iffparse.library Reference

Comprehensive function reference for iffparse.library, synthesised from the AmigaOS NDK 3.2 Release 4 (Autodocs/AG/iffparse).

This page documents 40 functions of iffparse.library. Each function entry follows the canonical autodoc format. struct Name, union Name, enum Name are clickable links to the type definition in the types reference.

Function index

AllocIFF()

AllocIFF -- create a new IFFHandle structure. (V36)

Synopsis

iff = AllocIFF() D0

IFFHandle*AllocIFF(VOID);

Function

Allocates and initializes a new IFFHandle structure. This function is the only supported way to create an IFFHandle structure since there are private fields that need to be initialized.

Results

iff - pointer to IFFHandle structure or NULL if the allocation failed.

See also

FreeIFF()

AllocLocalItem()

AllocLocalItem -- create a local context item structure. (V36)

Synopsis

item = AllocLocalItem(type, id, ident, dataSize); D0 D0 D1 D2 D3

LocalContextItem*AllocLocalItem(LONG, LONG, LONG, LONG);

Function

Allocates and initializes a LocalContextItem structure with "dataSize" bytes of associated user data. This is the only supported way to create such an item. The user data can be accessed with the LocalItemData() function. An item created with this function automatically has its purge vectors set up correctly to dispose of itself and its associated user data area. Any additional cleanup should be done with a user-supplied purge vector.

Inputs

type,id - additional longword identification values ident - longword identifier for class of context item dataSize - number of bytes of user data to allocate for this item

Results

item - pointer to initialized LocalContextItem or NULL if the allocation failed.

See also

FreeLocalItem(), LocalItemData(), StoreLocalItem(), StoreItemInContext(), SetLocalItemPurge()

CloseClipboard()

CloseClipboard -- close and free an open ClipboardHandle. (V36)

Synopsis

CloseClipboard(clipHandle); A0

VOID CloseClipboard(ClipboardHandle*);

Function

Closes the clipboard.device and frees the ClipboardHandle structure.

Inputs

clipHandle - pointer to ClipboardHandle struct created with OpenClipboard(). Starting with V39, this may be NULL.

See also

OpenClipboard(), InitIFFasClip()

CloseIFF()

CloseIFF -- close an IFF context. (V36)

Synopsis

CloseIFF(iff); A0

VOID CloseIFF(IFFHandle*);

Function

Completes an IFF read or write operation by closing the IFF context established for this IFFHandle structure. The IFFHandle structure itself is left ready for re-use and a new context can be opened with OpenIFF(). This function can be used for cleanup if a read or write fails partway through.

As part of its cleanup operation, CloseIFF() calls the client-
supplied stream hook vector. The IFFStreamCmd packet will be set
as follows:

    sc_Command: IFFCMD_CLEANUP
    sc_Buf:     (Not applicable)
    sc_NBytes:  (Not applicable)

This operation is NOT permitted to fail;  any error code returned
will be ignored (best to return 0, though). DO NOT write to this
structure.

Inputs

iff - pointer to IFFHandle structure previously opened with OpenIFF(). Starting with V39, this may be NULL.

See also

OpenIFF(), InitIFF()

CollectionChunk()

CollectionChunk -- declare a chunk type for collection. (V36)

Synopsis

error = CollectionChunk(iff, type, id); D0 A0 D0 D1

LONG CollectionChunk(IFFHandle*, LONG, LONG);

Function

Installs an entry handler for chunks with the given type and id so that the contents of those chunks will be stored as they are encountered. This is like PropChunk() except that more than one chunk of this type can be stored in lists which can be returned by FindCollection(). The storage of these chunks still follows the property chunk scoping rules for IFF files so that at any given point, stored collection chunks will be valid in the current context.

Inputs

iff - pointer to IFFHandle structure (does not need to be open) type - type code for the chunk to declare (ex. "ILBM") id - identifier for the chunk to declare (ex. "CRNG")

Results

error - 0 if successful or an IFFERR_#? error code if unsuccessful.

See also

CollectionChunks(), FindCollection(), PropChunk()

CollectionChunks()

CollectionChunks -- declare many collection chunks at once. (V36)

Synopsis

error = CollectionChunks(iff, propArray, numPairs); D0 A0 A1 D0

LONG CollectionChunks(IFFHandle*, LONG *, LONG);

Function

Declares multiple collection chunks from a list. The propArray argument is a pointer to an array of longwords arranged in pairs. The format for the list is as follows:

    TYPE1, ID1, TYPE2, ID2, ..., TYPEn, IDn

The argument numPairs is the number of pairs. CollectionChunks() just calls
CollectionChunk() numPairs times.

