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resources/lib/oojs/oojs.js

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/*!
 * OOjs v7.0.1
 * https://www.mediawiki.org/wiki/OOjs
 *
 * Copyright 2011-2023 OOjs Team and other contributors.
 * Released under the MIT license
 * https://oojs.mit-license.org
 */
( function ( global ) {

'use strict';

/* exported slice, toString */
/**
 * Namespace for all classes, static methods and static properties.
 *
 * @namespace OO
 */
var
    // eslint-disable-next-line no-redeclare
    OO = {},
    // Optimisation: Local reference to methods from a global prototype
    hasOwn = OO.hasOwnProperty,
    slice = Array.prototype.slice,
    // eslint-disable-next-line no-redeclare
    toString = OO.toString;

/* Class Methods */

/**
 * Utility to initialize a class for OO inheritance.
 *
 * Currently this just initializes an empty static object.
 *
 * @memberof OO
 * @method initClass
 * @param {Function} fn
 */
OO.initClass = function ( fn ) {
    fn.static = fn.static || {};
};

/**
 * Inherit from prototype to another using Object#create.
 *
 * Beware: This redefines the prototype, call before setting your prototypes.
 *
 * Beware: This redefines the prototype, can only be called once on a function.
 * If called multiple times on the same function, the previous prototype is lost.
 * This is how prototypal inheritance works, it can only be one straight chain
 * (just like classical inheritance in PHP for example). If you need to work with
 * multiple constructors consider storing an instance of the other constructor in a
 * property instead, or perhaps use a mixin (see OO.mixinClass).
 *
 *     function Thing() {}
 *     Thing.prototype.exists = function () {};
 *
 *     function Person() {
 *         Person.super.apply( this, arguments );
 *     }
 *     OO.inheritClass( Person, Thing );
 *     Person.static.defaultEyeCount = 2;
 *     Person.prototype.walk = function () {};
 *
 *     function Jumper() {
 *         Jumper.super.apply( this, arguments );
 *     }
 *     OO.inheritClass( Jumper, Person );
 *     Jumper.prototype.jump = function () {};
 *
 *     Jumper.static.defaultEyeCount === 2;
 *     var x = new Jumper();
 *     x.jump();
 *     x.walk();
 *     x instanceof Thing && x instanceof Person && x instanceof Jumper;
 *
 * @memberof OO
 * @method inheritClass
 * @param {Function} targetFn
 * @param {Function} originFn
 * @throws {Error} If target already inherits from origin
 */
OO.inheritClass = function ( targetFn, originFn ) {
    if ( !originFn ) {
        throw new Error( 'inheritClass: Origin is not a function (actually ' + originFn + ')' );
    }
    if ( targetFn.prototype instanceof originFn ) {
        throw new Error( 'inheritClass: Target already inherits from origin' );
    }

    var targetConstructor = targetFn.prototype.constructor;

    // [DEPRECATED] Provide .parent as alias for code supporting older browsers which
    // allows people to comply with their style guide.
    targetFn.super = targetFn.parent = originFn;

    targetFn.prototype = Object.create( originFn.prototype, {
        // Restore constructor property of targetFn
        constructor: {
            value: targetConstructor,
            enumerable: false,
            writable: true,
            configurable: true
        }
    } );

    // Extend static properties - always initialize both sides
    OO.initClass( originFn );
    targetFn.static = Object.create( originFn.static );
};

/**
 * Copy over *own* prototype properties of a mixin.
 *
 * The 'constructor' (whether implicit or explicit) is not copied over.
 *
 * This does not create inheritance to the origin. If you need inheritance,
 * use OO.inheritClass instead.
 *
 * Beware: This can redefine a prototype property, call before setting your prototypes.
 *
 * Beware: Don't call before OO.inheritClass.
 *
 *     function Foo() {}
 *     function Context() {}
 *
 *     // Avoid repeating this code
 *     function ContextLazyLoad() {}
 *     ContextLazyLoad.prototype.getContext = function () {
 *         if ( !this.context ) {
 *             this.context = new Context();
 *         }
 *         return this.context;
 *     };
 *
 *     function FooBar() {}
 *     OO.inheritClass( FooBar, Foo );
 *     OO.mixinClass( FooBar, ContextLazyLoad );
 *
 * @memberof OO
 * @method mixinClass
 * @param {Function} targetFn
 * @param {Function} originFn
 */
OO.mixinClass = function ( targetFn, originFn ) {
    if ( !originFn ) {
        throw new Error( 'mixinClass: Origin is not a function (actually ' + originFn + ')' );
    }

    var key;
    // Copy prototype properties
    for ( key in originFn.prototype ) {
        if ( key !== 'constructor' && hasOwn.call( originFn.prototype, key ) ) {
            targetFn.prototype[ key ] = originFn.prototype[ key ];
        }
    }

    // Copy static properties - always initialize both sides
    OO.initClass( targetFn );
    if ( originFn.static ) {
        for ( key in originFn.static ) {
            if ( hasOwn.call( originFn.static, key ) ) {
                targetFn.static[ key ] = originFn.static[ key ];
            }
        }
    } else {
        OO.initClass( originFn );
    }
};

/**
 * Test whether one class is a subclass of another, without instantiating it.
 *
 * Every class is considered a subclass of Object and of itself.
 *
 * @memberof OO
 * @method isSubClass
 * @param {Function} testFn The class to be tested
 * @param {Function} baseFn The base class
 * @return {boolean} Whether testFn is a subclass of baseFn (or equal to it)
 */
OO.isSubclass = function ( testFn, baseFn ) {
    return testFn === baseFn || testFn.prototype instanceof baseFn;
};

/* Object Methods */

/**
 * Get a deeply nested property of an object using variadic arguments, protecting against
 * undefined property errors.
 *
 * `quux = OO.getProp( obj, 'foo', 'bar', 'baz' );` is equivalent to `quux = obj.foo.bar.baz;`
 * except that the former protects against JS errors if one of the intermediate properties
 * is undefined. Instead of throwing an error, this function will return undefined in
 * that case.
 *
 * @memberof OO
 * @method getProp
 * @param {Object} obj
 * @param {...any} [keys]
 * @return {Object|undefined} obj[arguments[1]][arguments[2]].... or undefined
 */
OO.getProp = function ( obj ) {
    var retval = obj;
    for ( var i = 1; i < arguments.length; i++ ) {
        if ( retval === undefined || retval === null ) {
            // Trying to access a property of undefined or null causes an error
            return undefined;
        }
        retval = retval[ arguments[ i ] ];
    }
    return retval;
};

