###
#
# More info at [www.dropzonejs.com](http://www.dropzonejs.com)
#
# Copyright (c) 2012, Matias Meno
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
###


noop = ->


# The Emitter class provides the ability to call `.on()` on Dropzone to listen
# to events.
# It is strongly based on component's emitter class, and I removed the
# functionality because of the dependency hell with different frameworks.
class Emitter

  # Add an event listener for given event
  addEventListener: @::on
  on: (event, fn) ->
    @_callbacks = @_callbacks || {}
    # Create namespace for this event
    @_callbacks[event] = [] unless @_callbacks[event]
    @_callbacks[event].push fn
    return @


  emit: (event, args...) ->
    @_callbacks = @_callbacks || {}
    callbacks = @_callbacks[event]

    if callbacks
      callback.apply @, args for callback in callbacks

    return @

  # Remove event listener for given event. If fn is not provided, all event
  # listeners for that event will be removed. If neither is provided, all
  # event listeners will be removed.
  removeListener: @::off
  removeAllListeners: @::off
  removeEventListener: @::off
  off: (event, fn) ->
    if !@_callbacks || arguments.length == 0
      @_callbacks = {}
      return @

    # specific event
    callbacks = @_callbacks[event]
    return @ unless callbacks

    # remove all handlers
    if arguments.length == 1
      delete @_callbacks[event]
      return @

    # remove specific handler
    for callback, i in callbacks
      if callback == fn
        callbacks.splice i, 1
        break

    return @

class Dropzone extends Emitter

  # Exposing the emitter class, mainly for tests
  Emitter: Emitter

  ###
  This is a list of all available events you can register on a dropzone object.

  You can register an event handler like this:

      dropzone.on("dragEnter", function() { });

  ###
  events: [
    "drop"
    "dragstart"
    "dragend"
    "dragenter"
    "dragover"
    "dragleave"
    "addedfile"
    "removedfile"
    "thumbnail"
    "error"
    "errormultiple"
    "processing"
    "processingmultiple"
    "uploadprogress"
    "totaluploadprogress"
    "sending"
    "sendingmultiple"
    "success"
    "successmultiple"
    "canceled"
    "canceledmultiple"
    "complete"
    "completemultiple"
    "reset"
    "maxfilesexceeded"
    "maxfilesreached"
    "queuecomplete"
  ]



  defaultOptions:
    url: null
    method: "post"
    withCredentials: no
    parallelUploads: 2
    uploadMultiple: no # Whether to send multiple files in one request.
    maxFilesize: 256 # in MB
    paramName: "file" # The name of the file param that gets transferred.
    createImageThumbnails: true
    maxThumbnailFilesize: 10 # in MB. When the filename exceeds this limit, the thumbnail will not be generated.
    thumbnailWidth: 120
    thumbnailHeight: 120

    # The base that is used to calculate the filesize. You can change this to
    # 1024 if you would rather display kibibytes, mebibytes, etc...
    filesizeBase: 1000

    # Can be used to limit the maximum number of files that will be handled
    # by this Dropzone
    maxFiles: null

    # The base used to calculate filesizes. 1024 is technically incorrect,
    # because `1024 bytes` are `1 kibibyte` not `1 kilobyte`.
    # You can change this to `1024` if you don't care about validity.
    filesizeBase: 1000

    # Can be an object of additional parameters to transfer to the server.
    # This is the same as adding hidden input fields in the form element.
    params: { }

    # If true, the dropzone will present a file selector when clicked.
    clickable: yes

    # Whether hidden files in directories should be ignored.
    ignoreHiddenFiles: yes

    # You can set accepted mime types here.
    #
    # The default implementation of the `accept()` function will check this
    # property, and if the Dropzone is clickable this will be used as
    # `accept` attribute.
    #
    # This is a comma separated list of mime types or extensions. E.g.:
    #
    #     audio/*,video/*,image/png,.pdf
    #
    # See https://developer.mozilla.org/en-US/docs/HTML/Element/input#attr-accept
    # for a reference.
    acceptedFiles: null

    # @deprecated
    # Use acceptedFiles instead.
    acceptedMimeTypes: null

    # If false, files will be added to the queue but the queue will not be
    # processed automatically.
    # This can be useful if you need some additional user input before sending
    # files (or if you want want all files sent at once).
    # If you're ready to send the file simply call myDropzone.processQueue()
    autoProcessQueue: on

    # If false, files added to the dropzone will not be queued by default.
    # You'll have to call `enqueueFile(file)` manually.
    autoQueue: on

    # If true, Dropzone will add a link to each file preview to cancel/remove
    # the upload.
    # See dictCancelUpload and dictRemoveFile to use different words.
    addRemoveLinks: no

    # A CSS selector or HTML element for the file previews container.
    # If null, the dropzone element itself will be used.
    # If false, previews won't be rendered.
    previewsContainer: null

    # If null, no capture type will be specified
    # If camera, mobile devices will skip the file selection and choose camera
    # If microphone, mobile devices will skip the file selection and choose the microphone
    # If camcorder, mobile devices will skip the file selection and choose the camera in video mode
    # On apple devices multiple must be set to false.  AcceptedFiles may need to
    # be set to an appropriate mime type (e.g. "image/*", "audio/*", or "video/*").
    capture: null

    # Dictionary

    # The text used before any files are dropped
    dictDefaultMessage: "Drop files here to upload"

    # The text that replaces the default message text it the browser is not supported
    dictFallbackMessage: "Your browser does not support drag'n'drop file uploads."

    # The text that will be added before the fallback form
    # If null, no text will be added at all.
    dictFallbackText: "Please use the fallback form below to upload your files like in the olden days."

    # If the filesize is too big.
    dictFileTooBig: "File is too big ({{filesize}}MiB). Max filesize: {{maxFilesize}}MiB."

    # If the file doesn't match the file type.
    dictInvalidFileType: "You can't upload files of this type."

    # If the server response was invalid.
    dictResponseError: "Server responded with {{statusCode}} code."

    # If used, the text to be used for the cancel upload link.
    dictCancelUpload: "Cancel upload"

    # If used, the text to be used for confirmation when cancelling upload.
    dictCancelUploadConfirmation: "Are you sure you want to cancel this upload?"

    # If used, the text to be used to remove a file.
    dictRemoveFile: "Remove file"

    # If this is not null, then the user will be prompted before removing a file.
    dictRemoveFileConfirmation: null

    # Displayed when the maxFiles have been exceeded
    # You can use {{maxFiles}} here, which will be replaced by the option.
    dictMaxFilesExceeded: "You can not upload any more files."