Inputs

iff - pointer to IFFHandle structure (does not need to be open) propArray - pointer to array of longword chunk types and identifiers numPairs - number of pairs in array.

Results

error - 0 if successful or an IFFERR_#? error code if unsuccessful

See also

CollectionChunk()

CurrentChunk()

CurrentChunk -- get context node for current chunk. (V36)

Synopsis

top = CurrentChunk(iff); D0 A0

ContextNode*CurrentChunk(IFFHandle*);

Function

Returns the top context node for the given IFFHandle structure. The top context node corresponds to the chunk most recently pushed on the stack, which is the chunk where the stream is currently positioned. The ContextNode structure contains information on the type of chunk currently being parsed (or written), its size and the current position within the chunk.

Inputs

iff - pointer to IFFHandle structure

Results

top - pointer to top context node or NULL if none

See also

PushChunk(), PopChunk(), ParseIFF(), ParentChunk()

EntryHandler()

EntryHandler -- add an entry handler to the IFFHandle context. (V36)

Synopsis

error = EntryHandler(iff, type, id, position, handler, object); D0 A0 D0 D1 D2 A1 A2

LONG EntryHandler(IFFHandle*, LONG, LONG, LONG, Hook*, APTR);

Function

Installs an entry handler vector for a specific type of chunk into the context for the given IFFHandle structure. Type and id are the longword identifiers for the chunk to handle. The handler is a client- supplied standard Hook structure, properly initialized. position tells where to put the handler in the context. The handler will be called whenever the parser enters a chunk of the given type, so the IFF stream will be positioned to read the first data byte in the chunk. The handler will execute in the same context as whoever called ParseIFF(). The handler will be called (through the hook) with the following arguments:

    A0: the Hook pointer you passed.
    A2: the 'object' pointer you passed.
    A1: pointer to a LONG containing the value
        IFFCMD_ENTRY.

The error code your call-back routine returns will affect the parser
in three different ways:

Return value        Result
------------        ------
0:          Normal success;  ParseIFF() will continue
            through the file.
IFF_RETURN2CLIENT:  ParseIFF() will stop and return the value 0.
            (StopChunk() is internally implemented using
            this return value.)
Any other value:    ParseIFF() will stop and return the value
            you supplied. This is how errors should be
            returned.

Inputs

iff - pointer to IFFHandle structure. type - type code for chunk to handle (ex. "ILBM"). id - ID code for chunk to handle (ex. "CMAP"). position- local context item position. One of the IFFSLI_#? codes. handler - pointer to Hook structure. object - a client-defined pointer which is passed in A2 during call- back.

Results

error - 0 if successful or an IFFERR_#? error code if unsuccessful.

Bugs

Returning the values IFFERR_EOF or IFFERR_EOC from the call-back routine may confuse the parser.

There is no way to explicitly remove a handler once installed.
However, by installing a do-nothing handler using IFFSLI_TOP,
previous handlers will be overridden until the context expires.

See also

ExitHandler(), StoreLocalItem(), StoreItemInContext()

ExitHandler()

ExitHandler -- add an exit handler to the IFFHandle context. (V36)

Synopsis

error = ExitHandler(iff, type, id, position, handler, object); D0 A0 D0 D1 D2 A1 A2

LONG ExitHandler(IFFHandle*, LONG, LONG, LONG, Hook*, APTR object(;

Function

Installs an exit handler vector for a specific type of chunk into the context for the given IFFHandle structure. Type and id are the longword identifiers for the chunk to handle. The handler is a client-supplied standard Hook structure, properly initialized. Position tells where to put the handler in the context. The handler will be called just before the parser exits the given chunk in the "pause" parse state. The IFF stream may not be positioned predictably within the chunk. The handler will execute in the same context as whoever called ParseIFF(). The handler will be called (through the hook) with the following arguments:

    A0: the Hook pointer you passed.
    A2: the 'object' pointer you passed.
    A1: pointer to a LONG containing the value
        IFFCMD_EXIT.

The error code your call-back routine returns will affect the parser
in three different ways:

Return value        Result
------------        ------
0:          Normal success;  ParseIFF() will continue
            through the file.
IFF_RETURN2CLIENT:  ParseIFF() will stop and return the value 0.
            (StopChunk() is internally implemented using
            this return value.)
Any other value:    ParseIFF() will stop and return the value
            you supplied. This is how errors should be
            returned.

Inputs

iff - pointer to IFFHandle structure. type - type code for chunk to handle (ex. "ILBM"). id - identifier code for chunk to handle (ex. "CMAP"). position - local context item position. One of the IFFSLI_#? codes. handler - pointer to Hook structure. object - a client-defined pointer which is passed in A2 during call- back.