/**
 * Set a deeply nested property of an object using variadic arguments, protecting against
 * undefined property errors.
 *
 * `OO.setProp( obj, 'foo', 'bar', 'baz' );` is equivalent to `obj.foo.bar = baz;` except that
 * the former protects against JS errors if one of the intermediate properties is
 * undefined. Instead of throwing an error, undefined intermediate properties will be
 * initialized to an empty object. If an intermediate property is not an object, or if obj itself
 * is not an object, this function will silently abort.
 *
 * @memberof OO
 * @method setProp
 * @param {Object} obj
 * @param {...any} [keys]
 * @param {any} [value]
 */
OO.setProp = function ( obj ) {
    if ( Object( obj ) !== obj || arguments.length < 2 ) {
        return;
    }
    var prop = obj;
    for ( var i = 1; i < arguments.length - 2; i++ ) {
        if ( prop[ arguments[ i ] ] === undefined ) {
            prop[ arguments[ i ] ] = {};
        }
        if ( Object( prop[ arguments[ i ] ] ) !== prop[ arguments[ i ] ] ) {
            return;
        }
        prop = prop[ arguments[ i ] ];
    }
    prop[ arguments[ arguments.length - 2 ] ] = arguments[ arguments.length - 1 ];
};

/**
 * Delete a deeply nested property of an object using variadic arguments, protecting against
 * undefined property errors, and deleting resulting empty objects.
 *
 * @memberof OO
 * @method deleteProp
 * @param {Object} obj
 * @param {...any} [keys]
 */
OO.deleteProp = function ( obj ) {
    if ( Object( obj ) !== obj || arguments.length < 2 ) {
        return;
    }
    var prop = obj;
    var props = [ prop ];
    var i = 1;
    for ( ; i < arguments.length - 1; i++ ) {
        if (
            prop[ arguments[ i ] ] === undefined ||
            Object( prop[ arguments[ i ] ] ) !== prop[ arguments[ i ] ]
        ) {
            return;
        }
        prop = prop[ arguments[ i ] ];
        props.push( prop );
    }
    delete prop[ arguments[ i ] ];
    // Walk back through props removing any plain empty objects
    while (
        props.length > 1 &&
        ( prop = props.pop() ) &&

        OO.isPlainObject( prop ) && !Object.keys( prop ).length
    ) {
        delete props[ props.length - 1 ][ arguments[ props.length ] ];
    }
};

/**
 * Create a new object that is an instance of the same
 * constructor as the input, inherits from the same object
 * and contains the same own properties.
 *
 * This makes a shallow non-recursive copy of own properties.
 * To create a recursive copy of plain objects, use #copy.
 *
 *     var foo = new Person( mom, dad );
 *     foo.setAge( 21 );
 *     var foo2 = OO.cloneObject( foo );
 *     foo.setAge( 22 );
 *
 *     // Then
 *     foo2 !== foo; // true
 *     foo2 instanceof Person; // true
 *     foo2.getAge(); // 21
 *     foo.getAge(); // 22
 *
 * @memberof OO
 * @method cloneObject
 * @param {Object} origin
 * @return {Object} Clone of origin
 */
OO.cloneObject = function ( origin ) {
    var r = Object.create( origin.constructor.prototype );

    for ( var key in origin ) {
        if ( hasOwn.call( origin, key ) ) {
            r[ key ] = origin[ key ];
        }
    }

    return r;
};

/**
 * Get an array of all property values in an object.
 *
 * @memberof OO
 * @method getObjectValues
 * @param {Object} obj Object to get values from
 * @return {Array} List of object values
 */
OO.getObjectValues = function ( obj ) {
    if ( obj !== Object( obj ) ) {
        throw new TypeError( 'Called on non-object' );
    }

    var values = [];
    for ( var key in obj ) {
        if ( hasOwn.call( obj, key ) ) {
            values[ values.length ] = obj[ key ];
        }
    }

    return values;
};

/**
 * Use binary search to locate an element in a sorted array.
 *
 * searchFunc is given an element from the array. `searchFunc(elem)` must return a number
 * above 0 if the element we're searching for is to the right of (has a higher index than) elem,
 * below 0 if it is to the left of elem, or zero if it's equal to elem.
 *
 * To search for a specific value with a comparator function (a `function cmp(a,b)` that returns
 * above 0 if `a > b`, below 0 if `a < b`, and 0 if `a == b`), you can use
 * `searchFunc = cmp.bind( null, value )`.
 *
 * @memberof OO
 * @method binarySearch
 * @param {Array} arr Array to search in
 * @param {Function} searchFunc Search function
 * @param {boolean} [forInsertion] If not found, return index where val could be inserted
 * @return {number|null} Index where val was found, or null if not found
 */
OO.binarySearch = function ( arr, searchFunc, forInsertion ) {
    var left = 0;
    var right = arr.length;
    while ( left < right ) {
        // Equivalent to Math.floor( ( left + right ) / 2 ) but much faster
        // eslint-disable-next-line no-bitwise
        var mid = ( left + right ) >> 1;
        var cmpResult = searchFunc( arr[ mid ] );
        if ( cmpResult < 0 ) {
            right = mid;
        } else if ( cmpResult > 0 ) {
            left = mid + 1;
        } else {
            return mid;
        }
    }
    return forInsertion ? right : null;
};

