The system returns notification messages to applications to indicate OS/2 multimedia events such as completing a media device function or passing ownership of a media device from one process to another. Following is a list of OS/2 multimedia notification messages.
旼컴컴컴컴컴컴컴컴컴컴쩡컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴커 쿙otification Message 쿝eason for Notification � 쳐컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿘M_MCICUEPOINT 쿌 cue point was detected. Cue points are set with � � 퀃he playlist CUEPOINT instruction or the � � 쿘CI_SET_CUEPOINT command message. � 쳐컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿘M_MCIEVENT 쿌 device has generated an event. � 쳐컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿘M_MCINOTIFY 쿌 device has completed an action, or an error has � � 쿽ccurred. � 쳐컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿘M_MCIPASSDEVICE 쿌 shared device is being lost or gained. � 쳐컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿘M_MCIPLAYLISTMESSAGE쿌 MESSAGE instruction was encountered in a � � 쿾laylist. � 쳐컴컴컴컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿘M_MCIPOSITIONCHANGE 쿟he time period or position specified with the � � 쿘CI_SET_POSITION_ADVISE command message has � � 쿾assed. � 읕컴컴컴컴컴컴컴컴컴컴좔컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴켸
With the exception of MM_MCIEVENT, the system returns notification messages asynchronously to applications using WinPostMsg; MM_MCIEVENT notifications are returned synchronously with WinSendMsg.
A PM application receives notifications by passing its message queue window handle as a parameter on the mciSendCommand or mciSendString call. Applications can also receive notifications by passing a handle to a Control Program queue. For more information see Using a Control Program Queue for Notifications.
If an application sends a command message with mciSendCommand and specifies the MCI_NOTIFY flag, control returns immediately to the application. The media control interface posts a notification message to the window specified in the callback window handle after the command completes processing. The MM_MCINOTIFY message is returned asynchronously to the application using WinPostMsg. It can have any of the following values:
旼컴컴컴컴컴컴컴컴컴컴컴컫컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿙otification Code 쿘eaning � 쳐컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿘CI_NOTIFY_SUCCESSFUL 쿟he command completed successfully. � 쳐컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿘CI_NOTIFY_SUPERSEDED 쿌nother command is being processed. � 쳐컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿘CI_NOTIFY_ABORTED 쿌nother command interrupted this � � 쿽ne. � 읕컴컴컴컴컴컴컴컴컴컴컴컨컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴�
Note: If none of the above notification codes are returned, an error code is returned, indicating that the asynchronous processing of the command ended in an error condition. To convert the error code to a textual description of the error, the application calls the mciGetErrorString function.
The following code fragment illustrates how the Audio Recorder Sample program, provided in the Toolkit (\TOOLKIT\SAMPLES\MM\RECORDER), handles the MM_MCINOTIFY notification message.
case MM_MCINOTIFY:
/*
* This message is returned to an application when a device
* successfully completes a command that was issued with a NOTIFY
* flag, or when an error occurs with the command.
*
* This message returns two values. A user parameter (mp1) and
* the command message (mp2) that was issued. The low word of mp1
* is the Notification Message Code, which indicates the status of the
* command like success or failure. The high word of mp2 is the
* Command Message which indicates the source of the command.
*/
usNotifyCode = (USHORT) SHORT1FROMMP( mp1); /* low-word */
usCommandMessage = (USHORT) SHORT2FROMMP( mp2); /* high-word */
switch (usCommandMessage)
{
case MCI_PLAY:
switch (usNotifyCode)
{
case MCI_NOTIFY_SUCCESSFUL:
if (eState != ST_STOPPED)
{
/*
* Update the status line with appropriate message.
*/
UpdateTheStatusLine(hwnd, IDS_STOPPED);
eState = ST_STOPPED;
/*
* Stop the play button animation
*/
WinSendMsg( hwndPlayPB, /* Play button handle */
GBM_ANIMATE, /* Animation control */
MPFROMSHORT(FALSE),/* Animation flag */
NULL ); /* Ignore return data */
}
break;
case MCI_NOTIFY_SUPERSEDED:
case MCI_NOTIFY_ABORTED:
/* we don't need to handle these messages. */
break;
default:
/*
* If the message is none of the above, then it must be
* a notification error message.
*/
ShowMCIErrorMessage( usNotifyCode);
eState = ST_STOPPED;
/*
* Stop the play button animation and update the status
* line with appropriate text.
*/
WinSendMsg( hwndPlayPB, /* Play button handle */
GBM_ANIMATE, /* Animation control */
MPFROMSHORT(FALSE), /* Animation flag */
NULL ); /* Ignore return data */
UpdateTheStatusLine(hwnd, IDS_STOPPED);
break;
}
break;
}
return( (MRESULT) 0);