# Source: src/input/Gamepad.js

    /**
    * @author       @karlmacklin <tacklemcclean@gmail.com>
    * @copyright    2016 Photon Storm Ltd.
    * @license      {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
    */

    /**
    * The Gamepad class handles gamepad input and dispatches gamepad events.
    *
    * Remember to call `gamepad.start()`.
    *
    * HTML5 GAMEPAD API SUPPORT IS AT AN EXPERIMENTAL STAGE!
    * At moment of writing this (end of 2013) only Chrome supports parts of it out of the box. Firefox supports it
    * via prefs flags (about:config, search gamepad). The browsers map the same controllers differently.
    * This class has constants for Windows 7 Chrome mapping of XBOX 360 controller.
    *
    * @class Phaser.Gamepad
    * @constructor
    * @param {Phaser.Game} game - A reference to the currently running game.
    */
    Phaser.Gamepad = function (game) {

        /**
        * @property {Phaser.Game} game - Local reference to game.
        */
        this.game = game;

        /**
        * @property {object} _gamepadIndexMap - Maps the browsers gamepad indices to our Phaser Gamepads
        * @private
        */
        this._gamepadIndexMap = {};

        /**
        * @property {Array} _rawPads - The raw state of the gamepads from the browser
        * @private
        */
        this._rawPads = [];

        /**
        * @property {boolean} _active - Private flag for whether or not the API is polled
        * @private
        * @default
        */
        this._active = false;

        /**
        * Gamepad input will only be processed if enabled.
        * @property {boolean} enabled
        * @default
        */
        this.enabled = true;

        /**
        * Whether or not gamepads are supported in the current browser. Note that as of Dec. 2013 this check is actually not accurate at all due to poor implementation.
        * @property {boolean} _gamepadSupportAvailable - Are gamepads supported in this browser or not?
        * @private
        */
        this._gamepadSupportAvailable = !!navigator.webkitGetGamepads || !!navigator.webkitGamepads || (navigator.userAgent.indexOf('Firefox/') !== -1) || !!navigator.getGamepads;

        /**
        * Used to check for differences between earlier polls and current state of gamepads.
        * @property {Array} _prevRawGamepadTypes
        * @private
        * @default
        */
        this._prevRawGamepadTypes = [];

        /**
        * Used to check for differences between earlier polls and current state of gamepads.
        * @property {Array} _prevTimestamps
        * @private
        * @default
        */
        this._prevTimestamps = [];

        /**
        * @property {object} callbackContext - The context under which the callbacks are run.
        */
        this.callbackContext = this;

        /**
        * @property {function} onConnectCallback - This callback is invoked every time any gamepad is connected
        */
        this.onConnectCallback = null;

        /**
        * @property {function} onDisconnectCallback - This callback is invoked every time any gamepad is disconnected
        */
        this.onDisconnectCallback = null;

        /**
        * @property {function} onDownCallback - This callback is invoked every time any gamepad button is pressed down.
        */
        this.onDownCallback = null;

        /**
        * @property {function} onUpCallback - This callback is invoked every time any gamepad button is released.
        */
        this.onUpCallback = null;

        /**
        * @property {function} onAxisCallback - This callback is invoked every time any gamepad axis is changed.
        */
        this.onAxisCallback = null;

        /**
        * @property {function} onFloatCallback - This callback is invoked every time any gamepad button is changed to a value where value > 0 and value < 1.
        */
        this.onFloatCallback = null;

        /**
        * @property {function} _ongamepadconnected - Private callback for Firefox gamepad connection handling
        * @private
        */
        this._ongamepadconnected = null;

        /**
        * @property {function} _gamepaddisconnected - Private callback for Firefox gamepad connection handling
        * @private
        */
        this._gamepaddisconnected = null;

        /**
        * @property {Array<Phaser.SinglePad>} _gamepads - The four Phaser Gamepads.
        * @private
        */
        this._gamepads = [
            new Phaser.SinglePad(game, this),
            new Phaser.SinglePad(game, this),
            new Phaser.SinglePad(game, this),
            new Phaser.SinglePad(game, this)
        ];

    };