    # If `done()` is called without argument the file is accepted
    # If you call it with an error message, the file is rejected
    # (This allows for asynchronous validation).
    accept: (file, done) -> done()


    # Called when dropzone initialized
    # You can add event listeners here
    init: -> noop

    # Used to debug dropzone and force the fallback form.
    forceFallback: off

    # Called when the browser does not support drag and drop
    fallback: ->
      # This code should pass in IE7... :(
      @element.className = "#{@element.className} dz-browser-not-supported"

      for child in @element.getElementsByTagName "div"
        if /(^| )dz-message($| )/.test child.className
          messageElement = child
          child.className = "dz-message" # Removes the 'dz-default' class
          continue
      unless messageElement
        messageElement = Dropzone.createElement """<div class="dz-message"><span></span></div>"""
        @element.appendChild messageElement

      span = messageElement.getElementsByTagName("span")[0]
      span.textContent = @options.dictFallbackMessage if span

      @element.appendChild @getFallbackForm()



    # Gets called to calculate the thumbnail dimensions.
    #
    # You can use file.width, file.height, options.thumbnailWidth and
    # options.thumbnailHeight to calculate the dimensions.
    #
    # The dimensions are going to be used like this:
    #
    #     var info = @options.resize.call(this, file);
    #     ctx.drawImage(img, info.srcX, info.srcY, info.srcWidth, info.srcHeight, info.trgX, info.trgY, info.trgWidth, info.trgHeight);
    #
    #  srcX, srcy, trgX and trgY can be omitted (in which case 0 is assumed).
    #  trgWidth and trgHeight can be omitted (in which case the options.thumbnailWidth / options.thumbnailHeight are used)
    resize: (file) ->
      info =
        srcX: 0
        srcY: 0
        srcWidth: file.width
        srcHeight: file.height

      srcRatio = file.width / file.height

      info.optWidth = @options.thumbnailWidth
      info.optHeight = @options.thumbnailHeight

      # automatically calculate dimensions if not specified
      if !info.optWidth? and !info.optHeight?
        info.optWidth = info.srcWidth
        info.optHeight = info.srcHeight
      else if !info.optWidth?
        info.optWidth = srcRatio * info.optHeight
      else if !info.optHeight?
        info.optHeight = (1/srcRatio) * info.optWidth

      trgRatio = info.optWidth / info.optHeight

      if file.height < info.optHeight or file.width < info.optWidth
        # This image is smaller than the canvas
        info.trgHeight = info.srcHeight
        info.trgWidth = info.srcWidth

      else
        # Image is bigger and needs rescaling
        if srcRatio > trgRatio
          info.srcHeight = file.height
          info.srcWidth = info.srcHeight * trgRatio
        else
          info.srcWidth = file.width
          info.srcHeight = info.srcWidth / trgRatio

      info.srcX = (file.width - info.srcWidth) / 2
      info.srcY = (file.height - info.srcHeight) / 2

      return info


    ###
    Those functions register themselves to the events on init and handle all
    the user interface specific stuff. Overwriting them won't break the upload
    but can break the way it's displayed.
    You can overwrite them if you don't like the default behavior. If you just
    want to add an additional event handler, register it on the dropzone object
    and don't overwrite those options.
    ###




    # Those are self explanatory and simply concern the DragnDrop.
    drop: (e) -> @element.classList.remove "dz-drag-hover"
    dragstart: noop
    dragend: (e) -> @element.classList.remove "dz-drag-hover"
    dragenter: (e) -> @element.classList.add "dz-drag-hover"
    dragover: (e) -> @element.classList.add "dz-drag-hover"
    dragleave: (e) -> @element.classList.remove "dz-drag-hover"

    paste: noop

    # Called whenever there are no files left in the dropzone anymore, and the
    # dropzone should be displayed as if in the initial state.
    reset: ->
      @element.classList.remove "dz-started"

    # Called when a file is added to the queue
    # Receives `file`
    addedfile: (file) ->
      @element.classList.add "dz-started" if @element == @previewsContainer

      if @previewsContainer
        file.previewElement = Dropzone.createElement @options.previewTemplate.trim()
        file.previewTemplate = file.previewElement # Backwards compatibility

        @previewsContainer.appendChild file.previewElement
        node.textContent = file.name for node in file.previewElement.querySelectorAll("[data-dz-name]")
        node.innerHTML = @filesize file.size for node in file.previewElement.querySelectorAll("[data-dz-size]")

        if @options.addRemoveLinks
          file._removeLink = Dropzone.createElement """<a class="dz-remove" href="javascript:undefined;" data-dz-remove>#{@options.dictRemoveFile}</a>"""
          file.previewElement.appendChild file._removeLink

        removeFileEvent = (e) =>
          e.preventDefault()
          e.stopPropagation()
          if file.status == Dropzone.UPLOADING
            Dropzone.confirm @options.dictCancelUploadConfirmation, => @removeFile file
          else
            if @options.dictRemoveFileConfirmation
              Dropzone.confirm @options.dictRemoveFileConfirmation, => @removeFile file
            else
              @removeFile file

        removeLink.addEventListener "click", removeFileEvent for removeLink in file.previewElement.querySelectorAll("[data-dz-remove]")


    # Called whenever a file is removed.
    removedfile: (file) ->
      file.previewElement?.parentNode.removeChild file.previewElement if file.previewElement
      @_updateMaxFilesReachedClass()

    # Called when a thumbnail has been generated
    # Receives `file` and `dataUrl`
    thumbnail: (file, dataUrl) ->
      if file.previewElement
        file.previewElement.classList.remove "dz-file-preview"
        for thumbnailElement in file.previewElement.querySelectorAll("[data-dz-thumbnail]")
          thumbnailElement.alt = file.name
          thumbnailElement.src = dataUrl

        setTimeout (=> file.previewElement.classList.add "dz-image-preview"), 1

    # Called whenever an error occurs
    # Receives `file` and `message`
    error: (file, message) ->
      if file.previewElement
        file.previewElement.classList.add "dz-error"
        message = message.error if typeof message != "String" and message.error
        node.textContent = message for node in file.previewElement.querySelectorAll("[data-dz-errormessage]")

    errormultiple: noop

    # Called when a file gets processed. Since there is a cue, not all added
    # files are processed immediately.
    # Receives `file`
    processing: (file) ->
      if file.previewElement
        file.previewElement.classList.add "dz-processing"
        file._removeLink.textContent = @options.dictCancelUpload if file._removeLink

    processingmultiple: noop

    # Called whenever the upload progress gets updated.
    # Receives `file`, `progress` (percentage 0-100) and `bytesSent`.
    # To get the total number of bytes of the file, use `file.size`
    uploadprogress: (file, progress, bytesSent) ->
      if file.previewElement
        for node in file.previewElement.querySelectorAll("[data-dz-uploadprogress]")
          if node.nodeName is 'PROGRESS'
            node.value = progress
          else
            node.style.width = "#{progress}%"

