   initialize: (@pane) ->
     @on 'dragstart', '.sortable', @onDragStart
     @on 'dragend', '.sortable', @onDragEnd
+    @on 'dragleave', @onDragLeave
     @on 'dragover', @onDragOver
     @on 'drop', @onDrop
 

    el.addClass 'is-dragging'
    event.originalEvent.dataTransfer.setData 'sortable-index', el.index()

    @placeholderEl = $('<li/>', class: 'placeholder')

    pane = $(event.target).closest('.pane')
    paneIndex = @paneContainer.indexOfPane(pane)
    event.originalEvent.dataTransfer.setData 'from-pane-index', paneIndex


    @find(".is-dragging").removeClass 'is-dragging'
    @removeDropTargetClasses()
    @removePlaceholderElement()

    event.stopPropagation()

