Event: Leverage native events for focus/blur/click; propagate additional data

Summary of the changes/fixes:
1. Trigger checkbox and radio click events identically (cherry-picked from
   b442abacbb that was reverted before).
2. Manually trigger a native event before checkbox/radio handlers.
3. Add test coverage for triggering namespaced native-backed events.
4. Propagate extra parameters passed when triggering the click event to
   the handlers.
5. Intercept and preserve namespaced native-backed events.
6. Leverage native events for focus and blur.
7. Accept that focusin handlers may fire more than once for now.

Fixes gh-1741
Fixes gh-3423
Fixes gh-3751
Fixes gh-4139
Closes gh-4279
Ref gh-1367
Ref gh-3494

src/event.js

@@ -4,6 +4,7 @@ define( [
 	"./var/documentElement",
 	"./var/isFunction",
 	"./var/rnothtmlwhite",
+	"./var/rcheckableType",
 	"./var/slice",
 	"./data/var/dataPriv",
 	"./core/nodeName",
@@ -11,7 +12,7 @@ define( [
 	"./core/init",
 	"./selector"
 ], function( jQuery, document, documentElement, isFunction, rnothtmlwhite,
-	slice, dataPriv, nodeName ) {
+	rcheckableType, slice, dataPriv, nodeName ) {
 
 "use strict";
 
@@ -329,9 +330,10 @@ jQuery.event = {
 			while ( ( handleObj = matched.handlers[ j++ ] ) &&
 				!event.isImmediatePropagationStopped() ) {
 
-				// Triggered event must either 1) have no namespace, or 2) have namespace(s)
-				// a subset or equal to those in the bound event (both can have no namespace).
-				if ( !event.rnamespace || event.rnamespace.test( handleObj.namespace ) ) {
+				// If the event is namespaced, then each handler is only invoked if it is
+				// specially universal or its namespaces are a superset of the event's.
+				if ( !event.rnamespace || handleObj.namespace === false ||
+					event.rnamespace.test( handleObj.namespace ) ) {
 
 					event.handleObj = handleObj;
 					event.data = handleObj.data;
@@ -457,37 +459,101 @@ jQuery.event = {
 		},
 		focus: {
 
-			// Fire native event if possible so blur/focus sequence is correct
-			trigger: function() {
-				if ( this !== safeActiveElement() && this.focus ) {
-					this.focus();
-					return false;
-				}
+			// Utilize native event if possible so blur/focus sequence is correct
+			setup: function() {
+
+				// Claim the first handler
+				// dataPriv.set( this, "focus", ... )
+				leverageNative( this, "focus", false, function( el ) {
+					return el !== safeActiveElement();
+				} );
+
+				// Return false to allow normal processing in the caller
+				return false;
 			},
+			trigger: function() {
+
+				// Force setup before trigger
+				leverageNative( this, "focus", returnTrue );
+
+				// Return non-false to allow normal event-path propagation
+				return true;
+			},
+
 			delegateType: "focusin"
 		},
 		blur: {
-			trigger: function() {
-				if ( this === safeActiveElement() && this.blur ) {
-					this.blur();
-					return false;
-				}
+
+			// Utilize native event if possible so blur/focus sequence is correct
+			setup: function() {
+
+				// Claim the first handler
+				// dataPriv.set( this, "blur", ... )
+				leverageNative( this, "blur", false, function( el ) {
+					return el === safeActiveElement();
+				} );
+
+				// Return false to allow normal processing in the caller
+				return false;
 			},
+			trigger: function() {
+
+				// Force setup before trigger
+				leverageNative( this, "blur", returnTrue );
+
+				// Return non-false to allow normal event-path propagation
+				return true;
+			},
+
 			delegateType: "focusout"
 		},
 		click: {
 
