InputPlugin.js

/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @copyright    2018 Photon Storm Ltd.
 * @license      {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
 */

var Circle = require('../geom/circle/Circle');
var CircleContains = require('../geom/circle/Contains');
var Class = require('../utils/Class');
var CreateInteractiveObject = require('./CreateInteractiveObject');
var CreatePixelPerfectHandler = require('./CreatePixelPerfectHandler');
var DistanceBetween = require('../math/distance/DistanceBetween');
var Ellipse = require('../geom/ellipse/Ellipse');
var EllipseContains = require('../geom/ellipse/Contains');
var EventEmitter = require('eventemitter3');
var GetFastValue = require('../utils/object/GetFastValue');
var InputPluginCache = require('./InputPluginCache');
var IsPlainObject = require('../utils/object/IsPlainObject');
var PluginCache = require('../plugins/PluginCache');
var Rectangle = require('../geom/rectangle/Rectangle');
var RectangleContains = require('../geom/rectangle/Contains');
var Triangle = require('../geom/triangle/Triangle');
var TriangleContains = require('../geom/triangle/Contains');

/**
 * @classdesc
 * The Input Plugin belongs to a Scene and handles all input related events and operations for it.
 *
 * You can access it from within a Scene using `this.input`.
 *
 * It emits events directly. For example, you can do:
 *
 * ```javascript
 * this.input.on('pointerdown', callback, context);
 * ```
 *
 * To listen for a pointer down event anywhere on the game canvas.
 *
 * Game Objects can be enabled for input by calling their `setInteractive` method. After which they
 * will directly emit input events:
 *
 * ```javascript
 * var sprite = this.add.sprite(x, y, texture);
 * sprite.setInteractive();
 * sprite.on('pointerdown', callback, context);
 * ```
 *
 * Please see the Input examples and tutorials for more information.
 *
 * @class InputPlugin
 * @extends Phaser.Events.EventEmitter
 * @memberOf Phaser.Input
 * @constructor
 * @since 3.0.0
 *
 * @param {Phaser.Scene} scene - A reference to the Scene that this Input Plugin is responsible for.
 */
var InputPlugin = new Class({

    Extends: EventEmitter,

    initialize:

    function InputPlugin (scene)
    {
        EventEmitter.call(this);

        /**
         * A reference to the Scene that this Input Plugin is responsible for.
         *
         * @name Phaser.Input.InputPlugin#scene
         * @type {Phaser.Scene}
         * @since 3.0.0
         */
        this.scene = scene;

        /**
         * A reference to the Scene Systems class.
         *
         * @name Phaser.Input.InputPlugin#systems
         * @type {Phaser.Scenes.Systems}
         * @since 3.0.0
         */
        this.systems = scene.sys;

        /**
         * A reference to the Scene Systems Settings.
         *
         * @name Phaser.Input.InputPlugin#settings
         * @type {Phaser.Scenes.Settings.Object}
         * @since 3.5.0
         */
        this.settings = scene.sys.settings;

        /**
         * A reference to the Game Input Manager.
         *
         * @name Phaser.Input.InputPlugin#manager
         * @type {Phaser.Input.InputManager}
         * @since 3.0.0
         */
        this.manager = scene.sys.game.input;

        /**
         * Internal event queue used for plugins only.
         *
         * @name Phaser.Input.InputPlugin#pluginEvents
         * @type {Phaser.Events.EventEmitter}
         * @private
         * @since 3.10.0
         */
        this.pluginEvents = new EventEmitter();

        /**
         * If set, the Input Plugin will run its update loop every frame.
         *
         * @name Phaser.Input.InputPlugin#enabled
         * @type {boolean}
         * @default true
         * @since 3.5.0
         */
        this.enabled = true;

        /**
         * A reference to the Scene Display List. This property is set during the `boot` method.
         *
         * @name Phaser.Input.InputPlugin#displayList
         * @type {Phaser.GameObjects.DisplayList}
         * @since 3.0.0
         */
        this.displayList;

        /**
         * A reference to the Scene Cameras Manager. This property is set during the `boot` method.
         *
         * @name Phaser.Input.InputPlugin#cameras
         * @type {Phaser.Cameras.Scene2D.CameraManager}
         * @since 3.0.0
         */
        this.cameras;

        //  Inject the available input plugins into this class
        InputPluginCache.install(this);

        /**
         * A reference to the Mouse Manager.
         * 
         * This property is only set if Mouse support has been enabled in your Game Configuration file.
         * 
         * If you just wish to get access to the mouse pointer, use the `mousePointer` property instead.
         *
         * @name Phaser.Input.InputPlugin#mouse
         * @type {?Phaser.Input.Mouse.MouseManager}
         * @since 3.0.0
         */
        this.mouse = this.manager.mouse;

        /**
         * When set to `true` (the default) the Input Plugin will emulate DOM behavior by only emitting events from
         * the top-most Game Objects in the Display List.
         *
         * If set to `false` it will emit events from all Game Objects below a Pointer, not just the top one.
         *
         * @name Phaser.Input.InputPlugin#topOnly
         * @type {boolean}
         * @default true
         * @since 3.0.0
         */
        this.topOnly = true;

        /**
         * How often should the Pointers be checked?
         * 
         * The value is a time, given in ms, and is the time that must have elapsed between game steps before
         * the Pointers will be polled again. When a pointer is polled it runs a hit test to see which Game
         * Objects are currently below it, or being interacted with it.
         * 
         * Pointers will *always* be checked if they have been moved by the user, or press or released.
         * 
         * This property only controls how often they will be polled if they have not been updated.
         * You should set this if you want to have Game Objects constantly check against the pointers, even
         * if the pointer didn't move itself.
         * 
         * Set to 0 to poll constantly. Set to -1 to only poll on user movement.
         *
         * @name Phaser.Input.InputPlugin#pollRate
         * @type {integer}
         * @default -1
         * @since 3.0.0
         */
        this.pollRate = -1;

        /**
         * Internal poll timer value.
         *
         * @name Phaser.Input.InputPlugin#_pollTimer
         * @type {number}
         * @private
         * @default 0
         * @since 3.0.0
         */
        this._pollTimer = 0;

        /**
         * The distance, in pixels, a pointer has to move while being held down, before it thinks it is being dragged.
         *
         * @name Phaser.Input.InputPlugin#dragDistanceThreshold
         * @type {number}
         * @default 0
         * @since 3.0.0
         */
        this.dragDistanceThreshold = 0;

        /**
         * The amount of time, in ms, a pointer has to be held down before it thinks it is dragging.
         *
         * @name Phaser.Input.InputPlugin#dragTimeThreshold
         * @type {number}
         * @default 0
         * @since 3.0.0
         */
        this.dragTimeThreshold = 0;

        /**
         * Used to temporarily store the results of the Hit Test
         *
         * @name Phaser.Input.InputPlugin#_temp
         * @type {array}
         * @private
         * @default []
         * @since 3.0.0
         */
        this._temp = [];

        /**
         * Used to temporarily store the results of the Hit Test dropZones
         *
         * @name Phaser.Input.InputPlugin#_tempZones
         * @type {array}
         * @private
         * @default []
         * @since 3.0.0
         */
        this._tempZones = [];

        /**
         * A list of all Game Objects that have been set to be interactive in the Scene this Input Plugin is managing.
         *
         * @name Phaser.Input.InputPlugin#_list
         * @type {Phaser.GameObjects.GameObject[]}
         * @private
         * @default []
         * @since 3.0.0
         */
        this._list = [];

        /**
         * Objects waiting to be inserted to the list on the next call to 'begin'.
         *
         * @name Phaser.Input.InputPlugin#_pendingInsertion
         * @type {Phaser.GameObjects.GameObject[]}
         * @private
         * @default []
         * @since 3.0.0
         */
        this._pendingInsertion = [];

        /**
         * Objects waiting to be removed from the list on the next call to 'begin'.
         *
         * @name Phaser.Input.InputPlugin#_pendingRemoval
         * @type {Phaser.GameObjects.GameObject[]}
         * @private
         * @default []
         * @since 3.0.0
         */
        this._pendingRemoval = [];

        /**
         * A list of all Game Objects that have been enabled for dragging.
         *
         * @name Phaser.Input.InputPlugin#_draggable
         * @type {Phaser.GameObjects.GameObject[]}
         * @private
         * @default []
         * @since 3.0.0
         */
        this._draggable = [];

