     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

    @style.removeAttribute('disabled')
    event.dataTransfer.effectAllowed = 'link'
    event.dataTransfer.setData('Text', '')
    return

  onDrag: (event) =>

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

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