Event: Simplify leverageNative

mgol · mgol · commit 8cc5ff1a96b8 · 2023-03-14T00:56:11.000+01:00
With IE now using `focusin` to simulate `focus` and `focusout`
to simulate `blur`, we don't have to deal with async events
in `leverageNative`.
diff --git a/src/event.js b/src/event.js
@@ -1,5 +1,4 @@
 import jQuery from "./core.js";
-import document from "./var/document.js";
 import documentElement from "./var/documentElement.js";
 import rnothtmlwhite from "./var/rnothtmlwhite.js";
 import rcheckableType from "./var/rcheckableType.js";
@@ -22,16 +21,6 @@ function returnFalse() {
 	return false;
 }
 
-// Support: IE <=9 - 11+
-// focus() and blur() are asynchronous, except when they are no-op.
-// So expect focus to be synchronous when the element is already active,
-// and blur to be synchronous when the element is not already active.
-// (focus and blur are always synchronous in other supported browsers,
-// this just defines when we can count on it).
-function expectSync( elem, type ) {
-	return ( elem === document.activeElement ) === ( type === "focus" );
-}
-
 function on( elem, types, selector, data, fn, one ) {
 	var origFn, type;
 
@@ -460,7 +449,7 @@ jQuery.event = {
 					el.click && nodeName( el, "input" ) ) {
 
 					// dataPriv.set( el, "click", ... )
-					leverageNative( el, "click", returnTrue );
+					leverageNative( el, "click", true );
 				}
 
 				// Return false to allow normal processing in the caller
@@ -512,10 +501,10 @@ jQuery.event = {
 // synthetic events by interrupting progress until reinvoked in response to
 // *native* events that it fires directly, ensuring that state changes have
 // already occurred before other listeners are invoked.
-function leverageNative( el, type, expectSync ) {
+function leverageNative( el, type, isSetup ) {
 
-	// Missing expectSync indicates a trigger call, which must force setup through jQuery.event.add
-	if ( !expectSync ) {
+	// Missing `isSetup` indicates a trigger call, which must force setup through jQuery.event.add
+	if ( !isSetup ) {
 		if ( dataPriv.get( el, type ) === undefined ) {
 			jQuery.event.add( el, type, returnTrue );
 		}
@@ -527,15 +516,13 @@ function leverageNative( el, type, expectSync ) {
 	jQuery.event.add( el, type, {
 		namespace: false,
 		handler: function( event ) {
-			var notAsync, result,
+			var result,
 				saved = dataPriv.get( this, type );
 
 			if ( ( event.isTrigger & 1 ) && this[ type ] ) {
 
 				// Interrupt processing of the outer synthetic .trigger()ed event
-				// Saved data should be false in such cases, but might be a leftover capture object
-				// from an async native handler (gh-4350)
-				if ( !saved.length ) {
+				if ( !saved ) {
 
 					// Store arguments for use when handling the inner native event
 					// There will always be at least one argument (an event object), so this array
@@ -544,16 +531,10 @@ function leverageNative( el, type, expectSync ) {
 					dataPriv.set( this, type, saved );
 
 					// Trigger the native event and capture its result
-					// Support: IE <=9 - 11+
-					// focus() and blur() are asynchronous
-					notAsync = expectSync( this, type );
 					this[ type ]();
 					result = dataPriv.get( this, type );
-					if ( saved !== result || notAsync ) {
-						dataPriv.set( this, type, false );
-					} else {
-						result = {};
-					}
+					dataPriv.set( this, type, false );
+
 					if ( saved !== result ) {
 
 						// Cancel the outer synthetic event
@@ -756,7 +737,7 @@ jQuery.each( { focus: "focusin", blur: "focusout" }, function( type, delegateTyp
 			// Claim the first handler
 			// dataPriv.set( this, "focus", ... )
 			// dataPriv.set( this, "blur", ... )
-			leverageNative( this, type, expectSync );
+			leverageNative( this, type, true );
 
 			if ( isIE ) {
 				this.addEventListener( delegateType, focusMappedHandler );