-			// For checkbox, fire native event so checked state will be right
-			trigger: function() {
-				if ( this.type === "checkbox" && this.click && nodeName( this, "input" ) ) {
-					this.click();
-					return false;
+			// Utilize native event to ensure correct state for checkable inputs
+			setup: function( data ) {
+
+				// For mutual compressibility with _default, replace `this` access with a local var.
+				// `|| data` is dead code meant only to preserve the variable through minification.
+				var el = this || data;
+
+				// Claim the first handler
+				if ( rcheckableType.test( el.type ) &&
+					el.click && nodeName( el, "input" ) &&
+					dataPriv.get( el, "click" ) === undefined ) {
+
+					// dataPriv.set( el, "click", ... )
+					leverageNative( el, "click", false, returnFalse );
 				}
+
+				// Return false to allow normal processing in the caller
+				return false;
+			},
+			trigger: function( data ) {
+
+				// For mutual compressibility with _default, replace `this` access with a local var.
+				// `|| data` is dead code meant only to preserve the variable through minification.
+				var el = this || data;
+
+				// Force setup before triggering a click
+				if ( rcheckableType.test( el.type ) &&
+					el.click && nodeName( el, "input" ) &&
+					dataPriv.get( el, "click" ) === undefined ) {
+
+					leverageNative( el, "click", returnTrue );
+				}
+
+				// Return non-false to allow normal event-path propagation
+				return true;
 			},
 
-			// For cross-browser consistency, don't fire native .click() on links
+			// For cross-browser consistency, suppress native .click() on links
+			// Also prevent it if we're currently inside a leveraged native-event stack
 			_default: function( event ) {
-				return nodeName( event.target, "a" );
+				var target = event.target;
+				return rcheckableType.test( target.type ) &&
+					target.click && nodeName( target, "input" ) &&
+					dataPriv.get( target, "click" ) ||
+					nodeName( target, "a" );
 			}
 		},
 
@@ -504,6 +570,77 @@ jQuery.event = {
 	}
 };
 
+// Ensure the presence of an event listener that handles manually-triggered
+// 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, forceAdd, allowAsync ) {
+
+	// Setup must go through jQuery.event.add
+	if ( forceAdd ) {
+		jQuery.event.add( el, type, forceAdd );
+		return;
+	}
+
+	// Register the controller as a special universal handler for all event namespaces
+	dataPriv.set( el, type, forceAdd );
+	jQuery.event.add( el, type, {
+		namespace: false,
+		handler: function( event ) {
+			var maybeAsync, result,
+				saved = dataPriv.get( this, type );
+
+			// Interrupt processing of the outer synthetic .trigger()ed event
+			if ( ( event.isTrigger & 1 ) && this[ type ] && !saved ) {
+
+				// Store arguments for use when handling the inner native event
+				saved = slice.call( arguments );
+				dataPriv.set( this, type, saved );
+
+				// Trigger the native event and capture its result
+				// Support: IE <=9 - 11+
+				// focus() and blur() are asynchronous
+				maybeAsync = allowAsync( this, type );
+				this[ type ]();
+				result = dataPriv.get( this, type );
+				if ( result !== saved ) {
+					dataPriv.set( this, type, false );
+
+					// Cancel the outer synthetic event
+					event.stopImmediatePropagation();
+					event.preventDefault();
+					return result;
+				} else if ( maybeAsync ) {
+
+					// Cancel the outer synthetic event in expectation of a followup
+					event.stopImmediatePropagation();
+					event.preventDefault();
+					return;
+				} else {
+					dataPriv.set( this, type, false );
+				}
+
+			// If this is a native event triggered above, everything is now in order
+			// Fire an inner synthetic event with the original arguments
+			} else if ( !event.isTrigger && saved ) {
+
+				// ...and capture the result
+				dataPriv.set( this, type, jQuery.event.trigger(
+
+					// Support: IE <=9 - 11+
+					// Extend with the prototype to reset the above stopImmediatePropagation()
+					jQuery.extend( saved.shift(), jQuery.Event.prototype ),
+					saved,
+					this
+				) );
+
+				// Abort handling of the native event
+				event.stopImmediatePropagation();
+			}
+		}
+	} );
+}
+
 jQuery.removeEvent = function( elem, type, handle ) {
 