    # Called whenever the total upload progress gets updated.
    # Called with totalUploadProgress (0-100), totalBytes and totalBytesSent
    totaluploadprogress: noop

    # Called just before the file is sent. Gets the `xhr` object as second
    # parameter, so you can modify it (for example to add a CSRF token) and a
    # `formData` object to add additional information.
    sending: noop

    sendingmultiple: noop

    # When the complete upload is finished and successful
    # Receives `file`
    success: (file) ->
      file.previewElement.classList.add "dz-success" if file.previewElement

    successmultiple: noop

    # When the upload is canceled.
    canceled: (file) -> @emit "error", file, "Upload canceled."

    canceledmultiple: noop

    # When the upload is finished, either with success or an error.
    # Receives `file`
    complete: (file) ->
      file._removeLink.textContent = @options.dictRemoveFile if file._removeLink
      file.previewElement.classList.add "dz-complete" if file.previewElement

    completemultiple: noop

    maxfilesexceeded: noop

    maxfilesreached: noop
    
    queuecomplete: noop



    # This template will be chosen when a new file is dropped.
    previewTemplate:  """
                      <div class="dz-preview dz-file-preview">
                        <div class="dz-image"><img data-dz-thumbnail /></div>
                        <div class="dz-details">
                          <div class="dz-size"><span data-dz-size></span></div>
                          <div class="dz-filename"><span data-dz-name></span></div>
                        </div>
                        <div class="dz-progress"><span class="dz-upload" data-dz-uploadprogress></span></div>
                        <div class="dz-error-message"><span data-dz-errormessage></span></div>
                        <div class="dz-success-mark">
                          <svg width="54px" height="54px" viewBox="0 0 54 54" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:sketch="http://www.bohemiancoding.com/sketch/ns">
                            <title>Check</title>
                            <defs></defs>
                            <g id="Page-1" stroke="none" stroke-width="1" fill="none" fill-rule="evenodd" sketch:type="MSPage">
                              <path d="M23.5,31.8431458 L17.5852419,25.9283877 C16.0248253,24.3679711 13.4910294,24.366835 11.9289322,25.9289322 C10.3700136,27.4878508 10.3665912,30.0234455 11.9283877,31.5852419 L20.4147581,40.0716123 C20.5133999,40.1702541 20.6159315,40.2626649 20.7218615,40.3488435 C22.2835669,41.8725651 24.794234,41.8626202 26.3461564,40.3106978 L43.3106978,23.3461564 C44.8771021,21.7797521 44.8758057,19.2483887 43.3137085,17.6862915 C41.7547899,16.1273729 39.2176035,16.1255422 37.6538436,17.6893022 L23.5,31.8431458 Z M27,53 C41.3594035,53 53,41.3594035 53,27 C53,12.6405965 41.3594035,1 27,1 C12.6405965,1 1,12.6405965 1,27 C1,41.3594035 12.6405965,53 27,53 Z" id="Oval-2" stroke-opacity="0.198794158" stroke="#747474" fill-opacity="0.816519475" fill="#FFFFFF" sketch:type="MSShapeGroup"></path>
                            </g>
                          </svg>
                        </div>
                        <div class="dz-error-mark">
                          <svg width="54px" height="54px" viewBox="0 0 54 54" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:sketch="http://www.bohemiancoding.com/sketch/ns">
                            <title>Error</title>
                            <defs></defs>
                            <g id="Page-1" stroke="none" stroke-width="1" fill="none" fill-rule="evenodd" sketch:type="MSPage">
                              <g id="Check-+-Oval-2" sketch:type="MSLayerGroup" stroke="#747474" stroke-opacity="0.198794158" fill="#FFFFFF" fill-opacity="0.816519475">
                                <path d="M32.6568542,29 L38.3106978,23.3461564 C39.8771021,21.7797521 39.8758057,19.2483887 38.3137085,17.6862915 C36.7547899,16.1273729 34.2176035,16.1255422 32.6538436,17.6893022 L27,23.3431458 L21.3461564,17.6893022 C19.7823965,16.1255422 17.2452101,16.1273729 15.6862915,17.6862915 C14.1241943,19.2483887 14.1228979,21.7797521 15.6893022,23.3461564 L21.3431458,29 L15.6893022,34.6538436 C14.1228979,36.2202479 14.1241943,38.7516113 15.6862915,40.3137085 C17.2452101,41.8726271 19.7823965,41.8744578 21.3461564,40.3106978 L27,34.6568542 L32.6538436,40.3106978 C34.2176035,41.8744578 36.7547899,41.8726271 38.3137085,40.3137085 C39.8758057,38.7516113 39.8771021,36.2202479 38.3106978,34.6538436 L32.6568542,29 Z M27,53 C41.3594035,53 53,41.3594035 53,27 C53,12.6405965 41.3594035,1 27,1 C12.6405965,1 1,12.6405965 1,27 C1,41.3594035 12.6405965,53 27,53 Z" id="Oval-2" sketch:type="MSShapeGroup"></path>
                              </g>
                            </g>
                          </svg>
                        </div>
                      </div>
                      """

  # global utility
  extend = (target, objects...) ->
    for object in objects
      target[key] = val for key, val of object
    target

  constructor: (@element, options) ->
    # For backwards compatibility since the version was in the prototype previously
    @version = Dropzone.version

    @defaultOptions.previewTemplate = @defaultOptions.previewTemplate.replace /\n*/g, ""

    @clickableElements = [ ]
    @listeners = [ ]
    @files = [] # All files

    @element = document.querySelector @element if typeof @element == "string"

    # Not checking if instance of HTMLElement or Element since IE9 is extremely weird.
    throw new Error "Invalid dropzone element." unless @element and @element.nodeType?

