workbench/libs/iffparse/openiff.c

   1 /*
   2     Copyright © 1995-2004, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #define DEBUG 0
   7 #include <aros/debug.h>
   8 #include "iffparse_intern.h"
   9
  10 /* NOTE: Original iffparse.library doesn't have this check here. - Piru */
  11 #define USE_IFFVALIDITYCHECK    1
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16 #include <proto/iffparse.h>
  17
  18         AROS_LH2(LONG, OpenIFF,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(struct IFFHandle *, iff, A0),
  22         AROS_LHA(LONG              , rwMode, D0),
  23
  24 /*  LOCATION */
  25         struct Library *, IFFParseBase, 6, IFFParse)
  26
  27 /*  FUNCTION
  28         Initializes an IFFHandle struct for a new session of reading or
  29         writing. The direction of the I/O is determined by the rwMode flags
  30         supplied (IFFF_READ or IFFF_WRITE).
  31
  32     INPUTS
  33         iff - pointer to IFFHandle struct.
  34         ewMode - IFFF_READ or IFFF_WRITE
  35
  36
  37     RESULT
  38         error -  0 if successfull, IFFERR_#? elsewise.
  39
  40     NOTES
  41          This function tells the custom stream handler to initialize
  42         by sending it a IFFCMD_INIT IFFStreamCmd.
  43
  44     EXAMPLE
  45
  46     BUGS
  47
  48     SEE ALSO
  49         CloseIFF(), InitIFF()
  50
  51     INTERNALS
  52
  53 *****************************************************************************/
  54 {
  55     AROS_LIBFUNC_INIT
  56     AROS_LIBBASE_EXT_DECL(struct Library *,IFFParseBase)
  57     LONG  err;
  58     struct IFFStreamCmd cmd;
  59
  60     if (iff == NULL)
  61     {
  62         D(bug("openiff error: IFFERR_NOMEM\n"));
  63         return (IFFERR_NOMEM);
  64     }
  65
  66     /* Check that a valid StreamHandler Hook has been supplied */
  67     if (!( GetIntIH(iff)->iff_StreamHandler) )
  68     {
  69         D(bug("openiff error: IFFERR_NOHOOK\n"));
  70         return (IFFERR_NOHOOK);
  71     }
  72
  73     /* Tell the custom stream to initialize itself */
  74
  75     cmd.sc_Command = IFFCMD_INIT;
  76     err = CallHookPkt (GetIntIH(iff)->iff_StreamHandler, iff, &cmd);
  77
  78     if (!err)
  79     {
  80 #if USE_IFFVALIDITYCHECK
  81         /* If we are opend in read mode we should test if we have a valid IFF-File */
  82         if (rwMode == IFFF_READ && iff->iff_Stream)
  83         {
  84             struct ContextNode *cn;
  85
  86             D(bug("testing if it's a valid IFF file\n"));
  87             /* Get header of iff-stream */
  88             err = GetChunkHeader(iff, IPB(IFFParseBase));
  89
  90             /* Valid IFF header ? */
  91             if (!err)
  92             {
  93                 /* We have now entried the chunk */
  94                 D(bug("entered the chunk\n"));
  95                 GetIntIH(iff)->iff_CurrentState = IFFSTATE_COMPOSITE;
  96
  97                 cn = TopChunk(iff);
  98
  99                 /* We must see if we have a IFF header ("FORM", "CAT" or "LIST") */
 100                 if (GetIntCN(cn)->cn_Composite)
 101                 {
 102                     D(bug("an iff header\n"));
 103                     /* Everything went OK */
 104                     /* Set the acess mode, and mark the stream as opened */
 105                     iff->iff_Flags &= ~IFFF_RWBITS;
 106                     iff->iff_Flags |= (rwMode | IFFF_OPEN | IFFF_NEWFILE);
 107
 108                     err = 0L;
 109                 }
 110                 else
 111                 {
 112                     err = IFFERR_NOTIFF;
 113                     D(bug("OpenIFF: not an IFF header, pop the context node\n"));
 114
 115                     /* Pop the contextnode */
 116                     PopContextNode(iff, IPB(IFFParseBase));
 117                 }
 118             }
 119             else
 120             {
 121                 if (err  == IFFERR_MANGLED)
 122                 {
 123                     err = IFFERR_NOTIFF;
 124                     D(bug("openiff error: IFFERR_MANGLED\n"));
 125                 }
 126
 127                 /* Fail. We should send CLEANUP to the stream */
 128                 cmd.sc_Command = IFFCMD_CLEANUP;
 129                 err = CallHookPkt
 130                 (
 131                     GetIntIH(iff)->iff_StreamHandler,
 132                     iff,
 133                     &cmd
 134                 );
 135             }
 136         } /* IFFF_READ */
 137         else
 138 #endif /* USE_IFFVALIDITYCHECK */
 139         {
 140             iff->iff_Flags &= ~IFFF_RWBITS;
 141             iff->iff_Flags |= (rwMode | IFFF_OPEN | IFFF_NEWFILE);
 142             err = 0L;
 143         }
 144
 145     } /* if (!err) */
 146
 147     D(bug("openiff: return %d\n", err));
 148     return (err);
 149     AROS_LIBFUNC_EXIT
 150 } /* OpenIFF */