        /**
         * A list of all Interactive Objects currently considered as being 'draggable' by any pointer, indexed by pointer ID.
         *
         * @name Phaser.Input.InputPlugin#_drag
         * @type {{0:Array,2:Array,3:Array,4:Array,5:Array,6:Array,7:Array,8:Array,9:Array}}
         * @private
         * @since 3.0.0
         */
        this._drag = { 0: [], 1: [], 2: [], 3: [], 4: [], 5: [], 6: [], 7: [], 8: [], 9: [], 10: [] };

        /**
         * A list of all Interactive Objects currently considered as being 'over' by any pointer, indexed by pointer ID.
         *
         * @name Phaser.Input.InputPlugin#_over
         * @type {{0:Array,2:Array,3:Array,4:Array,5:Array,6:Array,7:Array,8:Array,9:Array}}
         * @private
         * @since 3.0.0
         */
        this._over = { 0: [], 1: [], 2: [], 3: [], 4: [], 5: [], 6: [], 7: [], 8: [], 9: [], 10: [] };

        /**
         * A list of valid DOM event types.
         *
         * @name Phaser.Input.InputPlugin#_validTypes
         * @type {string[]}
         * @private
         * @since 3.0.0
         */
        this._validTypes = [ 'onDown', 'onUp', 'onOver', 'onOut', 'onMove', 'onDragStart', 'onDrag', 'onDragEnd', 'onDragEnter', 'onDragLeave', 'onDragOver', 'onDrop' ];

        scene.sys.events.once('boot', this.boot, this);
        scene.sys.events.on('start', this.start, this);
    },

    /**
     * This method is called automatically, only once, when the Scene is first created.
     * Do not invoke it directly.
     *
     * @method Phaser.Input.InputPlugin#boot
     * @private
     * @since 3.5.1
     */
    boot: function ()
    {
        this.cameras = this.systems.cameras;

        this.displayList = this.systems.displayList;

        this.systems.events.once('destroy', this.destroy, this);

        //  Registered input plugins listen for this
        this.pluginEvents.emit('boot');
    },

    /**
     * This method is called automatically by the Scene when it is starting up.
     * It is responsible for creating local systems, properties and listening for Scene events.
     * Do not invoke it directly.
     *
     * @method Phaser.Input.InputPlugin#start
     * @private
     * @since 3.5.0
     */
    start: function ()
    {
        var eventEmitter = this.systems.events;

        eventEmitter.on('transitionstart', this.transitionIn, this);
        eventEmitter.on('transitionout', this.transitionOut, this);
        eventEmitter.on('transitioncomplete', this.transitionComplete, this);
        eventEmitter.on('preupdate', this.preUpdate, this);
        eventEmitter.on('update', this.update, this);

        eventEmitter.once('shutdown', this.shutdown, this);

        this.enabled = true;

        //  Registered input plugins listen for this
        this.pluginEvents.emit('start');
    },

    /**
     * The pre-update handler is responsible for checking the pending removal and insertion lists and
     * deleting old Game Objects.
     *
     * @method Phaser.Input.InputPlugin#preUpdate
     * @private
     * @since 3.0.0
     */
    preUpdate: function ()
    {
        //  Registered input plugins listen for this
        this.pluginEvents.emit('preUpdate');

        var removeList = this._pendingRemoval;
        var insertList = this._pendingInsertion;

        var toRemove = removeList.length;
        var toInsert = insertList.length;

        if (toRemove === 0 && toInsert === 0)
        {
            //  Quick bail
            return;
        }

        var current = this._list;

        //  Delete old gameObjects
        for (var i = 0; i < toRemove; i++)
        {
            var gameObject = removeList[i];

            var index = current.indexOf(gameObject);

            if (index > -1)
            {
                current.splice(index, 1);

                this.clear(gameObject);
            }
        }

        //  Clear the removal list
        removeList.length = 0;
        this._pendingRemoval.length = 0;

        //  Move pendingInsertion to list (also clears pendingInsertion at the same time)
        this._list = current.concat(insertList.splice(0));
    },

    /**
     * Checks to see if both this plugin and the Scene to which it belongs is active.
     *
     * @method Phaser.Input.InputPlugin#isActive
     * @since 3.10.0
     *
     * @return {boolean} `true` if the plugin and the Scene it belongs to is active.
     */
    isActive: function ()
    {
        return (this.enabled && this.scene.sys.isActive());
    },

    /**
     * The internal update loop for the Input Plugin.
     * Called automatically by the Scene Systems step.
     *
     * @method Phaser.Input.InputPlugin#update
     * @private
     * @since 3.0.0
     *
     * @param {number} time - The time value from the most recent Game step. Typically a high-resolution timer value, or Date.now().
     * @param {number} delta - The delta value since the last frame. This is smoothed to avoid delta spikes by the TimeStep class.
     */
    update: function (time, delta)
    {
        if (!this.isActive())
        {
            return;
        }

        this.pluginEvents.emit('update', time, delta);

        var manager = this.manager;

        //  Another Scene above this one has already consumed the input events, or we're in transition
        if (manager.globalTopOnly && manager.ignoreEvents)
        {
            return;
        }

        var runUpdate = (manager.dirty || this.pollRate === 0);

        if (this.pollRate > -1)
        {
            this._pollTimer -= delta;

            if (this._pollTimer < 0)
            {
                runUpdate = true;

                //  Discard timer diff
                this._pollTimer = this.pollRate;
            }
        }

        if (!runUpdate)
        {
            return;
        }

        var pointers = this.manager.pointers;

        for (var i = 0; i < this.manager.pointersTotal; i++)
        {
            var pointer = pointers[i];

            //  Always reset this array
            this._tempZones = [];

            //  _temp contains a hit tested and camera culled list of IO objects
            this._temp = this.hitTestPointer(pointer);

            this.sortGameObjects(this._temp);
            this.sortGameObjects(this._tempZones);

            if (this.topOnly)
            {
                //  Only the top-most one counts now, so safely ignore the rest
                if (this._temp.length)
                {
                    this._temp.splice(1);
                }

                if (this._tempZones.length)
                {
                    this._tempZones.splice(1);
                }
            }

            var total = this.processDragEvents(pointer, time);

            //  TODO: Enable for touch
            if (!pointer.wasTouch)
            {
                total += this.processOverOutEvents(pointer);
            }

            if (pointer.justDown)
            {
                total += this.processDownEvents(pointer);
            }

            if (pointer.justUp)
            {
                total += this.processUpEvents(pointer);
            }

            if (pointer.justMoved)
            {
                total += this.processMoveEvents(pointer);
            }

            if (total > 0 && manager.globalTopOnly)
            {
                //  We interacted with an event in this Scene, so block any Scenes below us from doing the same this frame
                manager.ignoreEvents = true;
            }
        }
    },

    /**
     * Clears a Game Object so it no longer has an Interactive Object associated with it.
     * The Game Object is then queued for removal from the Input Plugin on the next update.
     *
     * @method Phaser.Input.InputPlugin#clear
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.GameObject} gameObject - The Game Object that will have its Interactive Object removed.
     *
     * @return {Phaser.GameObjects.GameObject} The Game Object that had its Interactive Object removed.
     */
    clear: function (gameObject)
    {
        var input = gameObject.input;

        // If GameObject.input already cleared from higher class
        if (!input)
        {
            return;
        }

        this.queueForRemoval(gameObject);

        input.gameObject = undefined;
        input.target = undefined;
        input.hitArea = undefined;
        input.hitAreaCallback = undefined;
        input.callbackContext = undefined;

        gameObject.input = null;

        //  Clear from _draggable, _drag and _over
        var index = this._draggable.indexOf(gameObject);

        if (index > -1)
        {
            this._draggable.splice(index, 1);
        }

        index = this._drag[0].indexOf(gameObject);

        if (index > -1)
        {
            this._drag[0].splice(index, 1);
        }

        index = this._over[0].indexOf(gameObject);

        if (index > -1)
        {
            this._over[0].splice(index, 1);
        }

        return gameObject;
    },

    /**
     * Disables Input on a single Game Object.
     *
     * An input disabled Game Object still retains its Interactive Object component and can be re-enabled
     * at any time, by passing it to `InputPlugin.enable`.
     *
     * @method Phaser.Input.InputPlugin#disable
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.GameObject} gameObject - The Game Object to have its input system disabled.
     */
    disable: function (gameObject)
    {
        gameObject.input.enabled = false;
    },