/**
 * Recursively compare properties between two objects.
 *
 * A false result may be caused by property inequality or by properties in one object missing from
 * the other. An asymmetrical test may also be performed, which checks only that properties in the
 * first object are present in the second object, but not the inverse.
 *
 * If either a or b is null or undefined it will be treated as an empty object.
 *
 * @memberof OO
 * @method compare
 * @param {Object|undefined|null} a First object to compare
 * @param {Object|undefined|null} b Second object to compare
 * @param {boolean} [asymmetrical] Whether to check only that a's values are equal to b's
 *  (i.e. a is a subset of b)
 * @return {boolean} If the objects contain the same values as each other
 */
OO.compare = function ( a, b, asymmetrical ) {
    if ( a === b ) {
        return true;
    }

    a = a || {};
    b = b || {};

    if ( typeof a.nodeType === 'number' && typeof a.isEqualNode === 'function' ) {
        return a.isEqualNode( b );
    }

    for ( var k in a ) {
        if ( !hasOwn.call( a, k ) || a[ k ] === undefined || a[ k ] === b[ k ] ) {
            // Ignore undefined values, because there is no conceptual difference between
            // a key that is absent and a key that is present but whose value is undefined.
            continue;
        }

        var aValue = a[ k ];
        var bValue = b[ k ];
        var aType = typeof aValue;
        var bType = typeof bValue;
        if ( aType !== bType ||
            (
                ( aType === 'string' || aType === 'number' || aType === 'boolean' ) &&
                aValue !== bValue
            ) ||
            ( aValue === Object( aValue ) && !OO.compare( aValue, bValue, true ) ) ) {
            return false;
        }
    }
    // If the check is not asymmetrical, recursing with the arguments swapped will verify our result
    return asymmetrical ? true : OO.compare( b, a, true );
};

/**
 * Create a plain deep copy of any kind of object.
 *
 * Copies are deep, and will either be an object or an array depending on `source`.
 *
 * @memberof OO
 * @method copy
 * @param {Object} source Object to copy
 * @param {Function} [leafCallback] Applied to leaf values after they are cloned but before they are
 *  added to the clone
 * @param {Function} [nodeCallback] Applied to all values before they are cloned. If the
 *  nodeCallback returns a value other than undefined, the returned value is used instead of
 *  attempting to clone.
 * @return {Object} Copy of source object
 */
OO.copy = function ( source, leafCallback, nodeCallback ) {
    var destination;

    if ( nodeCallback ) {
        // Extensibility: check before attempting to clone source.
        destination = nodeCallback( source );
        if ( destination !== undefined ) {
            return destination;
        }
    }

    if ( Array.isArray( source ) ) {
        // Array (fall through)
        destination = new Array( source.length );
    } else if ( source && typeof source.clone === 'function' ) {
        // Duck type object with custom clone method
        return leafCallback ? leafCallback( source.clone() ) : source.clone();
    } else if ( source && typeof source.cloneNode === 'function' ) {
        // DOM Node
        return leafCallback ?
            leafCallback( source.cloneNode( true ) ) :
            source.cloneNode( true );
    } else if ( OO.isPlainObject( source ) ) {
        // Plain objects (fall through)
        destination = {};
    } else {
        // Non-plain objects (incl. functions) and primitive values
        return leafCallback ? leafCallback( source ) : source;
    }

    // source is an array or a plain object
    for ( var key in source ) {
        destination[ key ] = OO.copy( source[ key ], leafCallback, nodeCallback );
    }

    // This is an internal node, so we don't apply the leafCallback.
    return destination;
};

/**
 * Generate a hash of an object based on its name and data.
 *
 * Performance optimization: <http://jsperf.com/ve-gethash-201208#/toJson_fnReplacerIfAoForElse>
 *
 * To avoid two objects with the same values generating different hashes, we utilize the replacer
 * argument of JSON.stringify and sort the object by key as it's being serialized. This may or may
 * not be the fastest way to do this; we should investigate this further.
 *
 * Objects and arrays are hashed recursively. When hashing an object that has a .getHash()
 * function, we call that function and use its return value rather than hashing the object
 * ourselves. This allows classes to define custom hashing.
 *
 * @memberof OO
 * @method getHash
 * @param {Object} val Object to generate hash for
 * @return {string} Hash of object
 */
OO.getHash = function ( val ) {
    return JSON.stringify( val, OO.getHash.keySortReplacer );
};

/**
 * Sort objects by key (helper function for OO.getHash).
 *
 * This is a callback passed into JSON.stringify.
 *
 * @memberof OO
 * @method getHash_keySortReplacer
 * @param {string} key Property name of value being replaced
 * @param {any} val Property value to replace
 * @return {any} Replacement value
 */
OO.getHash.keySortReplacer = function ( key, val ) {
    if ( val && typeof val.getHashObject === 'function' ) {
        // This object has its own custom hash function, use it
        val = val.getHashObject();
    }
    if ( !Array.isArray( val ) && Object( val ) === val ) {
        // Only normalize objects when the key-order is ambiguous
        // (e.g. any object not an array).
        var normalized = {};

        var keys = Object.keys( val ).sort();
        for ( var i = 0, len = keys.length; i < len; i++ ) {
            normalized[ keys[ i ] ] = val[ keys[ i ] ];
        }
        return normalized;
    } else {
        // Primitive values and arrays get stable hashes
        // by default. Lets those be stringified as-is.
        return val;
    }
};

/**
 * Get the unique values of an array, removing duplicates.
 *
 * @memberof OO
 * @method unique
 * @param {Array} arr Array
 * @return {Array} Unique values in array
 */
OO.unique = function ( arr ) {
    return Array.from( new Set( arr ) );
};

/**
 * Compute the union (duplicate-free merge) of a set of arrays.
 *
 * @memberof OO
 * @method simpleArrayUnion
 * @param {Array} a First array
 * @param {...Array} rest Arrays to union
 * @return {Array} Union of the arrays
 */
OO.simpleArrayUnion = function ( a, ...rest ) {
    var set = new Set( a );

    for ( var i = 0; i < rest.length; i++ ) {
        var arr = rest[ i ];
        for ( var j = 0; j < arr.length; j++ ) {
            set.add( arr[ j ] );
        }
    }

    return Array.from( set );
};

/**
 * Combine arrays (intersection or difference).
 *
 * An intersection checks the item exists in 'b' while difference checks it doesn't.
 *
 * @private
 * @param {Array} a First array
 * @param {Array} b Second array
 * @param {boolean} includeB Whether to items in 'b'
 * @return {Array} Combination (intersection or difference) of arrays
 */
function simpleArrayCombine( a, b, includeB ) {
    var set = new Set( b );
    var result = [];

    for ( var j = 0; j < a.length; j++ ) {
        var isInB = set.has( a[ j ] );
        if ( isInB === includeB ) {
            result.push( a[ j ] );
        }
    }

    return result;
}

/**
 * Compute the intersection of two arrays (items in both arrays).
 *
 * @memberof OO
 * @method simpleArrayIntersection
 * @param {Array} a First array
 * @param {Array} b Second array
 * @return {Array} Intersection of arrays
 */
OO.simpleArrayIntersection = function ( a, b ) {
    return simpleArrayCombine( a, b, true );
};