    throw new Error "Dropzone already attached." if @element.dropzone

    # Now add this dropzone to the instances.
    Dropzone.instances.push @

    # Put the dropzone inside the element itself.
    @element.dropzone = @

    elementOptions = Dropzone.optionsForElement(@element) ? { }

    @options = extend { }, @defaultOptions, elementOptions, options ? { }

    # If the browser failed, just call the fallback and leave
    return @options.fallback.call this if @options.forceFallback or !Dropzone.isBrowserSupported()

    # @options.url = @element.getAttribute "action" unless @options.url?
    @options.url = @element.getAttribute "action" unless @options.url?

    throw new Error "No URL provided." unless @options.url

    throw new Error "You can't provide both 'acceptedFiles' and 'acceptedMimeTypes'. 'acceptedMimeTypes' is deprecated." if @options.acceptedFiles and @options.acceptedMimeTypes

    # Backwards compatibility
    if @options.acceptedMimeTypes
      @options.acceptedFiles = @options.acceptedMimeTypes
      delete @options.acceptedMimeTypes

    @options.method = @options.method.toUpperCase()

    if (fallback = @getExistingFallback()) and fallback.parentNode
      # Remove the fallback
      fallback.parentNode.removeChild fallback

    # Display previews in the previewsContainer element or the Dropzone element unless explicitly set to false
    if @options.previewsContainer != false
      if @options.previewsContainer
        @previewsContainer = Dropzone.getElement @options.previewsContainer, "previewsContainer"
      else
        @previewsContainer = @element

    if @options.clickable
      if @options.clickable == yes
        @clickableElements = [ @element ]
      else
        @clickableElements = Dropzone.getElements @options.clickable, "clickable"


    @init()


  # Returns all files that have been accepted
  getAcceptedFiles: -> file for file in @files when file.accepted

  # Returns all files that have been rejected
  # Not sure when that's going to be useful, but added for completeness.
  getRejectedFiles: -> file for file in @files when not file.accepted

  getFilesWithStatus: (status) -> file for file in @files when file.status == status

  # Returns all files that are in the queue
  getQueuedFiles: -> @getFilesWithStatus Dropzone.QUEUED

  getUploadingFiles: -> @getFilesWithStatus Dropzone.UPLOADING

  # Files that are either queued or uploading
  getActiveFiles: -> file for file in @files when file.status == Dropzone.UPLOADING or file.status == Dropzone.QUEUED


  init: ->
    # In case it isn't set already
    @element.setAttribute("enctype", "multipart/form-data") if @element.tagName == "form"

    if @element.classList.contains("dropzone") and !@element.querySelector(".dz-message")
      @element.appendChild Dropzone.createElement """<div class="dz-default dz-message"><span>#{@options.dictDefaultMessage}</span></div>"""

    if @clickableElements.length
      setupHiddenFileInput = =>
        document.body.removeChild @hiddenFileInput if @hiddenFileInput
        @hiddenFileInput = document.createElement "input"
        @hiddenFileInput.setAttribute "type", "file"
        @hiddenFileInput.setAttribute "multiple", "multiple" if !@options.maxFiles? || @options.maxFiles > 1
        @hiddenFileInput.className = "dz-hidden-input"

        @hiddenFileInput.setAttribute "accept", @options.acceptedFiles if @options.acceptedFiles?
        @hiddenFileInput.setAttribute "capture", @options.capture if @options.capture?

        # Not setting `display="none"` because some browsers don't accept clicks
        # on elements that aren't displayed.
        @hiddenFileInput.style.visibility = "hidden"
        @hiddenFileInput.style.position = "absolute"
        @hiddenFileInput.style.top = "0"
        @hiddenFileInput.style.left = "0"
        @hiddenFileInput.style.height = "0"
        @hiddenFileInput.style.width = "0"
        document.body.appendChild @hiddenFileInput
        @hiddenFileInput.addEventListener "change", =>
          files = @hiddenFileInput.files
          @addFile file for file in files if files.length
          setupHiddenFileInput()
      setupHiddenFileInput()

    @URL = window.URL ? window.webkitURL


    # Setup all event listeners on the Dropzone object itself.
    # They're not in @setupEventListeners() because they shouldn't be removed
    # again when the dropzone gets disabled.
    @on eventName, @options[eventName] for eventName in @events

    @on "uploadprogress", => @updateTotalUploadProgress()

    @on "removedfile", => @updateTotalUploadProgress()

    @on "canceled", (file) => @emit "complete", file

    # Emit a `queuecomplete` event if all files finished uploading.
    @on "complete", (file) =>
      if @getUploadingFiles().length == 0 and @getQueuedFiles().length == 0
        # This needs to be deferred so that `queuecomplete` really triggers after `complete`
        setTimeout (=> @emit "queuecomplete"), 0


    noPropagation = (e) ->
      e.stopPropagation()
      if e.preventDefault
        e.preventDefault()
      else
        e.returnValue = false

    # Create the listeners
    @listeners = [
      {
        element: @element
        events:
          "dragstart": (e) =>
            @emit "dragstart", e
          "dragenter": (e) =>
            noPropagation e
            @emit "dragenter", e
          "dragover": (e) =>
            # Makes it possible to drag files from chrome's download bar
            # http://stackoverflow.com/questions/19526430/drag-and-drop-file-uploads-from-chrome-downloads-bar
            # Try is required to prevent bug in Internet Explorer 11 (SCRIPT65535 exception)
            try efct = e.dataTransfer.effectAllowed
            e.dataTransfer.dropEffect = if 'move' == efct or 'linkMove' == efct then 'move' else 'copy'

            noPropagation e
            @emit "dragover", e
          "dragleave": (e) =>
            @emit "dragleave", e
          "drop": (e) =>
            noPropagation e
            @drop e
          "dragend": (e) =>
            @emit "dragend", e

          # This is disabled right now, because the browsers don't implement it properly.
          # "paste": (e) =>
          #   noPropagation e
          #   @paste e
      }
    ]

    @clickableElements.forEach (clickableElement) =>
      @listeners.push
        element: clickableElement
        events:
          "click": (evt) =>
            # Only the actual dropzone or the message element should trigger file selection
            if (clickableElement != @element) or (evt.target == @element or Dropzone.elementInside evt.target, @element.querySelector ".dz-message")
              @hiddenFileInput.click() # Forward the click


    @enable()