    /**
     * Enable a Game Object for interaction.
     *
     * If the Game Object already has an Interactive Object component, it is enabled and returned.
     *
     * Otherwise, a new Interactive Object component is created and assigned to the Game Object's `input` property.
     *
     * Input works by using hit areas, these are nearly always geometric shapes, such as rectangles or circles, that act as the hit area
     * for the Game Object. However, you can provide your own hit area shape and callback, should you wish to handle some more advanced
     * input detection.
     *
     * If no arguments are provided it will try and create a rectangle hit area based on the texture frame the Game Object is using. If
     * this isn't a texture-bound object, such as a Graphics or BitmapText object, this will fail, and you'll need to provide a specific
     * shape for it to use.
     *
     * You can also provide an Input Configuration Object as the only argument to this method.
     *
     * @method Phaser.Input.InputPlugin#enable
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.GameObject} gameObject - The Game Object to be enabled for input.
     * @param {(Phaser.Input.InputConfiguration|any)} [shape] - Either an input configuration object, or a geometric shape that defines the hit area for the Game Object. If not specified a Rectangle will be used.
     * @param {HitAreaCallback} [callback] - The 'contains' function to invoke to check if the pointer is within the hit area.
     * @param {boolean} [dropZone=false] - Is this Game Object a drop zone or not?
     *
     * @return {Phaser.Input.InputPlugin} This Input Plugin.
     */
    enable: function (gameObject, shape, callback, dropZone)
    {
        if (dropZone === undefined) { dropZone = false; }

        if (gameObject.input)
        {
            //  If it is already has an InteractiveObject then just enable it and return
            gameObject.input.enabled = true;
        }
        else
        {
            //  Create an InteractiveObject and enable it
            this.setHitArea(gameObject, shape, callback);
        }

        if (gameObject.input && dropZone && !gameObject.input.dropZone)
        {
            gameObject.input.dropZone = dropZone;
        }

        return this;
    },

    /**
     * Takes the given Pointer and performs a hit test against it, to see which interactive Game Objects
     * it is currently above.
     *
     * The hit test is performed against which-ever Camera the Pointer is over. If it is over multiple
     * cameras, it starts checking the camera at the top of the camera list, and if nothing is found, iterates down the list.
     *
     * @method Phaser.Input.InputPlugin#hitTestPointer
     * @since 3.0.0
     *
     * @param {Phaser.Input.Pointer} pointer - The Pointer to check against the Game Objects.
     *
     * @return {Phaser.GameObjects.GameObject[]} An array of all the interactive Game Objects the Pointer was above.
     */
    hitTestPointer: function (pointer)
    {
        var cameras = this.cameras.getCamerasBelowPointer(pointer);

        for (var c = 0; c < cameras.length; c++)
        {
            var camera = cameras[c];

            //  Get a list of all objects that can be seen by the camera below the pointer in the scene and store in 'output' array.
            //  All objects in this array are input enabled, as checked by the hitTest method, so we don't need to check later on as well.
            var over = this.manager.hitTest(pointer, this._list, camera);

            //  Filter out the drop zones
            for (var i = 0; i < over.length; i++)
            {
                var obj = over[i];

                if (obj.input.dropZone)
                {
                    this._tempZones.push(obj);
                }
            }

            if (over.length > 0)
            {
                pointer.camera = camera;

                return over;
            }
        }

        return [];
    },

    /**
     * An internal method that handles the Pointer down event.
     *
     * @method Phaser.Input.InputPlugin#processDownEvents
     * @private
     * @since 3.0.0
     *
     * @param {Phaser.Input.Pointer} pointer - The Pointer being tested.
     *
     * @return {integer} The total number of objects interacted with.
     */
    processDownEvents: function (pointer)
    {
        var currentlyOver = this._temp;

        //  Contains ALL Game Objects currently over in the array
        this.emit('pointerdown', pointer, currentlyOver);

        var total = 0;

        //  Go through all objects the pointer was over and fire their events / callbacks
        for (var i = 0; i < currentlyOver.length; i++)
        {
            var gameObject = currentlyOver[i];

            if (!gameObject.input)
            {
                continue;
            }

            total++;

            gameObject.emit('pointerdown', pointer, gameObject.input.localX, gameObject.input.localY, pointer.camera);

            this.emit('gameobjectdown', pointer, gameObject);
        }

        return total;
    },

    /**
     * An internal method that handles the Pointer drag events.
     *
     * @method Phaser.Input.InputPlugin#processDragEvents
     * @private
     * @since 3.0.0
     *
     * @param {Phaser.Input.Pointer} pointer - The Pointer to check against the Game Objects.
     * @param {number} time - The time stamp of the most recent Game step.
     *
     * @return {integer} The total number of objects interacted with.
     */
    processDragEvents: function (pointer, time)
    {
        if (this._draggable.length === 0)
        {
            //  There are no draggable items, so let's not even bother going further
            return 0;
        }

        var i;
        var gameObject;
        var list;
        var input;
        var currentlyOver = this._temp;

        //  0 = Not dragging anything
        //  1 = Primary button down and objects below, so collect a draglist
        //  2 = Pointer being checked if meets drag criteria
        //  3 = Pointer meets criteria, notify the draglist
        //  4 = Pointer actively dragging the draglist and has moved
        //  5 = Pointer actively dragging but has been released, notify draglist

        if (pointer.dragState === 0 && pointer.primaryDown && pointer.justDown && currentlyOver.length > 0)
        {
            pointer.dragState = 1;
        }
        else if (pointer.dragState > 0 && !pointer.primaryDown && pointer.justUp)
        {
            pointer.dragState = 5;
        }

        //  Process the various drag states

        //  1 = Primary button down and objects below, so collect a draglist
        if (pointer.dragState === 1)
        {
            //  Get draggable objects, sort them, pick the top (or all) and store them somewhere
            var draglist = [];

            for (i = 0; i < currentlyOver.length; i++)
            {
                gameObject = currentlyOver[i];

                if (gameObject.input.draggable)
                {
                    draglist.push(gameObject);
                }
            }

            if (draglist.length === 0)
            {
                pointer.dragState = 0;

                return 0;
            }
            else if (draglist.length > 1)
            {
                this.sortGameObjects(draglist);

                if (this.topOnly)
                {
                    draglist.splice(1);
                }
            }

            //  draglist now contains all potential candidates for dragging
            this._drag[pointer.id] = draglist;

            if (this.dragDistanceThreshold === 0 && this.dragTimeThreshold === 0)
            {
                //  No drag criteria, so snap immediately to mode 3
                pointer.dragState = 3;
            }
            else
            {
                //  Check the distance / time
                pointer.dragState = 2;
            }
        }

        //  2 = Pointer being checked if meets drag criteria
        if (pointer.dragState === 2)
        {
            //  Has it moved far enough to be considered a drag?
            if (this.dragDistanceThreshold > 0 && DistanceBetween(pointer.x, pointer.y, pointer.downX, pointer.downY) >= this.dragDistanceThreshold)
            {
                //  Alrighty, we've got a drag going on ...
                pointer.dragState = 3;
            }

            //  Held down long enough to be considered a drag?
            if (this.dragTimeThreshold > 0 && (time >= pointer.downTime + this.dragTimeThreshold))
            {
                //  Alrighty, we've got a drag going on ...
                pointer.dragState = 3;
            }
        }

        //  3 = Pointer meets criteria and is freshly down, notify the draglist
        if (pointer.dragState === 3)
        {
            list = this._drag[pointer.id];

            for (i = 0; i < list.length; i++)
            {
                gameObject = list[i];

                input = gameObject.input;

                input.dragState = 2;

                input.dragX = pointer.x - gameObject.x;
                input.dragY = pointer.y - gameObject.y;

                input.dragStartX = gameObject.x;
                input.dragStartY = gameObject.y;

                gameObject.emit('dragstart', pointer, input.dragX, input.dragY);

                this.emit('dragstart', pointer, gameObject);
            }

            pointer.dragState = 4;

            return list.length;
        }

        //  4 = Pointer actively dragging the draglist and has moved
        if (pointer.dragState === 4 && pointer.justMoved && !pointer.justUp)
        {
            var dropZones = this._tempZones;

            list = this._drag[pointer.id];

            for (i = 0; i < list.length; i++)
            {
                gameObject = list[i];

                input = gameObject.input;