Results

error - 0 if successful or an IFFERR_#? error code if unsuccessful.

Bugs

Returning the values IFFERR_EOF or IFFERR_EOC from the call-back routine may confuse the parser.

There is no way to explicitly remove a handler once installed.
However, by installing a do-nothing handler using IFFSLI_TOP,
previous handlers will be overridden until the context expires.

See also

EntryHandler(), StoreLocalItem(), StoreItemInContext()

FindCollection()

FindCollection -- get a pointer to the current list of collection items. (V36)

Synopsis

ci = FindCollection(iff, type, id); D0 A0 D0 D1

CollectionItem*FindCollection(IFFHandle*, LONG, LONG);

Function

Returns a pointer to a list of CollectionItem structures for each of the collection chunks of the given type encountered so far in the course of parsing this IFF file. The items appearing first in the list will be the ones encountered most recently.

Inputs

iff - pointer to IFFHandle structure. type - type code to search for. id - identifier code to search for.

Results

ci - pointer to last collection chunk encountered with links to previous ones.

See also

CollectionChunk(), CollectionChunks()

FindLocalItem()

FindLocalItem -- return a local context item from the context stack. (V36)

Synopsis

lci = FindLocalItem(iff, type, id, ident); D0 A0 D0 D1 D2

LocalContextItem*FindLocalItem(IFFHandle*, LONG, LONG, LONG);

Function

Searches the context stack of the given IFFHandle structure for a local context item which matches the given ident, type and id. This function searches the context stack from the most current context backwards, so that the item found (if any) will be the one with greatest precedence in the context stack.

Inputs

iff - pointer to IFFHandle structure. type - type code to search for. id - ID code to search for. ident - ident code for the class of context item to search for (ex. "exhd" -- exit handler).

Results

lci - pointer to local context item, or NULL if nothing matched.

See also

StoreLocalItem()

FindProp()

FindProp -- search for a stored property chunk. (V36)

Synopsis

sp = FindProp(iff, type, id); D0 A0 D0 D1

StoredProperty*FindProp(IFFHandle*, LONG, LONG);

Function

Searches for the stored property which is valid in the given context. Property chunks are automatically stored by ParseIFF() when pre-declared by PropChunk() or PropChunks(). The StoredProperty struct, if found, contains a pointer to a data buffer containing the contents of the stored property.

Inputs

iff - pointer to IFFHandle structure. type - type code for chunk to search for (ex. "ILBM"). id - identifier code for chunk to search for (ex. "CMAP").

Results

sp - pointer to stored property, or NULL if none found.

See also

PropChunk(), PropChunks()

FindPropContext()

FindPropContext -- get the property context for the current state. (V36)

Synopsis

cn = FindPropContext(iff); D0 A0

ContextNode*FindPropContext(IFFHandle*);

Function

Locates the context node which would be the scoping chunk for properties in the current parsing state. (Huh?) This is used for locating the proper scoping context for property chunks i.e. the scope from which a property would apply. This is usually the FORM or LIST with the highest precedence in the context stack.

If you don't understand this, read the IFF spec a couple more times.

Inputs

iff - pointer to IFFHandle structure.

Results

cn - ContextNode of property scoping chunk.

See also

CurrentChunk(), ParentChunk(), StoreItemInContext()

FreeIFF()

FreeIFF -- deallocate an IFFHandle structure. (V36)

Synopsis

FreeIFF(iff); A0

VOID FreeIFF(IFFHandle*);

Function

Deallocates all resources associated with this IFFHandle structure. The structure MUST have already been closed with CloseIFF().

Inputs

iff - pointer to IFFHandle structure to free. Starting with V39, this may be NULL.

See also

AllocIFF(), CloseIFF()

FreeLocalItem()

FreeLocalItem -- deallocate a local context item structure. (V36)

Synopsis

FreeLocalItem(localItem); A0

VOID FreeLocalItem(LocalContextItem*);

Function

Frees the memory for the local context item and any associated user memory as allocated with AllocLocalItem(). User purge vectors should call this function after they have freed any other resources associated with this item.

Note that FreeLocalItem() does NOT call the custom purge vector set
up through SetLocalItemPurge(); all it does is free the local context
item. (This implies that your custom purge vector would want to call
this to ultimately free the LocalContextItem.)

Inputs

localItem - pointer to LocalContextItem created with AllocLocalItem. Starting with V39, this may be NULL.

