IPC_PLAYLIST_GET_NEXT_SELECTED (Contributed by Saivert saivert@gmail.com )

#define IPC_PLAYLIST_GET_NEXT_SELECTED 3029

Example usage:

while((sel = SendMessage(plugin.hwndParent,WM_WA_IPC,sel,IPC_PLAYLIST_GET_NEXT_SELECTED))!=-1) {
  // For each iteration, sel is a selected playlist item index.
}

IPC_GET_RANDFUNC

#define IPC_GET_RANDFUNC 3015 // returns a function to get a random number
// int (*randfunc)(void) = SendMessage(hMainWindow, WM_WA_IPC, 0, IPC_GET_RANDFUNC);

IPC_REGISTER_LOWORD_COMMAND

#define IPC_REGISTER_LOWORD_COMMAND 3019 // assigns you a unique ID to make your own commands (for menus, etc)
// WORD id = SendMessage(hMainWindow, WM_WA_IPC, 0, IPC_REGISTER_LOWORD_COMMAND);

IPC_GET_PROXY_STRING

#define IPC_GET_PROXY_STRING 3023