                //  If this GO has a target then let's check it
                if (input.target)
                {
                    var index = dropZones.indexOf(input.target);

                    //  Got a target, are we still over it?
                    if (index === 0)
                    {
                        //  We're still over it, and it's still the top of the display list, phew ...
                        gameObject.emit('dragover', pointer, input.target);

                        this.emit('dragover', pointer, gameObject, input.target);
                    }
                    else if (index > 0)
                    {
                        //  Still over it but it's no longer top of the display list (targets must always be at the top)
                        gameObject.emit('dragleave', pointer, input.target);

                        this.emit('dragleave', pointer, gameObject, input.target);

                        input.target = dropZones[0];

                        gameObject.emit('dragenter', pointer, input.target);

                        this.emit('dragenter', pointer, gameObject, input.target);
                    }
                    else
                    {
                        //  Nope, we've moved on (or the target has!), leave the old target
                        gameObject.emit('dragleave', pointer, input.target);

                        this.emit('dragleave', pointer, gameObject, input.target);

                        //  Anything new to replace it?
                        //  Yup!
                        if (dropZones[0])
                        {
                            input.target = dropZones[0];

                            gameObject.emit('dragenter', pointer, input.target);

                            this.emit('dragenter', pointer, gameObject, input.target);
                        }
                        else
                        {
                            //  Nope
                            input.target = null;
                        }
                    }
                }
                else if (!input.target && dropZones[0])
                {
                    input.target = dropZones[0];

                    gameObject.emit('dragenter', pointer, input.target);

                    this.emit('dragenter', pointer, gameObject, input.target);
                }

                var dragX = pointer.x - gameObject.input.dragX;
                var dragY = pointer.y - gameObject.input.dragY;

                gameObject.emit('drag', pointer, dragX, dragY);

                this.emit('drag', pointer, gameObject, dragX, dragY);
            }

            return list.length;
        }

        //  5 = Pointer was actively dragging but has been released, notify draglist
        if (pointer.dragState === 5)
        {
            list = this._drag[pointer.id];

            for (i = 0; i < list.length; i++)
            {
                gameObject = list[i];

                input = gameObject.input;

                if (input.dragState === 2)
                {
                    input.dragState = 0;

                    input.dragX = input.localX - gameObject.displayOriginX;
                    input.dragY = input.localY - gameObject.displayOriginY;

                    var dropped = false;

                    if (input.target)
                    {
                        gameObject.emit('drop', pointer, input.target);

                        this.emit('drop', pointer, gameObject, input.target);

                        input.target = null;

                        dropped = true;
                    }

                    //  And finally the dragend event

                    gameObject.emit('dragend', pointer, input.dragX, input.dragY, dropped);

                    this.emit('dragend', pointer, gameObject, dropped);
                }
            }

            pointer.dragState = 0;

            list.splice(0);
        }

        return 0;
    },

    /**
     * An internal method that handles the Pointer movement event.
     *
     * @method Phaser.Input.InputPlugin#processMoveEvents
     * @private
     * @since 3.0.0
     *
     * @param {Phaser.Input.Pointer} pointer - The pointer to check for events against.
     *
     * @return {integer} The total number of objects interacted with.
     */
    processMoveEvents: function (pointer)
    {
        var currentlyOver = this._temp;

        this.emit('pointermove', pointer, currentlyOver);

        var total = 0;

        //  Go through all objects the pointer was over and fire their events / callbacks
        for (var i = 0; i < currentlyOver.length; i++)
        {
            var gameObject = currentlyOver[i];

            if (!gameObject.input)
            {
                continue;
            }

            total++;

            gameObject.emit('pointermove', pointer, gameObject.input.localX, gameObject.input.localY);

            this.emit('gameobjectmove', pointer, gameObject);

            if (this.topOnly)
            {
                break;
            }
        }

        return total;
    },

    /**
     * An internal method that handles the Pointer over and out events.
     *
     * @method Phaser.Input.InputPlugin#processOverOutEvents
     * @private
     * @since 3.0.0
     *
     * @param {Phaser.Input.Pointer} pointer - The pointer to check for events against.
     *
     * @return {integer} The total number of objects interacted with.
     */
    processOverOutEvents: function (pointer)
    {
        var currentlyOver = this._temp;

        var i;
        var gameObject;
        var justOut = [];
        var justOver = [];
        var stillOver = [];
        var previouslyOver = this._over[pointer.id];
        var currentlyDragging = this._drag[pointer.id];

        var manager = this.manager;

        //  Go through all objects the pointer was previously over, and see if it still is.
        //  Splits the previouslyOver array into two parts: justOut and stillOver

        for (i = 0; i < previouslyOver.length; i++)
        {
            gameObject = previouslyOver[i];

            if (currentlyOver.indexOf(gameObject) === -1 && currentlyDragging.indexOf(gameObject) === -1)
            {
                //  Not in the currentlyOver array, so must be outside of this object now
                justOut.push(gameObject);
            }
            else
            {
                //  In the currentlyOver array
                stillOver.push(gameObject);
            }
        }

        //  Go through all objects the pointer is currently over (the hit test results)
        //  and if not in the previouslyOver array we know it's a new entry, so add to justOver
        for (i = 0; i < currentlyOver.length; i++)
        {
            gameObject = currentlyOver[i];

            //  Is this newly over?

            if (previouslyOver.indexOf(gameObject) === -1)
            {
                justOver.push(gameObject);
            }
        }

        //  By this point the arrays are filled, so now we can process what happened...

        //  Process the Just Out objects
        var total = justOut.length;

        var totalInteracted = 0;

        if (total > 0)
        {
            this.sortGameObjects(justOut);

            this.emit('pointerout', pointer, justOut);

            //  Call onOut for everything in the justOut array
            for (i = 0; i < total; i++)
            {
                gameObject = justOut[i];

                if (!gameObject.input)
                {
                    continue;
                }

                this.emit('gameobjectout', pointer, gameObject);

                gameObject.emit('pointerout', pointer);

                manager.resetCursor(gameObject.input);

                totalInteracted++;
            }
        }

        //  Process the Just Over objects
        total = justOver.length;

        if (total > 0)
        {
            this.sortGameObjects(justOver);

            this.emit('pointerover', pointer, justOver);

            //  Call onOver for everything in the justOver array
            for (i = 0; i < total; i++)
            {
                gameObject = justOver[i];

                if (!gameObject.input)
                {
                    continue;
                }

                this.emit('gameobjectover', pointer, gameObject);

                gameObject.emit('pointerover', pointer, gameObject.input.localX, gameObject.input.localY);

                manager.setCursor(gameObject.input);

                totalInteracted++;
            }
        }

        //  Add the contents of justOver to the previously over array
        previouslyOver = stillOver.concat(justOver);

        //  Then sort it into display list order
        this._over[pointer.id] = this.sortGameObjects(previouslyOver);

        return totalInteracted;
    },

    /**
     * An internal method that handles the Pointer up events.
     *
     * @method Phaser.Input.InputPlugin#processUpEvents
     * @private
     * @since 3.0.0
     *
     * @param {Phaser.Input.Pointer} pointer - The pointer to check for events against.
     *
     * @return {integer} The total number of objects interacted with.
     */
    processUpEvents: function (pointer)
    {
        var currentlyOver = this._temp;

        //  Contains ALL Game Objects currently up in the array
        this.emit('pointerup', pointer, currentlyOver);

