box.h

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/*
 * Copyright 2005 James Bursa <bursa@users.sourceforge.net>
 * Copyright 2003 Phil Mellor <monkeyson@users.sourceforge.net>
 * Copyright 2020 Vincent Sanders <vince@netsurf-browser.org>
 *
 * 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 interface.
 *
 */
 
#ifndef NETSURF_HTML_BOX_H
#define NETSURF_HTML_BOX_H
 
#include <limits.h>
#include <stdbool.h>
#include <libcss/libcss.h>
 
#include "content/handlers/css/utils.h"
 
struct content;
struct box;
struct browser_window;
struct html_content;
struct nsurl;
struct dom_node;
struct dom_string;
struct rect;
 
#define UNKNOWN_WIDTH INT_MAX
#define UNKNOWN_MAX_WIDTH INT_MAX
 
 
typedef void (*box_construct_complete_cb)(struct html_content *c, bool success);
 
 
/**
 * 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_FLEX,
        BOX_INLINE_FLEX,
} 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 */
        REPLACE_DIM = 1 << 9,   /* replaced element has given dimensions */
        IFRAME      = 1 << 10,  /* box contains an iframe */
        CONVERT_CHILDREN = 1 << 11,  /* wanted children converting */
        IS_REPLACED = 1 << 12   /* box is a replaced element */
} 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) */
};
 
 
/**
 * 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;
};
 
 
/**
 * Linked list of object element parameters.
 */
struct object_param {
        char *name;
        char *value;
        char *type;
        char *valuetype;
        struct object_param *next;
};
 
 
/**
 * Parameters for object element and similar elements.
 */
struct object_params {
        struct nsurl *data;
        char *type;
        char *codetype;
        struct nsurl *codebase;
        struct nsurl *classid;
        struct object_param *params;
};
 
 
/**
 * Node in box tree. All dimensions are in pixels.
 */
struct box {
        /**
         * Type of box.
         */
        box_type type;
 
        /**
         * Box flags
         */
        box_flags flags;
 
        /**
         * DOM node that generated this box or NULL
         */
        struct dom_node *node;
 
        /**
         * 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;
 
        /**
         *  value of id attribute (or name for anchors)
         */
        lwc_string *id;
 
 
        /**
         * Next sibling box, or NULL.
         */
        struct box *next;
 
        /**
         * Previous sibling box, or NULL.
         */
        struct box *prev;
 
        /**
         * First child box, or NULL.
         */
        struct box *children;
 
        /**
         * Last child box, or NULL.
         */
        struct box *last;
 
        /**
         * Parent box, or NULL.
         */
        struct box *parent;
 
        /**
         * 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 NULL. 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;
 
        /**
         * Level below which floats have been placed.
         */
        int cached_place_below_level;
 
 
        /**
         * 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;
 
        /**
         * Width of content box (excluding padding etc.).
         */
        int width;
        /**
         * Height of content box (excluding padding etc.).
         */
        int height;
 
        /* 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 */
 
        /**
         * Margin: TOP, RIGHT, BOTTOM, LEFT.
         */
        int margin[4];
 
        /**
         * Padding: TOP, RIGHT, BOTTOM, LEFT.
         */
        int padding[4];
 
        /**
         * Border: TOP, RIGHT, BOTTOM, LEFT.
         */
        struct box_border border[4];
 
        /**
         * Horizontal scroll.
         */
        struct scrollbar *scroll_x;
 
        /**
         * Vertical scroll.
         */
        struct scrollbar *scroll_y;
 
        /**
         * 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;
 
 
        /**
         * Text, or NULL if none. Unterminated.
         */
        char *text;
 
        /**
         * Length of text.
         */
        size_t length;
 
        /**
         * Width of space after current text (depends on font and size).
         */
        int space;
 
        /**
         * Byte offset within a textual representation of this content.
         */
        size_t byte_offset;
 
 
        /**
         * Link, or NULL.
         */
        struct nsurl *href;
 
        /**
         * Link target, or NULL.
         */
        const char *target;
 
        /**
         * Title, or NULL.
         */
        const char *title;
 
 
        /**
         * Number of columns for TABLE / TABLE_CELL.
         */
        unsigned int columns;
 
        /**
         * Number of rows for TABLE only.
         */
        unsigned int rows;
 
        /**
         * Start column for TABLE_CELL only.
         */
        unsigned int start_column;
 
        /**
         * Array of table column data for TABLE only.
         */
        struct column *col;
 
        /**
         * List item value.
         */
        int list_value;
 
        /**
         * List marker box if this is a list-item, or NULL.
         */
        struct box *list_marker;
 
 
        /**
         * Form control data, or NULL if not a form control.
         */
        struct form_control* gadget;
 
 
        /**
         * (Image)map to use with this object, or NULL if none
         */
        char *usemap;
 
 
        /**
         * Background image for this box, or NULL if none
         */
        struct hlcache_handle *background;
 
 
        /**
         * Object in this box (usually an image), or NULL if none.
         */
        struct hlcache_handle* object;
 
        /**
         * Parameters for the object, or NULL.
         */
        struct object_params *object_params;
 
 
        /**
         * Iframe's browser_window, or NULL if none
         */
        struct browser_window *iframe;
 
};
 
 
#endif