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         PERCENT, /* stored in data.number as (whole*10)+part */
  93         STRING,
  94         CODE,
  95         DEFAULT
  96     } type;
  97
  98     union
  99     {
 100         int number;
 101         OFFSETTYPE(char*) text;
 102         OFFSETTYPE(struct skin_element*) code;
 103     } data;
 104
 105     char type_code;
 106
 107 };
 108
 109 /* Defines an element of a SKIN file,
 110  *
 111  * This is allocated a lot, so it's optimized for size */
 112 struct skin_element
 113 {
 114     /* Link to the next element */
 115     OFFSETTYPE(struct skin_element*) next;
 116     /* Pointer to an array of children */
 117     OFFSETTYPE(struct skin_element**) children;
 118     /* Placeholder for element data
 119      * TEXT and COMMENT uses it for the text string
 120      * TAG, VIEWPORT, LINE, etc may use it for post parse extra storage
 121      */
 122     OFFSETTYPE(void*) data;
 123
 124     /* The tag or conditional name */
 125     const struct tag_info *tag;
 126
 127     /* Pointer to an array of parameters */
 128     OFFSETTYPE(struct skin_tag_parameter*) params;
 129
 130     /* Number of elements in the children array */
 131     short children_count;
 132     /* The line on which it's defined in the source file */
 133     short line;
 134     /* Defines what type of element it is */
 135     enum skin_element_type type;
 136     /* Number of elements in the params array */
 137     char params_count;
 138 };
 139
 140 enum skin_cb_returnvalue
 141 {
 142     CALLBACK_ERROR = -666,
 143     FEATURE_NOT_AVAILABLE,
 144     CALLBACK_OK = 0,
 145     /* > 0 reserved for future use */
 146 };
 147 typedef int (*skin_callback)(struct skin_element* element, void* data);
 148
 149 /***********************************************************************
 150  ***** Functions *******************************************************
 151  **********************************************************************/
 152
 153 /* Parses a WPS document and returns a list of skin_element
 154    structures. */
 155 #ifdef ROCKBOX
 156 struct skin_element* skin_parse(const char* document,
 157                                 skin_callback callback, void* callback_data);
 158 #else
 159 struct skin_element* skin_parse(const char* document);
 160 #endif
 161 /* Memory management functions */
 162 struct skin_element* skin_alloc_element(void);
 163 OFFSETTYPE(struct skin_element*)* skin_alloc_children(int count);
 164 struct skin_tag_parameter* skin_alloc_params(int count);
 165 char* skin_alloc_string(int length);
 166
 167 void skin_free_tree(struct skin_element* root);
 168
 169
 170 #ifdef __cplusplus
 171 }
 172 #endif
 173
 174 #endif /* GENERIC_PARSER_H */