See also

AllocLocalItem()

GoodID()

GoodID -- test if an identifier follows the IFF 85 specification. (V36)

Synopsis

isok = GoodID(id); D0 D0

LONG GoodID(LONG);

Function

Tests the given longword identifier to see if it meets all the EA IFF 85 specifications for a chunk ID. If so, it returns non-zero, otherwise 0.

Inputs

id - potential 32 bit identifier.

Results

isok - non-zero if this is a valid ID, 0 otherwise.

See also

GoodType()

GoodType()

GoodType -- test if a type follows the IFF 85 specification. (V36)

Synopsis

isok = GoodType(type) D0 D0

LONG GoodType(LONG);

Function

Tests the given longword type identifier to see if it meets all the EA IFF 85 specifications for a FORM type (requirements for a FORM type are more stringent than those for a simple chunk ID). If it complies, GoodType() returns non-zero, otherwise 0.

Inputs

type - potential 32 bit format type identifier.

Results

isok - non-zero if this is a valid type id, 0 otherwise.

See also

GoodID()

IDtoStr()

IDtoStr -- convert a longword identifier to a null-terminated string. (V36)

Synopsis

str = IDtoStr(id, buf); D0 D0 A0

STRPTR IDtoStr(LONG, STRPTR);

Function

Writes the ASCII equivalent of the given longword ID into buf as a null-terminated string.

Inputs

id - longword ID. buf - character buffer to accept string (at least 5 chars).

Results

str - the value of 'buf'.

InitIFF()

InitIFF -- initialize an IFFHandle structure as a user stream. (V36)

Synopsis

InitIFF(iff, flags, streamHook); A0 D0 A1

VOID InitIFF(IFFHandle*, LONG,Hook*);

Function

Initializes an IFFHandle as a general user-defined stream by allowing the user to declare a hook that the library will call to accomplish the low-level reading, writing, and seeking of the stream. Flags are the stream I/O flags for the specified stream; typically a combination of the IFFF_?SEEK flags.

The stream vector is called with the following arguments:

    A0: pointer to streamhook.
    A2: pointer to IFFHandle structure.
    A1: pointer to IFFStreamCmd structure.

The IFFStreamCmd packet appears as follows:

    sc_Command: Contains an IFFCMD_#? value
    sc_Buf:     Pointer to memory buffer
    sc_NBytes:  Number of bytes involved in operation

The values taken on by sc_Command, and their meaning, are as follows:

IFFCMD_INIT:
    Prepare your stream for reading. This is used for certain
    streams that can't be read immediately upon opening, and need
    further preparation. (The clipboard.device is an example of
    such a stream.)  This operation is allowed to fail;  any
    error code will be returned directly to the client. sc_Buf
    and sc_NBytes have no meaning here.
IFFCMD_CLEANUP:
    Terminate the transaction with the associated stream. This
    is used with streams that can't simply be closed. (Again,
    the clipboard is an example of such a stream.)  This
    operation is not permitted to fail;  any error returned will
    be ignored (best to return 0, though). sc_Buf and sc_NBytes
    have no meaning here.
IFFCMD_READ:
    Read from the stream. You are to read sc_NBytes from the
    stream and place them in the buffer pointed to by sc_Buf.
    Any (non-zero) error returned will be remapped by the parser
    into IFFERR_READ.
IFFCMD_WRITE:
    Write to the stream. You are to write sc_NBytes to the
    stream from the buffer pointed to by sc_Buf. Any (non-zero)
    error returned will be remapped by the parser into
    IFFERR_WRITE.
IFFCMD_SEEK:
    Seek on the stream. You are to perform a seek on the stream
    relative to the current position. sc_NBytes is signed;
    negative values mean seek backward, positive values mean seek
    forward. sc_Buf has no meaning here. Any (non-zero) error
    returned will be remapped by the parser into IFFERR_SEEK.

All errors are returned in D0. A return of 0 indicates success.
UNDER NO CIRCUMSTANCES are you permitted to write to the IFFStreamCmd
structure.

Inputs

iff - pointer to IFFHandle structure to initialize. flags - stream I/O flags for the IFFHandle. streamHook - pointer to Hook structure.

InitIFFasClip()

InitIFFasClip -- initialize an IFFHandle as a clipboard stream. (V36)

Synopsis

InitIFFasClip(iff); A0

VOID InitIFFasClip(IFFHandle*);

Function

Initializes the given IFFHandle to be a clipboard stream. The function initializes the stream processing vectors to operate on streams of the ClipboardHandle type. The iff_Stream field will still need to be initialized to point to a ClipboardHandle as returned from OpenClipboard().

