     @style.removeAttribute('disabled')
     event.dataTransfer.effectAllowed = 'link'
     event.dataTransfer.setData('Text', '')
+    window.addEventListener("dragover", @onDrag);
     return
 
   onDrag: (event) =>

  @events:
    dragstart: 'onDragStart'
    dragend: 'onDragEnd'
    drag: 'onDrag'

  @isSupported: ->
    'ondragstart' of document.createElement('div') and !app.isMobile()

    return

  onDragEnd: (event) =>
    window.removeEventListener("dragover", @onDrag);
    value = event.pageX or (event.screenX - window.screenX)
    if @lastDragValue and not (@lastDragValue - 5 < value < @lastDragValue + 5) # https://github.com/Thibaut/devdocs/issues/265
      value = @lastDragValue
