[android] Fix state manager on unregistered gestures

[akwasniewski]

Description

The new StateManager is global and given handlerTag it can manually set the states of an arbitrary gesture. This causes errors, when the gesture, which state is being set, has not been yet recorded in the orchestrator. Recording gestures in the orchestrator on android is done lazily, thus if it never received touches it is not recorded.

Test plan

Tested on the following example

Details

import React from 'react';
import { View, Text, StyleSheet } from 'react-native';
import { GestureHandlerRootView, GestureDetector, useLongPressGesture, GestureStateManager, usePanGesture, useSimultaneousGestures, useTapGesture } from 'react-native-gesture-handler';

export default function TwoPressables() {
  const longPress = useLongPressGesture({
    onTouchesDown: (e) => {
      'worklet';
      console.log("touches down")
    },
    onActivate: () => {
      'worklet';
      console.log("long pressed")
    },
    minDuration: 100000000,
    disableReanimated: true
  })
  const pan = useTapGesture({
    onTouchesDown: () => {
      'worklet';
      console.log("tap")

      GestureStateManager.activate(longPress.tag)
    },
    disableReanimated: true
  });
  return (
    <GestureHandlerRootView>
      <View style={styles.root}>
        <GestureDetector gesture={longPress}>
          <View style={styles.outer}>
            <Text style={styles.label}>Long Press</Text>
          </View>
        </GestureDetector>
        <GestureDetector gesture={pan}>
          <View style={styles.outer}>
            <Text style={styles.label}>Pan</Text>
          </View>
        </GestureDetector>

      </View>
    </GestureHandlerRootView>
  );
}

const styles = StyleSheet.create({
  root: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#f7f7f7',
  },
  outer: {
    padding: 20,
    backgroundColor: '#ddd',
    borderRadius: 12,
    marginBottom: 50
  },
  label: {
    fontSize: 18,
    marginBottom: 10,
  },
})

[m-bert]

As said in the first comment, I'm not a big fan of ForManual suffix. I think we could either use overloading (where possible) or add more descriptive suffix.

[m-bert]

I think we should throw error when both, orchestrator and hostDetectorView are null. This may happen if gesture is defined, but is not assigned to any of the detectors. In that case I believe it will still crash, but with other, less descriptive error (probably NullPointerException).

[akwasniewski]

Thanks, f3c1e93, I will check whether this works on other platforms

[akwasniewski]

On web the error is more fitting, Expected delegate view to be HTMLElement and on iOS it fails silently

[m-bert]

On web the error is more fitting, Expected delegate view to be HTMLElement

I don't think it is more fitting in that case. It doesn't tell you what you've done wrong, so it won't be obvious for someone who tries to change state of the gesture.

on iOS it fails silently

I don't think it is good either. Such behaviour should be unified between platforms.

[j-piasecki]

Don't we have this exact method already defined somewhere? Maybe it's worth moving it to some utils, or making it an extension on View?

[akwasniewski]

Sure, I moved it to be companion object for the rootView in 8a4ffc9. Let me know what you think.

[j-piasecki]

Hmm, I'm not sure whether this.findGestureHandlerRootView()?... wouldn't have been cleaner, but I'll leave the final decision to you. Both work for me.