        //  Go through all objects the pointer was over and fire their events / callbacks
        for (var i = 0; i < currentlyOver.length; i++)
        {
            var gameObject = currentlyOver[i];

            if (!gameObject.input)
            {
                continue;
            }

            //  pointerupoutside

            gameObject.emit('pointerup', pointer, gameObject.input.localX, gameObject.input.localY);

            this.emit('gameobjectup', pointer, gameObject);
        }

        return currentlyOver.length;
    },

    /**
     * Queues a Game Object for insertion into this Input Plugin on the next update.
     *
     * @method Phaser.Input.InputPlugin#queueForInsertion
     * @private
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.GameObject} child - The Game Object to add.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    queueForInsertion: function (child)
    {
        if (this._pendingInsertion.indexOf(child) === -1 && this._list.indexOf(child) === -1)
        {
            this._pendingInsertion.push(child);
        }

        return this;
    },

    /**
     * Queues a Game Object for removal from this Input Plugin on the next update.
     *
     * @method Phaser.Input.InputPlugin#queueForRemoval
     * @private
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.GameObject} child - The Game Object to remove.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    queueForRemoval: function (child)
    {
        this._pendingRemoval.push(child);

        return this;
    },

    /**
     * Sets the draggable state of the given array of Game Objects.
     *
     * They can either be set to be draggable, or can have their draggable state removed by passing `false`.
     *
     * A Game Object will not fire drag events unless it has been specifically enabled for drag.
     *
     * @method Phaser.Input.InputPlugin#setDraggable
     * @since 3.0.0
     *
     * @param {(Phaser.GameObjects.GameObject|Phaser.GameObjects.GameObject[])} gameObjects - An array of Game Objects to change the draggable state on.
     * @param {boolean} [value=true] - Set to `true` if the Game Objects should be made draggable, `false` if they should be unset.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setDraggable: function (gameObjects, value)
    {
        if (value === undefined) { value = true; }

        if (!Array.isArray(gameObjects))
        {
            gameObjects = [ gameObjects ];
        }

        for (var i = 0; i < gameObjects.length; i++)
        {
            var gameObject = gameObjects[i];

            gameObject.input.draggable = value;

            var index = this._draggable.indexOf(gameObject);

            if (value && index === -1)
            {
                this._draggable.push(gameObject);
            }
            else if (!value && index > -1)
            {
                this._draggable.splice(index, 1);
            }
        }

        return this;
    },

    /**
     * Creates a function that can be passed to `setInteractive`, `enable` or `setHitArea` that will handle
     * pixel-perfect input detection on an Image or Sprite based Game Object, or any custom class that extends them.
     *
     * The following will create a sprite that is clickable on any pixel that has an alpha value >= 1.
     *
     * ```javascript
     * this.add.sprite(x, y, key).setInteractive(this.input.makePixelPerfect());
     * ```
     * 
     * The following will create a sprite that is clickable on any pixel that has an alpha value >= 150.
     *
     * ```javascript
     * this.add.sprite(x, y, key).setInteractive(this.input.makePixelPerfect(150));
     * ```
     *
     * Once you have made an Interactive Object pixel perfect it impacts all input related events for it: down, up,
     * dragstart, drag, etc.
     *
     * As a pointer interacts with the Game Object it will constantly poll the texture, extracting a single pixel from
     * the given coordinates and checking its color values. This is an expensive process, so should only be enabled on
     * Game Objects that really need it.
     * 
     * You cannot make non-texture based Game Objects pixel perfect. So this will not work on Graphics, BitmapText,
     * Render Textures, Text, Tilemaps, Containers or Particles.
     *
     * @method Phaser.Input.InputPlugin#makePixelPerfect
     * @since 3.10.0
     *
     * @param {integer} [alphaTolerance=1] - The alpha level that the pixel should be above to be included as a successful interaction.
     *
     * @return {function} A Pixel Perfect Handler for use as a hitArea shape callback.
     */
    makePixelPerfect: function (alphaTolerance)
    {
        if (alphaTolerance === undefined) { alphaTolerance = 1; }

        var textureManager = this.systems.textures;

        return CreatePixelPerfectHandler(textureManager, alphaTolerance);
    },

    /**
     * @typedef {object} Phaser.Input.InputConfiguration
     *
     * @property {any} [hitArea] - The object / shape to use as the Hit Area. If not given it will try to create a Rectangle based on the texture frame.
     * @property {function} [hitAreaCallback] - The callback that determines if the pointer is within the Hit Area shape or not.
     * @property {boolean} [draggable=false] - If `true` the Interactive Object will be set to be draggable and emit drag events.
     * @property {boolean} [dropZone=false] - If `true` the Interactive Object will be set to be a drop zone for draggable objects.
     * @property {boolean} [useHandCursor=false] - If `true` the Interactive Object will set the `pointer` hand cursor when a pointer is over it. This is a short-cut for setting `cursor: 'pointer'`.
     * @property {string} [cursor] - The CSS string to be used when the cursor is over this Interactive Object.
     * @property {boolean} [pixelPerfect=false] - If `true` the a pixel perfect function will be set for the hit area callback. Only works with texture based Game Objects.
     * @property {integer} [alphaTolerance=1] - If `pixelPerfect` is set, this is the alpha tolerance threshold value used in the callback.
     */

    /**
     * Sets the hit area for the given array of Game Objects.
     *
     * A hit area is typically one of the geometric shapes Phaser provides, such as a `Phaser.Geom.Rectangle`
     * or `Phaser.Geom.Circle`. However, it can be any object as long as it works with the provided callback.
     *
     * If no hit area is provided a Rectangle is created based on the size of the Game Object, if possible
     * to calculate.
     *
     * The hit area callback is the function that takes an `x` and `y` coordinate and returns a boolean if
     * those values fall within the area of the shape or not. All of the Phaser geometry objects provide this,
     * such as `Phaser.Geom.Rectangle.Contains`.
     *
     * @method Phaser.Input.InputPlugin#setHitArea
     * @since 3.0.0
     *
     * @param {(Phaser.GameObjects.GameObject|Phaser.GameObjects.GameObject[])} gameObjects - An array of Game Objects to set the hit area on.
     * @param {(Phaser.Input.InputConfiguration|any)} [shape] - Either an input configuration object, or a geometric shape that defines the hit area for the Game Object. If not specified a Rectangle will be used.
     * @param {HitAreaCallback} [callback] - The 'contains' function to invoke to check if the pointer is within the hit area.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setHitArea: function (gameObjects, shape, callback)
    {
        if (shape === undefined)
        {
            return this.setHitAreaFromTexture(gameObjects);
        }

        if (!Array.isArray(gameObjects))
        {
            gameObjects = [ gameObjects ];
        }

        var draggable = false;
        var dropZone = false;
        var cursor = false;
        var useHandCursor = false;

        //  Config object?
        if (IsPlainObject(shape))
        {
            var config = shape;

            shape = GetFastValue(config, 'hitArea', null);
            callback = GetFastValue(config, 'hitAreaCallback', null);
            draggable = GetFastValue(config, 'draggable', false);
            dropZone = GetFastValue(config, 'dropZone', false);
            cursor = GetFastValue(config, 'cursor', false);
            useHandCursor = GetFastValue(config, 'useHandCursor', false);

            var pixelPerfect = GetFastValue(config, 'pixelPerfect', false);
            var alphaTolerance = GetFastValue(config, 'alphaTolerance', 1);

            if (pixelPerfect)
            {
                shape = {};
                callback = this.makePixelPerfect(alphaTolerance);
            }

            //  Still no hitArea or callback?
            if (!shape || !callback)
            {
                this.setHitAreaFromTexture(gameObjects);
            }
        }
        else if (typeof shape === 'function' && !callback)
        {
            callback = shape;
            shape = {};
        }

        for (var i = 0; i < gameObjects.length; i++)
        {
            var gameObject = gameObjects[i];

            var io = (!gameObject.input) ? CreateInteractiveObject(gameObject, shape, callback) : gameObject.input;

            io.dropZone = dropZone;
            io.cursor = (useHandCursor) ? 'pointer' : cursor;

            gameObject.input = io;

            if (draggable)
            {
                this.setDraggable(gameObject);
            }

            this.queueForInsertion(gameObject);
        }

        return this;
    },

    /**
     * Sets the hit area for an array of Game Objects to be a `Phaser.Geom.Circle` shape, using
     * the given coordinates and radius to control its position and size.
     *
     * @method Phaser.Input.InputPlugin#setHitAreaCircle
     * @since 3.0.0
     *
     * @param {(Phaser.GameObjects.GameObject|Phaser.GameObjects.GameObject[])} gameObjects - An array of Game Objects to set as having a circle hit area.
     * @param {number} x - The center of the circle.
     * @param {number} y - The center of the circle.
     * @param {number} radius - The radius of the circle.
     * @param {HitAreaCallback} [callback] - The hit area callback. If undefined it uses Circle.Contains.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setHitAreaCircle: function (gameObjects, x, y, radius, callback)
    {
        if (callback === undefined) { callback = CircleContains; }