/**
 * Compute the difference of two arrays (items in 'a' but not 'b').
 *
 * @memberof OO
 * @method simpleArrayDifference
 * @param {Array} a First array
 * @param {Array} b Second array
 * @return {Array} Intersection of arrays
 */
OO.simpleArrayDifference = function ( a, b ) {
    return simpleArrayCombine( a, b, false );
};

/* eslint-disable-next-line no-redeclare */
/* global hasOwn, toString */

/**
 * Assert whether a value is a plain object or not.
 *
 * @memberof OO
 * @param {any} obj
 * @return {boolean}
 */
OO.isPlainObject = function ( obj ) {
    // Optimise for common case where internal [[Class]] property is not "Object"
    if ( !obj || toString.call( obj ) !== '[object Object]' ) {
        return false;
    }

    var proto = Object.getPrototypeOf( obj );

    // Objects without prototype (e.g., `Object.create( null )`) are considered plain
    if ( !proto ) {
        return true;
    }

    // The 'isPrototypeOf' method is set on Object.prototype.
    return hasOwn.call( proto, 'isPrototypeOf' );
};

/* global hasOwn, slice */

( function () {

    /**
     * @class
     */
    OO.EventEmitter = function OoEventEmitter() {
        // Properties

        /**
         * Storage of bound event handlers by event name.
         *
         * @private
         * @property {Object} bindings
         */
        this.bindings = {};
    };

    OO.initClass( OO.EventEmitter );

    /* Private helper functions */

    /**
     * Validate a function or method call in a context
     *
     * For a method name, check that it names a function in the context object
     *
     * @private
     * @param {Function|string} method Function or method name
     * @param {any} context The context of the call
     * @throws {Error} A method name is given but there is no context
     * @throws {Error} In the context object, no property exists with the given name
     * @throws {Error} In the context object, the named property is not a function
     */
    function validateMethod( method, context ) {
        // Validate method and context
        if ( typeof method === 'string' ) {
            // Validate method
            if ( context === undefined || context === null ) {
                throw new Error( 'Method name "' + method + '" has no context.' );
            }
            if ( typeof context[ method ] !== 'function' ) {
                // Technically the property could be replaced by a function before
                // call time. But this probably signals a typo.
                throw new Error( 'Property "' + method + '" is not a function' );
            }
        } else if ( typeof method !== 'function' ) {
            throw new Error( 'Invalid callback. Function or method name expected.' );
        }
    }

    /**
     * @private
     * @param {OO.EventEmitter} eventEmitter Event emitter
     * @param {string} event Event name
     * @param {Object} binding
     */
    function addBinding( eventEmitter, event, binding ) {
        var bindings;
        // Auto-initialize bindings list
        if ( hasOwn.call( eventEmitter.bindings, event ) ) {
            bindings = eventEmitter.bindings[ event ];
        } else {
            bindings = eventEmitter.bindings[ event ] = [];
        }
        // Add binding
        bindings.push( binding );
    }

    /* Methods */

    /**
     * Add a listener to events of a specific event.
     *
     * The listener can be a function or the string name of a method; if the latter, then the
     * name lookup happens at the time the listener is called.
     *
     * @param {string} event Type of event to listen to
     * @param {Function|string} method Function or method name to call when event occurs
     * @param {Array} [args] Arguments to pass to listener, will be prepended to emitted arguments
     * @param {Object} [context=null] Context object for function or method call
     * @return {OO.EventEmitter}
     * @throws {Error} Listener argument is not a function or a valid method name
     */
    OO.EventEmitter.prototype.on = function ( event, method, args, context ) {
        validateMethod( method, context );

        // Ensure consistent object shape (optimisation)
        addBinding( this, event, {
            method: method,
            args: args,
            context: ( arguments.length < 4 ) ? null : context,
            once: false
        } );
        return this;
    };

    /**
     * Add a one-time listener to a specific event.
     *
     * @param {string} event Type of event to listen to
     * @param {Function} listener Listener to call when event occurs
     * @return {OO.EventEmitter}
     */
    OO.EventEmitter.prototype.once = function ( event, listener ) {
        validateMethod( listener );

        // Ensure consistent object shape (optimisation)
        addBinding( this, event, {
            method: listener,
            args: undefined,
            context: null,
            once: true
        } );
        return this;
    };

    /**
     * Remove a specific listener from a specific event.
     *
     * @param {string} event Type of event to remove listener from
     * @param {Function|string} [method] Listener to remove. Must be in the same form as was passed
     * to "on". Omit to remove all listeners.
     * @param {Object} [context=null] Context object function or method call
     * @return {OO.EventEmitter}
     * @throws {Error} Listener argument is not a function or a valid method name
     */
    OO.EventEmitter.prototype.off = function ( event, method, context ) {
        if ( arguments.length === 1 ) {
            // Remove all bindings for event
            delete this.bindings[ event ];
            return this;
        }

        validateMethod( method, context );

        if ( !hasOwn.call( this.bindings, event ) || !this.bindings[ event ].length ) {
            // No matching bindings
            return this;
        }

        // Default to null context
        if ( arguments.length < 3 ) {
            context = null;
        }

        // Remove matching handlers
        var bindings = this.bindings[ event ];
        var i = bindings.length;
        while ( i-- ) {
            if ( bindings[ i ].method === method && bindings[ i ].context === context ) {
                bindings.splice( i, 1 );
            }
        }

        // Cleanup if now empty
        if ( bindings.length === 0 ) {
            delete this.bindings[ event ];
        }
        return this;
    };