    @options.init.call @

  # Not fully tested yet
  destroy: ->
    @disable()
    @removeAllFiles true
    if @hiddenFileInput?.parentNode
      @hiddenFileInput.parentNode.removeChild @hiddenFileInput
      @hiddenFileInput = null
    delete @element.dropzone
    Dropzone.instances.splice Dropzone.instances.indexOf(this), 1


  updateTotalUploadProgress: ->
    totalBytesSent = 0
    totalBytes = 0

    activeFiles = @getActiveFiles()

    if activeFiles.length
      for file in @getActiveFiles()
        totalBytesSent += file.upload.bytesSent
        totalBytes += file.upload.total
      totalUploadProgress = 100 * totalBytesSent / totalBytes
    else
      totalUploadProgress = 100

    @emit "totaluploadprogress", totalUploadProgress, totalBytes, totalBytesSent

  # @options.paramName can be a function taking one parameter rather than a string.
  # A parameter name for a file is obtained simply by calling this with an index number.
  _getParamName: (n) ->
    if typeof @options.paramName is "function"
      @options.paramName n
    else
      "#{@options.paramName}#{if @options.uploadMultiple then "[#{n}]" else ""}"

  # Returns a form that can be used as fallback if the browser does not support DragnDrop
  #
  # If the dropzone is already a form, only the input field and button are returned. Otherwise a complete form element is provided.
  # This code has to pass in IE7 :(
  getFallbackForm: ->
    return existingFallback if existingFallback = @getExistingFallback()

    fieldsString = """<div class="dz-fallback">"""
    fieldsString += """<p>#{@options.dictFallbackText}</p>""" if @options.dictFallbackText
    fieldsString += """<input type="file" name="#{@_getParamName 0}" #{if @options.uploadMultiple then 'multiple="multiple"' } /><input type="submit" value="Upload!"></div>"""

    fields = Dropzone.createElement fieldsString
    if @element.tagName isnt "FORM"
      form = Dropzone.createElement("""<form action="#{@options.url}" enctype="multipart/form-data" method="#{@options.method}"></form>""")
      form.appendChild fields
    else
      # Make sure that the enctype and method attributes are set properly
      @element.setAttribute "enctype", "multipart/form-data"
      @element.setAttribute "method", @options.method
    form ? fields


  # Returns the fallback elements if they exist already
  #
  # This code has to pass in IE7 :(
  getExistingFallback: ->
    getFallback = (elements) -> return el for el in elements when /(^| )fallback($| )/.test el.className

    for tagName in [ "div", "form" ]
      return fallback if fallback = getFallback @element.getElementsByTagName tagName


  # Activates all listeners stored in @listeners
  setupEventListeners: ->
    for elementListeners in @listeners
      elementListeners.element.addEventListener event, listener, false for event, listener of elementListeners.events


  # Deactivates all listeners stored in @listeners
  removeEventListeners: ->
    for elementListeners in @listeners
      elementListeners.element.removeEventListener event, listener, false for event, listener of elementListeners.events

  # Removes all event listeners and cancels all files in the queue or being processed.
  disable: ->
    @clickableElements.forEach (element) -> element.classList.remove "dz-clickable"
    @removeEventListeners()

    @cancelUpload file for file in @files

  enable: ->
    @clickableElements.forEach (element) -> element.classList.add "dz-clickable"
    @setupEventListeners()

  # Returns a nicely formatted filesize
  filesize: (size) ->
    units = [ 'TB', 'GB', 'MB', 'KB', 'b' ]
    selectedSize = selectedUnit = null

    for unit, i in units
      cutoff = Math.pow(@options.filesizeBase, 4 - i) / 10

      if size >= cutoff
        selectedSize = size / Math.pow(@options.filesizeBase, 4 - i)
        selectedUnit = unit
        break

    selectedSize = Math.round(10 * selectedSize) / 10 # Cutting of digits

    "<strong>#{selectedSize}</strong> #{selectedUnit}"


  # Adds or removes the `dz-max-files-reached` class from the form.
  _updateMaxFilesReachedClass: ->
    if @options.maxFiles? and @getAcceptedFiles().length >= @options.maxFiles
      @emit 'maxfilesreached', @files if @getAcceptedFiles().length == @options.maxFiles
      @element.classList.add "dz-max-files-reached"
    else
      @element.classList.remove "dz-max-files-reached"



  drop: (e) ->
    return unless e.dataTransfer
    @emit "drop", e

    files = e.dataTransfer.files

    # Even if it's a folder, files.length will contain the folders.
    if files.length
      items = e.dataTransfer.items
      if items and items.length and (items[0].webkitGetAsEntry?)
        # The browser supports dropping of folders, so handle items instead of files
        @_addFilesFromItems items
      else
        @handleFiles files
    return

  paste: (e) ->
    return unless e?.clipboardData?.items?

    @emit "paste", e
    items = e.clipboardData.items

    @_addFilesFromItems items if items.length


  handleFiles: (files) ->
    @addFile file for file in files

  # When a folder is dropped (or files are pasted), items must be handled
  # instead of files.
  _addFilesFromItems: (items) ->
    for item in items
      if item.webkitGetAsEntry? and entry = item.webkitGetAsEntry()
        if entry.isFile
          @addFile item.getAsFile()
        else if entry.isDirectory
          # Append all files from that directory to files
          @_addFilesFromDirectory entry, entry.name
      else if item.getAsFile?
        if !item.kind? or item.kind == "file"
          @addFile item.getAsFile()


  # Goes through the directory, and adds each file it finds recursively
  _addFilesFromDirectory: (directory, path) ->
    dirReader = directory.createReader()

    entriesReader = (entries) =>
      for entry in entries
        if entry.isFile
          entry.file (file) =>
            return if @options.ignoreHiddenFiles and file.name.substring(0, 1) is '.'
            file.fullPath = "#{path}/#{file.name}"
            @addFile file
        else if entry.isDirectory
          @_addFilesFromDirectory entry, "#{path}/#{entry.name}"
      return

    dirReader.readEntries entriesReader, (error) -> console?.log? error



  # If `done()` is called without argument the file is accepted
  # If you call it with an error message, the file is rejected
  # (This allows for asynchronous validation)
  #
  # This function checks the filesize, and if the file.type passes the
  # `acceptedFiles` check.
  accept: (file, done) ->
    if file.size > @options.maxFilesize * 1024 * 1024
      done @options.dictFileTooBig.replace("{{filesize}}", Math.round(file.size / 1024 / 10.24) / 100).replace("{{maxFilesize}}", @options.maxFilesize)
    else unless Dropzone.isValidFile file, @options.acceptedFiles
      done @options.dictInvalidFileType
    else if @options.maxFiles? and @getAcceptedFiles().length >= @options.maxFiles
      done @options.dictMaxFilesExceeded.replace "{{maxFiles}}", @options.maxFiles
      @emit "maxfilesexceeded", file
    else
      @options.accept.call this, file, done

  addFile: (file) ->
    file.upload =
      progress: 0
      # Setting the total upload size to file.size for the beginning
      # It's actual different than the size to be transmitted.
      total: file.size
      bytesSent: 0
    @files.push file

    file.status = Dropzone.ADDED

    @emit "addedfile", file

    @_enqueueThumbnail file

    @accept file, (error) =>
      if error
        file.accepted = false
        @_errorProcessing [ file ], error # Will set the file.status
      else
        file.accepted = true
        @enqueueFile file if @options.autoQueue # Will set .accepted = true
      @_updateMaxFilesReachedClass()


