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diff --git a/developer b/developer deleted file mode 100644 index a8c443cec..000000000 --- a/developer +++ /dev/null @@ -1,109 +0,0 @@ -Documentation for Developers - -This document contains an overview of the code for NetSurf, and any other -information useful to developers. - -________________________________________________________________________________ - -Source Code Overview - -The source is split at top level as follows: - -content -- fetching, caching, and converting content -css -- CSS parser and interfaces -desktop -- non-platform specific front-end -render -- HTML processing and layout -riscos -- RISC OS specific code -utils -- misc. useful functions - -________________________________________________________________________________ - -content -- fetching, caching, and converting content - -Each URL is stored in a struct content. This structure contains a union with -fields for each type of data (HTML, CSS, images). - -The content_* functions provide a general interface for handling these -structures. A content of a specified type is created using content_create(), -data is fed to it using content_process_data(), terminated by a call to -content_convert(), which converts the content into a structure which can be -displayed easily. - -The cache stores this converted content. When content is retrieved from the -cache, content_revive() should result in content which can be displayed (eg. by -loading any images and styles required and updating pointers to them). - -Code should not usually use the fetch_* and cache_* functions directly, except -for cache_free(). Instead use fetchcache(), which checks the cache for a url and -fetches, converts, and caches it if not present. - -________________________________________________________________________________ - -css -- CSS parser and interfaces - -CSS is tokenised by a flex-generated scanner (scanner.l), and then parsed into a -memory representation by a lemon-generated parser (parser.y, ruleset.c). - -Styles are retrieved using css_get_style(). They can be cascaded by -css_cascade(). - -http://lex.sourceforge.net/ -http://www.hwaci.com/sw/lemon/ - -________________________________________________________________________________ - -render -- HTML processing and layout - -This is the process to render an HTML document: - -First the HTML is parsed to a tree of xmlNodes using the HTML parser in libxml. -This happens simultaneously with the fetch [html_process_data()]. - -Any stylesheets which the document depends on are fetched and parsed. - -The tree is converted to a 'box tree' by xml_to_box(). The box tree contains a -node for each block, inline element, table, etc. The aim of this stage is to -determine the 'display' or 'float' CSS property of each element, and create the -corresponding node in the box tree. At this stage the style for each element is -also calculated (from CSS rules and element attributes). The tree is normalised -so that each node only has children of permitted types (eg. TABLE_CELLs must be -within TABLE_ROWs) by adding missing boxes. - -The box tree is passed to the layout engine [layout_document()], which finds the -space required by each element and assigns coordinates to the boxes, based on -the style of each element and the available width. This includes formatting -inline elements into lines, laying out tables, and positioning floats. The -layout engine can be invoked again on a already laid out box tree to reformat it -to a new width. Coordinates in the box tree are relative to the position of the -parent node. - -The box tree can then be rendered using each node's coordinates. - -box.[ch] -- definition of the box tree, conversion from xml tree, normalising -html.[ch] -- interface to HTML processing -layout.[ch] -- layout engine - -________________________________________________________________________________ - -Specifications - -HTML 4.01 http://www.w3.org/TR/html401/ -XHTML 1.0 http://www.w3.org/TR/xhtml1/ -CSS2 http://www.w3.org/TR/REC-CSS2/ -HTTP/1.1 http://www.w3.org/Protocols/rfc2616/rfc2616.html -PNG http://www.w3.org/Graphics/PNG/ - -________________________________________________________________________________ - -Libraries - -Get these compiled for RISC OS with headers from -http://netsurf.strcprstskrzkrk.co.uk/developer/ - -libxml (XML and HTML parser) http://xmlsoft.org/ -libcurl (HTTP, FTP, etc) http://curl.haxx.se/libcurl/ -OSLib (C interface to RISC OS SWIs) http://ro-oslib.sourceforge.net/ -libpng (PNG support) http://www.libpng.org/pub/png/libpng.html -zlib http://www.gzip.org/zlib/ - -________________________________________________________________________________ |