    Phaser.Gamepad.prototype = {

        /**
        * Add callbacks to the main Gamepad handler to handle connect/disconnect/button down/button up/axis change/float value buttons.
        *
        * @method Phaser.Gamepad#addCallbacks
        * @param {object} context - The context under which the callbacks are run.
        * @param {object} callbacks - Object that takes six different callback methods:
        * onConnectCallback, onDisconnectCallback, onDownCallback, onUpCallback, onAxisCallback, onFloatCallback
        */
        addCallbacks: function (context, callbacks) {

            if (typeof callbacks !== 'undefined')
            {
                this.onConnectCallback = (typeof callbacks.onConnect === 'function') ? callbacks.onConnect : this.onConnectCallback;
                this.onDisconnectCallback = (typeof callbacks.onDisconnect === 'function') ? callbacks.onDisconnect : this.onDisconnectCallback;
                this.onDownCallback = (typeof callbacks.onDown === 'function') ? callbacks.onDown : this.onDownCallback;
                this.onUpCallback = (typeof callbacks.onUp === 'function') ? callbacks.onUp : this.onUpCallback;
                this.onAxisCallback = (typeof callbacks.onAxis === 'function') ? callbacks.onAxis : this.onAxisCallback;
                this.onFloatCallback = (typeof callbacks.onFloat === 'function') ? callbacks.onFloat : this.onFloatCallback;
                this.callbackContext = context;
            }

        },

        /**
        * Starts the Gamepad event handling.
        * This MUST be called manually before Phaser will start polling the Gamepad API.
        *
        * @method Phaser.Gamepad#start
        */
        start: function () {

            if (this._active)
            {
                //  Avoid setting multiple listeners
                return;
            }

            this._active = true;

            var _this = this;

            this._onGamepadConnected = function (event) {
                return _this.onGamepadConnected(event);
            };

            this._onGamepadDisconnected = function (event) {
                return _this.onGamepadDisconnected(event);
            };

            window.addEventListener('gamepadconnected', this._onGamepadConnected, false);
            window.addEventListener('gamepaddisconnected', this._onGamepadDisconnected, false);

        },

        /**
         * Handles the connection of a Gamepad.
         *
         * @method onGamepadConnected
         * @private
         * @param {object} event - The DOM event.
         */
        onGamepadConnected: function (event) {

            var newPad = event.gamepad;
            this._rawPads.push(newPad);
            this._gamepads[newPad.index].connect(newPad);

        },

        /**
         * Handles the disconnection of a Gamepad.
         *
         * @method onGamepadDisconnected
         * @private
         * @param {object} event - The DOM event.
         */
        onGamepadDisconnected: function (event) {

            var removedPad = event.gamepad;

            for (var i in this._rawPads)
            {
                if (this._rawPads[i].index === removedPad.index)
                {
                    this._rawPads.splice(i,1);
                }
            }

            this._gamepads[removedPad.index].disconnect();

        },

        /**
        * Main gamepad update loop. Should not be called manually.
        * @method Phaser.Gamepad#update
        * @protected
        */
        update: function () {

            this._pollGamepads();

            this.pad1.pollStatus();
            this.pad2.pollStatus();
            this.pad3.pollStatus();
            this.pad4.pollStatus();

        },

        /**
        * Updating connected gamepads (for Google Chrome). Should not be called manually.
        *
        * @method Phaser.Gamepad#_pollGamepads
        * @private
        */
        _pollGamepads: function () {

            if (!this._active)
            {
                return;
            }

            if (navigator['getGamepads'])
            {
                var rawGamepads = navigator.getGamepads();
            }
            else if (navigator['webkitGetGamepads'])
            {
                var rawGamepads = navigator.webkitGetGamepads();
            }
            else if (navigator['webkitGamepads'])
            {
                var rawGamepads = navigator.webkitGamepads();
            }

            if (rawGamepads)
            {
                this._rawPads = [];

                var gamepadsChanged = false;

                for (var i = 0; i < rawGamepads.length; i++)
                {
                    if (typeof rawGamepads[i] !== this._prevRawGamepadTypes[i])
                    {
                        gamepadsChanged = true;
                        this._prevRawGamepadTypes[i] = typeof rawGamepads[i];
                    }

                    if (rawGamepads[i])
                    {
                        this._rawPads.push(rawGamepads[i]);
                    }

