workbench/libs/camd/nextcluster.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: English
   7 */
   8
   9
  10
  11 #include "camd_intern.h"
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16
  17         AROS_LH1(struct MidiCluster *, NextCluster,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(struct MidiCluster *, last, A0),
  21
  22 /*  LOCATION */
  23         struct CamdBase *, CamdBase, 21, Camd)
  24
  25 /*  FUNCTION
  26                 Finds the next cluster in camds list of clusters.
  27
  28     INPUTS
  29                 last - cluster to start searching for.
  30
  31     RESULT
  32                 Next cluster in list, or first if 'last' is NULL.
  33
  34     NOTES
  35                 - CL_Linkages must be locked.
  36
  37                 - Often, a program wants to use this function for finding available
  38                   clusters a user can choose from. It is then recommended to also
  39                   let the user have the possibility to write in the name of a new cluster,
  40                   so that camd can make new clusters automatically to be used for
  41                   communication between various applications without having hardware-drivers
  42                   etc. interfere with the datastreams. Applications do
  43                   not need to make special concerns about how cluster works or
  44                   what they contain; that is all managed by camd.
  45
  46     EXAMPLE
  47
  48                 #include <stdio.h>
  49                 #include <proto/exec.h>
  50                 #include <proto/camd.h>
  51                 #include <midi/camd.h>
  52
  53                 int main(){
  54
  55                         APTR lock;
  56                         struct MidiCluster *cluster;
  57
  58                         struct Library *CamdBase=OpenLibrary("camd.library",0L);
  59                         if(CamdBase!=NULL){
  60
  61                                 lock=LockCAMD(CD_Linkages);
  62
  63                                 cluster=NextCluster(NULL);
  64                                 if(cluster==NULL){
  65
  66                                         printf("No clusters available.\n");
  67
  68                                 }else{
  69
  70                                         do{
  71                                                 printf("clustername: -%s-\n",cluster->mcl_Node.ln_Name);
  72                                                 cluster=NextCluster(cluster);
  73                                         }while(cluster!=NULL);
  74
  75                                 }
  76
  77                                 UnlockCAMD(lock);
  78                                 CloseLibrary(CamdBase);
  79
  80                         }else{
  81                                 printf("Could not open camd.library.\n");
  82                                 return 1;
  83                         }
  84
  85                         return 0;
  86                 }
  87
  88
  89     BUGS
  90
  91     SEE ALSO
  92                 NextMidiLink(), NextMidi(), FindCluster()
  93
  94     INTERNALS
  95
  96     HISTORY
  97
  98         2001-01-12 ksvalast first created
  99
 100 *****************************************************************************/
 101 {
 102     AROS_LIBFUNC_INIT
 103
 104         if(last==NULL){
 105                 if(IsListEmpty(&CB(CamdBase)->midiclusters)){
 106                         return NULL;
 107                 }
 108                 return (struct MidiCluster *)CB(CamdBase)->midiclusters.lh_Head;
 109         }
 110         if(last->mcl_Node.ln_Succ->ln_Succ==NULL) return NULL;
 111
 112         return (struct MidiCluster *)last->mcl_Node.ln_Succ;
 113
 114    AROS_LIBFUNC_EXIT
 115 }
 116