activation.

Walkthrough

The Apple gesture handler now synchronizes the manual activation recognizer after configuration updates and manual activation changes. Configuration reset assigns the flag directly, while recognizer creation and removal use centralized synchronization logic.

Changes

Manual activation lifecycle

Layer / File(s)	Summary
Synchronize manual activation recognizer packages/react-native-gesture-handler/apple/RNGestureHandler.mm	resetConfig assigns _manualActivation directly. setConfig: synchronizes the recognizer after configuration updates. setManualActivation: delegates creation and removal to syncManualActivationRecognizer, which avoids redundant work.

Suggested reviewers: j-piasecki

Priority: ⬇️ Low

Merge Risk: ⚪ Minimal · up to fce63

The configuration update now preserves the manual activation behavior without an identified merge-blocking risk.

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly identifies the iOS bug and the affected manualActivation behavior after a mid-gesture configuration update. It accurately summarizes the main change.

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[Copilot]

🟢 Approval recommended

The activation blocker is preserved and synchronized correctly across configuration updates.

Pull request overview

Fixes iOS manualActivation being lost during mid-gesture configuration updates.

Changes:

• Preserves the activation blocker during config resets.
• Reconciles the blocker after applying configuration.

File summaries

File	Description
packages/react-native-gesture-handler/apple/RNGestureHandler.mm	Updates manual activation reset and blocker synchronization.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 0
• Review effort level: Lite

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