 	// This "if" is needed for plain objects

src/manipulation.js

@@ -4,8 +4,8 @@ define( [
 	"./var/concat",
 	"./var/isFunction",
 	"./var/push",
+	"./var/rcheckableType",
 	"./core/access",
-	"./manipulation/var/rcheckableType",
 	"./manipulation/var/rtagName",
 	"./manipulation/var/rscriptType",
 	"./manipulation/wrapMap",
@@ -24,8 +24,8 @@ define( [
 	"./traversing",
 	"./selector",
 	"./event"
-], function( jQuery, isAttached, concat, isFunction, push, access,
-	rcheckableType, rtagName, rscriptType,
+], function( jQuery, isAttached, concat, isFunction, push, rcheckableType,
+	access, rtagName, rscriptType,
 	wrapMap, getAll, setGlobalEval, buildFragment, support,
 	dataPriv, dataUser, acceptData, DOMEval, nodeName ) {
 

src/serialize.js

@@ -1,7 +1,7 @@
 define( [
 	"./core",
 	"./core/toType",
-	"./manipulation/var/rcheckableType",
+	"./var/rcheckableType",
 	"./var/isFunction",
 	"./core/init",
 	"./traversing", // filter

test/unit/event.js

@@ -2383,12 +2383,14 @@ QUnit.test( "clone() delegated events (#11076)", function( assert ) {
 	clone.remove();
 } );
 
-QUnit.test( "checkbox state (#3827)", function( assert ) {
-	assert.expect( 9 );
+QUnit.test( "checkbox state (trac-3827)", function( assert ) {
+	assert.expect( 16 );
 
-	var markup = jQuery( "<div><input type=checkbox><div>" ).appendTo( "#qunit-fixture" ),
+	var markup = jQuery( "<div class='parent'><input type=checkbox><div>" ),
 		cb = markup.find( "input" )[ 0 ];
 
+	markup.appendTo( "#qunit-fixture" );
+
 	jQuery( cb ).on( "click", function() {
 		assert.equal( this.checked, false, "just-clicked checkbox is not checked" );
 	} );
@@ -2398,18 +2400,31 @@ QUnit.test( "checkbox state (#3827)", function( assert ) {
 
 	// Native click
 	cb.checked = true;
-	assert.equal( cb.checked, true, "native - checkbox is initially checked" );
+	assert.equal( cb.checked, true, "native event - checkbox is initially checked" );
 	cb.click();
-	assert.equal( cb.checked, false, "native - checkbox is no longer checked" );
+	assert.equal( cb.checked, false, "native event - checkbox is no longer checked" );
 
 	// jQuery click
 	cb.checked = true;
-	assert.equal( cb.checked, true, "jQuery - checkbox is initially checked" );
+	assert.equal( cb.checked, true, "jQuery event - checkbox is initially checked" );
 	jQuery( cb ).trigger( "click" );
-	assert.equal( cb.checked, false, "jQuery - checkbox is no longer checked" );
+	assert.equal( cb.checked, false, "jQuery event - checkbox is no longer checked" );
 
 	// Handlers only; checkbox state remains false
 	jQuery( cb ).triggerHandler( "click" );
+	assert.equal( cb.checked, false, "handlers only - checkbox is still unchecked" );
+
+	// Trigger parameters are preserved (trac-13353, gh-4139)
+	cb.checked = true;
+	assert.equal( cb.checked, true, "jQuery event with data - checkbox is initially checked" );
+	jQuery( cb ).on( "click", function( e, data ) {
+		assert.equal( data, "clicked", "trigger data passed to handler" );
+	} );
+	markup.on( "click", function( e, data ) {
+		assert.equal( data, "clicked", "trigger data passed to bubbled handler" );
+	} );
+	jQuery( cb ).trigger( "click", [ "clicked" ] );
+	assert.equal( cb.checked, false, "jQuery event with data - checkbox is no longer checked" );
 } );
 
