src/kmp3d/ui/observer.rb
def onTransactionUndo(_)
      return if !tool_active? || @undone

      @undone = true # prevent recursion
      Sketchup.undo # call a second undo since new operation has already started
      update_comp
      refresh_html
    end
# TODO: replace with onCancel at some point
replace with onCancel at some point
replace with onCancel at some point
def onTransactionUndo(_)
      return if !tool_active? || @undone
      @undone = true 
      Sketchup.undo 
      update_comp
      refresh_html
    end
def onTransactionUndo ( _ ) return if ! tool_active? || @undone @undone = true Sketchup . undo update_comp refresh_html end
TODO: replace with onCancel at some point
TODO : replace with onCancel at some point
# prevent recursion # call a second undo since new operation has already started
_