Collapse All
libZPlay documentation (Win32)
IndexReferenceHome
PreviousUpNext
libZPlayCpp::zplay_SetCallbackFunc Function

Set callback function.

C++
__stdcall __declspec(dllimport) int zplay_SetCallbackFunc(ZPLAY_HANDLE handle, TCallbackFunc pCallbackFunc, TCallbackMessage nMessages, void * user_data);
File
Parameters
Parameters 
Description 
ZPLAY_HANDLE handle 
ZPLAY handle. Get this handle with zplay_CreateZPlay. 
TCallbackFunc pCallbackFunc 
Pointer to callback function. Set this value to NULL to disable callback mechanism. 
TCallbackMessage nMessages 
Specify messages you need to receive with callback function. This parameter can be combination of multiple callback messages. 
void * user_data 
User data. This value will be passed to pCallbackFunc as parameter. 
Return Values
Return Values 
Description 
1 
All OK. 
0 
Error. To get error message read here. 
Remarks

All callback messages are sent from decoding thread. 

There are 2 types of callback messages, blocking (sync) and not blocking (async). 

Blocking message will block decoding thread until callback function returns. Non blocking mesage will not block decoding thread. 

Warning: callback function must have __stdcall calling convention. 

See Also
Example

ZPlay C++ Class interface 

// my callback function
int  __stdcall  CallbackFunc(void* instance, void *user_data, TCallbackMessage message, unsigned int param1, unsigned int param2)
{
  ZPlay *instance = (ZPlay*) instance;
  switch(message)
  {
    case MsgNextSongAsync:
    {
      printf("MsgNextSongAsync %u  %u", param1, param2);    
    }
    return 0;
        
    case MsgNextSong:
    {
      printf("MsgNextSong %u  %u", param1, param2);;
    }
    return 0;   
  }
return 0;
}

...

// set callback function to receive MsgNextSongAsync and MsgNextSong message
instance->SetCallbackFunc(CallbackFunc, (TCallbackMessage) (MsgNextSongAsync + MsgNextSong), 0);

 

C Style interface 

// my callback function
int  __stdcall  CallbackFunc(void* instance, void *user_data, TCallbackMessage message, unsigned int param1, unsigned int param2)
{
  ZPlay *instance = (ZPlay*) instance;
  switch(message)
  {
    case MsgNextSongAsync:
    {
      printf("MsgNextSongAsync %u  %u", param1, param2);    
    }
    return 0;
        
    case MsgNextSong:
    {
      printf("MsgNextSong %u  %u", param1, param2);;
    }
    return 0;   
  }
return 0;
}

...

// set callback function to receive MsgNextSongAsync and MsgNextSong message
zplay_SetCallbackFunc(instance, CallbackFunc, (TCallbackMessage) (MsgNextSongAsync + MsgNextSong), 0);
Group
Copyright (c) 2010. Zoran Cindori - All rights reserved.

Web: http://libzplay.sourceforge.net/

Email: zcindori@inet.hr

Made with Doc-O-Matic® Express

Doc-O-Matic