Phaser框架中虚拟控件类的问题

在我的游戏中，我需要一些可以在移动设备上工作的按钮（你可以在游戏中按下和/或按住的按钮）。我看到了这个例子（注意，这里使用的Phaser版本是旧的，但它仍然有效），并且能够暂时拥有一些工作按钮。以下是该示例的源代码。

然而，这个例子中创建这些虚拟游戏板按钮的代码有一件事让我很困扰：按钮的代码不是DRY（不要重复自己）。你可以在这里一次又一次地看到这些按钮是如何以同样的方式创建的：

// create our virtual game controller buttons 
buttonjump = game.add.button(660, 340, 'buttonjump', null, this, 0, 1, 0, 1);  //game, x, y, key, callback, callbackContext, overFrame, outFrame, downFrame, upFrame
buttonjump.anchor.setTo(0.5, 0.5);
buttonjump.fixedToCamera = true;  //our buttons should stay on the same place  
buttonjump.events.onInputOver.add(function(){jump=true;});
buttonjump.events.onInputOut.add(function(){jump=false;});
buttonjump.events.onInputDown.add(function(){jump=true;});
buttonjump.events.onInputUp.add(function(){jump=false;});
buttonfire = game.add.button(750, 340, 'buttonfire', null, this, 0, 1, 0, 1);
buttonfire.anchor.setTo(0.5, 0.5);
buttonfire.fixedToCamera = true;
buttonfire.events.onInputOver.add(function(){fire=true;});
buttonfire.events.onInputOut.add(function(){fire=false;});
buttonfire.events.onInputDown.add(function(){fire=true;});
buttonfire.events.onInputUp.add(function(){fire=false;});        
buttonleft = game.add.button(40, 312, 'buttonhorizontal', null, this, 0, 1, 0, 1);
buttonleft.anchor.setTo(0.5, 0.5);
buttonleft.fixedToCamera = true;
buttonleft.events.onInputOver.add(function(){left=true;});
buttonleft.events.onInputOut.add(function(){left=false;});
buttonleft.events.onInputDown.add(function(){left=true;});
buttonleft.events.onInputUp.add(function(){left=false;});
buttonbottomleft = game.add.button(48, 352, 'buttondiagonal', null, this, 6, 4, 6, 4);
buttonbottomleft.anchor.setTo(0.5, 0.5);
buttonbottomleft.fixedToCamera = true;
buttonbottomleft.events.onInputOver.add(function(){left=true;duck=true;});
buttonbottomleft.events.onInputOut.add(function(){left=false;duck=false;});
buttonbottomleft.events.onInputDown.add(function(){left=true;duck=true;});
buttonbottomleft.events.onInputUp.add(function(){left=false;duck=false;});
buttonright = game.add.button(136, 312, 'buttonhorizontal', null, this, 0, 1, 0, 1);
buttonright.anchor.setTo(0.5, 0.5);
buttonright.fixedToCamera = true;
buttonright.events.onInputOver.add(function(){right=true;});
buttonright.events.onInputOut.add(function(){right=false;});
buttonright.events.onInputDown.add(function(){right=true;});
buttonright.events.onInputUp.add(function(){right=false;});
buttonbottomright = game.add.button(128, 352, 'buttondiagonal', null, this, 7, 5, 7, 5);
buttonbottomright.anchor.setTo(0.5, 0.5);
buttonbottomright.fixedToCamera = true;
buttonbottomright.events.onInputOver.add(function(){right=true;duck=true;});
buttonbottomright.events.onInputOut.add(function(){right=false;duck=false;});
buttonbottomright.events.onInputDown.add(function(){right=true;duck=true;});
buttonbottomright.events.onInputUp.add(function(){right=false;duck=false;});
buttondown = game.add.button(88, 360, 'buttonvertical', null, this, 0, 1, 0, 1);
buttondown.anchor.setTo(0.5, 0.5);
buttondown.fixedToCamera = true;
buttondown.events.onInputOver.add(function(){duck=true;});
buttondown.events.onInputOut.add(function(){duck=false;});
buttondown.events.onInputDown.add(function(){duck=true;});
buttondown.events.onInputUp.add(function(){duck=false;});