                    // Support max 4 pads at the moment
                    if (i === 3)
                    {
                        break;
                    }
                }

                for (var g = 0; g < this._gamepads.length; g++)
                {
                    this._gamepads[g]._rawPad = this._rawPads[g];
                }

                if (gamepadsChanged)
                {
                    var validConnections = { rawIndices: {}, padIndices: {} };
                    var singlePad;

                    for (var j = 0; j < this._gamepads.length; j++)
                    {
                        singlePad = this._gamepads[j];

                        if (singlePad.connected)
                        {
                            for (var k = 0; k < this._rawPads.length; k++)
                            {
                                if (this._rawPads[k].index === singlePad.index)
                                {
                                    validConnections.rawIndices[singlePad.index] = true;
                                    validConnections.padIndices[j] = true;
                                }
                            }
                        }
                    }

                    for (var l = 0; l < this._gamepads.length; l++)
                    {
                        singlePad = this._gamepads[l];

                        if (validConnections.padIndices[l])
                        {
                            continue;
                        }

                        if (this._rawPads.length < 1)
                        {
                            singlePad.disconnect();
                        }

                        for (var m = 0; m < this._rawPads.length; m++)
                        {
                            if (validConnections.padIndices[l])
                            {
                                break;
                            }

                            var rawPad = this._rawPads[m];

                            if (rawPad)
                            {
                                if (validConnections.rawIndices[rawPad.index])
                                {
                                    singlePad.disconnect();
                                    continue;
                                }
                                else
                                {
                                    singlePad.connect(rawPad);
                                    validConnections.rawIndices[rawPad.index] = true;
                                    validConnections.padIndices[l] = true;
                                }
                            }
                            else
                            {
                                singlePad.disconnect();
                            }
                        }
                    }
                }
            }
        },

        /**
        * Sets the deadZone variable for all four gamepads
        * @method Phaser.Gamepad#setDeadZones
        */
        setDeadZones: function (value) {

            for (var i = 0; i < this._gamepads.length; i++)
            {
                this._gamepads[i].deadZone = value;
            }

        },

        /**
        * Stops the Gamepad event handling.
        *
        * @method Phaser.Gamepad#stop
        */
        stop: function () {

            this._active = false;

            window.removeEventListener('gamepadconnected', this._onGamepadConnected);
            window.removeEventListener('gamepaddisconnected', this._onGamepadDisconnected);

        },

        /**
        * Reset all buttons/axes of all gamepads
        * @method Phaser.Gamepad#reset
        */
        reset: function () {

            this.update();

            for (var i = 0; i < this._gamepads.length; i++)
            {
                this._gamepads[i].reset();
            }

        },

        /**
        * Returns the "just pressed" state of a button from ANY gamepad connected. Just pressed is considered true if the button was pressed down within the duration given (default 250ms).
        * @method Phaser.Gamepad#justPressed
        * @param {number} buttonCode - The buttonCode of the button to check for.
        * @param {number} [duration=250] - The duration below which the button is considered as being just pressed.
        * @return {boolean} True if the button is just pressed otherwise false.
        */
        justPressed: function (buttonCode, duration) {

            for (var i = 0; i < this._gamepads.length; i++)
            {
                if (this._gamepads[i].justPressed(buttonCode, duration) === true)
                {
                    return true;
                }
            }

            return false;

        },

        /**
        * Returns the "just released" state of a button from ANY gamepad connected. Just released is considered as being true if the button was released within the duration given (default 250ms).
        * @method Phaser.Gamepad#justPressed
        * @param {number} buttonCode - The buttonCode of the button to check for.
        * @param {number} [duration=250] - The duration below which the button is considered as being just released.
        * @return {boolean} True if the button is just released otherwise false.
        */
        justReleased: function (buttonCode, duration) {

            for (var i = 0; i < this._gamepads.length; i++)
            {
                if (this._gamepads[i].justReleased(buttonCode, duration) === true)
                {
                    return true;
                }
            }

            return false;