Inputs

iff - pointer to IFFHandle structure.

See also

InitIFF(), OpenClipboard()

InitIFFasDOS()

InitIFFasDOS -- initialize an IFFHandle as a DOS stream. (V36)

Synopsis

InitIFFasDOS(iff) A0

InitIFFasDOS(IFFHandle*);

Function

The function initializes the given IFFHandle to operate on DOS streams. The iff_Stream field will need to be initialized as a BPTR returned from the DOS function Open().

Inputs

iff - pointer to IFFHandle structure.

See also

InitIFF()

LocalItemData()

LocalItemData -- get pointer to user data for local context item. (V36)

Synopsis

data = LocalItemData(localItem); D0 A0

APTR LocalItemData(LocalContextItem*);

Function

Returns pointer to the user data associated with the given local context item. The size of the data area depends on the "dataSize" argument used when allocating this item. If the pointer to the item given (localItem) is NULL, this function returns NULL.

Inputs

localItem - pointer to local context item or NULL.

Results

data - pointer to user data area or NULL if localItem is NULL.

Bugs

Currently, there is no way to determine the size of the user data area; you have to 'know'.

See also

AllocLocalItem(), FreeLocalItem()

OpenClipboard()

OpenClipboard -- create a handle on a clipboard unit. (V36)

Synopsis

ch = OpenClipboard(unitNumber) D0 D0

ClipboardHandle*OpenClipboard(LONG);

Function

Opens the clipboard.device and opens a stream for the specified unit (usually PRIMARY_CLIP). This handle structure will be used as the clipboard stream for IFFHandles initialized as clipboard streams by InitIFFasClip().

Inputs

unitNumber - clipboard unit number (usually PRIMARY_CLIP).

Results

ch - pointer to ClipboardHandle structure or NULL if unsuccessful.

Bugs

This function had several bugs prior to V39.

   First bug was that if the clipboard.device couldn't open, two calls
to FreeSignal() were made with uninitialized values as parameters.
The result of this was a corrupt signal mask in the Task field.

Second bug was that OpenDevice() was called with an IO request that
didn't have a valid MsgPort pointer in it.

Third bug was that the two message ports allocated by the function
(ClipboardHandle->cbh_CBport and ClipboardHandle->cbh_SatisfyPort)
were not being initialized correctly and would cause a system crash
if a message ever got to either of them.

See also

InitIFFasClip(), CloseClipboard()

OpenIFF()

OpenIFF -- prepare an IFFHandle to read or write a new IFF stream. (V36)

Synopsis

error = OpenIFF(iff, rwMode); D0 A0 D0

LONG OpenIFF(IFFHandle*, LONG);

Function

Initializes an IFFHandle structure for a new read or write. The direction of the I/O is given by the value of rwMode, which can be either IFFF_READ or IFFF_WRITE.

As part of its initialization procedure, OpenIFF() calls the client-
supplied stream hook vector. The IFFStreamCmd packet will contain
the following:

    sc_Command: IFFCMD_INIT
    sc_Buf:     (Not applicable)
    sc_NBytes:  (Not applicable)

This operation is permitted to fail. DO NOT write to this structure.

Inputs

iff - pointer to IFFHandle structure. Starting with V39, this may be NULL, in which case IFFERR_NOMEM is returned. rwMode - IFFF_READ or IFFF_WRITE

Results

error - contains an error code or 0 if successful

See also

CloseIFF(), InitIFF()

ParentChunk()

ParentChunk -- get the nesting context node for the given chunk. (V36)

Synopsis

parent = ParentChunk(contextNode); D0 A0

ContextNode*ParentChunk(ContextNode*);

Function

Returns a context node for the chunk containing the chunk for the given context node. This function effectively moves down the context stack into previously pushed contexts. For example, to get a ContextNode pointer for the enclosing FORM chunk while reading a data chunk, use: ParentChunk(CurrentChunk(iff)) to find this pointer. The ContextNode structure contains information on the type of chunk and its size.

Inputs

contextNode - pointer to a context node.

Results

parent - pointer to the enclosing context node or NULL if none.

See also

CurrentChunk()

ParseIFF()

ParseIFF -- parse an IFF file from an IFFHandle structure stream. (V36)

Synopsis

error = ParseIFF(iff, control); D0 A0 D0

LONG ParseIFF(IFFHandle*, LONG);

Function

This is the biggie.

