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