Comment 6 for bug 1180872

> The QWidget enabled state gives us exactly that through the hierarchical nature of the enabled state.

We could do this via the Mixxx engine itself but this would be kind of onerous. For example, if passthrough is enabled then we would have to set every single EngineBuffer CO to disabled by hand. The skin writer, on the other hand, could just attach the passthrough indicator variable to the widget group containing.

Alternatively, we could create a parent hierarchy within the control system for doing this.