Traverses a file opened for read by pushing chunks onto the context
stack and popping them off directed by the generic syntax of IFF
files. As it pushes each new chunk, it searches the context stack
for handlers to apply to chunks of that type. If it finds an entry
handler it will invoke it just after entering the chunk. If it finds
an exit handler it will invoke it just before leaving the chunk.
Standard handlers include entry handlers for pre-declared
property chunks and collection chunks and entry and exit handlers for
for stop chunks - that is, chunks which will cause the ParseIFF()
function to return control to the client. Client programs can also
provide their own custom handlers.

The control flag can have three values:

IFFPARSE_SCAN:
    In this normal mode, ParseIFF() will only return control to
    the caller when either:
        1) an error is encountered,
        2) a stop chunk is encountered, or a user handler
           returns the special IFF_RETURN2CLIENT code, or
        3) the end of the logical file is reached, in which
           case IFFERR_EOF is returned.

    ParseIFF() will continue pushing and popping chunks until one
    of these conditions occurs. If ParseIFF() is called again
    after returning, it will continue to parse the file where it
    left off.

IFFPARSE_STEP and _RAWSTEP:
    In these two modes, ParseIFF() will return control to the
    caller after every step in the parse, specifically, after
    each push of a context node and just before each pop. If
    returning just before a pop, ParseIFF() will return
    IFFERR_EOC, which is not an error, per se, but is just an
    indication that the most recent context is ending. In STEP
    mode, ParseIFF() will invoke the handlers for chunks, if
    any, before returning. In RAWSTEP mode, ParseIFF() will not
    invoke any handlers and will return right away. In both
    cases the function can be called multiple times to step
    through the parsing of the IFF file.

Inputs

iff - pointer to IFFHandle structure. control - control code (IFFPARSE_SCAN, _STEP or _RAWSTEP).

Results

error - 0 or IFFERR_#? value or return value from user handler.

See also

PushChunk(), PopChunk(), EntryHandler(), ExitHandler(), PropChunk(), CollectionChunk(), StopChunk(), StopOnExit()

PopChunk()

PopChunk -- pop top context node off context stack. (V36)

Synopsis

error = PopChunk(iff); D0 A0

LONG PopChunk(IFFHandle*);

Function

Pops top context chunk and frees all associated local context items. The function is normally called only for writing files and signals the end of a chunk.

Inputs

iff - pointer to IFFHandle structure.

Results

error - 0 if successful or an IFFERR_#? error code if unsuccessful.

See also

PushChunk()

PropChunk()

PropChunk -- specify a property chunk to store. (V36)

Synopsis

error = PropChunk(iff, type, id); D0 A0 D0 D1

LONG PropChunk(IFFHandle*, LONG, LONG);

Function

Installs an entry handler for chunks with the given type and ID so that the contents of those chunks will be stored as they are encountered. The storage of these chunks follows the property chunk scoping rules for IFF files so that at any given point, a stored property chunk returned by FindProp() will be the valid property for the current context.

Inputs

iff - pointer to IFFHandle structure (does not need to be open). type - type code for the chunk to declare (ex. "ILBM"). id - identifier for the chunk to declare (ex. "CMAP").

Results

error - 0 if successful or an IFFERR_#? error code if unsuccessful.

See also

PropChunks(), FindProp(), CollectionChunk()

PropChunks()

PropChunks -- declare many property chunks at once. (V36)

Synopsis

error = PropChunks(iff, propArray, numPairs); D0 A0 A1 D0

LONG PropChunks(IFFHandle*, LONG *, LONG);

Function

Declares multiple property chunks from a list. The propArray argument if a pointer to an array of longwords arranged in pairs, and has the following format:

    TYPE1, ID1, TYPE2, ID2, ..., TYPEn, IDn

The argument numPairs is the number of pairs. PropChunks() just calls
PropChunk() numPairs times.

Inputs

iff - pointer to IFFHandle structure. propArray - pointer to array of longword chunk types and identifiers. numPairs - number of pairs in the array.

Results

error - 0 if successful or an IFFERR_#? error code if unsuccessful.

See also

PropChunk()

PushChunk()

PushChunk -- push a new context node on the context stack. (V36)

Synopsis

error = PushChunk(iff, type, id, size); D0 A0 D0 D1 D2

LONG PushChunk(IFFHandle*, LONG, LONG, LONG);

Function

Pushes a new context node on the context stack by reading it from the stream if this is a read file, or by creating it from the passed parameters if this is a write file. Normally this function is only called in write mode, where the type and id codes specify the new chunk to create. If this is a leaf chunk, i.e. a local chunk inside a FORM or PROP chunk, then the type argument is ignored. If the size is specified then the chunk writing functions will enforce this size. If the size is given as IFFSIZE_UNKNOWN, the chunk will expand to accommodate whatever is written into it.

