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diff --git a/Docs/02-layout b/Docs/02-layout deleted file mode 100644 index 7702366d3..000000000 --- a/Docs/02-layout +++ /dev/null @@ -1,57 +0,0 @@ -HTML processing and layout -========================== - -The modules in the render directory process and layout HTML pages. - -Overview --------- -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. - -Lists ------ -Lists are one or more elements with 'display: list-item' (which is set for 'li' -by the default CSS). A list-item is constructed as a BLOCK box and a box for the -marker attached at block->list_marker. The marker contains the bullet, number, -or similar, depending on the list-style-type. - -Layout of the block is as normal. A pass of layout after main layout places list -marker boxes to the left of their block (see layout_lists()). - -Absolute positioning --------------------- -Absolutely positioned boxes are constructed in the box tree in the same place as -if they were not absolutely positioned. Inline boxes are created as -INLINE_BLOCK, tables as TABLE, and other boxes as BLOCK (see -box_solve_display()). - -During layout, absolutely positioned boxes in block context (BLOCK or TABLE) are -given a position in layout_block_context(), but treated as having no height. In -inline context (INLINE_BLOCK), they are given a position in layout_line(), but -treated as having no width or height. This is done to determine the static -position. - -An additional pass after main layout positions and layouts all absolutely -positioned boxes (see layout_position_absolute()). |