        },

        /**
        * Returns true if the button is currently pressed down, on ANY gamepad.
        * @method Phaser.Gamepad#isDown
        * @param {number} buttonCode - The buttonCode of the button to check for.
        * @return {boolean} True if a button is currently down.
        */
        isDown: function (buttonCode) {

            for (var i = 0; i < this._gamepads.length; i++)
            {
                if (this._gamepads[i].isDown(buttonCode) === true)
                {
                    return true;
                }
            }

            return false;
        },

        /**
         * Destroys this object and the associated event listeners.
         *
         * @method Phaser.Gamepad#destroy
         */
        destroy: function () {

            this.stop();

            for (var i = 0; i < this._gamepads.length; i++)
            {
                this._gamepads[i].destroy();
            }

        }

    };

    Phaser.Gamepad.prototype.constructor = Phaser.Gamepad;

    /**
    * If the gamepad input is active or not - if not active it should not be updated from Input.js
    * @name Phaser.Gamepad#active
    * @property {boolean} active - If the gamepad input is active or not.
    * @readonly
    */
    Object.defineProperty(Phaser.Gamepad.prototype, "active", {

        get: function () {
            return this._active;
        }

    });

    /**
    * Whether or not gamepads are supported in current browser.
    * @name Phaser.Gamepad#supported
    * @property {boolean} supported - Whether or not gamepads are supported in current browser.
    * @readonly
    */
    Object.defineProperty(Phaser.Gamepad.prototype, "supported", {

        get: function () {
            return this._gamepadSupportAvailable;
        }

    });

    /**
    * How many live gamepads are currently connected.
    * @name Phaser.Gamepad#padsConnected
    * @property {number} padsConnected - How many live gamepads are currently connected.
    * @readonly
    */
    Object.defineProperty(Phaser.Gamepad.prototype, "padsConnected", {

        get: function () {
            return this._rawPads.length;
        }

    });

    /**
    * Gamepad #1
    * @name Phaser.Gamepad#pad1
    * @property {Phaser.SinglePad} pad1 - Gamepad #1;
    * @readonly
    */
    Object.defineProperty(Phaser.Gamepad.prototype, "pad1", {

        get: function () {
            return this._gamepads[0];
        }

    });

    /**
    * Gamepad #2
    * @name Phaser.Gamepad#pad2
    * @property {Phaser.SinglePad} pad2 - Gamepad #2
    * @readonly
    */
    Object.defineProperty(Phaser.Gamepad.prototype, "pad2", {

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

    });

    /**
    * Gamepad #3
    * @name Phaser.Gamepad#pad3
    * @property {Phaser.SinglePad} pad3 - Gamepad #3
    * @readonly
    */
    Object.defineProperty(Phaser.Gamepad.prototype, "pad3", {

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

    });

    /**
    * Gamepad #4
    * @name Phaser.Gamepad#pad4
    * @property {Phaser.SinglePad} pad4 - Gamepad #4
    * @readonly
    */
    Object.defineProperty(Phaser.Gamepad.prototype, "pad4", {

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

    });

    Phaser.Gamepad.BUTTON_0 = 0;
    Phaser.Gamepad.BUTTON_1 = 1;
    Phaser.Gamepad.BUTTON_2 = 2;
    Phaser.Gamepad.BUTTON_3 = 3;
    Phaser.Gamepad.BUTTON_4 = 4;
    Phaser.Gamepad.BUTTON_5 = 5;
    Phaser.Gamepad.BUTTON_6 = 6;
    Phaser.Gamepad.BUTTON_7 = 7;
    Phaser.Gamepad.BUTTON_8 = 8;
    Phaser.Gamepad.BUTTON_9 = 9;
    Phaser.Gamepad.BUTTON_10 = 10;
    Phaser.Gamepad.BUTTON_11 = 11;
    Phaser.Gamepad.BUTTON_12 = 12;
    Phaser.Gamepad.BUTTON_13 = 13;
    Phaser.Gamepad.BUTTON_14 = 14;
    Phaser.Gamepad.BUTTON_15 = 15;

