What events are available to add a listener to for uicontrol objects? (specifically push button)

I have successfully added listeners for property changes with a popup menu via:

listener = addlistener(popupH, 'Value', 'PostSet', @testFcn2);

and for seeing user interaction with the figure containing the controls:

listener = addlistener(fh, 'WindowButtonDown', @testFcn);

etc from the documentation page Matlab > Graphics > Graphics Objects > Object Property Operations > "Callback Properties for Graphics Objects" and just deleting the 'Fcn' from the properties to get the event name.

But now I want to look more into responding to events of particular ui controls. I tried the following for a push button:

listener = addlistener(buttonH, 'ButtonDown', @testFcn);

but I get the error "The specified event is not supported by the object". So then I thought, I will just figure out which events a uicontrol object publishes. So I managed to get a real reference to the uicontrol push button object by successfully adding a listener to one of the property changes, breakpointing within my @testFcn, and calling

events(eventData.AffectedObject)

but it said "No events for class uicontrol".

Can someone shed some light on this for me? I just want to figure out how to look at the event names exported by ui controls.

Thanks! Will