        var shape = new Circle(x, y, radius);

        return this.setHitArea(gameObjects, shape, callback);
    },

    /**
     * Sets the hit area for an array of Game Objects to be a `Phaser.Geom.Ellipse` shape, using
     * the given coordinates and dimensions to control its position and size.
     *
     * @method Phaser.Input.InputPlugin#setHitAreaEllipse
     * @since 3.0.0
     *
     * @param {(Phaser.GameObjects.GameObject|Phaser.GameObjects.GameObject[])} gameObjects - An array of Game Objects to set as having an ellipse hit area.
     * @param {number} x - The center of the ellipse.
     * @param {number} y - The center of the ellipse.
     * @param {number} width - The width of the ellipse.
     * @param {number} height - The height of the ellipse.
     * @param {HitAreaCallback} [callback] - The hit area callback. If undefined it uses Ellipse.Contains.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setHitAreaEllipse: function (gameObjects, x, y, width, height, callback)
    {
        if (callback === undefined) { callback = EllipseContains; }

        var shape = new Ellipse(x, y, width, height);

        return this.setHitArea(gameObjects, shape, callback);
    },

    /**
     * Sets the hit area for an array of Game Objects to be a `Phaser.Geom.Rectangle` shape, using
     * the Game Objects texture frame to define the position and size of the hit area.
     *
     * @method Phaser.Input.InputPlugin#setHitAreaFromTexture
     * @since 3.0.0
     *
     * @param {(Phaser.GameObjects.GameObject|Phaser.GameObjects.GameObject[])} gameObjects - An array of Game Objects to set as having an ellipse hit area.
     * @param {HitAreaCallback} [callback] - The hit area callback. If undefined it uses Rectangle.Contains.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setHitAreaFromTexture: function (gameObjects, callback)
    {
        if (callback === undefined) { callback = RectangleContains; }

        if (!Array.isArray(gameObjects))
        {
            gameObjects = [ gameObjects ];
        }

        for (var i = 0; i < gameObjects.length; i++)
        {
            var gameObject = gameObjects[i];

            var frame = gameObject.frame;

            var width = 0;
            var height = 0;

            if (frame)
            {
                width = frame.realWidth;
                height = frame.realHeight;
            }
            else if (gameObject.width)
            {
                width = gameObject.width;
                height = gameObject.height;
            }

            if (gameObject.type === 'Container' && (width === 0 || height === 0))
            {
                console.warn('Container.setInteractive() must specify a Shape or call setSize() first');
                continue;
            }

            if (width !== 0 && height !== 0)
            {
                gameObject.input = CreateInteractiveObject(gameObject, new Rectangle(0, 0, width, height), callback);

                this.queueForInsertion(gameObject);
            }
        }

        return this;
    },

    /**
     * Sets the hit area for an array of Game Objects to be a `Phaser.Geom.Rectangle` shape, using
     * the given coordinates and dimensions to control its position and size.
     *
     * @method Phaser.Input.InputPlugin#setHitAreaRectangle
     * @since 3.0.0
     *
     * @param {(Phaser.GameObjects.GameObject|Phaser.GameObjects.GameObject[])} gameObjects - An array of Game Objects to set as having a rectangular hit area.
     * @param {number} x - The top-left of the rectangle.
     * @param {number} y - The top-left of the rectangle.
     * @param {number} width - The width of the rectangle.
     * @param {number} height - The height of the rectangle.
     * @param {HitAreaCallback} [callback] - The hit area callback. If undefined it uses Rectangle.Contains.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setHitAreaRectangle: function (gameObjects, x, y, width, height, callback)
    {
        if (callback === undefined) { callback = RectangleContains; }

        var shape = new Rectangle(x, y, width, height);

        return this.setHitArea(gameObjects, shape, callback);
    },

    /**
     * Sets the hit area for an array of Game Objects to be a `Phaser.Geom.Triangle` shape, using
     * the given coordinates to control the position of its points.
     *
     * @method Phaser.Input.InputPlugin#setHitAreaTriangle
     * @since 3.0.0
     *
     * @param {(Phaser.GameObjects.GameObject|Phaser.GameObjects.GameObject[])} gameObjects - An array of Game Objects to set as having a  triangular hit area.
     * @param {number} x1 - The x coordinate of the first point of the triangle.
     * @param {number} y1 - The y coordinate of the first point of the triangle.
     * @param {number} x2 - The x coordinate of the second point of the triangle.
     * @param {number} y2 - The y coordinate of the second point of the triangle.
     * @param {number} x3 - The x coordinate of the third point of the triangle.
     * @param {number} y3 - The y coordinate of the third point of the triangle.
     * @param {HitAreaCallback} [callback] - The hit area callback. If undefined it uses Triangle.Contains.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setHitAreaTriangle: function (gameObjects, x1, y1, x2, y2, x3, y3, callback)
    {
        if (callback === undefined) { callback = TriangleContains; }

        var shape = new Triangle(x1, y1, x2, y2, x3, y3);

        return this.setHitArea(gameObjects, shape, callback);
    },

    /**
     * Sets the Pointers to always poll.
     * 
     * When a pointer is polled it runs a hit test to see which Game Objects are currently below it,
     * or being interacted with it, regardless if the Pointer has actually moved or not.
     *
     * You should enable this if you want objects in your game to fire over / out events, and the objects
     * are constantly moving, but the pointer may not have. Polling every frame has additional computation
     * costs, especially if there are a large number of interactive objects in your game.
     *
     * @method Phaser.Input.InputPlugin#setPollAlways
     * @since 3.0.0
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setPollAlways: function ()
    {
        this.pollRate = 0;
        this._pollTimer = 0;

        return this;
    },

    /**
     * Sets the Pointers to only poll when they are moved or updated.
     * 
     * When a pointer is polled it runs a hit test to see which Game Objects are currently below it,
     * or being interacted with it.
     *
     * @method Phaser.Input.InputPlugin#setPollOnMove
     * @since 3.0.0
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setPollOnMove: function ()
    {
        this.pollRate = -1;
        this._pollTimer = 0;

        return this;
    },

    /**
     * Sets the poll rate value. This is the amount of time that should have elapsed before a pointer
     * will be polled again. See the `setPollAlways` and `setPollOnMove` methods.
     *
     * @method Phaser.Input.InputPlugin#setPollRate
     * @since 3.0.0
     *
     * @param {number} value - The amount of time, in ms, that should elapsed before re-polling the pointers.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setPollRate: function (value)
    {
        this.pollRate = value;
        this._pollTimer = 0;

        return this;
    },

    /**
     * When set to `true` the global Input Manager will emulate DOM behavior by only emitting events from
     * the top-most Game Objects in the Display List.
     *
     * If set to `false` it will emit events from all Game Objects below a Pointer, not just the top one.
     *
     * @method Phaser.Input.InputPlugin#setGlobalTopOnly
     * @since 3.0.0
     *
     * @param {boolean} value - `true` to only include the top-most Game Object, or `false` to include all Game Objects in a hit test.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setGlobalTopOnly: function (value)
    {
        this.manager.globalTopOnly = value;

        return this;
    },

    /**
     * When set to `true` this Input Plugin will emulate DOM behavior by only emitting events from
     * the top-most Game Objects in the Display List.
     *
     * If set to `false` it will emit events from all Game Objects below a Pointer, not just the top one.
     *
     * @method Phaser.Input.InputPlugin#setTopOnly
     * @since 3.0.0
     *
     * @param {boolean} value - `true` to only include the top-most Game Object, or `false` to include all Game Objects in a hit test.
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    setTopOnly: function (value)
    {
        this.topOnly = value;

        return this;
    },

    /**
     * Given an array of Game Objects, sort the array and return it, so that the objects are in depth index order
     * with the lowest at the bottom.
     *
     * @method Phaser.Input.InputPlugin#sortGameObjects
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.GameObject[]} gameObjects - An array of Game Objects to be sorted.
     *
     * @return {Phaser.GameObjects.GameObject[]} The sorted array of Game Objects.
     */
    sortGameObjects: function (gameObjects)
    {
        if (gameObjects.length < 2)
        {
            return gameObjects;
        }