  # Wrapper for enqueueFile
  enqueueFiles: (files) -> @enqueueFile file for file in files; null

  enqueueFile: (file) ->
    if file.status == Dropzone.ADDED and file.accepted == true
      file.status = Dropzone.QUEUED
      if @options.autoProcessQueue
        setTimeout (=> @processQueue()), 0 # Deferring the call
    else
      throw new Error "This file can't be queued because it has already been processed or was rejected."


  _thumbnailQueue: [ ]
  _processingThumbnail: no
  _enqueueThumbnail: (file) ->
    if @options.createImageThumbnails and file.type.match(/image.*/) and file.size <= @options.maxThumbnailFilesize * 1024 * 1024
      @_thumbnailQueue.push(file)
      setTimeout (=> @_processThumbnailQueue()), 0 # Deferring the call

  _processThumbnailQueue: ->
    return if @_processingThumbnail or @_thumbnailQueue.length == 0

    @_processingThumbnail = yes
    @createThumbnail @_thumbnailQueue.shift(), =>
      @_processingThumbnail = no
      @_processThumbnailQueue()


  # Can be called by the user to remove a file
  removeFile: (file) ->
    @cancelUpload file if file.status == Dropzone.UPLOADING
    @files = without @files, file

    @emit "removedfile", file
    @emit "reset" if @files.length == 0

  # Removes all files that aren't currently processed from the list
  removeAllFiles: (cancelIfNecessary = off) ->
    # Create a copy of files since removeFile() changes the @files array.
    for file in @files.slice()
      @removeFile file if file.status != Dropzone.UPLOADING || cancelIfNecessary
    return null

  createThumbnail: (file, callback) ->

    fileReader = new FileReader

    fileReader.onload = =>

      # Don't bother creating a thumbnail for SVG images since they're vector
      if file.type == "image/svg+xml"
        @emit "thumbnail", file, fileReader.result
        callback() if callback?
        return

      @createThumbnailFromUrl file, fileReader.result, callback

    fileReader.readAsDataURL file

  createThumbnailFromUrl: (file, imageUrl, callback) ->
    # Not using `new Image` here because of a bug in latest Chrome versions.
    # See https://github.com/enyo/dropzone/pull/226
    img = document.createElement "img"

    img.onload = =>
      file.width = img.width
      file.height = img.height

      resizeInfo = @options.resize.call @, file

      resizeInfo.trgWidth ?= resizeInfo.optWidth
      resizeInfo.trgHeight ?= resizeInfo.optHeight

      canvas = document.createElement "canvas"
      ctx = canvas.getContext "2d"
      canvas.width = resizeInfo.trgWidth
      canvas.height = resizeInfo.trgHeight

      # This is a bugfix for iOS' scaling bug.
      drawImageIOSFix ctx, img, resizeInfo.srcX ? 0, resizeInfo.srcY ? 0, resizeInfo.srcWidth, resizeInfo.srcHeight, resizeInfo.trgX ? 0, resizeInfo.trgY ? 0, resizeInfo.trgWidth, resizeInfo.trgHeight

      thumbnail = canvas.toDataURL "image/png"

      @emit "thumbnail", file, thumbnail
      callback() if callback?
      
    img.onerror = callback if callback?

    img.src = imageUrl


  # Goes through the queue and processes files if there aren't too many already.
  processQueue: ->
    parallelUploads = @options.parallelUploads
    processingLength = @getUploadingFiles().length
    i = processingLength

    # There are already at least as many files uploading than should be
    return if processingLength >= parallelUploads

    queuedFiles = @getQueuedFiles()

    return unless queuedFiles.length > 0

    if @options.uploadMultiple
      # The files should be uploaded in one request
      @processFiles queuedFiles.slice 0, (parallelUploads - processingLength)
    else
      while i < parallelUploads
        return unless queuedFiles.length # Nothing left to process
        @processFile queuedFiles.shift()
        i++


  # Wrapper for `processFiles`
  processFile: (file) -> @processFiles [ file ]


  # Loads the file, then calls finishedLoading()
  processFiles: (files) ->
    for file in files
      file.processing = yes # Backwards compatibility
      file.status = Dropzone.UPLOADING

      @emit "processing", file

    @emit "processingmultiple", files if @options.uploadMultiple

    @uploadFiles files



  _getFilesWithXhr: (xhr) -> files = (file for file in @files when file.xhr == xhr)


  # Cancels the file upload and sets the status to CANCELED
  # **if** the file is actually being uploaded.
  # If it's still in the queue, the file is being removed from it and the status
  # set to CANCELED.
  cancelUpload: (file) ->
    if file.status == Dropzone.UPLOADING
      groupedFiles = @_getFilesWithXhr file.xhr
      groupedFile.status = Dropzone.CANCELED for groupedFile in groupedFiles
      file.xhr.abort()
      @emit "canceled", groupedFile for groupedFile in groupedFiles
      @emit "canceledmultiple", groupedFiles if @options.uploadMultiple

    else if file.status in [ Dropzone.ADDED, Dropzone.QUEUED ]
      file.status = Dropzone.CANCELED
      @emit "canceled", file
      @emit "canceledmultiple", [ file ] if @options.uploadMultiple

    @processQueue() if @options.autoProcessQueue

  resolveOption = (option, args...) ->
    if typeof option == 'function'
      return option.apply(@, args)
    option

  # Wrapper for uploadFiles()
  uploadFile: (file) -> @uploadFiles [ file ]

  uploadFiles: (files) ->
    xhr = new XMLHttpRequest()

    # Put the xhr object in the file objects to be able to reference it later.
    file.xhr = xhr for file in files

    method = resolveOption @options.method, files
    url = resolveOption @options.url, files
    xhr.open method, url, true