    /**
     * Emit an event.
     *
     * All listeners for the event will be called synchronously, in an
     * unspecified order. If any listeners throw an exception, this won't
     * disrupt the calls to the remaining listeners; however, the exception
     * won't be thrown until the next tick.
     *
     * Listeners should avoid mutating the emitting object, as this is
     * something of an anti-pattern which can easily result in
     * hard-to-understand code with hidden side-effects and dependencies.
     *
     * @param {string} event Type of event
     * @param {...any} [args] Arguments passed to the event handler
     * @return {boolean} Whether the event was handled by at least one listener
     */
    OO.EventEmitter.prototype.emit = function ( event ) {
        if ( !hasOwn.call( this.bindings, event ) ) {
            return false;
        }

        // Slicing ensures that we don't get tripped up by event
        // handlers that add/remove bindings
        var bindings = this.bindings[ event ].slice();
        var args = slice.call( arguments, 1 );
        for ( var i = 0; i < bindings.length; i++ ) {
            var binding = bindings[ i ];
            var method;
            if ( typeof binding.method === 'string' ) {
                // Lookup method by name (late binding)
                method = binding.context[ binding.method ];
            } else {
                method = binding.method;
            }
            if ( binding.once ) {
                // Unbind before calling, to avoid any nested triggers.
                this.off( event, method );
            }
            try {
                method.apply(
                    binding.context,
                    binding.args ? binding.args.concat( args ) : args
                );
            } catch ( e ) {
                // If one listener has an unhandled error, don't have it
                // take down the emitter. But rethrow asynchronously so
                // debuggers can break with a full async stack trace.
                setTimeout( ( function ( error ) {
                    throw error;
                } ).bind( null, e ) );
            }

        }
        return true;
    };

    /**
     * Emit an event, propagating the first exception some listener throws
     *
     * All listeners for the event will be called synchronously, in an
     * unspecified order. If any listener throws an exception, this won't
     * disrupt the calls to the remaining listeners. The first exception
     * thrown will be propagated back to the caller; any others won't be
     * thrown until the next tick.
     *
     * Listeners should avoid mutating the emitting object, as this is
     * something of an anti-pattern which can easily result in
     * hard-to-understand code with hidden side-effects and dependencies.
     *
     * @param {string} event Type of event
     * @param {...any} [args] Arguments passed to the event handler
     * @return {boolean} Whether the event was handled by at least one listener
     */
    OO.EventEmitter.prototype.emitThrow = function ( event ) {
        // We tolerate code duplication with #emit, because the
        // alternative is an extra level of indirection which will
        // appear in very many stack traces.
        if ( !hasOwn.call( this.bindings, event ) ) {
            return false;
        }

        var firstError;
        // Slicing ensures that we don't get tripped up by event
        // handlers that add/remove bindings
        var bindings = this.bindings[ event ].slice();
        var args = slice.call( arguments, 1 );
        for ( var i = 0; i < bindings.length; i++ ) {
            var binding = bindings[ i ];
            var method;
            if ( typeof binding.method === 'string' ) {
                // Lookup method by name (late binding)
                method = binding.context[ binding.method ];
            } else {
                method = binding.method;
            }
            if ( binding.once ) {
                // Unbind before calling, to avoid any nested triggers.
                this.off( event, method );
            }
            try {
                method.apply(
                    binding.context,
                    binding.args ? binding.args.concat( args ) : args
                );
            } catch ( e ) {
                if ( firstError === undefined ) {
                    firstError = e;
                } else {
                    // If one listener has an unhandled error, don't have it
                    // take down the emitter. But rethrow asynchronously so
                    // debuggers can break with a full async stack trace.
                    setTimeout( ( function ( error ) {
                        throw error;
                    } ).bind( null, e ) );
                }
            }

        }
        if ( firstError !== undefined ) {
            throw firstError;
        }
        return true;
    };

    /**
     * Connect event handlers to an object.
     *
     * @param {Object} context Object to call methods on when events occur
     * @param {Object.<string,string>|Object.<string,Function>|Object.<string,Array>} methods
     *  List of event bindings keyed by event name containing either method names, functions or
     *  arrays containing method name or function followed by a list of arguments to be passed to
     *  callback before emitted arguments.
     * @return {OO.EventEmitter}
     */
    OO.EventEmitter.prototype.connect = function ( context, methods ) {
        for ( var event in methods ) {
            var method = methods[ event ];
            var args;
            // Allow providing additional args
            if ( Array.isArray( method ) ) {
                args = method.slice( 1 );
                method = method[ 0 ];
            } else {
                args = [];
            }
            // Add binding
            this.on( event, method, args, context );
        }
        return this;
    };

    /**
     * Disconnect event handlers from an object.
     *
     * @param {Object} context Object to disconnect methods from
     * @param {Object.<string,string>|Object.<string,Function>|Object.<string,Array>} [methods]
     *  List of event bindings keyed by event name. Values can be either method names, functions or
     *  arrays containing a method name.
     *  NOTE: To allow matching call sites with connect(), array values are allowed to contain the
     *  parameters as well, but only the method name is used to find bindings. It is discouraged to
     *  have multiple bindings for the same event to the same listener, but if used (and only the
     *  parameters vary), disconnecting one variation of (event name, event listener, parameters)
     *  will disconnect other variations as well.
     * @return {OO.EventEmitter}
     */
    OO.EventEmitter.prototype.disconnect = function ( context, methods ) {
        var event;
        if ( methods ) {
            // Remove specific connections to the context
            for ( event in methods ) {
                var method = methods[ event ];
                if ( Array.isArray( method ) ) {
                    method = method[ 0 ];
                }
                this.off( event, method, context );
            }
        } else {
            // Remove all connections to the context
            for ( event in this.bindings ) {
                var bindings = this.bindings[ event ];
                var i = bindings.length;
                while ( i-- ) {
                    // bindings[i] may have been removed by the previous step's
                    // this.off so check it still exists
                    if ( bindings[ i ] && bindings[ i ].context === context ) {
                        this.off( event, bindings[ i ].method, context );
                    }
                }
            }
        }

        return this;
    };

}() );

( function () {

    /**
     * Contain and manage a list of @{link OO.EventEmitter} items.
     *
     * Aggregates and manages their events collectively.
     *
     * This mixin must be used in a class that also mixes in @{link OO.EventEmitter}.
     *
     * @abstract
     * @class
     */
    OO.EmitterList = function OoEmitterList() {
        this.items = [];
        this.aggregateItemEvents = {};
    };

