lineGetStatusMessages

The lineGetStatusMessages function enables an application to query which notification messages the application is set up to receive for events related to status changes for the specified line or any of its addresses.

LONG lineGetStatusMessages(

HLINE hLine,

LPDWORD lpdwLineStates,

LPDWORD lpdwAddressStates

);

Parameters

hLine

A handle to the line device.

lpdwLineStates

A bit array that identifies for which line device status changes a message is to be sent to the application. If a flag is TRUE, that message is enabled; if FALSE, it is disabled. Note that multiple flags can be set. This parameter uses the following LINEDEVSTATE_ constants:

LINEDEVSTATE_OTHER

Device-status items other than those listed below have changed. The application should check the current device status to determine which items have changed.

LINEDEVSTATE_RINGING

The switch tells the line to alert the user. Service providers notify applications on each ring cycle by sending LINE_LINEDEVSTATE messages containing this constant. For example, in the United States, service providers send a message with this constant every six seconds.

LINEDEVSTATE_CONNECTED

The line was previously disconnected and is now connected to TAPI.

LINEDEVSTATE_NUMCOMPLETIONS

The number of outstanding call completions on the line device has changed.

LINEDEVSTATE_DISCONNECTED

This line was previously connected and is now disconnected from TAPI.

LINEDEVSTATE_MSGWAITON

The "message waiting" indicator is turned on.

LINEDEVSTATE_MSGWAITOFF

The "message waiting" indicator is turned off.

LINEDEVSTATE_INSERVICE

The line is connected to TAPI. This happens when TAPI is first activated or when the line wire is physically plugged in and in service at the switch while TAPI is active.

LINEDEVSTATE_OUTOFSERVICE

The line is out of service at the switch or physically disconnected. TAPI cannot be used to operate on the line device.

LINEDEVSTATE_MAINTENANCE

Maintenance is being performed on the line at the switch. TAPI cannot be used to operate on the line device.

LINEDEVSTATE_OPEN

The line has been opened by some application.

LINEDEVSTATE_CLOSE

The line has been closed by some application.

LINEDEVSTATE_NUMCALLS

The number of calls on the line device has changed.

LINEDEVSTATE_TERMINALS

The terminal settings have changed.

LINEDEVSTATE_ROAMMODE

The roam mode of the line device has changed.

LINEDEVSTATE_BATTERY

The battery level has changed significantly (cellular).

LINEDEVSTATE_SIGNAL

The signal level has changed significantly (cellular).

LINEDEVSTATE_DEVSPECIFIC

The line's device-specific information has changed.

LINEDEVSTATE_REINIT

Items have changed in the configuration of line devices. To become aware of these changes (for example, the appearance of new line devices) the application should reinitialize its use of TAPI. The hDevice parameter of the LINE_LINEDEVSTATE message is left NULL for this state change as it applies to any of the lines in the system.

LINEDEVSTATE_LOCK

The locked status of the line device has changed.

LINEDEVSTATE_REMOVED

The device is being removed from the system by the service provider (most likely through user action, through a control panel or similar utility). A LINE_LINEDEVSTATE message with this value will normally be immediately followed by a LINE_CLOSE message on the device. Subsequent attempts to access the device prior to TAPI being reinitialized will result in LINEERR_NODEVICE being returned to the application. If a service provider sends a LINE_LINEDEVSTATE message containing this value to TAPI, TAPI will pass it along to applications which have negotiated TAPI version 0x00010004 or above; applications negotiating a previous API version will not receive any notification.

lpdwAddressStates

A bit array that identifies for which address status changes a message is to be sent to the application. If a flag is TRUE, that message is enabled; if FALSE, disabled. Multiple flags can be set. This parameter uses the following LINEADDRESSSTATE_ constants:

LINEADDRESSSTATE_OTHER

Address-status items other than those listed below have changed. The application should check the current address status to determine which items have changed.

LINEADDRESSSTATE_DEVSPECIFIC

The device-specific item of the address status has changed.

LINEADDRESSSTATE_INUSEZERO

The address has changed to idle (it is now in use by zero stations).

LINEADDRESSSTATE_INUSEONE

The address has changed from being idle or from being in use by many bridged stations to being in use by just one station.

LINEADDRESSSTATE_INUSEMANY

The monitored or bridged address has changed from being in use by one station to being used by more than one station.

LINEADDRESSSTATE_NUMCALLS

The number of calls on the address has changed. This is the result of events such as a new inbound call, an outbound call on the address, or a call changing its hold status.

LINEADDRESSSTATE_FORWARD

The forwarding status of the address has changed, including the number of rings for determining a "no answer" condition. The application should check the address status to determine details about the address's current forwarding status.

LINEADDRESSSTATE_TERMINALS

The terminal settings for the address have changed.

Return Values

Returns zero if the request is successful or a negative error number if an error has occurred. Possible return values are:

LINEERR_INVALLINEHANDLE, LINEERR_OPERATIONFAILED, LINEERR_INVALPOINTER, LINEERR_RESOURCEUNAVAIL, LINEERR_NOMEM, LINEERR_UNINITIALIZED.

Remarks

TAPI defines a number of messages that notify applications about events occurring on lines and addresses. An application may not be interested in receiving all address and line status change messages. The lineSetStatusMessages function can be used to select which messages the application wants to receive. By default, address status and line status reporting is disabled.

See Also

LINE_CLOSE, LINE_LINEDEVSTATE, lineSetStatusMessages

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