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AuElementNotifyEvent(3)                     DragonFly Library Functions Manual

Name
       AuElementNotifyEvent - element notify event structure

Structures
       #include <audio/audiolib.h>

       typedef union _AuEvent
       {
           . . .
           AuElementNotifyEvent auelementnotify;
           . . .
       }AuEvent;

       typedef struct _AuElementNotifyEvent
       {
           int type;
           AuUint32 serial;
           AuBool send_event;
           AuServer *server;
           AuTime time;
           AuFlowID flow;
           unsigned char element_num;
           unsigned char kind;
           unsigned char prev_state;
           unsigned char cur_state;
           unsigned char reason;
           AuUint32 num_bytes;
       }AuElementNotifyEvent;

Members
       type      The event type.  ElementNotify events are type
                 AuEventTypeElementNotify.

       serial    The serial ID of the event expanded from the 16 bit value
                 sent by the server.

       send_event
                 AuTrue if the event came from a SendEvent protocol request.

       server    The connection to the audio server that the event was read
                 from.

       time      The server time in milliseconds when the event was generated.

       flow      The ID of the flow that caused the event.

       element_num
                 The index of the element that caused the event or
                 AuElementAll to indicate the flow.

       kind      The kind of notify event.  This will be one of these
                 constants: AuElementNotifyKindLowWater,
                 AuElementNotifyKindHighWater, or AuElementNotifyKindState.

       prev_state
                 The previous state of the element indexed by element_num.
                 This will be one of these constants: AuStateStop,
                 AuStateStart, or AuStatePause.

       cur_state The current state of the element indexed by element_num.
                 This will be one of these constants: AuStateStop,
                 AuStateStart, or AuStatePause.

       reason    The reason for the notify event.  This will be one of these
                 constants: AuReasonUser, AuReasonUnderrun, AuReasonOverrun,
                 AuReasonEOF, AuReasonWatermark, or AuReasonHardware.

       num_bytes The number of bytes to send or receive.  Only valid if the
                 the element indexed by element_num is an ImportClient or
                 ExportClient.

Description
       ElementNotify events are sent to client applications to notify them of
       a watermark condition or state change.  If kind is
       AuElementNotifyKindLowWater, the ImportClient element indexed by
       element_num in flow is ready to receive num_bytes of audio data from
       the client application.  If kind is AuElementNotifyKindHighWater, the
       ExportClient element indexed by element_num in flow is ready to send
       num_bytes of audio data to the client application.  If kind is
       AuElementNotifyKindState, the element indexed by element_num (or flow
       if element_num is AuElementAll) has made a state transition from
       prev_state to cur_state triggering the event.  Reguardless of kind,
       prev_state and cur_state contain the old and new states and reason
       contains the reason for the event.

See Also
       AuAnyEvent, AuErrorEvent, AuGrabNotifyEvent, AuMakeSendNotifyAction,
       AuMonitorNotifyEvent.

       audiolib - Network Audio System C Language Interface

audiolib - events                    1.9.4             AuElementNotifyEvent(3)