The detail passed on for this emission
The stage the signal emission is currently in, this field will contain one of %G_SIGNAL_RUN_FIRST, %G_SIGNAL_RUN_LAST or %G_SIGNAL_RUN_CLEANUP and %G_SIGNAL_ACCUMULATOR_FIRST_RUN. %G_SIGNAL_ACCUMULATOR_FIRST_RUN is only set for the first run of the accumulator function for a signal emission.
The signal id of the signal invoking the callback
The #GSignalInvocationHint structure is used to pass on additional information to callbacks during a signal emission.