        this.scene.sys.depthSort();

        return gameObjects.sort(this.sortHandlerGO.bind(this));
    },

    /**
     * Return the child lowest down the display list (with the smallest index)
     * Will iterate through all parent containers, if present.
     *
     * @method Phaser.Input.InputPlugin#sortHandlerGO
     * @private
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.GameObject} childA - The first Game Object to compare.
     * @param {Phaser.GameObjects.GameObject} childB - The second Game Object to compare.
     *
     * @return {integer} Returns either a negative or positive integer, or zero if they match.
     */
    sortHandlerGO: function (childA, childB)
    {
        if (!childA.parentContainer && !childB.parentContainer)
        {
            //  Quick bail out when neither child has a container
            return this.displayList.getIndex(childB) - this.displayList.getIndex(childA);
        }
        else if (childA.parentContainer === childB.parentContainer)
        {
            //  Quick bail out when both children have the same container
            return childB.parentContainer.getIndex(childB) - childA.parentContainer.getIndex(childA);
        }
        else if (childA.parentContainer === childB)
        {
            //  Quick bail out when childA is a child of childB
            return -1;
        }
        else if (childB.parentContainer === childA)
        {
            //  Quick bail out when childA is a child of childB
            return 1;
        }
        else
        {
            //  Container index check
            var listA = childA.getIndexList();
            var listB = childB.getIndexList();
            var len = Math.min(listA.length, listB.length);

            for (var i = 0; i < len; i++)
            {
                var indexA = listA[i];
                var indexB = listB[i];

                if (indexA === indexB)
                {
                    //  Go to the next level down
                    continue;
                }
                else
                {
                    //  Non-matching parents, so return
                    return indexB - indexA;
                }
            }
        }

        //  Technically this shouldn't happen, but ...
        return 0;
    },

    /**
     * Causes the Input Manager to stop emitting any events for the remainder of this game step.
     *
     * @method Phaser.Input.InputPlugin#stopPropagation
     * @since 3.0.0
     *
     * @return {Phaser.Input.InputPlugin} This InputPlugin object.
     */
    stopPropagation: function ()
    {
        if (this.manager.globalTopOnly)
        {
            this.manager.ignoreEvents = true;
        }

        return this;
    },

    /**
     * Adds a callback to be invoked whenever the native DOM `mouseup` or `touchend` events are received.
     * By setting the `isOnce` argument you can control if the callback is called once,
     * or every time the DOM event occurs.
     *
     * Callbacks passed to this method are invoked _immediately_ when the DOM event happens,
     * within the scope of the DOM event handler. Therefore, they are considered as 'native'
     * from the perspective of the browser. This means they can be used for tasks such as
     * opening new browser windows, or anything which explicitly requires user input to activate.
     * However, as a result of this, they come with their own risks, and as such should not be used
     * for general game input, but instead be reserved for special circumstances.
     *
     * If all you're trying to do is execute a callback when a pointer is released, then
     * please use the internal Input event system instead.
     *
     * Please understand that these callbacks are invoked when the browser feels like doing so,
     * which may be entirely out of the normal flow of the Phaser Game Loop. Therefore, you should absolutely keep
     * Phaser related operations to a minimum in these callbacks. For example, don't destroy Game Objects,
     * change Scenes or manipulate internal systems, otherwise you run a very real risk of creating
     * heisenbugs (https://en.wikipedia.org/wiki/Heisenbug) that prove a challenge to reproduce, never mind
     * solve.
     *
     * @method Phaser.Input.InputPlugin#addUpCallback
     * @since 3.10.0
     *
     * @param {function} callback - The callback to be invoked on this DOM event.
     * @param {boolean} [isOnce=true] - `true` if the callback will only be invoked once, `false` to call every time this event happens.
     *
     * @return {this} The Input Plugin.
     */
    addUpCallback: function (callback, isOnce)
    {
        this.manager.addUpCallback(callback, isOnce);

        return this;
    },

    /**
     * Adds a callback to be invoked whenever the native DOM `mousedown` or `touchstart` events are received.
     * By setting the `isOnce` argument you can control if the callback is called once,
     * or every time the DOM event occurs.
     *
     * Callbacks passed to this method are invoked _immediately_ when the DOM event happens,
     * within the scope of the DOM event handler. Therefore, they are considered as 'native'
     * from the perspective of the browser. This means they can be used for tasks such as
     * opening new browser windows, or anything which explicitly requires user input to activate.
     * However, as a result of this, they come with their own risks, and as such should not be used
     * for general game input, but instead be reserved for special circumstances.
     *
     * If all you're trying to do is execute a callback when a pointer is down, then
     * please use the internal Input event system instead.
     *
     * Please understand that these callbacks are invoked when the browser feels like doing so,
     * which may be entirely out of the normal flow of the Phaser Game Loop. Therefore, you should absolutely keep
     * Phaser related operations to a minimum in these callbacks. For example, don't destroy Game Objects,
     * change Scenes or manipulate internal systems, otherwise you run a very real risk of creating
     * heisenbugs (https://en.wikipedia.org/wiki/Heisenbug) that prove a challenge to reproduce, never mind
     * solve.
     *
     * @method Phaser.Input.InputPlugin#addDownCallback
     * @since 3.10.0
     *
     * @param {function} callback - The callback to be invoked on this dom event.
     * @param {boolean} [isOnce=true] - `true` if the callback will only be invoked once, `false` to call every time this event happens.
     *
     * @return {this} The Input Plugin.
     */
    addDownCallback: function (callback, isOnce)
    {
        this.manager.addDownCallback(callback, isOnce);

        return this;
    },

    /**
     * Adds a callback to be invoked whenever the native DOM `mousemove` or `touchmove` events are received.
     * By setting the `isOnce` argument you can control if the callback is called once,
     * or every time the DOM event occurs.
     *
     * Callbacks passed to this method are invoked _immediately_ when the DOM event happens,
     * within the scope of the DOM event handler. Therefore, they are considered as 'native'
     * from the perspective of the browser. This means they can be used for tasks such as
     * opening new browser windows, or anything which explicitly requires user input to activate.
     * However, as a result of this, they come with their own risks, and as such should not be used
     * for general game input, but instead be reserved for special circumstances.
     *
     * If all you're trying to do is execute a callback when a pointer is moved, then
     * please use the internal Input event system instead.
     *
     * Please understand that these callbacks are invoked when the browser feels like doing so,
     * which may be entirely out of the normal flow of the Phaser Game Loop. Therefore, you should absolutely keep
     * Phaser related operations to a minimum in these callbacks. For example, don't destroy Game Objects,
     * change Scenes or manipulate internal systems, otherwise you run a very real risk of creating
     * heisenbugs (https://en.wikipedia.org/wiki/Heisenbug) that prove a challenge to reproduce, never mind
     * solve.
     *
     * @method Phaser.Input.InputPlugin#addMoveCallback
     * @since 3.10.0
     *
     * @param {function} callback - The callback to be invoked on this dom event.
     * @param {boolean} [isOnce=false] - `true` if the callback will only be invoked once, `false` to call every time this event happens.
     *
     * @return {this} The Input Plugin.
     */
    addMoveCallback: function (callback, isOnce)
    {
        this.manager.addMoveCallback(callback, isOnce);

        return this;
    },

    /**
     * Adds new Pointer objects to the Input Manager.
     *
     * By default Phaser creates 2 pointer objects: `mousePointer` and `pointer1`.
     *
     * You can create more either by calling this method, or by setting the `input.activePointers` property
     * in the Game Config, up to a maximum of 10 pointers.
     *
     * The first 10 pointers are available via the `InputPlugin.pointerX` properties, once they have been added
     * via this method.
     *
     * @method Phaser.Input.InputPlugin#addPointer
     * @since 3.10.0
     * 
     * @param {integer} [quantity=1] The number of new Pointers to create. A maximum of 10 is allowed in total.
     *
     * @return {Phaser.Input.Pointer[]} An array containing all of the new Pointer objects that were created.
     */
    addPointer: function (quantity)
    {
        return this.manager.addPointer(quantity);
    },

