Widget: Improve `remove` event bindings for `classes` options

Fixes #15078
Fixes #15082
Fixes #15095
Fixes #15136
Fixes #15152
Closes gh-1769

1 files changed, 21 insertions, 5 deletions

diff --git a/ui/widget.js b/ui/widget.js
index 726f70735..f87675712 100644
--- a/ui/widget.js
+++ b/ui/widget.js
@@ -493,11 +493,29 @@ $.Widget.prototype = {
 			classes: this.options.classes || {}
 		}, options );
 
+		function bindRemoveEvent() {
+			options.element.each( function( _, element ) {
+				var isTracked = $.map( that.classesElementLookup, function( elements ) {
+					return elements;
+				} )
+					.some( function( elements ) {
+						return elements.is( element );
+					} );
+
+				if ( !isTracked ) {
+					that._on( $( element ), {
+						remove: "_untrackClassesElement"
+					} );
+				}
+			} );
+		}
+
 		function processClassString( classes, checkOption ) {
 			var current, i;
 			for ( i = 0; i < classes.length; i++ ) {
 				current = that.classesElementLookup[ classes[ i ] ] || $();
 				if ( options.add ) {
+					bindRemoveEvent();
 					current = $( $.unique( current.get().concat( options.element.get() ) ) );
 				} else {
 					current = $( current.not( options.element ).get() );
@@ -510,10 +528,6 @@ $.Widget.prototype = {
 			}
 		}
 
-		this._on( options.element, {
-			"remove": "_untrackClassesElement"
-		} );
-
 		if ( options.keys ) {
 			processClassString( options.keys.match( /\S+/g ) || [], true );
 		}
@@ -531,6 +545,8 @@ $.Widget.prototype = {
 				that.classesElementLookup[ key ] = $( value.not( event.target ).get() );
 			}
 		} );
+
+		this._off( $( event.target ) );
 	},
 
 	_removeClass: function( element, keys, extra ) {
@@ -611,7 +627,7 @@ $.Widget.prototype = {
 	_off: function( element, eventName ) {
 		eventName = ( eventName || "" ).split( " " ).join( this.eventNamespace + " " ) +
 			this.eventNamespace;
-		element.off( eventName ).off( eventName );
+		element.off( eventName );
 
 		// Clear the stack to avoid memory leaks (#10056)
 		this.bindings = $( this.bindings.not( element ).get() );