    OO.initClass( OO.EmitterList );

    /* Events */

    /**
     * Item has been added.
     *
     * @event OO.EmitterList#add
     * @param {OO.EventEmitter} item Added item
     * @param {number} index Index items were added at
     */

    /**
     * Item has been moved to a new index.
     *
     * @event OO.EmitterList#move
     * @param {OO.EventEmitter} item Moved item
     * @param {number} index Index item was moved to
     * @param {number} oldIndex The original index the item was in
     */

    /**
     * Item has been removed.
     *
     * @event OO.EmitterList#remove
     * @param {OO.EventEmitter} item Removed item
     * @param {number} index Index the item was removed from
     */

    /**
     * The list has been cleared of items.
     *
     * @event OO.EmitterList#clear
     */

    /* Methods */

    /**
     * Normalize requested index to fit into the bounds of the given array.
     *
     * @private
     * @static
     * @param {Array} arr Given array
     * @param {number|undefined} index Requested index
     * @return {number} Normalized index
     */
    function normalizeArrayIndex( arr, index ) {
        return ( index === undefined || index < 0 || index >= arr.length ) ?
            arr.length :
            index;
    }

    /**
     * Get all items.
     *
     * @return {OO.EventEmitter[]} Items in the list
     */
    OO.EmitterList.prototype.getItems = function () {
        return this.items.slice( 0 );
    };

    /**
     * Get the index of a specific item.
     *
     * @param {OO.EventEmitter} item Requested item
     * @return {number} Index of the item
     */
    OO.EmitterList.prototype.getItemIndex = function ( item ) {
        return this.items.indexOf( item );
    };

    /**
     * Get number of items.
     *
     * @return {number} Number of items in the list
     */
    OO.EmitterList.prototype.getItemCount = function () {
        return this.items.length;
    };

    /**
     * Check if a list contains no items.
     *
     * @return {boolean} Group is empty
     */
    OO.EmitterList.prototype.isEmpty = function () {
        return !this.items.length;
    };

    /**
     * Aggregate the events emitted by the group.
     *
     * When events are aggregated, the group will listen to all contained items for the event,
     * and then emit the event under a new name. The new event will contain an additional leading
     * parameter containing the item that emitted the original event. Other arguments emitted from
     * the original event are passed through.
     *
     * @param {Object.<string,string|null>} events An object keyed by the name of the event that
     *  should be aggregated  (e.g., ‘click’) and the value of the new name to use
     *  (e.g., ‘groupClick’). A `null` value will remove aggregated events.
     * @throws {Error} If aggregation already exists
     */
    OO.EmitterList.prototype.aggregate = function ( events ) {
        var i, item;
        for ( var itemEvent in events ) {
            var groupEvent = events[ itemEvent ];

            // Remove existing aggregated event
            if ( Object.prototype.hasOwnProperty.call( this.aggregateItemEvents, itemEvent ) ) {
                // Don't allow duplicate aggregations
                if ( groupEvent ) {
                    throw new Error( 'Duplicate item event aggregation for ' + itemEvent );
                }
                // Remove event aggregation from existing items
                for ( i = 0; i < this.items.length; i++ ) {
                    item = this.items[ i ];
                    if ( item.connect && item.disconnect ) {
                        var remove = {};
                        remove[ itemEvent ] = [ 'emit', this.aggregateItemEvents[ itemEvent ], item ];
                        item.disconnect( this, remove );
                    }
                }
                // Prevent future items from aggregating event
                delete this.aggregateItemEvents[ itemEvent ];
            }

            // Add new aggregate event
            if ( groupEvent ) {
                // Make future items aggregate event
                this.aggregateItemEvents[ itemEvent ] = groupEvent;
                // Add event aggregation to existing items
                for ( i = 0; i < this.items.length; i++ ) {
                    item = this.items[ i ];
                    if ( item.connect && item.disconnect ) {
                        var add = {};
                        add[ itemEvent ] = [ 'emit', groupEvent, item ];
                        item.connect( this, add );
                    }
                }
            }
        }
    };

    /**
     * Add items to the list.
     *
     * @param {OO.EventEmitter|OO.EventEmitter[]} items Item to add or
     *  an array of items to add
     * @param {number} [index] Index to add items at. If no index is
     *  given, or if the index that is given is invalid, the item
     *  will be added at the end of the list.
     * @return {OO.EmitterList}
     * @fires OO.EmitterList#add
     * @fires OO.EmitterList#move
     */
    OO.EmitterList.prototype.addItems = function ( items, index ) {
        if ( !Array.isArray( items ) ) {
            items = [ items ];
        }

        if ( items.length === 0 ) {
            return this;
        }

        index = normalizeArrayIndex( this.items, index );
        for ( var i = 0; i < items.length; i++ ) {
            var oldIndex = this.items.indexOf( items[ i ] );
            if ( oldIndex !== -1 ) {
                // Move item to new index
                index = this.moveItem( items[ i ], index );
                this.emit( 'move', items[ i ], index, oldIndex );
            } else {
                // insert item at index
                index = this.insertItem( items[ i ], index );
                this.emit( 'add', items[ i ], index );
            }
            index++;
        }

        return this;
    };

    /**
     * Move an item from its current position to a new index.
     *
     * The item is expected to exist in the list. If it doesn't,
     * the method will throw an exception.
     *
     * @private
     * @param {OO.EventEmitter} item Items to add
     * @param {number} newIndex Index to move the item to
     * @return {number} The index the item was moved to
     * @throws {Error} If item is not in the list
     */
    OO.EmitterList.prototype.moveItem = function ( item, newIndex ) {
        var existingIndex = this.items.indexOf( item );

        if ( existingIndex === -1 ) {
            throw new Error( 'Item cannot be moved, because it is not in the list.' );
        }

        newIndex = normalizeArrayIndex( this.items, newIndex );

        // Remove the item from the current index
        this.items.splice( existingIndex, 1 );

        // If necessary, adjust new index after removal
        if ( existingIndex < newIndex ) {
            newIndex--;
        }

        // Move the item to the new index
        this.items.splice( newIndex, 0, item );

        return newIndex;
    };

