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+/*
+ * 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 dom_nodes (produced by libdom)
+ * 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_HTML_BOX_H
+#define NETSURF_HTML_BOX_H
+
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <libcss/libcss.h>
+
+#include "content/handlers/css/utils.h"
+
+struct content;
+struct box;
+struct browser_window;
+struct column;
+struct object_params;
+struct object_param;
+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_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) */
+};
+
+/** 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 scrollbar *scroll_x; /**< Horizontal scroll. */
+ struct scrollbar *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;
+
+ struct nsurl *href; /**< Link, or 0. */
+ const char *target; /**< Link target, or 0. */
+ const 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;
+
+ /* Level below which floats have been placed. */
+ int cached_place_below_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 */
+ lwc_string *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;
+
+ /** Iframe's browser_window, or NULL if none */
+ struct browser_window *iframe;
+
+ struct dom_node *node; /**< DOM node that generated this box or NULL */
+};
+
+/** 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 element and similar elements. */
+struct object_params {
+ struct nsurl *data;
+ char *type;
+ char *codetype;
+ struct nsurl *codebase;
+ struct nsurl *classid;
+ struct object_param *params;
+};
+
+/** Linked list of object element 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;
+
+
+
+struct box * box_create(css_select_results *styles, css_computed_style *style,
+ bool style_owned, struct nsurl *href, const char *target,
+ const char *title, lwc_string *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_bounds(struct box *box, struct rect *r);
+void box_coords(struct box *box, int *x, int *y);
+struct box *box_at_point(
+ const nscss_len_ctx *len_ctx,
+ struct box *box, const int x, const int y,
+ int *box_x, int *box_y);
+struct box *box_pick_text_box(struct html_content *html,
+ int x, int y, int dir, int *dx, int *dy);
+struct box *box_find_by_id(struct box *box, lwc_string *id);
+bool box_visible(struct box *box);
+void box_dump(FILE *stream, struct box *box, unsigned int depth, bool style);
+
+/**
+ * Extract a URL from a relative link, handling junk like whitespace and
+ * attempting to read a real URL from "javascript:" links.
+ *
+ * \param content html content
+ * \param dsrel relative URL text taken from page
+ * \param base base for relative URLs
+ * \param result updated to target URL on heap, unchanged if extract failed
+ * \return true on success, false on memory exhaustion
+ */
+bool box_extract_link(const struct html_content *content, const struct dom_string *dsrel, struct nsurl *base, struct nsurl **result);
+
+bool box_handle_scrollbars(struct content *c, struct box *box,
+ bool bottom, bool right);
+bool box_vscrollbar_present(const struct box *box);
+bool box_hscrollbar_present(const struct box *box);
+
+nserror dom_to_box(struct dom_node *n, struct html_content *c,
+ box_construct_complete_cb cb);
+
+bool box_normalise_block(
+ struct box *block,
+ const struct box *root,
+ struct html_content *c);
+
+/**
+ * Check if layout box is a first child.
+ *
+ * \param[in] b Box to check.
+ * \return true iff box is first child.
+ */
+static inline bool box_is_first_child(struct box *b)
+{
+ return (b->parent == NULL || b == b->parent->children);
+}
+
+#endif