Inside Macintosh: Telephony /

Chapter 4 - Call Appearances / Call Appearance Reference

Constants

Call Appearance Feature Flags

Although a variety of features may apply to a call appearance, not all features can be applied to all calls. For instance, if the telephone tool your application uses does not support the Conference feature, calls cannot be conferenced. Or, if a given call is on hold, the Hold feature cannot be applied to it again.

The call appearance structure contains, in the featureFlags field, a set of bit flags indicating the relationship between certain features and a particular call. A given feature can be subscribed, available, or active.

A feature is subscribed if the user's telephone network switch provides it and if the terminal supports it. A feature is available if the call appearance of interest is in a state in which using the feature is valid. A feature is active if the feature is currently in use by the call appearance.

The names of the feature flags are typically xxxSub, xxxAvail, and xxxActive, where xxx is the name of the feature. For instance, the flags holdSub, holdAvail, and holdActive indicate whether the Hold feature is subscribed, whether it is available, and whether it is active.

To specify the features of a given call appearance, the Telephone Manager defines the TELCAFeatureFlags and the TELCAOtherFeatures (page 4-17) data types. The TELCAFeatureFlags data type is defined as follows:

typedef unsigned long      TELCAFeatureFlags;

All unused bits in the featureFlags field are reserved.

enum {
   holdSub                 = 1L << 0,
   holdAvail               = 1L << 1,
   holdActive              = 1L << 2,
   conferenceSub           = 1L << 3,
   conferenceAvail         = 1L << 4,
   conferenceActive        = 1L << 5,
   conferenceDropSub       = 1L << 6,
   conferenceDropAvail     = 1L << 7,
   conferenceSplitSub      = 1L << 8,
   conferenceSplitAvail    = 1L << 9,
   numToConferenceRequired = 1L << 10,
   transferSub             = 1L << 11,
   transferAvail           = 1L << 12,
   transferActive          = 1L << 13,
   caRelated               = 1L << 14
};

Constant descriptions

holdSub

If this bit is set, the Hold feature is subscribed.

holdAvail

If this bit is set, the Hold feature is available.

holdActive

If this bit is set, the Hold feature is active.

conferenceSub

If this bit is set, the Conference feature is subscribed.

conferenceAvail

If this bit is set, the Conference feature is available.

conferenceActive

If this bit is set, the Conference feature is active.

conferenceDropSub

If this bit is set, the Conference Drop feature is subscribed.

conferenceDropAvail

If this bit is set, the Conference Drop feature is available.

conferenceSplitSub

If this bit is set, the Conference Split feature is subscribed.

conferenceSplitAvail

If this bit is set, the Conference Split feature is available.

numToConferenceRequired

If this bit is set, this call appearance has a limit to the number of calls that you can join in a conference. If this bit is set, you need to indicate the number of calls to conference when you call the TELConferencePrep function (page 4-39) to set it up. The conference limit value is stored in the conferenceLimit field in the TELCARecord structure (page 4-19).

transferSub

If this bit is set, the Transfer feature is subscribed.

transferAvail

If this bit is set, the Transfer feature is available.

transferActive

If this bit is set, the Transfer feature is active.

caRelated

If this bit is set, this call appearance is specified in the relatedCA field of another TELCARecord structure (page 4-19).