TouchManager.js

var $ = require('jquery')

var TouchManager = function (callbacks) {

    this.touchState = {
        currentY: null,
        currentX: null,

        startY: null,
        startX: null,

        lastDeltaY: null,
        lastDeltaX: null,

        lastDirection: null
    }

    this.callbacks = callbacks || {}    

    this.doBindings()    
}


TouchManager.prototype.doBindings = function() {    
    $('body').on('touchstart', this.touchStart.bind(this))        
    $('body').on('touchmove', this.touchMove.bind(this))        
    $('body').on('touchend touchleave touchcancel', this.touchEnd.bind(this))        
}

TouchManager.prototype.touchStart = function(e) {
    this.touchState.currentY = e.originalEvent.touches[0].clientY
    this.touchState.startY = e.originalEvent.touches[0].clientY

    this.touchState.currentX = e.originalEvent.touches[0].clientX
    this.touchState.startX = e.originalEvent.touches[0].clientX
    
    this.touchState.lastDeltaY = this.touchState.lastDeltaX = 0

    if (this.callbacks.onStart)
        this.callbacks.onStart()    
}

TouchManager.prototype.touchMove = function(e) {
    e.preventDefault()

    var eventY = e.originalEvent.touches[0].clientY,
        eventX = e.originalEvent.touches[0].clientX
    
    console.log(this.touchState)

    this.touchState.lastDeltaY = eventY - this.touchState.currentY    
    this.touchState.lastDeltaX = eventX - this.touchState.currentX

    this.touchState.currentY = eventY
    this.touchState.currentX = eventX

    if (this.callbacks.onMove)
        this.callbacks.onMove(this.touchState)    

    if (Math.abs(this.touchState.lastDeltaY) > Math.abs(this.touchState.lastDeltaX) 
        || (!this.callbacks.onRight && !this.callbacks.onLeft) ) {

        if (this.touchState.lastDeltaY > 0) {
            this.touchState.lastDirection = 'up'
            if (this.callbacks.onUp)
                this.callbacks.onUp(this.touchState)
        }

        else if (this.touchState.lastDeltaY < 0) {
            this.touchState.lastDirection = 'down'
            if (this.callbacks.onDown)
                this.callbacks.onDown(this.touchState)
        }

    }

    if (Math.abs(this.touchState.lastDeltaX) > Math.abs(this.touchState.lastDeltaY)
        || (!this.callbacks.onUp && !this.callbacks.onDown) ) {

        if (this.touchState.lastDeltaX > 0) {
            this.touchState.lastDirection = 'right'
            if (this.callbacks.onRight)
                this.callbacks.onRight(this.touchState)
        }

        else if (this.touchState.lastDeltaX < 0) {
            this.touchState.lastDirection = 'left'
            if (this.callbacks.onLeft)
                this.callbacks.onLeft(this.touchState)
        }
    }

    console.log(this.touchState)
}

TouchManager.prototype.touchEnd = function(e) {
    if (this.callbacks.onEnd)
        this.callbacks.onEnd(this.touchState)


    this.touchState.currentY = null
    this.lastDeltaY = null
    this.lastDirection = null
}

module.exports = TouchManager