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WebSurf/content/handlers/html/layout.c

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/*
* Copyright 2005 Richard Wilson <info@tinct.net>
* Copyright 2006 James Bursa <bursa@users.sourceforge.net>
* Copyright 2008 Michael Drake <tlsa@netsurf-browser.org>
* 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
* HTML layout implementation.
*
* Layout is carried out in two stages:
*
* 1. + calculation of minimum / maximum box widths, and
* + determination of whether block level boxes will have >zero height
*
* 2. + layout (position and dimensions)
*
* In most cases the functions for the two stages are a corresponding pair
* layout_minmax_X() and layout_X().
*/
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <dom/dom.h>
#include "utils/log.h"
#include "utils/talloc.h"
#include "utils/utils.h"
#include "utils/nsoption.h"
#include "utils/corestrings.h"
#include "utils/nsurl.h"
#include "netsurf/inttypes.h"
#include "netsurf/content.h"
#include "netsurf/browser_window.h"
#include "netsurf/layout.h"
#include "content/content.h"
#include "content/content_protected.h"
#include "css/utils.h"
#include "desktop/scrollbar.h"
#include "desktop/textarea.h"
#include "html/html.h"
#include "html/html_save.h"
#include "html/private.h"
#include "html/box.h"
#include "html/box_inspect.h"
#include "html/font.h"
#include "html/form_internal.h"
#include "html/layout.h"
#include "html/table.h"
#define AUTO INT_MIN
/* Fixed point percentage (a) of an integer (b), to an integer */
#define FPCT_OF_INT_TOINT(a, b) (FIXTOINT(FDIV((a * b), F_100)))
typedef uint8_t (*css_len_func)(
const css_computed_style *style,
css_fixed *length, css_unit *unit);
typedef uint8_t (*css_border_style_func)(
const css_computed_style *style);
typedef uint8_t (*css_border_color_func)(
const css_computed_style *style,
css_color *color);
/** Array of per-side access functions for computed style margins. */
static const css_len_func margin_funcs[4] = {
[TOP] = css_computed_margin_top,
[RIGHT] = css_computed_margin_right,
[BOTTOM] = css_computed_margin_bottom,
[LEFT] = css_computed_margin_left,
};
/** Array of per-side access functions for computed style paddings. */
static const css_len_func padding_funcs[4] = {
[TOP] = css_computed_padding_top,
[RIGHT] = css_computed_padding_right,
[BOTTOM] = css_computed_padding_bottom,
[LEFT] = css_computed_padding_left,
};
/** Array of per-side access functions for computed style border_widths. */
static const css_len_func border_width_funcs[4] = {
[TOP] = css_computed_border_top_width,
[RIGHT] = css_computed_border_right_width,
[BOTTOM] = css_computed_border_bottom_width,
[LEFT] = css_computed_border_left_width,
};
/** Array of per-side access functions for computed style border styles. */
static const css_border_style_func border_style_funcs[4] = {
[TOP] = css_computed_border_top_style,
[RIGHT] = css_computed_border_right_style,
[BOTTOM] = css_computed_border_bottom_style,
[LEFT] = css_computed_border_left_style,
};
/** Array of per-side access functions for computed style border colors. */
static const css_border_color_func border_color_funcs[4] = {
[TOP] = css_computed_border_top_color,
[RIGHT] = css_computed_border_right_color,
[BOTTOM] = css_computed_border_bottom_color,
[LEFT] = css_computed_border_left_color,
};
/* forward declaration to break cycles */
static bool layout_block_context(
struct box *block,
int viewport_height,
html_content *content);
static void layout_minmax_block(
struct box *block,
const struct gui_layout_table *font_func,
const html_content *content);
/**
* Compute the size of replaced boxes with auto dimensions, according to
* content.
*
* \param box Box with object
* \param width Width value in px or AUTO. If AUTO, updated to value in px.
* \param height Height value in px or AUTO. If AUTO, updated to value in px.
* \param min_width Box's min width, as given by layout_find_dimensions.
* \param max_width Box's max width, as given by layout_find_dimensions.
* \param min_height Box's min height, as given by layout_find_dimensions.
* \param max_height Box's max height, as given by layout_find_dimensions.