Inputs

iff - pointer to IFFHandle structure. type - chunk type specifier (ex. ILBM) (ignored for read mode or leaf chunks). id - chunk id specifier (ex. CMAP) (ignored for read mode). size - size of the chunk to create or IFFSIZE_UNKNOWN (ignored for read mode).

Results

error - 0 if successful or an IFFERR_#? error code if not unsuccessful.

See also

PopChunk(), WriteChunkRecords(), WriteChunkBytes()

ReadChunkBytes()

ReadChunkBytes -- read bytes from the current chunk into a buffer. (V36)

Synopsis

actual = ReadChunkBytes(iff, buf, numBytes); D0 A0 A1 D0

LONG ReadChunkBytes(IFFHandle*, APTR buf, LONG);

Function

Reads the IFFHandle stream into the buffer for the specified number of bytes. Reads are limited to the size of the current chunk and attempts to read past the end of the chunk will truncate. This function returns positive number of bytes read or a negative error code.

Inputs

iff - pointer to IFFHandle structure. buf - pointer to buffer area to receive data. numBytes - number of bytes to read.

Results

actual - (positive) number of bytes read if successful or a (negative) IFFERR_#? error code if unsuccessful.

See also

ReadChunkRecords(), ParseIFF(), WriteChunkBytes()

ReadChunkRecords()

ReadChunkRecords -- read record elements from the current chunk into a buffer. (V36)

Synopsis

actual = ReadChunkRecords(iff, buf, bytesPerRecord, numRecords); D0 A0 A1 D0 D1

LONG ReadChunkRecords(IFFHandle*, APTR, LONG, LONG);

Function

Reads records from the current chunk into buffer. Truncates attempts to read past end of chunk (only whole records are read; remaining bytes that are not of a whole record size are left unread and available for ReadChunkBytes()).

Inputs

iff - pointer to IFFHandle structure. buf - pointer to buffer area to receive data. bytesPerRecord - size of data records to read. numRecords - number of data records to read.

Results

actual - (positive) number of whole records read if successful or a (negative) IFFERR_#? error code if unsuccessful.

See also

ReadChunkBytes(), ParseIFF(), WriteChunkRecords()

SetLocalItemPurge()

SetLocalItemPurge -- set purge vector for a local context item. (V36)

Synopsis

SetLocalItemPurge(localItem, purgeHook); A0 A1

VOID SetLocalItemPurge(LocalContextItem*,Hook*);

Function

Sets a local context item to use a client-supplied cleanup (purge) vector for disposal when its context is popped. The purge vector will be called when the ContextNode containing this local item is popped off the context stack and is about to be deleted itself. If the purge vector has not been set, the parser will use FreeLocalItem() to delete the item, but if this function is used to set the purge vector, the supplied vector will be called with the following arguments:

    A0: pointer to purgeHook.
    A2: pointer to LocalContextItem to be freed.
    A1: pointer to a LONG containing the value
        IFFCMD_PURGELCI.

The user purge vector is then responsible for calling FreeLocalItem()
as part of its own cleanup. Although the purge vector can return a
value, it will be ignored -- purge vectors must always work (best to
return 0, though).

Inputs

localItem - pointer to a local context item. purgeHook - pointer to a Hook structure.

See also

AllocLocalItem(), FreeLocalItem()

StopChunk()

StopChunk -- declare a chunk which should cause ParseIFF to return. (V36)

Synopsis

error = StopChunk(iff, type, id); D0 A0 D0 D1

LONG StopChunk(IFFHandle*, LONG, LONG); type;

Function

Installs an entry handler for the specified chunk which will cause the ParseIFF() function to return control to the caller when this chunk is encountered. This is only of value when ParseIFF() is called with the IFFPARSE_SCAN control code.

Inputs

iff - pointer to IFFHandle structure (need not be open). type - type code for chunk to declare (ex. "ILBM"). id - identifier for chunk to declare (ex. "BODY").

Results

error - 0 if successful or an IFFERR_#? error code if unsuccessful.

See also

StopChunks(), ParseIFF()

StopChunks()

StopChunks -- declare many stop chunks at once. (V36)

Synopsis

error = StopChunks(iff, propArray, numPairs); D0 A0 A1 D0

LONG StopChunks(IFFHandle*, LONG *, LONG);

Function

(is to StopChunk() as PropChunks() is to PropChunk().)

Inputs

iff - pointer to IFFHandle structure. propArray - pointer to array of longword chunk types and identifiers. numPairs - number of pairs in the array.

Results

error - 0 if successful or an IFFERR_#? error code if unsuccessful.