 QUnit.test( "event object properties on natively-triggered event", function( assert ) {
@@ -2876,18 +2891,16 @@ QUnit.test(
 QUnit.test( "originalEvent type of simulated event", function( assert ) {
 	assert.expect( 2 );
 
-	var done = assert.async(),
-		outer = jQuery(
+	var outer = jQuery(
 			"<div id='donor-outer'>" +
 				"<form id='donor-form'>" +
-					"<input id='donor-input' type='checkbox' />" +
+					"<input id='donor-input' type='text' />" +
 				"</form>" +
 			"</div>"
 		).appendTo( "#qunit-fixture" ),
 		input = jQuery( "#donor-input" ),
-		expectedType = jQuery.support.focusin ? "focusin" : "focus",
+		done = assert.async(),
 		finish = function() {
-			finish = null;
 
 			// Remove jQuery handlers to ensure removal of capturing handlers on the document
 			outer.off( "focusin" );
@@ -2897,23 +2910,15 @@ QUnit.test( "originalEvent type of simulated event", function( assert ) {
 
 	outer.on( "focusin", function( event ) {
 		assert.equal( event.type, "focusin", "focusin event at ancestor" );
-		assert.equal( event.originalEvent.type, expectedType,
+		assert.equal( event.originalEvent.type, "click",
 			"focus event at ancestor has correct originalEvent type" );
 		setTimeout( finish );
 	} );
-	input.trigger( "focus" );
 
-	// DOM focus is unreliable in TestSwarm; set a simulated event workaround timeout
-	setTimeout( function() {
-		if ( !finish ) {
-			return;
-		}
-		input[ 0 ].addEventListener( "click", function( nativeEvent ) {
-			expectedType = nativeEvent.type;
-			jQuery.event.simulate( "focusin", this, jQuery.event.fix( nativeEvent ) );
-		} );
-		input[ 0 ].click();
-	}, QUnit.config.testTimeout / 4 || 1000 );
+	input[ 0 ].addEventListener( "click", function( nativeEvent ) {
+		jQuery.event.simulate( "focusin", this, jQuery.event.fix( nativeEvent ) );
+	} );
+	input[ 0 ].click();
 } );
 
 QUnit.test( "trigger('click') on radio passes extra params", function( assert ) {
@@ -2951,7 +2956,11 @@ QUnit.test( "Check order of focusin/focusout events", function( assert ) {
 		.on( "focus", function() {
 			focus = true;
 		} )
-		.on( "focusin", function() {
+
+		// PR gh-4279 fixed a lot of `focus`-related issues but made `focusin` fire twice.
+		// We've decided to accept this drawback for now. If it's fixed, change `one` to `on`
+		// in the following line:
+		.one( "focusin", function() {
 			assert.ok( !focus, "Focusin event should fire before focus does" );
 			focus = true;
 		} )
@@ -2984,11 +2993,11 @@ QUnit.test( "focus-blur order (#12868)", function( assert ) {
 
 	var order,
 		$text = jQuery( "#text1" ),
-		$radio = jQuery( "#radio1" ).trigger( "focus" ),
+		$radio = jQuery( "#radio1" ),
 
-		// Support: IE <=10 only
-		// IE8-10 fire focus/blur events asynchronously; this is the resulting mess.
-		// IE's browser window must be topmost for this to work properly!!
+		// Support: IE <=9 - 11+
+		// focus and blur events are asynchronous; this is the resulting mess.
+		// The browser window must be topmost for this to work properly!!
 		done = assert.async();
 