    Phaser.Gamepad.AXIS_0 = 0;
    Phaser.Gamepad.AXIS_1 = 1;
    Phaser.Gamepad.AXIS_2 = 2;
    Phaser.Gamepad.AXIS_3 = 3;
    Phaser.Gamepad.AXIS_4 = 4;
    Phaser.Gamepad.AXIS_5 = 5;
    Phaser.Gamepad.AXIS_6 = 6;
    Phaser.Gamepad.AXIS_7 = 7;
    Phaser.Gamepad.AXIS_8 = 8;
    Phaser.Gamepad.AXIS_9 = 9;

    // Below mapping applies to XBOX 360 Wired and Wireless controller on Google Chrome (tested on Windows 7).
    // - Firefox uses different map! Separate amount of buttons and axes. DPAD = axis and not a button.
    // In other words - discrepancies when using gamepads.

    Phaser.Gamepad.XBOX360_A = 0;
    Phaser.Gamepad.XBOX360_B = 1;
    Phaser.Gamepad.XBOX360_X = 2;
    Phaser.Gamepad.XBOX360_Y = 3;
    Phaser.Gamepad.XBOX360_LEFT_BUMPER = 4;
    Phaser.Gamepad.XBOX360_RIGHT_BUMPER = 5;
    Phaser.Gamepad.XBOX360_LEFT_TRIGGER = 6;
    Phaser.Gamepad.XBOX360_RIGHT_TRIGGER = 7;
    Phaser.Gamepad.XBOX360_BACK = 8;
    Phaser.Gamepad.XBOX360_START = 9;
    Phaser.Gamepad.XBOX360_STICK_LEFT_BUTTON = 10;
    Phaser.Gamepad.XBOX360_STICK_RIGHT_BUTTON = 11;

    Phaser.Gamepad.XBOX360_DPAD_LEFT = 14;
    Phaser.Gamepad.XBOX360_DPAD_RIGHT = 15;
    Phaser.Gamepad.XBOX360_DPAD_UP = 12;
    Phaser.Gamepad.XBOX360_DPAD_DOWN = 13;

    //  On FF 0 = Y, 1 = X, 2 = Y, 3 = X, 4 = left bumper, 5 = dpad left, 6 = dpad right
    Phaser.Gamepad.XBOX360_STICK_LEFT_X = 0;
    Phaser.Gamepad.XBOX360_STICK_LEFT_Y = 1;
    Phaser.Gamepad.XBOX360_STICK_RIGHT_X = 2;
    Phaser.Gamepad.XBOX360_STICK_RIGHT_Y = 3;

    //  PlayStation 3 controller (masquerading as xbox360 controller) button mappings

    Phaser.Gamepad.PS3XC_X = 0;
    Phaser.Gamepad.PS3XC_CIRCLE = 1;
    Phaser.Gamepad.PS3XC_SQUARE = 2;
    Phaser.Gamepad.PS3XC_TRIANGLE = 3;
    Phaser.Gamepad.PS3XC_L1 = 4;
    Phaser.Gamepad.PS3XC_R1 = 5;
    Phaser.Gamepad.PS3XC_L2 = 6; // analog trigger, range 0..1
    Phaser.Gamepad.PS3XC_R2 = 7; // analog trigger, range 0..1
    Phaser.Gamepad.PS3XC_SELECT = 8;
    Phaser.Gamepad.PS3XC_START = 9;
    Phaser.Gamepad.PS3XC_STICK_LEFT_BUTTON = 10;
    Phaser.Gamepad.PS3XC_STICK_RIGHT_BUTTON = 11;
    Phaser.Gamepad.PS3XC_DPAD_UP = 12;
    Phaser.Gamepad.PS3XC_DPAD_DOWN = 13;
    Phaser.Gamepad.PS3XC_DPAD_LEFT = 14;
    Phaser.Gamepad.PS3XC_DPAD_RIGHT = 15;
    Phaser.Gamepad.PS3XC_STICK_LEFT_X = 0; // analog stick, range -1..1
    Phaser.Gamepad.PS3XC_STICK_LEFT_Y = 1; // analog stick, range -1..1
    Phaser.Gamepad.PS3XC_STICK_RIGHT_X = 2; // analog stick, range -1..1
    Phaser.Gamepad.PS3XC_STICK_RIGHT_Y = 3; // analog stick, range -1..1