GParamFlags:
@G_PARAM_READABLE: the parameter is readable
@G_PARAM_WRITABLE: the parameter is writable
@G_PARAM_READWRITE: alias for %G_PARAM_READABLE | %G_PARAM_WRITABLE
@G_PARAM_CONSTRUCT: the parameter will be set upon object construction
@G_PARAM_CONSTRUCT_ONLY: the parameter can only be set upon object construction
@G_PARAM_LAX_VALIDATION: upon parameter conversion (see g_param_value_convert())
strict validation is not required
@G_PARAM_STATIC_NAME: the string used as name when constructing the
parameter is guaranteed to remain valid and
unmodified for the lifetime of the parameter.
Since 2.8
@G_PARAM_STATIC_NICK: the string used as nick when constructing the
parameter is guaranteed to remain valid and
unmmodified for the lifetime of the parameter.
Since 2.8
@G_PARAM_STATIC_BLURB: the string used as blurb when constructing the
parameter is guaranteed to remain valid and
unmodified for the lifetime of the parameter.
Since 2.8
@G_PARAM_EXPLICIT_NOTIFY: calls to g_object_set_property() for this
property will not automatically result in a “notify” signal being
emitted: the implementation must call g_object_notify() themselves
in case the property actually changes. Since: 2.42.
@G_PARAM_PRIVATE: internal
@G_PARAM_DEPRECATED: the parameter is deprecated and will be removed
in a future version. A warning will be generated if it is used
while running with G_ENABLE_DIAGNOSTIC=1.
Since 2.26