 	$radio[ 0 ].focus();
@@ -3035,3 +3044,97 @@ QUnit.test( "focus-blur order (#12868)", function( assert ) {
 		}, 50 );
 	}, 50 );
 } );
+
+QUnit.test( "native-backed events preserve trigger data (gh-1741, gh-4139)", function( assert ) {
+	assert.expect( 17 );
+
+	var parent = supportjQuery(
+			"<div class='parent'><input type='checkbox'><input type='radio'></div>"
+		).appendTo( "#qunit-fixture" ),
+		targets = jQuery( parent[ 0 ].childNodes ),
+		checkbox = jQuery( targets[ 0 ] ),
+		data = [ "arg1", "arg2" ],
+		slice = data.slice,
+
+		// Support: IE <=9 - 11+
+		// focus and blur events are asynchronous; this is the resulting mess.
+		// The browser window must be topmost for this to work properly!!
+		done = assert.async();
+
+	// click (gh-4139)
+	assert.strictEqual( targets[ 0 ].checked, false, "checkbox unchecked before click" );
+	assert.strictEqual( targets[ 1 ].checked, false, "radio unchecked before click" );
+	targets.add( parent ).on( "click", function( event ) {
+		var type = event.target.type,
+			level = event.currentTarget === parent[ 0 ] ? "parent" : "";
+		assert.strictEqual( event.target.checked, true,
+			type + " toggled before invoking " + level + " handler" );
+		assert.deepEqual( slice.call( arguments, 1 ), data,
+			type + " " + level + " handler received correct data" );
+	} );
+	targets.trigger( "click", data );
+	assert.strictEqual( targets[ 0 ].checked, true,
+		"checkbox toggled after click (default action)" );
+	assert.strictEqual( targets[ 1 ].checked, true,
+		"radio toggled after event (default action)" );
+
+	// focus (gh-1741)
+	assert.notEqual( document.activeElement, checkbox[ 0 ],
+		"element not focused before focus event" );
+	checkbox.on( "focus blur", function( event ) {
+		var type = event.type;
+		assert.deepEqual( slice.call( arguments, 1 ), data,
+			type + " handler received correct data" );
+	} );
+	checkbox.trigger( "focus", data );
+	setTimeout( function() {
+		assert.strictEqual( document.activeElement, checkbox[ 0 ],
+			"element focused after focus event (default action)" );
+		checkbox.trigger( "blur", data );
+		setTimeout( function() {
+			assert.notEqual( document.activeElement, checkbox[ 0 ],
+				"element not focused after blur event (default action)" );
+			done();
+		}, 50 );
+	}, 50 );
+} );
+
+// TODO replace with an adaptation of
+// https://github.com/jquery/jquery/pull/1367/files#diff-a215316abbaabdf71857809e8673ea28R2464
+( function() {
+	supportjQuery.each(
+		{
+			checkbox: "<input type='checkbox'>",
+			radio: "<input type='radio'>"
+		},
+		makeTestFor3751
+	);
+
+	function makeTestFor3751( type, html ) {
+		var testName = "native-backed namespaced clicks are handled correctly (gh-3751) - " + type;
+		QUnit.test( testName, function( assert ) {
+			assert.expect( 2 );
+
+			var parent = supportjQuery( "<div class='parent'>" + html + "</div>" ),
+				target = jQuery( parent[ 0 ].firstChild );
+
+			parent.appendTo( "#qunit-fixture" );
+
+			target.add( parent )
+				.on( "click.notFired", function( event ) {
+					assert.ok( false, "namespaced event should not be received" +
+						" by wrong-namespace listener at " + event.currentTarget.nodeName );
+				} )
+				.on( "click.fired", function( event ) {
+					assert.equal( event.target.checked, true,
+						"toggled before invoking handler at " + event.currentTarget.nodeName );
+				} )
+				.on( "click", function( event ) {
+					assert.ok( false, "namespaced event should not be received" +
+						" by non-namespaced listener at " + event.currentTarget.nodeName );
+				} );
+
+			target.trigger( "click.fired" );
+		} );
+	}
+} )();