netsurf/render/box.h

339 lines
11 KiB
C

/*
* Copyright 2005 James Bursa <bursa@users.sourceforge.net>
* Copyright 2003 Phil Mellor <monkeyson@users.sourceforge.net>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* NetSurf 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/** \file
* Box tree construction and manipulation (interface).
*
* This stage of rendering converts a tree of xmlNodes (produced by libxml2)
* to a tree of struct box. The box tree represents the structure of the
* document as given by the CSS display and float properties.
*
* For example, consider the following HTML:
* \code
* <h1>Example Heading</h1>
* <p>Example paragraph <em>with emphasised text</em> etc.</p> \endcode
*
* This would produce approximately the following box tree with default CSS
* rules:
* \code
* BOX_BLOCK (corresponds to h1)
* BOX_INLINE_CONTAINER
* BOX_INLINE "Example Heading"
* BOX_BLOCK (p)
* BOX_INLINE_CONTAINER
* BOX_INLINE "Example paragraph "
* BOX_INLINE "with emphasised text" (em)
* BOX_INLINE "etc." \endcode
*
* Note that the em has been collapsed into the INLINE_CONTAINER.
*
* If these CSS rules were applied:
* \code
* h1 { display: table-cell }
* p { display: table-cell }
* em { float: left; width: 5em } \endcode
*
* then the box tree would instead look like this:
* \code
* BOX_TABLE
* BOX_TABLE_ROW_GROUP
* BOX_TABLE_ROW
* BOX_TABLE_CELL (h1)
* BOX_INLINE_CONTAINER
* BOX_INLINE "Example Heading"
* BOX_TABLE_CELL (p)
* BOX_INLINE_CONTAINER
* BOX_INLINE "Example paragraph "
* BOX_FLOAT_LEFT (em)
* BOX_BLOCK
* BOX_INLINE_CONTAINER
* BOX_INLINE "with emphasised text"
* BOX_INLINE "etc." \endcode
*
* Here implied boxes have been added and a float is present.
*
* A box tree is "normalized" if the following is satisfied:
* \code
* parent permitted child nodes
* BLOCK, INLINE_BLOCK BLOCK, INLINE_CONTAINER, TABLE
* INLINE_CONTAINER INLINE, INLINE_BLOCK, FLOAT_LEFT, FLOAT_RIGHT, BR, TEXT,
* INLINE_END
* INLINE none
* TABLE at least 1 TABLE_ROW_GROUP
* TABLE_ROW_GROUP at least 1 TABLE_ROW
* TABLE_ROW at least 1 TABLE_CELL
* TABLE_CELL BLOCK, INLINE_CONTAINER, TABLE (same as BLOCK)
* FLOAT_(LEFT|RIGHT) exactly 1 BLOCK or TABLE
* \endcode
*/
#ifndef _NETSURF_RENDER_BOX_H_
#define _NETSURF_RENDER_BOX_H_
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <libxml/HTMLparser.h>
#include "desktop/browser.h"
#include "desktop/shape.h"
#include "css/css.h"
struct box;
struct column;
struct object_params;
struct object_param;
#define UNKNOWN_WIDTH INT_MAX
#define UNKNOWN_MAX_WIDTH INT_MAX
/** Type of a struct box. */
typedef enum {
BOX_BLOCK, BOX_INLINE_CONTAINER, BOX_INLINE,
BOX_TABLE, BOX_TABLE_ROW, BOX_TABLE_CELL,
BOX_TABLE_ROW_GROUP,
BOX_FLOAT_LEFT, BOX_FLOAT_RIGHT,
BOX_INLINE_BLOCK, BOX_BR, BOX_TEXT,
BOX_INLINE_END, BOX_NONE
} box_type;
/** Flags for a struct box. */
typedef enum {
NEW_LINE = 1 << 0, /* first inline on a new line */
STYLE_OWNED = 1 << 1, /* style is owned by this box */
PRINTED = 1 << 2, /* box has already been printed */
PRE_STRIP = 1 << 3, /* PRE tag needing leading newline stripped */
CLONE = 1 << 4, /* continuation of previous box from wrapping */
MEASURED = 1 << 5, /* text box width has been measured */
HAS_HEIGHT = 1 << 6, /* box has height (perhaps due to children) */
MAKE_HEIGHT = 1 << 7, /* box causes its own height */
NEED_MIN = 1 << 8 /* minimum width is required for layout */
} box_flags;
/* Sides of a box */
enum box_side { TOP, RIGHT, BOTTOM, LEFT };
/**
* Container for box border details
*/
struct box_border {
enum css_border_style_e style; /**< border-style */
css_color c; /**< border-color value */
int width; /**< border-width (pixels) */
};
/** Node in box tree. All dimensions are in pixels. */
struct box {
/** Type of box. */
box_type type;
/** Box flags */
box_flags flags;
/** Computed styles for elements and their pseudo elements. NULL on
* non-element boxes. */
css_select_results *styles;
/** Style for this box. 0 for INLINE_CONTAINER and FLOAT_*. Pointer into
* a box's 'styles' select results, except for implied boxes, where it
* is a pointer to an owned computed style. */
css_computed_style *style;
/** Coordinate of left padding edge relative to parent box, or relative
* to ancestor that contains this box in float_children for FLOAT_. */
int x;
/** Coordinate of top padding edge, relative as for x. */
int y;
int width; /**< Width of content box (excluding padding etc.). */
int height; /**< Height of content box (excluding padding etc.). */
/* These four variables determine the maximum extent of a box's
* descendants. They are relative to the x,y coordinates of the box.
*
* Their use depends on the overflow CSS property:
*
* Overflow: Usage:
* visible The content of the box is displayed within these
* dimensions.
