Event class

typedef enum { 	EVT_NONE		= 0x0, EVT_ESCAPE		= 0x0001,		/* Synonym for KBRD + key = ESCAPE */ EVT_KBRD		= 0x0002,		/* keypress */ EVT_MOUSE		= 0x0004,		/* mousepress */ EVT BACK		= 0x0008,		/* Up one level in heirarchical menus. */ 	EVT_MOVE		= 0x0010,		/* menu movement */ EVT_SELECT		= 0x0020,		/* Menu selection */ EVT_BUTTON		= 0x0040,		/* button press */ EVT_CMD			= 0x0080,		/* Command key execute */ EVT_OK			= 0x0100,		/* Callback successful */ /* For example, a command key action. */ 	EVT_REFRESH		= 0x0200,		/* Display refresh */ EVT_RESIZE		= 0x0400,		/* Display resize */ EVT_AGAIN		= 0x4000000,		/* Retry notification */ EVT_STOP		= 0x8000000		/* Loop stopped (never handled) */ } event_class;

Found in
z-term.h