See also

StopChunk()

StopOnExit()

StopOnExit -- declare a stop condition for exiting a chunk. (V36)

Synopsis

error = StopOnExit(iff, type, id); D0 A0 D0 D1

LONG StopOnExit(IFFHandle*, LONG, LONG);

Function

Installs an exit handler for the specified chunk which will cause the ParseIFF() function to return control to the caller when this chunk is exhausted. ParseIFF() will return IFFERR_EOC when the declared chunk is about to be popped. This is only of value when ParseIFF() is called with the IFFPARSE_SCAN control code.

Inputs

iff - pointer to IFFHandle structure (need not be open). type - type code for chunk to declare (ex. "ILBM"). id - identifier for chunk to declare (ex. "BODY").

Results

error - 0 if successful or an IFFERR_#? error code if unsuccessful.

See also

ParseIFF()

StoreItemInContext()

StoreItemInContext -- store local context item in given context node. (V36)

Synopsis

StoreItemInContext(iff, localItem, contextNode); A0 A1 A2

VOID StoreItemInContext(IFFHandle*,LocalContextItem*, ContextNode*);

Function

Adds the LocalContextItem to the list of items for the given context node. If an LCI with the same Type, ID, and Ident is already present in the ContextNode, it will be purged and replaced with the new one. This is a raw form of StoreLocalItem().

Inputs

iff - pointer to IFFHandle structure for this context. localItem - pointer to a LocalContextItem to be stored. contextNode - pointer to context node in which to store item.

See also

StoreLocalItem()

StoreLocalItem()

StoreLocalItem -- insert a local context item into the context stack. (V36)

Synopsis

error = StoreLocalItem(iff, localItem, position); D0 A0 A1 D0

LONG StoreLocalItem(IFFHandle*,LocalContextItem*, LONG);

Function

Adds the local context item to the list of items for one of the context nodes on the context stack and purges any other item in the same context with the same ident, type and id. The position argument determines where in the stack to add the item:

IFFSLI_ROOT:
    Add item to list at root (default) stack position.
IFFSLI_TOP:
    Add item to the top (current) context node.
IFFSLI_PROP:
    Add element in top property context. Top property context is
    either the top FORM chunk, or the top LIST chunk, whichever
    is closer to the top of the stack.

Items added to the root context, or added to the top context before
the IFFHandle has been opened or after it has been closed, are put in
the default context. That is, they will be the local items found
only after all other context nodes have been searched. Items in the
default context are also immune to being purged until the IFFHandle
structure itself is deleted with FreeIFF(). This means that handlers
installed in the root context will still be there after an IFFHandle
structure has been opened and closed. (Note that this implies that
items stored in a higher context will be deleted when that context
ends.)

Inputs

iff - pointer to IFFHandle structure. localItem - pointer to LocalContextItem struct to insert. position - where to store the item (IFFSLI_ROOT, _TOP or _PROP).

Results

error - 0 if successful or an IFFERR_#? error code if unsuccessful.

See also

FindLocalItem(), StoreItemInContext(), EntryHandler(), ExitHandler()

WriteChunkBytes()

WriteChunkBytes -- write data from a buffer into the current chunk. (V36)

Synopsis

error = WriteChunkBytes(iff, buf, numBytes); D0 A0 A1 D0

LONG WriteChunkBytes(IFFHandle*, APTR, LONG);

Function

Writes "numBytes" bytes from the specified buffer into the current chunk. If the current chunk was pushed with IFFSIZE_UNKNOWN, the size of the chunk gets increased by the size of the buffer written. If the size was specified for this chunk, attempts to write past the end of the chunk will be truncated.

Inputs

iff - pointer to IFFHandle structure. buf - pointer to buffer area with bytes to be written. numBytes - number of bytes to write.

Results

error - (positive) number of bytes written if successful or a (negative) IFFERR_#? error code if unsuccessful.

See also

PushChunk(), PopChunk(), WriteChunkRecords()

WriteChunkRecords()

WriteChunkRecords -- write records from a buffer to the current chunk. (V36)

Synopsis

error = WriteChunkRecords(iff, buf, recsize, numrec); D0 A0 A1 D0 D1

LONG WriteChunkRecords(IFFHandle*, APTR, LONG, LONG);

Function

Writes record elements from the buffer into the top chunk. This function operates much like ReadChunkBytes().

Inputs

iff - pointer to IFFHandle structure. buf - pointer to buffer area containing data. recsize - size of data records to write. numrec - number of data records to write.

Results

error - (positive) number of whole records written if successful or a (negative) IFFERR_#? error code if unsuccessful.

See also

WriteChunkBytes()