       @_refreshControls()
 
       # Fire shift callback
-      @onAfterShift? layerNum
-
-      # Update scrollbar
-      @scrollbar._instance.setPosition(layerNum, false) if @scrollbar.enabled
+      @onAfterShift? idx
+
+      # Update scrollbar with unmodified idx to prevent jumps
+      @scrollbar._instance.setPosition(idx, false) if @scrollbar.enabled
 
     getRelativeItemPosition: (idx, wrapIndices=@wrapIndices) =>
       distance = Math.abs(idx - @currentLayer)

            height: item.croppedSize.height
          , fadeTime, @funcEase if @cropThumbnails

        # Recenter icon if it's now resizeable
        unless item.small
          item.small = true
          if item.icon and not item.resizeable

      
      # Move items to starting positions
      @_focusedItem ?= @_getItem @currentLayer
      @shiftTo @currentLayer
      
    _onMobile: ->
