disabling parent node makes all children disabled too

[masciugo]

When you disable a checkbox all its children get disabled too. Maybe this is expected but in my use case I have SOME child checkboxes that are checked and disabled for external reasons. I need to prevent their parent from being unchecked because this would affect all children state so I tried by disabling it. But if I disable the parent ALL children get disabled and not only the ones that were supposed to. I would just need to disable the parent without consequences on its children. Of course the parent should be coherent with children states: if all children get unchecked it should become unchecked too and viceversa.