[react-events] Various core tweaks for event responder system (#16654)

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

@@ -12,7 +12,7 @@ import {
   PASSIVE_NOT_SUPPORTED,
 } from 'legacy-events/EventSystemFlags';
 import type {AnyNativeEvent} from 'legacy-events/PluginModuleType';
-import {HostComponent} from 'shared/ReactWorkTags';
+import {HostComponent, ScopeComponent} from 'shared/ReactWorkTags';
 import type {EventPriority} from 'shared/ReactTypes';
 import type {
   ReactDOMEventResponder,
@@ -66,6 +66,7 @@ type ResponderTimer = {|
   instance: ReactDOMEventResponderInstance,
   func: () => void,
   id: number,
+  targetFiber: Fiber | null,
   timeStamp: number,
 |};
 
@@ -80,6 +81,7 @@ let currentTimers = new Map();
 let currentInstance: null | ReactDOMEventResponderInstance = null;
 let currentTimerIDCounter = 0;
 let currentDocument: null | Document = null;
+let currentTargetFiber: null | Fiber = null;
 
 const eventResponderContext: ReactDOMResponderContext = {
   dispatchEvent(
@@ -158,16 +160,20 @@ const eventResponderContext: ReactDOMResponderContext = {
     validateResponderContext();
     const childFiber = getClosestInstanceFromNode(childTarget);
     const parentFiber = getClosestInstanceFromNode(parentTarget);
-    const parentAlternateFiber = parentFiber.alternate;
 
-    let node = childFiber;
-    while (node !== null) {
-      if (node === parentFiber || node === parentAlternateFiber) {
-        return true;
+    if (childFiber != null && parentFiber != null) {
+      const parentAlternateFiber = parentFiber.alternate;
+      let node = childFiber;
+      while (node !== null) {
+        if (node === parentFiber || node === parentAlternateFiber) {
+          return true;
+        }
+        node = node.return;
       }
-      node = node.return;
+      return false;
     }
-    return false;
+    // Fallback to DOM APIs
+    return parentTarget.contains(childTarget);
   },
   addRootEventTypes(rootEventTypes: Array<string>): void {
     validateResponderContext();
@@ -221,6 +227,7 @@ const eventResponderContext: ReactDOMResponderContext = {
       instance: ((currentInstance: any): ReactDOMEventResponderInstance),
       func,
       id: timerId,
+      targetFiber: currentTargetFiber,
       timeStamp: currentTimeStamp,
     });
     activeTimeouts.set(timerId, timeout);
@@ -260,6 +267,24 @@ const eventResponderContext: ReactDOMResponderContext = {
     return false;
   },
   enqueueStateRestore,
+  getCurrentTarget(): Element | null {
+    validateResponderContext();
+    const responderFiber = ((currentInstance: any): ReactDOMEventResponderInstance)
+      .fiber;
+    let fiber = currentTargetFiber;
+    let currentTarget = null;
+
+    while (fiber !== null) {
+      if (fiber.tag === HostComponent) {
+        currentTarget = fiber.stateNode;
+      }
+      if (fiber === responderFiber || fiber.alternate === responderFiber) {
+        break;
+      }
+      fiber = fiber.return;
+    }
+    return currentTarget;
+  },
 };
 
 function validateEventValue(eventValue: any): void {
@@ -317,7 +342,8 @@ function doesFiberHaveResponder(
   fiber: Fiber,
   responder: ReactDOMEventResponder,
 ): boolean {
-  if (fiber.tag === HostComponent) {
+  const tag = fiber.tag;
+  if (tag === HostComponent || tag === ScopeComponent) {
     const dependencies = fiber.dependencies;
     if (dependencies !== null) {
       const respondersMap = dependencies.responders;
@@ -341,8 +367,9 @@ function processTimers(
   try {
     batchedEventUpdates(() => {
       for (let i = 0; i < timersArr.length; i++) {
-        const {instance, func, id, timeStamp} = timersArr[i];
+        const {instance, func, id, timeStamp, targetFiber} = timersArr[i];
         currentInstance = instance;
+        currentTargetFiber = targetFiber;
         currentTimeStamp = timeStamp + delay;
         try {
           func();
@@ -355,6 +382,7 @@ function processTimers(
     currentTimers = null;
     currentInstance = null;
     currentTimeStamp = 0;
+    currentTargetFiber = null;
   }
 }
 
