Add part of the event responder system for experimental event API (#1…

…5179)

* Add part of the event responder system

packages/events/EventBatching.js

@@ -0,0 +1,66 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ * @flow
+ */
+
+import invariant from 'shared/invariant';
+import {rethrowCaughtError} from 'shared/ReactErrorUtils';
+
+import type {ReactSyntheticEvent} from './ReactSyntheticEventType';
+import accumulateInto from './accumulateInto';
+import forEachAccumulated from './forEachAccumulated';
+import {executeDispatchesInOrder} from './EventPluginUtils';
+
+/**
+ * Internal queue of events that have accumulated their dispatches and are
+ * waiting to have their dispatches executed.
+ */
+let eventQueue: ?(Array<ReactSyntheticEvent> | ReactSyntheticEvent) = null;
+
+/**
+ * Dispatches an event and releases it back into the pool, unless persistent.
+ *
+ * @param {?object} event Synthetic event to be dispatched.
+ * @private
+ */
+const executeDispatchesAndRelease = function(event: ReactSyntheticEvent) {
+  if (event) {
+    executeDispatchesInOrder(event);
+
+    if (!event.isPersistent()) {
+      event.constructor.release(event);
+    }
+  }
+};
+const executeDispatchesAndReleaseTopLevel = function(e) {
+  return executeDispatchesAndRelease(e);
+};
+
+export function runEventsInBatch(
+  events: Array<ReactSyntheticEvent> | ReactSyntheticEvent | null,
+) {
+  if (events !== null) {
+    eventQueue = accumulateInto(eventQueue, events);
+  }
+
+  // Set `eventQueue` to null before processing it so that we can tell if more
+  // events get enqueued while processing.
+  const processingEventQueue = eventQueue;
+  eventQueue = null;
+
+  if (!processingEventQueue) {
+    return;
+  }
+
+  forEachAccumulated(processingEventQueue, executeDispatchesAndReleaseTopLevel);
+  invariant(
+    !eventQueue,
+    'processEventQueue(): Additional events were enqueued while processing ' +
+      'an event queue. Support for this has not yet been implemented.',
+  );
+  // This would be a good time to rethrow if any of the event handlers threw.
+  rethrowCaughtError();
+}

packages/events/EventPluginHub.js

@@ -6,52 +6,23 @@
  * @flow
  */
 
-import {rethrowCaughtError} from 'shared/ReactErrorUtils';
 import invariant from 'shared/invariant';
 
 import {
   injectEventPluginOrder,
   injectEventPluginsByName,
   plugins,
 } from './EventPluginRegistry';
-import {
-  executeDispatchesInOrder,
-  getFiberCurrentPropsFromNode,
-} from './EventPluginUtils';
+import {getFiberCurrentPropsFromNode} from './EventPluginUtils';
 import accumulateInto from './accumulateInto';
-import forEachAccumulated from './forEachAccumulated';
+import {runEventsInBatch} from './EventBatching';
 
 import type {PluginModule} from './PluginModuleType';
 import type {ReactSyntheticEvent} from './ReactSyntheticEventType';
 import type {Fiber} from 'react-reconciler/src/ReactFiber';
 import type {AnyNativeEvent} from './PluginModuleType';
 import type {TopLevelType} from './TopLevelEventTypes';
 
-/**
- * Internal queue of events that have accumulated their dispatches and are
- * waiting to have their dispatches executed.
- */
-let eventQueue: ?(Array<ReactSyntheticEvent> | ReactSyntheticEvent) = null;
-
-/**
- * Dispatches an event and releases it back into the pool, unless persistent.
- *
- * @param {?object} event Synthetic event to be dispatched.
- * @private
- */
-const executeDispatchesAndRelease = function(event: ReactSyntheticEvent) {
-  if (event) {
-    executeDispatchesInOrder(event);
-
-    if (!event.isPersistent()) {
-      event.constructor.release(event);
-    }
-  }
-};
-const executeDispatchesAndReleaseTopLevel = function(e) {
-  return executeDispatchesAndRelease(e);
-};
-
 function isInteractive(tag) {
   return (
     tag === 'button' ||
@@ -158,7 +129,7 @@ export function getListener(inst: Fiber, registrationName: string) {
  * @return {*} An accumulation of synthetic events.
  * @internal
  */
-function extractEvents(
+function extractPluginEvents(
   topLevelType: TopLevelType,
   targetInst: null | Fiber,
   nativeEvent: AnyNativeEvent,
@@ -183,39 +154,13 @@ function extractEvents(
   return events;
 }
 