    /**
     * Tells the Input system to set a custom cursor.
     * 
     * This cursor will be the default cursor used when interacting with the game canvas.
     *
     * If an Interactive Object also sets a custom cursor, this is the cursor that is reset after its use.
     *
     * Any valid CSS cursor value is allowed, including paths to image files, i.e.:
     *
     * ```javascript
     * this.input.setDefaultCursor('url(assets/cursors/sword.cur), pointer');
     * ```
     * 
     * Please read about the differences between browsers when it comes to the file formats and sizes they support:
     *
     * https://developer.mozilla.org/en-US/docs/Web/CSS/cursor
     * https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_User_Interface/Using_URL_values_for_the_cursor_property
     *
     * It's up to you to pick a suitable cursor format that works across the range of browsers you need to support.
     *
     * @method Phaser.Input.InputPlugin#setDefaultCursor
     * @since 3.10.0
     * 
     * @param {string} cursor - The CSS to be used when setting the default cursor.
     *
     * @return {Phaser.Input.InputPlugin} This Input instance.
     */
    setDefaultCursor: function (cursor)
    {
        this.manager.setDefaultCursor(cursor);

        return this;
    },

    /**
     * The Scene that owns this plugin is transitioning in.
     *
     * @method Phaser.Input.InputPlugin#transitionIn
     * @private
     * @since 3.5.0
     */
    transitionIn: function ()
    {
        this.enabled = this.settings.transitionAllowInput;
    },

    /**
     * The Scene that owns this plugin has finished transitioning in.
     *
     * @method Phaser.Input.InputPlugin#transitionComplete
     * @private
     * @since 3.5.0
     */
    transitionComplete: function ()
    {
        if (!this.settings.transitionAllowInput)
        {
            this.enabled = true;
        }
    },

    /**
     * The Scene that owns this plugin is transitioning out.
     *
     * @method Phaser.Input.InputPlugin#transitionOut
     * @private
     * @since 3.5.0
     */
    transitionOut: function ()
    {
        this.enabled = this.settings.transitionAllowInput;
    },

    /**
     * The Scene that owns this plugin is shutting down.
     * We need to kill and reset all internal properties as well as stop listening to Scene events.
     *
     * @method Phaser.Input.InputPlugin#shutdown
     * @private
     * @since 3.0.0
     */
    shutdown: function ()
    {
        //  Registered input plugins listen for this
        this.pluginEvents.emit('shutdown');

        this._temp.length = 0;
        this._list.length = 0;
        this._draggable.length = 0;
        this._pendingRemoval.length = 0;
        this._pendingInsertion.length = 0;

        for (var i = 0; i < 10; i++)
        {
            this._drag[i] = [];
            this._over[i] = [];
        }

        this.removeAllListeners();

        var eventEmitter = this.systems.events;

        eventEmitter.off('transitionstart', this.transitionIn, this);
        eventEmitter.off('transitionout', this.transitionOut, this);
        eventEmitter.off('transitioncomplete', this.transitionComplete, this);

        eventEmitter.off('preupdate', this.preUpdate, this);
        eventEmitter.off('update', this.update, this);
        eventEmitter.off('shutdown', this.shutdown, this);
    },

    /**
     * The Scene that owns this plugin is being destroyed.     
     * We need to shutdown and then kill off all external references.
     *
     * @method Phaser.Input.InputPlugin#destroy
     * @private
     * @since 3.0.0
     */
    destroy: function ()
    {
        this.shutdown();

        //  Registered input plugins listen for this
        this.pluginEvents.emit('destroy');

        this.pluginEvents.removeAllListeners();

        this.scene.sys.events.off('start', this.start, this);

        this.scene = null;
        this.cameras = null;
        this.manager = null;
        this.events = null;
        this.mouse = null;
    },

    /**
     * The x coordinates of the ActivePointer based on the first camera in the camera list.
     * This is only safe to use if your game has just 1 non-transformed camera and doesn't use multi-touch.
     *
     * @name Phaser.Input.InputPlugin#x
     * @type {number}
     * @readOnly
     * @since 3.0.0
     */
    x: {

        get: function ()
        {
            return this.manager.activePointer.x;
        }

    },

    /**
     * The y coordinates of the ActivePointer based on the first camera in the camera list.
     * This is only safe to use if your game has just 1 non-transformed camera and doesn't use multi-touch.
     *
     * @name Phaser.Input.InputPlugin#y
     * @type {number}
     * @readOnly
     * @since 3.0.0
     */
    y: {

        get: function ()
        {
            return this.manager.activePointer.y;
        }

    },

    /**
     * The mouse has its own unique Pointer object, which you can reference directly if making a _desktop specific game_.
     * If you are supporting both desktop and touch devices then do not use this property, instead use `activePointer`
     * which will always map to the most recently interacted pointer.
     *
     * @name Phaser.Input.InputPlugin#mousePointer
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.10.0
     */
    mousePointer: {

        get: function ()
        {
            return this.manager.mousePointer;
        }

    },

    /**
     * The current active input Pointer.
     *
     * @name Phaser.Input.InputPlugin#activePointer
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.0.0
     */
    activePointer: {

        get: function ()
        {
            return this.manager.activePointer;
        }

    },

    /**
     * A touch-based Pointer object.
     * This will be `undefined` by default unless you add a new Pointer using `addPointer`.
     *
     * @name Phaser.Input.InputPlugin#pointer1
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.10.0
     */
    pointer1: {

        get: function ()
        {
            return this.manager.pointers[1];
        }

    },

    /**
     * A touch-based Pointer object.
     * This will be `undefined` by default unless you add a new Pointer using `addPointer`.
     *
     * @name Phaser.Input.InputPlugin#pointer2
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.10.0
     */
    pointer2: {

        get: function ()
        {
            return this.manager.pointers[2];
        }

    },

    /**
     * A touch-based Pointer object.
     * This will be `undefined` by default unless you add a new Pointer using `addPointer`.
     *
     * @name Phaser.Input.InputPlugin#pointer3
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.10.0
     */
    pointer3: {

        get: function ()
        {
            return this.manager.pointers[3];
        }

    },

    /**
     * A touch-based Pointer object.
     * This will be `undefined` by default unless you add a new Pointer using `addPointer`.
     *
     * @name Phaser.Input.InputPlugin#pointer4
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.10.0
     */
    pointer4: {

        get: function ()
        {
            return this.manager.pointers[4];
        }

    },

    /**
     * A touch-based Pointer object.
     * This will be `undefined` by default unless you add a new Pointer using `addPointer`.
     *
     * @name Phaser.Input.InputPlugin#pointer5
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.10.0
     */
    pointer5: {

        get: function ()
        {
            return this.manager.pointers[5];
        }

    },

    /**
     * A touch-based Pointer object.
     * This will be `undefined` by default unless you add a new Pointer using `addPointer`.
     *
     * @name Phaser.Input.InputPlugin#pointer6
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.10.0
     */
    pointer6: {

        get: function ()
        {
            return this.manager.pointers[6];
        }

    },

    /**
     * A touch-based Pointer object.
     * This will be `undefined` by default unless you add a new Pointer using `addPointer`.
     *
     * @name Phaser.Input.InputPlugin#pointer7
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.10.0
     */
    pointer7: {

        get: function ()
        {
            return this.manager.pointers[7];
        }

    },

    /**
     * A touch-based Pointer object.
     * This will be `undefined` by default unless you add a new Pointer using `addPointer`.
     *
     * @name Phaser.Input.InputPlugin#pointer8
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.10.0
     */
    pointer8: {

        get: function ()
        {
            return this.manager.pointers[8];
        }

    },

    /**
     * A touch-based Pointer object.
     * This will be `undefined` by default unless you add a new Pointer using `addPointer`.
     *
     * @name Phaser.Input.InputPlugin#pointer9
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.10.0
     */
    pointer9: {

        get: function ()
        {
            return this.manager.pointers[9];
        }

    },

    /**
     * A touch-based Pointer object.
     * This will be `undefined` by default unless you add a new Pointer using `addPointer`.
     *
     * @name Phaser.Input.InputPlugin#pointer10
     * @type {Phaser.Input.Pointer}
     * @readOnly
     * @since 3.10.0
     */
    pointer10: {

        get: function ()
        {
            return this.manager.pointers[10];
        }

    }

});

PluginCache.register('InputPlugin', InputPlugin, 'input');

module.exports = InputPlugin;