@@ -386,7 +414,6 @@ function createDOMResponderEvent(
     passiveSupported,
     pointerId,
     pointerType: eventPointerType,
-    responderTarget: null,
     target: nativeEventTarget,
     type: topLevelType,
   };
@@ -443,13 +470,16 @@ function traverseAndHandleEventResponderInstances(
   let node = targetFiber;
   while (node !== null) {
     const {dependencies, tag} = node;
-    if (tag === HostComponent && dependencies !== null) {
+    if (
+      (tag === HostComponent || tag === ScopeComponent) &&
+      dependencies !== null
+    ) {
       const respondersMap = dependencies.responders;
       if (respondersMap !== null) {
         const responderInstances = Array.from(respondersMap.values());
         for (let i = 0, length = responderInstances.length; i < length; i++) {
           const responderInstance = responderInstances[i];
-          const {props, responder, state, target} = responderInstance;
+          const {props, responder, state} = responderInstance;
           if (
             !visitedResponders.has(responder) &&
             validateResponderTargetEventTypes(eventType, responder)
@@ -458,9 +488,6 @@ function traverseAndHandleEventResponderInstances(
             const onEvent = responder.onEvent;
             if (onEvent !== null) {
               currentInstance = responderInstance;
-              responderEvent.responderTarget = ((target: any):
-                | Element
-                | Document);
               onEvent(responderEvent, eventResponderContext, props, state);
             }
           }
@@ -478,11 +505,10 @@ function traverseAndHandleEventResponderInstances(
 
     for (let i = 0; i < responderInstances.length; i++) {
       const responderInstance = responderInstances[i];
-      const {props, responder, state, target} = responderInstance;
+      const {props, responder, state} = responderInstance;
       const onRootEvent = responder.onRootEvent;
       if (onRootEvent !== null) {
         currentInstance = responderInstance;
-        responderEvent.responderTarget = ((target: any): Element | Document);
         onRootEvent(responderEvent, eventResponderContext, props, state);
       }
     }
@@ -562,7 +588,9 @@ export function dispatchEventForResponderEventSystem(
     const previousTimers = currentTimers;
     const previousTimeStamp = currentTimeStamp;
     const previousDocument = currentDocument;
+    const previousTargetFiber = currentTargetFiber;
     currentTimers = null;
+    currentTargetFiber = targetFiber;
     // nodeType 9 is DOCUMENT_NODE
     currentDocument =
       (nativeEventTarget: any).nodeType === 9
@@ -585,6 +613,7 @@ export function dispatchEventForResponderEventSystem(
       currentInstance = previousInstance;
       currentTimeStamp = previousTimeStamp;
       currentDocument = previousDocument;
+      currentTargetFiber = previousTargetFiber;
     }
   }
 }

packages/react-dom/src/events/__tests__/DOMEventResponderSystem-test.internal.js

@@ -1017,7 +1017,7 @@ describe('DOMEventResponderSystem', () => {
         const obj = {
           counter,
           timeStamp: context.getTimeStamp(),
-          target: event.responderTarget,
+          target: context.getCurrentTarget(),
           type: 'click-test',
         };
         context.dispatchEvent(obj, props.onClick, DiscreteEvent);

packages/react-events/README.md

@@ -22,7 +22,6 @@ type ResponderEventType = string;
 
 type ResponderEvent = {|
   nativeEvent: any,
-  responderTarget: Element | Document,
   target: Element | Document,
   pointerType: string,
   type: string,

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

@@ -289,7 +289,7 @@ const focusResponderImpl = {
 
     switch (type) {
       case 'focus': {
-        state.focusTarget = event.responderTarget;
+        state.focusTarget = context.getCurrentTarget();
         // Limit focus events to the direct child of the event component.
         // Browser focus is not expected to bubble.
         if (!state.isFocused && state.focusTarget === target) {
@@ -427,7 +427,7 @@ const focusWithinResponderImpl = {
 
     switch (type) {
       case 'focus': {
-        state.focusTarget = event.responderTarget;
+        state.focusTarget = context.getCurrentTarget();
         // Limit focus events to the direct child of the event component.
         // Browser focus is not expected to bubble.
         if (!state.isFocused) {

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

@@ -235,7 +235,7 @@ const hoverResponderImpl = {
       // START
       case 'pointerover': {
         if (!state.isHovered && pointerType !== 'touch') {
-          state.hoverTarget = event.responderTarget;
+          state.hoverTarget = context.getCurrentTarget();
           dispatchHoverStartEvents(event, context, props, state);
         }
         break;
@@ -295,7 +295,7 @@ const hoverResponderFallbackImpl = {
       // START
       case 'mouseover': {
         if (!state.isHovered && !state.ignoreEmulatedMouseEvents) {
-          state.hoverTarget = event.responderTarget;
+          state.hoverTarget = context.getCurrentTarget();
           dispatchHoverStartEvents(event, context, props, state);
         }
         break;

