key-event.js

/* eslint-env node, browser */
var KeyEvent = function (data, type) {
  'use strict'
  this.keyCode = 'keyCode' in data ? data.keyCode : 0
  this.charCode = 'charCode' in data ? data.charCode : 0

  var modifiers = 'modifiers' in data ? data.modifiers : []

  this.ctrlKey = false
  this.metaKey = false
  this.altKey = false
  this.shiftKey = false

  for (var i = 0; i < modifiers.length; i++) {
    this[modifiers[i] + 'Key'] = true
  }

  this.type = type || 'keypress'
}

KeyEvent.prototype.toNative = function () {
  'use strict'
  var event = document.createEvent ? document.createEvent('Event') : document.createEventObject()

  if (event.initEvent) {
    event.initEvent(this.type, true, true)
  }

  event.keyCode = this.keyCode
  event.which = this.charCode || this.keyCode
  event.shiftKey = this.shiftKey
  event.metaKey = this.metaKey
  event.altKey = this.altKey
  event.ctrlKey = this.ctrlKey

  return event
}

KeyEvent.prototype.fire = function (element) {
  'use strict'
  var event = this.toNative()
  if (element.dispatchEvent) {
    element.dispatchEvent(event)
    return
  }

  element.fireEvent('on' + this.type, event)
}

// simulates complete key event as if the user pressed the key in the browser
// triggers a keydown, then a keypress, then a keyup
KeyEvent.simulate = function (charCode, keyCode, modifiers, element, repeat) {
  'use strict'
  modifiers = modifiers || []

  if (element === undefined) {
    element = document.documentElement
  }

  if (repeat === undefined) {
    repeat = 1
  }

  var modifierToKeyCode = {
    'shift': 16,
    'ctrl': 17,
    'alt': 18,
    'meta': 91
  }

  // if the key is a modifier then take it out of the regular
  // keypress/keydown
  if (keyCode === 16 || keyCode === 17 || keyCode === 18 || keyCode === 91) {
    repeat = 0
  }

  var modifiersToInclude = []
  var keyEvents = []

  // modifiers would go down first
  for (var i = 0; i < modifiers.length; i++) {
    modifiersToInclude.push(modifiers[i])
    keyEvents.push(new KeyEvent({
      charCode: 0,
      keyCode: modifierToKeyCode[modifiers[i]],
      modifiers: modifiersToInclude
    }, 'keydown'))
  }

  // @todo factor in duration for these
  while (repeat > 0) {
    keyEvents.push(new KeyEvent({
      charCode: 0,
      keyCode: keyCode,
      modifiers: modifiersToInclude
    }, 'keydown'))

    keyEvents.push(new KeyEvent({
      charCode: charCode,
      keyCode: charCode,
      modifiers: modifiersToInclude
    }, 'keypress'))

    repeat--
  }

  keyEvents.push(new KeyEvent({
    charCode: 0,
    keyCode: keyCode,
    modifiers: modifiersToInclude
  }, 'keyup'))

  // now lift up the modifier keys
  for (i = 0; i < modifiersToInclude.length; i++) {
    var modifierKeyCode = modifierToKeyCode[modifiersToInclude[i]]
    modifiersToInclude.splice(i, 1)
    keyEvents.push(new KeyEvent({
      charCode: 0,
      keyCode: modifierKeyCode,
      modifiers: modifiersToInclude
    }, 'keyup'))
  }

  for (i = 0; i < keyEvents.length; i++) {
    // console.log("firing", keyEvents[i].type, keyEvents[i].keyCode, keyEvents[i].charCode)
    keyEvents[i].fire(element)
  }
}

module.exports = KeyEvent