    # Has to be after `.open()`. See https://github.com/enyo/dropzone/issues/179
    xhr.withCredentials = !!@options.withCredentials


    response = null

    handleError = =>
      for file in files
        @_errorProcessing files, response || @options.dictResponseError.replace("{{statusCode}}", xhr.status), xhr


    updateProgress = (e) =>
      if e?
        progress = 100 * e.loaded / e.total

        for file in files
          file.upload =
            progress: progress
            total: e.total
            bytesSent: e.loaded
      else
        # Called when the file finished uploading

        allFilesFinished = yes

        progress = 100

        for file in files
          allFilesFinished = no unless file.upload.progress == 100 and file.upload.bytesSent == file.upload.total
          file.upload.progress = progress
          file.upload.bytesSent = file.upload.total

        # Nothing to do, all files already at 100%
        return if allFilesFinished

      for file in files
        @emit "uploadprogress", file, progress, file.upload.bytesSent

    xhr.onload = (e) =>
      return if files[0].status == Dropzone.CANCELED

      return unless xhr.readyState is 4

      response = xhr.responseText

      if xhr.getResponseHeader("content-type") and ~xhr.getResponseHeader("content-type").indexOf "application/json"
        try
          response = JSON.parse response
        catch e
          response = "Invalid JSON response from server."

      updateProgress()

      unless 200 <= xhr.status < 300
        handleError()
      else
        @_finished files, response, e

    xhr.onerror = =>
      return if files[0].status == Dropzone.CANCELED
      handleError()

    # Some browsers do not have the .upload property
    progressObj = xhr.upload ? xhr
    progressObj.onprogress = updateProgress

    headers =
      "Accept": "application/json",
      "Cache-Control": "no-cache",
      "X-Requested-With": "XMLHttpRequest",

    extend headers, @options.headers if @options.headers

    xhr.setRequestHeader headerName, headerValue for headerName, headerValue of headers

    formData = new FormData()

    # Adding all @options parameters
    formData.append key, value for key, value of @options.params if @options.params

    # Let the user add additional data if necessary
    @emit "sending", file, xhr, formData for file in files
    @emit "sendingmultiple", files, xhr, formData if @options.uploadMultiple


    # Take care of other input elements
    if @element.tagName == "FORM"
      for input in @element.querySelectorAll "input, textarea, select, button"
        inputName = input.getAttribute "name"
        inputType = input.getAttribute "type"

        if input.tagName == "SELECT" and input.hasAttribute "multiple"
          # Possibly multiple values
          formData.append inputName, option.value for option in input.options when option.selected
        else if !inputType or (inputType.toLowerCase() not in [ "checkbox", "radio" ]) or input.checked
          formData.append inputName, input.value


    # Finally add the file
    # Has to be last because some servers (eg: S3) expect the file to be the
    # last parameter
    formData.append @_getParamName(i), files[i], files[i].name for i in [0..files.length-1]

    xhr.send formData


  # Called internally when processing is finished.
  # Individual callbacks have to be called in the appropriate sections.
  _finished: (files, responseText, e) ->
    for file in files
      file.status = Dropzone.SUCCESS
      @emit "success", file, responseText, e
      @emit "complete", file
    if @options.uploadMultiple
      @emit "successmultiple", files, responseText, e
      @emit "completemultiple", files

    @processQueue() if @options.autoProcessQueue

  # Called internally when processing is finished.
  # Individual callbacks have to be called in the appropriate sections.
  _errorProcessing: (files, message, xhr) ->
    for file in files
      file.status = Dropzone.ERROR
      @emit "error", file, message, xhr
      @emit "complete", file
    if @options.uploadMultiple
      @emit "errormultiple", files, message, xhr
      @emit "completemultiple", files

    @processQueue() if @options.autoProcessQueue



Dropzone.version = "4.0.1"


# This is a map of options for your different dropzones. Add configurations
# to this object for your different dropzone elemens.
#
# Example:
#
#     Dropzone.options.myDropzoneElementId = { maxFilesize: 1 };
#
# To disable autoDiscover for a specific element, you can set `false` as an option:
#
#     Dropzone.options.myDisabledElementId = false;
#
# And in html:
#
#     <form action="/upload" id="my-dropzone-element-id" class="dropzone"></form>
Dropzone.options = { }


# Returns the options for an element or undefined if none available.
Dropzone.optionsForElement = (element) ->
  # Get the `Dropzone.options.elementId` for this element if it exists
  if element.getAttribute("id") then Dropzone.options[camelize element.getAttribute "id"] else undefined


# Holds a list of all dropzone instances
Dropzone.instances = [ ]

# Returns the dropzone for given element if any
Dropzone.forElement = (element) ->
  element = document.querySelector element if typeof element == "string"
  throw new Error "No Dropzone found for given element. This is probably because you're trying to access it before Dropzone had the time to initialize. Use the `init` option to setup any additional observers on your Dropzone." unless element?.dropzone?
  return element.dropzone


# Set to false if you don't want Dropzone to automatically find and attach to .dropzone elements.
Dropzone.autoDiscover = on

# Looks for all .dropzone elements and creates a dropzone for them
Dropzone.discover = ->
  if document.querySelectorAll
    dropzones = document.querySelectorAll ".dropzone"
  else
    dropzones = [ ]
    # IE :(
    checkElements = (elements) ->
      for el in elements
        dropzones.push el if /(^| )dropzone($| )/.test el.className
    checkElements document.getElementsByTagName "div"
    checkElements document.getElementsByTagName "form"

  for dropzone in dropzones
    # Create a dropzone unless auto discover has been disabled for specific element
    new Dropzone dropzone unless Dropzone.optionsForElement(dropzone) == false



# Since the whole Drag'n'Drop API is pretty new, some browsers implement it,
# but not correctly.
# So I created a blacklist of userAgents. Yes, yes. Browser sniffing, I know.
# But what to do when browsers *theoretically* support an API, but crash
# when using it.
#
# This is a list of regular expressions tested against navigator.userAgent
#
# ** It should only be used on browser that *do* support the API, but
# incorrectly **
#
Dropzone.blacklistedBrowsers = [
  # The mac os version of opera 12 seems to have a problem with the File drag'n'drop API.
  /opera.*Macintosh.*version\/12/i
  # /MSIE\ 10/i
]