-export function runEventsInBatch(
-  events: Array<ReactSyntheticEvent> | ReactSyntheticEvent | null,
-) {
-  if (events !== null) {
-    eventQueue = accumulateInto(eventQueue, events);
-  }
-
-  // Set `eventQueue` to null before processing it so that we can tell if more
-  // events get enqueued while processing.
-  const processingEventQueue = eventQueue;
-  eventQueue = null;
-
-  if (!processingEventQueue) {
-    return;
-  }
-
-  forEachAccumulated(processingEventQueue, executeDispatchesAndReleaseTopLevel);
-  invariant(
-    !eventQueue,
-    'processEventQueue(): Additional events were enqueued while processing ' +
-      'an event queue. Support for this has not yet been implemented.',
-  );
-  // This would be a good time to rethrow if any of the event handlers threw.
-  rethrowCaughtError();
-}
-
-export function runExtractedEventsInBatch(
+export function runExtractedPluginEventsInBatch(
   topLevelType: TopLevelType,
   targetInst: null | Fiber,
   nativeEvent: AnyNativeEvent,
   nativeEventTarget: EventTarget,
 ) {
-  const events = extractEvents(
+  const events = extractPluginEvents(
     topLevelType,
     targetInst,
     nativeEvent,

packages/events/__tests__/ResponderEventPlugin-test.internal.js

@@ -11,7 +11,7 @@
 
 const {HostComponent} = require('shared/ReactWorkTags');
 
-let EventPluginHub;
+let EventBatching;
 let EventPluginUtils;
 let ResponderEventPlugin;
 
@@ -321,7 +321,7 @@ const run = function(config, hierarchyConfig, nativeEventConfig) {
   // At this point the negotiation events have been dispatched as part of the
   // extraction process, but not the side effectful events. Below, we dispatch
   // side effectful events.
-  EventPluginHub.runEventsInBatch(extractedEvents);
+  EventBatching.runEventsInBatch(extractedEvents);
 
   // Ensure that every event that declared an `order`, was actually dispatched.
   expect('number of events dispatched:' + runData.dispatchCount).toBe(
@@ -403,7 +403,7 @@ describe('ResponderEventPlugin', () => {
     jest.resetModules();
 
     const ReactDOMUnstableNativeDependencies = require('react-dom/unstable-native-dependencies');
-    EventPluginHub = require('events/EventPluginHub');
+    EventBatching = require('events/EventBatching');
     EventPluginUtils = require('events/EventPluginUtils');
     ResponderEventPlugin =
       ReactDOMUnstableNativeDependencies.ResponderEventPlugin;

packages/react-dom/src/client/ReactDOM.js

@@ -44,10 +44,8 @@ import {
   enqueueStateRestore,
   restoreStateIfNeeded,
 } from 'events/ReactControlledComponent';
-import {
-  injection as EventPluginHubInjection,
-  runEventsInBatch,
-} from 'events/EventPluginHub';
+import {injection as EventPluginHubInjection} from 'events/EventPluginHub';
+import {runEventsInBatch} from 'events/EventBatching';
 import {eventNameDispatchConfigs} from 'events/EventPluginRegistry';
 import {
   accumulateTwoPhaseDispatches,

packages/react-dom/src/client/ReactDOMHostConfig.js

@@ -862,29 +862,33 @@ export function handleEventComponent(
   rootContainerInstance: Container,
   internalInstanceHandle: Object,
 ): void {
-  const rootElement = rootContainerInstance.ownerDocument;
-  listenToEventResponderEvents(eventResponder, rootElement);
+  if (enableEventAPI) {
+    const rootElement = rootContainerInstance.ownerDocument;
+    listenToEventResponderEvents(eventResponder, rootElement);
+  }
 }
 
 export function handleEventTarget(
   type: Symbol | number,
   props: Props,
   internalInstanceHandle: Object,
 ): void {
-  // Touch target hit slop handling
-  if (type === REACT_EVENT_TARGET_TOUCH_HIT) {
-    // Validates that there is a single element
-    const element = getElementFromTouchHitTarget(internalInstanceHandle);
-    if (element !== null) {
-      // We update the event target state node to be that of the element.
-      // We can then diff this entry to determine if we need to add the
-      // hit slop element, or change the dimensions of the hit slop.
-      const lastElement = internalInstanceHandle.stateNode;
-      if (lastElement !== element) {
-        internalInstanceHandle.stateNode = element;
-        // TODO: Create the hit slop element and attach it to the element
-      } else {
-        // TODO: Diff the left, top, right, bottom props
+  if (enableEventAPI) {
+    // Touch target hit slop handling
+    if (type === REACT_EVENT_TARGET_TOUCH_HIT) {
+      // Validates that there is a single element
+      const element = getElementFromTouchHitTarget(internalInstanceHandle);
+      if (element !== null) {
+        // We update the event target state node to be that of the element.
+        // We can then diff this entry to determine if we need to add the
+        // hit slop element, or change the dimensions of the hit slop.
+        const lastElement = internalInstanceHandle.stateNode;
+        if (lastElement !== element) {
+          internalInstanceHandle.stateNode = element;
+          // TODO: Create the hit slop element and attach it to the element
+        } else {
+          // TODO: Diff the left, top, right, bottom props
+        }
       }
     }
   }

packages/react-dom/src/events/ChangeEventPlugin.js

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {runEventsInBatch} from 'events/EventPluginHub';
+import {runEventsInBatch} from 'events/EventBatching';
 import {accumulateTwoPhaseDispatches} from 'events/EventPropagators';
 import {enqueueStateRestore} from 'events/ReactControlledComponent';
 import {batchedUpdates} from 'events/ReactGenericBatching';