index.js

var Emitter = require('events/')
var map = [
  'left',
  'middle',
  'right'
]

module.exports = pressed

function pressed (element, preventDefault) {
  var mouse = new Emitter()

  mouse.left = false
  mouse.right = false
  mouse.middle = false
  mouse.dispose = dispose

  if (typeof window !== 'undefined') {
    element = element || window
    element.addEventListener('mousedown', mousedown, false)
    window.addEventListener('mouseup', mouseup, false)

    if (preventDefault) {
      element.addEventListener('contextmenu', preventDefaulter, false)
    }
  }

  return mouse

  function mousedown (e) {
    mouse.right = false
    mouse[map[e.button]] = true
    mouse.emit('down', e)

    if (!preventDefault) return
    if (!e.preventDefault) return false
    e.preventDefault()
    e.stopPropagation()
  }

  function mouseup (e) {
    mouse.right = false
    mouse[map[e.button]] = false
    mouse.emit('up', e)

    if (!preventDefault) return
    if (!e.preventDefault) return
    e.preventDefault()
    e.stopPropagation()
  }

  function preventDefaulter (e) {
    return e.preventDefault && e.preventDefault() && false
  }

  function dispose () {
    mouse.left = false
    mouse.right = false
    mouse.middle = false

    if (element) {
      element.removeEventListener('contextmenu', preventDefaulter, false)
      element.removeEventListener('mousedown', mousedown, false)
      window.removeEventListener('mouseup', mouseup, false)
    }
  }
}