lib/skin_parser/skin_parser.h

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2010 Robert Bieber
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #ifndef GENERIC_PARSER_H
  23 #define GENERIC_PARSER_H
  24
  25 #ifdef __cplusplus
  26 extern "C"
  27 {
  28 #endif
  29 #include <stdlib.h>
  30 #include <stdbool.h>
  31
  32 #if defined(ROCKBOX) && !defined(__PCTOOL__)
  33 /* Use this type and macro to convert a pointer from the
  34  * skin buffer to a useable pointer */
  35 typedef long skinoffset_t;
  36 #define SKINOFFSETTOPTR(base, offset) ((offset) < 0 ? NULL : ((void*)&base[offset]))
  37 #define PTRTOSKINOFFSET(base, pointer) ((pointer) ? ((void*)pointer-(void*)base) : -1)
  38 /* Use this macro when declaring a variable to self-document the code.
  39  * type is the actual type being pointed to (i.e OFFSETTYPE(char*) foo )
  40  *
  41  * WARNING: Don't use the PTRTOSKINOFFSET() around a function call as it wont
  42  * do what you expect.
  43  */
  44 #define OFFSETTYPE(type) skinoffset_t
  45 #else
  46 #define SKINOFFSETTOPTR(base, offset) offset
  47 #define PTRTOSKINOFFSET(base, pointer) pointer
  48 #define OFFSETTYPE(type) type
  49 #endif
  50
  51 /********************************************************************
  52  ****** Data Structures *********************************************
  53  *******************************************************************/
  54
  55 /* Possible types of element in a WPS file */
  56 enum skin_element_type
  57 {
  58     UNKNOWN = -1,
  59     VIEWPORT,
  60     LINE_ALTERNATOR,
  61     LINE,
  62     CONDITIONAL,
  63     TAG,
  64     TEXT,
  65     COMMENT,
  66 };
  67
  68 enum skin_errorcode
  69 {
  70     MEMORY_LIMIT_EXCEEDED,
  71     NEWLINE_EXPECTED,
  72     ILLEGAL_TAG,
  73     ARGLIST_EXPECTED,
  74     TOO_MANY_ARGS,
  75     DEFAULT_NOT_ALLOWED,
  76     UNEXPECTED_NEWLINE,
  77     INSUFFICIENT_ARGS,
  78     INT_EXPECTED,
  79     DECIMAL_EXPECTED,
  80     SEPARATOR_EXPECTED,
  81     CLOSE_EXPECTED,
  82     MULTILINE_EXPECTED
  83 };
  84
  85 /* Holds a tag parameter, either numeric or text */
  86 struct skin_tag_parameter
  87 {
  88     enum
  89     {
  90         INTEGER,
  91         DECIMAL, /* stored in data.number as (whole*10)+part */
  92         STRING,
  93         CODE,
  94         DEFAULT
  95     } type;
  96
  97     union
  98     {
  99         int number;
 100         OFFSETTYPE(char*) text;
 101         OFFSETTYPE(struct skin_element*) code;
 102     } data;
 103
 104     char type_code;
 105
 106 };
 107
 108 /* Defines an element of a SKIN file,
 109  *
 110  * This is allocated a lot, so it's optimized for size */
 111 struct skin_element
 112 {
 113     /* Link to the next element */
 114     OFFSETTYPE(struct skin_element*) next;
 115     /* Pointer to an array of children */
 116     OFFSETTYPE(struct skin_element**) children;
 117     /* Placeholder for element data
 118      * TEXT and COMMENT uses it for the text string
 119      * TAG, VIEWPORT, LINE, etc may use it for post parse extra storage
 120      */
 121     OFFSETTYPE(void*) data;
 122
 123     /* The tag or conditional name */
 124     const struct tag_info *tag;
 125
 126     /* Pointer to an array of parameters */
 127     OFFSETTYPE(struct skin_tag_parameter*) params;
 128
 129     /* Number of elements in the children array */
 130     short children_count;
 131     /* The line on which it's defined in the source file */
 132     short line;
 133     /* Defines what type of element it is */
 134     enum skin_element_type type;
 135     /* Number of elements in the params array */
 136     char params_count;
 137 };
 138
 139 enum skin_cb_returnvalue
 140 {
 141     CALLBACK_ERROR = -666,
 142     FEATURE_NOT_AVAILABLE,
 143     CALLBACK_OK = 0,
 144     /* > 0 reserved for future use */
 145 };
 146 typedef int (*skin_callback)(struct skin_element* element, void* data);
 147
 148 /***********************************************************************
 149  ***** Functions *******************************************************
 150  **********************************************************************/
 151
 152 /* Parses a WPS document and returns a list of skin_element
 153    structures. */
 154 #ifdef ROCKBOX
 155 struct skin_element* skin_parse(const char* document,
 156                                 skin_callback callback, void* callback_data);
 157 #else
 158 struct skin_element* skin_parse(const char* document);
 159 #endif
 160 /* Memory management functions */
 161 struct skin_element* skin_alloc_element(void);
 162 OFFSETTYPE(struct skin_element*)* skin_alloc_children(int count);
 163 struct skin_tag_parameter* skin_alloc_params(int count);
 164 char* skin_alloc_string(int length);
 165
 166 void skin_free_tree(struct skin_element* root);
 167
 168
 169 #ifdef __cplusplus
 170 }
 171 #endif
 172
 173 #endif /* GENERIC_PARSER_H */