    /**
     * Utility method to insert an item into the list, and
     * connect it to aggregate events.
     *
     * Don't call this directly unless you know what you're doing.
     * Use #addItems instead.
     *
     * This method can be extended in child classes to produce
     * different behavior when an item is inserted. For example,
     * inserted items may also be attached to the DOM or may
     * interact with some other nodes in certain ways. Extending
     * this method is allowed, but if overridden, the aggregation
     * of events must be preserved, or behavior of emitted events
     * will be broken.
     *
     * If you are extending this method, please make sure the
     * parent method is called.
     *
     * @protected
     * @param {OO.EventEmitter|Object} item Item to add
     * @param {number} index Index to add items at
     * @return {number} The index the item was added at
     */
    OO.EmitterList.prototype.insertItem = function ( item, index ) {
        // Throw an error if null or item is not an object.
        if ( item === null || typeof item !== 'object' ) {
            throw new Error( 'Expected object, but item is ' + typeof item );
        }

        // Add the item to event aggregation
        if ( item.connect && item.disconnect ) {
            var events = {};
            for ( var event in this.aggregateItemEvents ) {
                events[ event ] = [ 'emit', this.aggregateItemEvents[ event ], item ];
            }
            item.connect( this, events );
        }

        index = normalizeArrayIndex( this.items, index );

        // Insert into items array
        this.items.splice( index, 0, item );
        return index;
    };

    /**
     * Remove items.
     *
     * @param {OO.EventEmitter|OO.EventEmitter[]} items Items to remove
     * @return {OO.EmitterList}
     * @fires OO.EmitterList#remove
     */
    OO.EmitterList.prototype.removeItems = function ( items ) {
        if ( !Array.isArray( items ) ) {
            items = [ items ];
        }

        if ( items.length === 0 ) {
            return this;
        }

        // Remove specific items
        for ( var i = 0; i < items.length; i++ ) {
            var item = items[ i ];
            var index = this.items.indexOf( item );
            if ( index !== -1 ) {
                if ( item.connect && item.disconnect ) {
                    // Disconnect all listeners from the item
                    item.disconnect( this );
                }
                this.items.splice( index, 1 );
                this.emit( 'remove', item, index );
            }
        }

        return this;
    };

    /**
     * Clear all items.
     *
     * @return {OO.EmitterList}
     * @fires OO.EmitterList#clear
     */
    OO.EmitterList.prototype.clearItems = function () {
        var cleared = this.items.splice( 0, this.items.length );

        // Disconnect all items
        for ( var i = 0; i < cleared.length; i++ ) {
            var item = cleared[ i ];
            if ( item.connect && item.disconnect ) {
                item.disconnect( this );
            }
        }

        this.emit( 'clear' );

        return this;
    };

}() );

/**
 * Manage a sorted list of OO.EmitterList objects.
 *
 * The sort order is based on a callback that compares two items. The return value of
 * callback( a, b ) must be less than zero if a < b, greater than zero if a > b, and zero
 * if a is equal to b. The callback should only return zero if the two objects are
 * considered equal.
 *
 * When an item changes in a way that could affect their sorting behavior, it must
 * emit the {@link OO.SortedEmitterList#event:itemSortChange itemSortChange} event.
 * This will cause it to be re-sorted automatically.
 *
 * This mixin must be used in a class that also mixes in {@link OO.EventEmitter}.
 *
 * @abstract
 * @class
 * @mixes OO.EmitterList
 * @param {Function} sortingCallback Callback that compares two items.
 */
OO.SortedEmitterList = function OoSortedEmitterList( sortingCallback ) {
    // Mixin constructors
    OO.EmitterList.call( this );

    this.sortingCallback = sortingCallback;

    // Listen to sortChange event and make sure
    // we re-sort the changed item when that happens
    this.aggregate( {
        sortChange: 'itemSortChange'
    } );

    this.connect( this, {
        itemSortChange: 'onItemSortChange'
    } );
};

OO.mixinClass( OO.SortedEmitterList, OO.EmitterList );

/* Events */

/**
 * An item has changed properties that affect its sort positioning
 * inside the list.
 *
 * @private
 * @event OO.SortedEmitterList#itemSortChange
 */

/* Methods */

/**
 * Handle a case where an item changed a property that relates
 * to its sorted order.
 *
 * @param {OO.EventEmitter} item Item in the list
 */
OO.SortedEmitterList.prototype.onItemSortChange = function ( item ) {
    // Remove the item
    this.removeItems( item );
    // Re-add the item so it is in the correct place
    this.addItems( item );
};

/**
 * Change the sorting callback for this sorted list.
 *
 * The callback receives two items. The return value of callback(a, b) must be less than zero
 * if a < b, greater than zero if a > b, and zero if a is equal to b.
 *
 * @param {Function} sortingCallback Sorting callback
 */
OO.SortedEmitterList.prototype.setSortingCallback = function ( sortingCallback ) {
    var items = this.getItems();

    this.sortingCallback = sortingCallback;

    // Empty the list
    this.clearItems();
    // Re-add the items in the new order
    this.addItems( items );
};

/**
 * Add items to the sorted list.
 *
 * @param {OO.EventEmitter|OO.EventEmitter[]} items Item to add or
 *  an array of items to add
 * @return {OO.SortedEmitterList}
 */
OO.SortedEmitterList.prototype.addItems = function ( items ) {
    if ( !Array.isArray( items ) ) {
        items = [ items ];
    }

    if ( items.length === 0 ) {
        return this;
    }

    for ( var i = 0; i < items.length; i++ ) {
        // Find insertion index
        var insertionIndex = this.findInsertionIndex( items[ i ] );

        // Check if the item exists using the sorting callback
        // and remove it first if it exists
        if (
            // First make sure the insertion index is not at the end
            // of the list (which means it does not point to any actual
            // items)
            insertionIndex <= this.items.length &&
            // Make sure there actually is an item in this index
            this.items[ insertionIndex ] &&
            // The callback returns 0 if the items are equal
            this.sortingCallback( this.items[ insertionIndex ], items[ i ] ) === 0
        ) {
            // Remove the existing item
            this.removeItems( this.items[ insertionIndex ] );
        }