* hidden These are ignored. Content is plotted within the box
* dimensions.
* scroll These are used to determine the extent of the
* scrollable area.
* auto As "scroll".
*/
int descendant_x0; /**< left edge of descendants */
int descendant_y0; /**< top edge of descendants */
int descendant_x1; /**< right edge of descendants */
int descendant_y1; /**< bottom edge of descendants */
int margin[4]; /**< Margin: TOP, RIGHT, BOTTOM, LEFT. */
int padding[4]; /**< Padding: TOP, RIGHT, BOTTOM, LEFT. */
struct box_border border[4]; /**< Border: TOP, RIGHT, BOTTOM, LEFT. */
struct scroll *scroll_x; /**< Horizontal scroll. */
struct scroll *scroll_y; /**< Vertical scroll. */
/** Width of box taking all line breaks (including margins etc). Must
* be non-negative. */
int min_width;
/** Width that would be taken with no line breaks. Must be
* non-negative. */
int max_width;
/**< Byte offset within a textual representation of this content. */
size_t byte_offset;
char *text; /**< Text, or 0 if none. Unterminated. */
size_t length; /**< Length of text. */
/** Width of space after current text (depends on font and size). */
int space;
char *href; /**< Link, or 0. */
const char *target; /**< Link target, or 0. */
char *title; /**< Title, or 0. */
unsigned int columns; /**< Number of columns for TABLE / TABLE_CELL. */
unsigned int rows; /**< Number of rows for TABLE only. */
unsigned int start_column; /**< Start column for TABLE_CELL only. */
struct box *next; /**< Next sibling box, or 0. */
struct box *prev; /**< Previous sibling box, or 0. */
struct box *children; /**< First child box, or 0. */
struct box *last; /**< Last child box, or 0. */
struct box *parent; /**< Parent box, or 0. */
/** INLINE_END box corresponding to this INLINE box, or INLINE box
* corresponding to this INLINE_END box. */
struct box *inline_end;
/** First float child box, or 0. Float boxes are in the tree twice, in
* this list for the block box which defines the area for floats, and
* also in the standard tree given by children, next, prev, etc. */
struct box *float_children;
/** Next sibling float box. */
struct box *next_float;
/** If box is a float, points to box's containing block */
struct box *float_container;
/** Level below which subsequent floats must be cleared.
* This is used only for boxes with float_children */
int clear_level;
/** List marker box if this is a list-item, or 0. */
struct box *list_marker;
struct column *col; /**< Array of table column data for TABLE only. */
/** Form control data, or 0 if not a form control. */
struct form_control* gadget;
char *usemap; /** (Image)map to use with this object, or 0 if none */
char *id; /**< value of id attribute (or name for anchors) */
/** Background image for this box, or 0 if none */
struct hlcache_handle *background;
/** Object in this box (usually an image), or 0 if none. */
struct hlcache_handle* object;
/** Parameters for the object, or 0. */
struct object_params *object_params;
};
/** Table column data. */
struct column {
/** Type of column. */
enum { COLUMN_WIDTH_UNKNOWN, COLUMN_WIDTH_FIXED,
COLUMN_WIDTH_AUTO, COLUMN_WIDTH_PERCENT,
COLUMN_WIDTH_RELATIVE } type;
/** Preferred width of column. Pixels for FIXED, percentage for PERCENT,
* relative units for RELATIVE, unused for AUTO. */
int width;
/** Minimum width of content. */
int min;
/** Maximum width of content. */
int max;
/** Whether all of column's cells are css positioned. */
bool positioned;
};
/** Parameters for <object> and similar elements. */
struct object_params {
char *data;
char *type;
char *codetype;
char *codebase;
char *classid;
struct object_param *params;
};
/** Linked list of <object> parameters. */
struct object_param {
char *name;
char *value;
char *type;
char *valuetype;
struct object_param *next;
};
/** Frame target names (constant pointers to save duplicating the strings many
* times). We convert _blank to _top for user-friendliness. */
extern const char *TARGET_SELF;
extern const char *TARGET_PARENT;
extern const char *TARGET_TOP;
extern const char *TARGET_BLANK;
void *box_style_alloc(void *ptr, size_t len, void *pw);
struct box * box_create(css_select_results *styles, css_computed_style *style,
bool style_owned, char *href, const char *target, char *title,
char *id, void *context);
void box_add_child(struct box *parent, struct box *child);
void box_insert_sibling(struct box *box, struct box *new_box);
void box_unlink_and_free(struct box *box);
void box_free(struct box *box);
void box_free_box(struct box *box);
void box_free_object_params(struct object_params *op);
void box_bounds(struct box *box, struct rect *r);
void box_coords(struct box *box, int *x, int *y);
struct box *box_at_point(struct box *box, const int x, const int y,
int *box_x, int *box_y, struct hlcache_handle **content);
struct box *box_object_at_point(struct hlcache_handle *h, int x, int y);
struct box *box_href_at_point(struct hlcache_handle *h, int x, int y);
struct box *box_pick_text_box(struct hlcache_handle *h,
int x, int y, int dir, int *dx, int *dy);
struct box *box_find_by_id(struct box *box, const char *id);
bool box_visible(struct box *box);
void box_dump(FILE *stream, struct box *box, unsigned int depth);
bool box_extract_link(const char *rel, const char *base, char **result);
bool box_handle_scrollbars(struct browser_window *bw, struct box *box,
bool bottom, bool right);
bool box_vscrollbar_present(const struct box *box);
bool box_hscrollbar_present(const struct box *box);
bool xml_to_box(xmlNode *n, struct content *c);
bool box_normalise_block(struct box *block, struct content *c);
#endif