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

@@ -179,30 +179,31 @@ const inputResponderImpl = {
     context: ReactDOMResponderContext,
     props: InputResponderProps,
   ): void {
-    const {responderTarget, type, target} = event;
+    const {type, target} = event;
 
     if (props.disabled) {
       return;
     }
-    if (target !== responderTarget || responderTarget === null) {
+    const currentTarget = context.getCurrentTarget();
+    if (target !== currentTarget || currentTarget === null) {
       return;
     }
     switch (type) {
       default: {
         if (shouldUseChangeEvent(target) && type === 'change') {
-          dispatchBothChangeEvents(event, context, props, responderTarget);
+          dispatchBothChangeEvents(event, context, props, currentTarget);
         } else if (
           isTextInputElement(target) &&
           (type === 'input' || type === 'change') &&
           updateValueIfChanged(target)
         ) {
-          dispatchBothChangeEvents(event, context, props, responderTarget);
+          dispatchBothChangeEvents(event, context, props, currentTarget);
         } else if (
           isCheckable(target) &&
           type === 'click' &&
           updateValueIfChanged(target)
         ) {
-          dispatchBothChangeEvents(event, context, props, responderTarget);
+          dispatchBothChangeEvents(event, context, props, currentTarget);
         }
         break;
       }

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

@@ -131,7 +131,6 @@ function createKeyboardEvent(
   event: ReactDOMResponderEvent,
   context: ReactDOMResponderContext,
   type: KeyboardEventType,
-  target: Document | Element,
   defaultPrevented: boolean,
 ): KeyboardEvent {
   const nativeEvent = (event: any).nativeEvent;
@@ -144,6 +143,7 @@ function createKeyboardEvent(
     repeat,
     shiftKey,
   } = nativeEvent;
+  const target = ((context.getCurrentTarget(): any): Element);
 
   return {
     altKey,
@@ -166,14 +166,12 @@ function dispatchKeyboardEvent(
   listener: KeyboardEvent => void,
   context: ReactDOMResponderContext,
   type: KeyboardEventType,
-  target: Element | Document,
   defaultPrevented: boolean,
 ): void {
   const syntheticEvent = createKeyboardEvent(
     event,
     context,
     type,
-    target,
     defaultPrevented,
   );
   context.dispatchEvent(syntheticEvent, listener, DiscreteEvent);
@@ -186,7 +184,7 @@ const keyboardResponderImpl = {
     context: ReactDOMResponderContext,
     props: KeyboardProps,
   ): void {
-    const {responderTarget, type} = event;
+    const {type} = event;
     const nativeEvent: any = event.nativeEvent;
 
     if (props.disabled) {
@@ -227,7 +225,6 @@ const keyboardResponderImpl = {
           onKeyDown,
           context,
           'keydown',
-          ((responderTarget: any): Element | Document),
           defaultPrevented,
         );
       }
@@ -239,7 +236,6 @@ const keyboardResponderImpl = {
           onKeyUp,
           context,
           'keyup',
-          ((responderTarget: any): Element | Document),
           defaultPrevented,
         );
       }

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

@@ -582,7 +582,7 @@ const pressResponderImpl = {
           // We set these here, before the button check so we have this
           // data around for handling of the context menu
           state.pointerType = pointerType;
-          const pressTarget = (state.pressTarget = event.responderTarget);
+          const pressTarget = (state.pressTarget = context.getCurrentTarget());
           if (isPointerEvent) {
             state.activePointerId = pointerId;
           } else if (isTouchEvent) {
@@ -634,7 +634,7 @@ const pressResponderImpl = {
 
         if (isFunction(onPress) && isScreenReaderVirtualClick(nativeEvent)) {
           state.pointerType = 'keyboard';
-          state.pressTarget = event.responderTarget;
+          state.pressTarget = context.getCurrentTarget();
           const preventDefault = props.preventDefault;
 
           if (preventDefault !== false) {

packages/react-events/src/rn/Press.js

@@ -412,7 +412,7 @@ const pressResponderImpl = {
     if (type === 'topTouchStart') {
       if (!state.isPressed) {
         state.pointerType = 'touch';
-        const pressTarget = (state.pressTarget = event.responderTarget);
+        const pressTarget = (state.pressTarget = context.getCurrentTarget());
         const touchEvent = getTouchFromPressEvent(nativeEvent);
         if (touchEvent === null) {
           return;