EventHandler[expr, {"event_1" :> action_1, "event_2" :> action_2, ...}] displays as expr, evaluating action_i whenever "event_i" occurs in connection with expr.

CellEventActions is an option for Cell that gives a list of actions to perform when specified events occur in connection with a cell in a notebook.

NotebookEventActions is a notebook option that gives a list of actions to perform when specified events occur in connection with the notebook.

PassEventsUp is an option to EventHandler that specifies whether events handled by a particular event handler should be passed up to event handlers in outer expressions.

PassEventsDown is an option to EventHandler which specifies whether events handled by a particular event handler should be passed down to event handlers nested inside.

PreemptProtect[expr] evaluates expr, without any interruption from preemptive evaluations.

FrontEndEventActions is an option for the notebook front end that gives a list of actions to perform when specified user-interface events occur.

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GestureHandler[expr, {"gesture_1" :> fun_1, "gesture_2" :> fun_2, ...] displays as expr, evaluating fun_i whenever "gesture_i" occurs within the screen space occupied by expr.