libs-base/Source/objects/Coding.h
mccallum 496bde0f95 (CommonCoding, Encoding, Decoding): New protocols.
(SelfCoding): New category of NSObject, interface only, no
implementation.  This takes the place of the Coding Protocol.
(Coding): Protocol removed.


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@332 72102866-910b-0410-8b05-ffd578937521
1995-04-09 01:52:11 +00:00

174 lines
4.9 KiB
Objective-C

/* Protocol for GNU Objective-C objects that can write/read to a coder
Copyright (C) 1993, 1994, 1995 Free Software Foundation, Inc.
Written by: R. Andrew McCallum <mccallum@gnu.ai.mit.edu>
Date: July 1994
This file is part of the GNU Objective C Class Library.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef __Coding_h_OBJECTS_INCLUDE
#define __Coding_h_OBJECTS_INCLUDE
#include <objects/stdobjects.h>
@class Coder; /* xxx remove this eventually */
@class Stream; /* xxx remove this eventually */
@protocol CommonCoding
- (BOOL) isDecoding;
+ (int) coderFormatVersion;
+ (int) coderConcreteFormatVersion;
+ (const char *) coderSignature;
- doInitOnStream: (Stream *)s isDecoding: (BOOL)f;
/* Internal designated initializer. Override it, but don't call it yourself.
This method name may change. */
@end
@protocol Encoding <CommonCoding>
- initEncodingOnStream: (Stream *)s;
- initEncoding;
- (void) encodeValueOfType: (const char*)type
at: (const void*)d
withName: (const char *)name;
- (void) encodeWithName: (const char *)name
valuesOfTypes: (const char *)types, ...;
- (void) encodeArrayOfType: (const char *)type
at: (const void *)d
count: (unsigned)c
withName: (const char *)name;
- (void) encodeObject: anObj
withName: (const char *)name;
- (void) encodeObjectBycopy: anObj
withName: (const char *)name;
- (void) encodeRootObject: anObj
withName: (const char *)name;
- (void) encodeObjectReference: anObj
withName: (const char *)name;
- (void) startEncodingInterconnectedObjects;
- (void) finishEncodingInterconnectedObjects;
- (void) encodeAtomicString: (const char*)sp
withName: (const char*)name;
- (void) encodeClass: aClass;
/* For inserting a name into a TextCoder stream */
- (void) encodeName: (const char*)n;
/* For subclasses that want to keep track of recursion */
- (void) encodeIndent;
- (void) encodeUnindent;
/* Implemented by concrete subclasses */
- (void) encodeValueOfSimpleType: (const char*)type
at: (const void*)d
withName: (const char *)name;
- (void) encodeBytes: (const char *)b
count: (unsigned)c
withName: (const char *)name;
@end
@protocol Decoding <CommonCoding>
- initDecodingOnStream: (Stream *)s;
- initDecoding;
- (void) decodeValueOfType: (const char*)type
at: (void*)d
withName: (const char **)namePtr;
- (void) decodeWithName: (const char **)name
valuesOfTypes: (const char *)types, ...;
- (void) decodeArrayOfType: (const char *)type
at: (void *)d
count: (unsigned *)c
withName: (const char **)name;
- (void) decodeObjectAt: (id*)anObjPtr
withName: (const char **)name;
- (void) startDecodingInterconnectedObjects;
- (void) finishDecodingInterconnectedObjects;
- (const char *) decodeAtomicStringWithName: (const char **)name;
- decodeClass;
/* For inserting a name into a TextCoder stream */
- (void) decodeName: (const char**)n;
/* For subclasses that want to keep track of recursion */
- (void) decodeIndent;
- (void) decodeUnindent;
/* Implemented by concrete subclasses */
- (void) decodeValueOfSimpleType: (const char*)type
at: (void*)d
withName: (const char **)namePtr;
- (void) decodeBytes: (char *)b
count: (unsigned*)c
withName: (const char **)name;
@end
@interface NSObject (SelfCoding)
- (void) encodeWithCoder: (id <Encoding>)anEncoder;
- (id) initWithCoder: (id <Decoding>)aDecoder;
+ (id) newWithCoder: (id <Decoding>)aDecoder;
/* NOTE:
If the class responds to +newWithCoder Coder will send it for
decoding, otherwise Coder will allocate the object itself and send
initWithCoder instead.
+newWithCoder is useful because many classes keep track of their
instances and only allow one instance of each configuration. For
example, see the designated initializers of SocketPort, Connection,
and Proxy.
Using +new.. instead of -init.. prevents us from having to waste
the effort of allocating space for an object to be decoded, then
immediately deallocating that space because we're just returning a
pre-existing object.
The newWithCoder and initWithCoder methods must return the decoded
object.
This is not a Protocol, because objects are not required to
implement newWithCoder or initWithCoder. They probably want to
implement one of them, though.
-mccallum */
@end
#endif /* __Coding_h_OBJECTS_INCLUDE */