layer.draggable.isDragging < boolean>

Whether the layer is currently being dragged (returns false when animating). (Read-only)
译：是否层目前正在拖当动画时，将返回false。（只读）

layerA = new Layer
layerA.draggable.enabled = true

# Check if the layer is being dragged 
layerA.on Events.DragMove, ->
    print layerA.draggable.isDragging