因为它们是以一种非DRY的方式创建的，而且我觉得效率很低，所以我决定我的按钮应该有一个游戏板按钮类，它们都继承自这个类。不幸的是，我在尝试使这个按钮类工作时遇到了很多问题。

我在这里有一个例子，它模拟了我在游戏中要做的事情。

（这是我的例子的源代码）

// Global constants
var GAME_WIDTH = 800;
var GAME_HEIGHT = 600;
var ORIGIN = 0;
var TEXT_X_POS = 50;
var TEXT_Y_POS = 100;
var TEXT_STYLE = { fontSize: "16px" };
var RIGHT_BUTTON_X_POS = 600;
var RIGHT_BUTTON_Y_POS = 400;
var LEFT_BUTTON_X_POS = 100;
var LEFT_BUTTON_Y_POS = 400;
var PHASER_DUDE_Y_POS = 300;
var PHASER_DUDE_GRAVITY = 300;
var PHASER_DUDE_RIGHT_VELOCITY = 100;
var PHASER_DUDE_LEFT_VELOCITY = -100;
var STOPPED = 0;
// Global variables
var background;
var rightButton;
var movingRight;
var rightButtonDown;
var leftButton;
var movingLeft;
var leftButtonDown;
var phaserDude;
var rightKey;
var leftKey;
// New instance of Phaser.Game
var game = new Phaser.Game(GAME_WIDTH, GAME_HEIGHT, Phaser.AUTO, "game", {preload: preload, create: create, update: update});
// Mobile button class
var MobileButton = function (button, movingInADirection, isTheButtonDown, pressedMethod) {
    button.events.onInputOver.add(function () {
        if (isTheButtonDown === true) {
            movingInADirection = true;
        }
    });
    button.events.onInputDown.add(function () {
        isTheButtonDown = true;
        movingInADirection = true;
    });
    button.events.onInputUp.add(function () {
        movingInADirection = false;
    });
};
function preload () {
    game.load.image("background", "sprites/sky.png");
    game.load.image("left arrow", "sprites/left_arrow.png");
    game.load.image("right arrow", "sprites/right_arrow.png");
    game.load.image("phaser dude", "sprites/phaser_dude.png");
}
function create () {
    background = game.add.image(ORIGIN, ORIGIN, "background");
    game.add.text(TEXT_X_POS, TEXT_Y_POS, "Use the arrow keys or the arrow buttons below to move", TEXT_STYLE);
    rightButton = game.add.button(RIGHT_BUTTON_X_POS, RIGHT_BUTTON_Y_POS, "right arrow", moveRight);
    leftButtonDown = game.add.button(LEFT_BUTTON_X_POS, LEFT_BUTTON_Y_POS, "left arrow", moveLeft);
    phaserDude = game.add.sprite(game.world.centerX, PHASER_DUDE_Y_POS, "phaser dude");
    game.physics.arcade.enable(phaserDude);
    phaserDude.body.collideWorldBounds = true;
    phaserDude.body.gravity.y = PHASER_DUDE_GRAVITY;
    rightKey = game.input.keyboard.addKey(Phaser.Keyboard.RIGHT);
    leftKey = game.input.keyboard.addKey(Phaser.Keyboard.LEFT);
}
function update () {
    stopMoving();
    if (leftKey.isDown || movingLeft === true) {
        moveLeft();
    }
    if (rightKey.isDown || movingRight === true) {
        moveRight();
    }
}
function moveRight () {
    phaserDude.body.velocity.x = PHASER_DUDE_RIGHT_VELOCITY;
}
function moveLeft () {
    phaserDude.body.velocity.x = PHASER_DUDE_LEFT_VELOCITY;
}
function stopMoving () {
    phaserDude.body.velocity.x = STOPPED;
}

正如你所看到的，箭头键可以很好地移动精灵，但移动按钮不能很好地工作；他们只移动精灵一帧，然后它又停止移动。我不知道为什么钥匙能用，但移动按钮却不行。问题似乎是类中的代码没有按照我认为应该运行的方式运行（即，似乎所有与onInputOver、onInputDown和onInputUp事件有关的代码都没有正确运行，并且类只关注按下按钮时要运行的方法）。有人能弄清楚我的按钮类出了什么问题吗？