gio:action-group-action-state-hint (group name)

group -- a g:action-group instance
name -- a string for the name of the action to query

The g:variant parameter with the state range hint, or cffi:null-pointer.

Requests a hint about the valid range of values for the state of the named action within the action group.

If a cffi:null-pointer is returned it either means that the action is not stateful or that there is no hint about the valid range of values for the state of the action.

If a g:variant parameter array is returned then each item in the array is a possible value for the state. If a g:variant parameter pair, that is two-tuple, is returned then the tuple specifies the inclusive lower and upper bound of valid values for the state.

In any case, the information is merely a hint. It may be possible to have a state value outside of the hinted range and setting a value within the range may fail.