| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | * |
| 7 | * @flow |
| 8 | */ |
| 9 | |
| 10 | import type { |
| 11 | AnyNativeEvent, |
| 12 | LegacyPluginModule, |
| 13 | } from './legacy-events/PluginModuleType'; |
| 14 | import type {Fiber} from 'react-reconciler/src/ReactInternalTypes'; |
| 15 | import type {ReactSyntheticEvent} from './legacy-events/ReactSyntheticEventType'; |
| 16 | import type { |
| 17 | RNTopLevelEventType, |
| 18 | TopLevelType, |
| 19 | } from './legacy-events/TopLevelEventTypes'; |
| 20 | |
| 21 | import { |
| 22 | registrationNameModules, |
| 23 | plugins, |
| 24 | } from './legacy-events/EventPluginRegistry'; |
| 25 | import {batchedUpdates} from './legacy-events/ReactGenericBatching'; |
| 26 | import accumulateInto from './legacy-events/accumulateInto'; |
| 27 | |
| 28 | import getListener from './ReactNativeGetListener'; |
| 29 | import {runEventsInBatch} from './legacy-events/EventBatching'; |
| 30 | |
| 31 | import { |
| 32 | RawEventEmitter, |
| 33 | dispatchNativeEvent, |
| 34 | } from 'react-native/react-private-interface'; |
| 35 | import {getPublicInstance} from './ReactFiberConfigFabric'; |
| 36 | import {enableNativeEventTargetEventDispatching} from './ReactNativeFeatureFlags'; |
| 37 | |
| 38 | export {getListener, registrationNameModules as registrationNames}; |
| 39 | |
| 40 | /** |
| 41 | * Allows registered plugins an opportunity to extract events from top-level |
| 42 | * native browser events. |
| 43 | * |
| 44 | * @return {*} An accumulation of synthetic events. |
| 45 | * @internal |
| 46 | */ |
| 47 | function extractPluginEvents( |
| 48 | topLevelType: TopLevelType, |
| 49 | targetInst: null | Fiber, |
| 50 | nativeEvent: AnyNativeEvent, |
| 51 | nativeEventTarget: null | EventTarget, |
| 52 | ): Array<ReactSyntheticEvent> | ReactSyntheticEvent | null { |
| 53 | let events: Array<ReactSyntheticEvent> | ReactSyntheticEvent | null = null; |
| 54 | const legacyPlugins = plugins as any as Array< |
| 55 | LegacyPluginModule<AnyNativeEvent>, |
| 56 | >; |
| 57 | for (let i = 0; i < legacyPlugins.length; i++) { |
| 58 | // Not every plugin in the ordering may be loaded at runtime. |
| 59 | const possiblePlugin = legacyPlugins[i]; |
| 60 | if (possiblePlugin) { |
| 61 | const extractedEvents = possiblePlugin.extractEvents( |
| 62 | topLevelType, |
| 63 | targetInst, |
| 64 | nativeEvent, |
| 65 | nativeEventTarget, |
| 66 | ); |
| 67 | if (extractedEvents) { |
| 68 | events = accumulateInto(events, extractedEvents); |
| 69 | } |
| 70 | } |
| 71 | } |
| 72 | return events; |
| 73 | } |
| 74 | |
| 75 | function runExtractedPluginEventsInBatch( |
| 76 | topLevelType: TopLevelType, |
| 77 | targetInst: null | Fiber, |
| 78 | nativeEvent: AnyNativeEvent, |
| 79 | nativeEventTarget: null | EventTarget, |
| 80 | ) { |
| 81 | const events = extractPluginEvents( |
| 82 | topLevelType, |
| 83 | targetInst, |
| 84 | nativeEvent, |
| 85 | nativeEventTarget, |
| 86 | ); |
| 87 | runEventsInBatch(events); |
| 88 | } |
| 89 | |
| 90 | export function dispatchEvent( |
| 91 | target: null | Object, |
| 92 | topLevelType: RNTopLevelEventType, |
| 93 | nativeEventParam: mixed, |
| 94 | ) { |
| 95 | const nativeEvent: AnyNativeEvent = |
| 96 | nativeEventParam != null && typeof nativeEventParam === 'object' |
| 97 | ? (nativeEventParam as any) |
| 98 | : {}; |
| 99 | const targetFiber = target as null | Fiber; |
| 100 | |
| 101 | let eventTarget = null; |
| 102 | if (targetFiber != null) { |
| 103 | const stateNode = targetFiber.stateNode; |
| 104 | // Guard against Fiber being unmounted |
| 105 | if (stateNode != null) { |
| 106 | // $FlowExpectedError[incompatible-type] public instances in Fabric do not implement `EventTarget` yet. |
| 107 | eventTarget = getPublicInstance(stateNode) as EventTarget; |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | batchedUpdates(function () { |
| 112 | // Emit event to the RawEventEmitter. This is an unused-by-default EventEmitter |
| 113 | // that can be used to instrument event performance monitoring (primarily - could be useful |
| 114 | // for other things too). |
| 115 | // |
| 116 | // NOTE: this merely emits events into the EventEmitter below. |
| 117 | // If *you* do not add listeners to the `RawEventEmitter`, |
| 118 | // then all of these emitted events will just blackhole and are no-ops. |
| 119 | // It is available (although not officially supported... yet) if you want to collect |
| 120 | // perf data on event latency in your application, and could also be useful for debugging |
| 121 | // low-level events issues. |
| 122 | // |
| 123 | // If you do not have any event perf monitoring and are extremely concerned about event perf, |
| 124 | // it is safe to disable these "emit" statements; it will prevent checking the size of |
| 125 | // an empty array twice and prevent two no-ops. Practically the overhead is so low that |
| 126 | // we don't think it's worth thinking about in prod; your perf issues probably lie elsewhere. |
| 127 | // |
| 128 | // We emit two events here: one for listeners to this specific event, |
| 129 | // and one for the catchall listener '*', for any listeners that want |
| 130 | // to be notified for all events. |
| 131 | // Note that extracted events are *not* emitted, |
| 132 | // only events that have a 1:1 mapping with a native event, at least for now. |
| 133 | const event = {eventName: topLevelType, nativeEvent}; |
| 134 | RawEventEmitter.emit(topLevelType, event); |
| 135 | RawEventEmitter.emit('*', event); |
| 136 | |
| 137 | if (enableNativeEventTargetEventDispatching()) { |
| 138 | if (eventTarget != null) { |
| 139 | dispatchNativeEvent(eventTarget, topLevelType, nativeEvent); |
| 140 | } |
| 141 | } else { |
| 142 | // Heritage plugin event system |
| 143 | runExtractedPluginEventsInBatch( |
| 144 | topLevelType, |
| 145 | targetFiber, |
| 146 | nativeEvent, |
| 147 | eventTarget, |
| 148 | ); |
| 149 | } |
| 150 | }); |
| 151 | // React Native doesn't use ReactControlledComponent but if it did, here's |
| 152 | // where it would do it. |
| 153 | } |