Is it possible for a control to define a handler for an event, that the control can't itself raise?

yes

Yes, It's is possible for a control to define a handler for an event, that the control can't itself raise. These incidents are called attached events. For example, a button controls in a grid. The button class defines a click event, but the grid class doest not. However, you can still define a handler for buttons in the grid by attaching the Click events of the button control.