# Checks if the browser is supported
Dropzone.isBrowserSupported = ->
  capableBrowser = yes

  if window.File and window.FileReader and window.FileList and window.Blob and window.FormData and document.querySelector
    unless "classList" of document.createElement "a"
      capableBrowser = no
    else
      # The browser supports the API, but may be blacklisted.
      for regex in Dropzone.blacklistedBrowsers
        if regex.test navigator.userAgent
          capableBrowser = no
          continue
  else
    capableBrowser = no

  capableBrowser




# Returns an array without the rejected item
without = (list, rejectedItem) -> item for item in list when item isnt rejectedItem

# abc-def_ghi -> abcDefGhi
camelize = (str) -> str.replace /[\-_](\w)/g, (match) -> match.charAt(1).toUpperCase()

# Creates an element from string
Dropzone.createElement = (string) ->
  div = document.createElement "div"
  div.innerHTML = string
  div.childNodes[0]

# Tests if given element is inside (or simply is) the container
Dropzone.elementInside = (element, container) ->
  return yes if element == container # Coffeescript doesn't support do/while loops
  return yes while element = element.parentNode when element == container
  return no



Dropzone.getElement = (el, name) ->
  if typeof el == "string"
    element = document.querySelector el
  else if el.nodeType?
    element = el
  throw new Error "Invalid `#{name}` option provided. Please provide a CSS selector or a plain HTML element." unless element?
  return element


Dropzone.getElements = (els, name) ->
  if els instanceof Array
    elements = [ ]
    try
      elements.push @getElement el, name for el in els
    catch e
      elements = null
  else if typeof els == "string"
    elements = [ ]
    elements.push el for el in document.querySelectorAll els
  else if els.nodeType?
    elements = [ els ]

  throw new Error "Invalid `#{name}` option provided. Please provide a CSS selector, a plain HTML element or a list of those." unless elements? and elements.length

  return elements

# Asks the user the question and calls accepted or rejected accordingly
#
# The default implementation just uses `window.confirm` and then calls the
# appropriate callback.
Dropzone.confirm = (question, accepted, rejected) ->
  if window.confirm question
    accepted()
  else if rejected?
    rejected()

# Validates the mime type like this:
#
# https://developer.mozilla.org/en-US/docs/HTML/Element/input#attr-accept
Dropzone.isValidFile = (file, acceptedFiles) ->
  return yes unless acceptedFiles # If there are no accepted mime types, it's OK
  acceptedFiles = acceptedFiles.split ","

  mimeType = file.type
  baseMimeType = mimeType.replace /\/.*$/, ""

  for validType in acceptedFiles
    validType = validType.trim()
    if validType.charAt(0) == "."
      return yes if file.name.toLowerCase().indexOf(validType.toLowerCase(), file.name.length - validType.length) != -1
    else if /\/\*$/.test validType
      # This is something like a image/* mime type
      return yes if baseMimeType == validType.replace /\/.*$/, ""
    else
      return yes if mimeType == validType

  return no


# Augment jQuery
if jQuery?
  jQuery.fn.dropzone = (options) ->
    this.each -> new Dropzone this, options




if module?
  module.exports = Dropzone
else
  window.Dropzone = Dropzone





# Dropzone file status codes
Dropzone.ADDED = "added"

Dropzone.QUEUED = "queued"
# For backwards compatibility. Now, if a file is accepted, it's either queued
# or uploading.
Dropzone.ACCEPTED = Dropzone.QUEUED

Dropzone.UPLOADING = "uploading"
Dropzone.PROCESSING = Dropzone.UPLOADING # alias

Dropzone.CANCELED = "canceled"
Dropzone.ERROR = "error"
Dropzone.SUCCESS = "success"





###

Bugfix for iOS 6 and 7
Source: http://stackoverflow.com/questions/11929099/html5-canvas-drawimage-ratio-bug-ios
based on the work of https://github.com/stomita/ios-imagefile-megapixel

###

# Detecting vertical squash in loaded image.
# Fixes a bug which squash image vertically while drawing into canvas for some images.
# This is a bug in iOS6 devices. This function from https://github.com/stomita/ios-imagefile-megapixel
detectVerticalSquash = (img) ->
  iw = img.naturalWidth
  ih = img.naturalHeight
  canvas = document.createElement("canvas")
  canvas.width = 1
  canvas.height = ih
  ctx = canvas.getContext("2d")
  ctx.drawImage img, 0, 0
  data = ctx.getImageData(0, 0, 1, ih).data


  # search image edge pixel position in case it is squashed vertically.
  sy = 0
  ey = ih
  py = ih
  while py > sy
    alpha = data[(py - 1) * 4 + 3]

    if alpha is 0 then ey = py else sy = py

    py = (ey + sy) >> 1
  ratio = (py / ih)

  if (ratio is 0) then 1 else ratio

# A replacement for context.drawImage
# (args are for source and destination).
drawImageIOSFix = (ctx, img, sx, sy, sw, sh, dx, dy, dw, dh) ->
  vertSquashRatio = detectVerticalSquash img
  ctx.drawImage img, sx, sy, sw, sh, dx, dy, dw, dh / vertSquashRatio








###
# contentloaded.js
#
# Author: Diego Perini (diego.perini at gmail.com)
# Summary: cross-browser wrapper for DOMContentLoaded
# Updated: 20101020
# License: MIT
# Version: 1.2
#
# URL:
# http://javascript.nwbox.com/ContentLoaded/
# http://javascript.nwbox.com/ContentLoaded/MIT-LICENSE
###

# @win window reference
# @fn function reference
contentLoaded = (win, fn) ->
  done = false
  top = true
  doc = win.document
  root = doc.documentElement
  add = (if doc.addEventListener then "addEventListener" else "attachEvent")
  rem = (if doc.addEventListener then "removeEventListener" else "detachEvent")
  pre = (if doc.addEventListener then "" else "on")
  init = (e) ->
    return  if e.type is "readystatechange" and doc.readyState isnt "complete"
    ((if e.type is "load" then win else doc))[rem] pre + e.type, init, false
    fn.call win, e.type or e  if not done and (done = true)

  poll = ->
    try
      root.doScroll "left"
    catch e
      setTimeout poll, 50
      return
    init "poll"

  unless doc.readyState is "complete"
    if doc.createEventObject and root.doScroll
      try
        top = not win.frameElement
      poll()  if top
    doc[add] pre + "DOMContentLoaded", init, false
    doc[add] pre + "readystatechange", init, false
    win[add] pre + "load", init, false


# As a single function to be able to write tests.
Dropzone._autoDiscoverFunction = -> Dropzone.discover() if Dropzone.autoDiscover
contentLoaded window, Dropzone._autoDiscoverFunction