        // Insert item at the insertion index
        var index = this.insertItem( items[ i ], insertionIndex );
        this.emit( 'add', items[ i ], index );
    }

    return this;
};

/**
 * Find the index a given item should be inserted at. If the item is already
 * in the list, this will return the index where the item currently is.
 *
 * @param {OO.EventEmitter} item Items to insert
 * @return {number} The index the item should be inserted at
 */
OO.SortedEmitterList.prototype.findInsertionIndex = function ( item ) {
    var list = this;

    return OO.binarySearch(
        this.items,
        // Fake a this.sortingCallback.bind( null, item ) call here
        // otherwise this doesn't pass tests in phantomJS
        function ( otherItem ) {
            return list.sortingCallback( item, otherItem );
        },
        true
    );

};

/* global hasOwn */

/**
 * A map interface for associating arbitrary data with a symbolic name. Used in
 * place of a plain object to provide additional {@link OO.Registry#register registration}
 * or {@link OO.Registry#lookup lookup} functionality.
 *
 * See <https://www.mediawiki.org/wiki/OOjs/Registries_and_factories>.
 *
 * @class
 * @mixes OO.EventEmitter
 */
OO.Registry = function OoRegistry() {
    // Mixin constructors
    OO.EventEmitter.call( this );

    // Properties
    this.registry = {};
};

/* Inheritance */

OO.mixinClass( OO.Registry, OO.EventEmitter );

/* Events */

/**
 * @event OO.Registry#register
 * @param {string} name
 * @param {any} data
 */

/**
 * @event OO.Registry#unregister
 * @param {string} name
 * @param {any} data Data removed from registry
 */

/* Methods */

/**
 * Associate one or more symbolic names with some data.
 *
 * Any existing entry with the same name will be overridden.
 *
 * @param {string|string[]} name Symbolic name or list of symbolic names
 * @param {any} data Data to associate with symbolic name
 * @fires OO.Registry#register
 * @throws {Error} Name argument must be a string or array
 */
OO.Registry.prototype.register = function ( name, data ) {
    if ( typeof name === 'string' ) {
        this.registry[ name ] = data;
        this.emit( 'register', name, data );
    } else if ( Array.isArray( name ) ) {
        for ( var i = 0, len = name.length; i < len; i++ ) {
            this.register( name[ i ], data );
        }
    } else {
        throw new Error( 'Name must be a string or array, cannot be a ' + typeof name );
    }
};

/**
 * Remove one or more symbolic names from the registry.
 *
 * @param {string|string[]} name Symbolic name or list of symbolic names
 * @fires OO.Registry#unregister
 * @throws {Error} Name argument must be a string or array
 */
OO.Registry.prototype.unregister = function ( name ) {
    if ( typeof name === 'string' ) {
        var data = this.lookup( name );
        if ( data !== undefined ) {
            delete this.registry[ name ];
            this.emit( 'unregister', name, data );
        }
    } else if ( Array.isArray( name ) ) {
        for ( var i = 0, len = name.length; i < len; i++ ) {
            this.unregister( name[ i ] );
        }
    } else {
        throw new Error( 'Name must be a string or array, cannot be a ' + typeof name );
    }
};

/**
 * Get data for a given symbolic name.
 *
 * @param {string} name Symbolic name
 * @return {any|undefined} Data associated with symbolic name
 */
OO.Registry.prototype.lookup = function ( name ) {
    if ( hasOwn.call( this.registry, name ) ) {
        return this.registry[ name ];
    }
};

/**
 * @class
 * @extends OO.Registry
 */
OO.Factory = function OoFactory() {
    // Parent constructor
    OO.Factory.super.call( this );
};

/* Inheritance */

OO.inheritClass( OO.Factory, OO.Registry );

/* Methods */

/**
 * Register a class with the factory.
 *
 *     function MyClass() {};
 *     OO.initClass( MyClass );
 *     MyClass.key = 'hello';
 *
 *     // Register class with the factory
 *     factory.register( MyClass );
 *
 *     // Instantiate a class based on its registered key (also known as a "symbolic name")
 *     factory.create( 'hello' );
 *
 * @param {Function} constructor Class to use when creating an object
 * @param {string} [key] The key for #create().
 *  This parameter is usually omitted in favour of letting the class declare
 *  its own key, through `MyClass.key`.
 *  For backwards-compatiblity with OOjs 6.0 (2021) and older, it can also be declared
 *  via `MyClass.static.name`.
 * @throws {Error} If a parameter is invalid
 */
OO.Factory.prototype.register = function ( constructor, key ) {
    if ( typeof constructor !== 'function' ) {
        throw new Error( 'constructor must be a function, got ' + typeof constructor );
    }
    if ( arguments.length <= 1 ) {
        key = constructor.key || ( constructor.static && constructor.static.name );
    }
    if ( typeof key !== 'string' || key === '' ) {
        throw new Error( 'key must be a non-empty string' );
    }

    // Parent method
    OO.Factory.super.prototype.register.call( this, key, constructor );
};

/**
 * Unregister a class from the factory.
 *
 * @param {string|Function} key Constructor function or key to unregister
 * @throws {Error} If a parameter is invalid
 */
OO.Factory.prototype.unregister = function ( key ) {
    if ( typeof key === 'function' ) {
        key = key.key || ( key.static && key.static.name );
    }
    if ( typeof key !== 'string' || key === '' ) {
        throw new Error( 'key must be a non-empty string' );
    }

    // Parent method
    OO.Factory.super.prototype.unregister.call( this, key );
};

/**
 * Create an object based on a key.
 *
 * The key is used to look up the class to use, with any subsequent arguments passed to the
 * constructor function.
 *
 * @param {string} key Class key
 * @param {...any} [args] Arguments to pass to the constructor
 * @return {Object} The new object
 * @throws {Error} Unknown key
 */
OO.Factory.prototype.create = function ( key, ...args ) {
    var constructor = this.lookup( key );
    if ( !constructor ) {
        throw new Error( 'No class registered by that key: ' + key );
    }

    return new constructor( ...args );
};

/* eslint-env node */

/* istanbul ignore next */
if ( typeof module !== 'undefined' && module.exports ) {
    module.exports = OO;
} else {
    global.OO = OO;
}

}( this ) );