*
* See CSS 2.1 sections 10.3 and 10.6.
*/
static void
layout_get_object_dimensions(struct box *box,
int *width, int *height,
int min_width, int max_width,
int min_height, int max_height)
{
assert(box->object != NULL);
assert(width != NULL && height != NULL);
if (*width == AUTO && *height == AUTO) {
/* No given dimensions */
bool scaled = false;
int intrinsic_width = content_get_width(box->object);
int intrinsic_height = content_get_height(box->object);
/* use intrinsic dimensions */
*width = intrinsic_width;
*height = intrinsic_height;
/* Deal with min/max-width first */
if (min_width > 0 && min_width > *width) {
*width = min_width;
scaled = true;
}
if (max_width >= 0 && max_width < *width) {
*width = max_width;
scaled = true;
}
if (scaled && (intrinsic_width != 0)) {
/* Update height */
*height = (*width * intrinsic_height) /
intrinsic_width;
}
scaled = false;
/* Deal with min/max-height */
if (min_height > 0 && min_height > *height) {
*height = min_height;
scaled = true;
}
if (max_height >= 0 && max_height < *height) {
*height = max_height;
scaled = true;
}
if (scaled && (intrinsic_height != 0)) {
/* Update width */
*width = (*height * intrinsic_width) /
intrinsic_height;
}
} else if (*width == AUTO) {
/* Have given height; width is calculated from the given height
* and ratio of intrinsic dimensions */
int intrinsic_width = content_get_width(box->object);
int intrinsic_height = content_get_height(box->object);
if (intrinsic_height != 0)
*width = (*height * intrinsic_width) /
intrinsic_height;
else
*width = intrinsic_width;
if (min_width > 0 && min_width > *width)
*width = min_width;
if (max_width >= 0 && max_width < *width)
*width = max_width;
} else if (*height == AUTO) {
/* Have given width; height is calculated from the given width
* and ratio of intrinsic dimensions */
int intrinsic_width = content_get_width(box->object);
int intrinsic_height = content_get_height(box->object);
if (min_width > 0 && min_width > *width)
*width = min_width;
if (max_width >= 0 && max_width < *width)
*width = max_width;
if (intrinsic_width != 0)
*height = (*width * intrinsic_height) /
intrinsic_width;
else
*height = intrinsic_height;
}
}
/**
* Calculate the text-indent length.
*
* \param style style of block
* \param width width of containing block
* \return length of indent
*/
static int layout_text_indent(
const nscss_len_ctx *len_ctx,
const css_computed_style *style, int width)
{
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
css_computed_text_indent(style, &value, &unit);
if (unit == CSS_UNIT_PCT) {
return FPCT_OF_INT_TOINT(value, width);
} else {
return FIXTOINT(nscss_len2px(len_ctx, value, unit, style));
}
}
/**
* Determine width of margin, borders, and padding on one side of a box.
*
* \param len_ctx CSS length conversion context for document
* \param style style to measure
* \param side side of box to measure
* \param margin whether margin width is required
* \param border whether border width is required
* \param padding whether padding width is required
* \param fixed increased by sum of fixed margin, border, and padding
* \param frac increased by sum of fractional margin and padding
*/
static void
calculate_mbp_width(const nscss_len_ctx *len_ctx,
const css_computed_style *style,
unsigned int side,
bool margin,
bool border,
bool padding,
int *fixed,
float *frac)
{
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
assert(style);
/* margin */
if (margin) {
enum css_margin_e type;
type = margin_funcs[side](style, &value, &unit);
if (type == CSS_MARGIN_SET) {
if (unit == CSS_UNIT_PCT) {
*frac += FIXTOINT(FDIV(value, F_100));
} else {
*fixed += FIXTOINT(nscss_len2px(len_ctx,
value, unit, style));
}
}
}
/* border */
if (border) {
if (border_style_funcs[side](style) !=
CSS_BORDER_STYLE_NONE) {
border_width_funcs[side](style, &value, &unit);
*fixed += FIXTOINT(nscss_len2px(len_ctx,
value, unit, style));
}
}
/* padding */
if (padding) {
padding_funcs[side](style, &value, &unit);
if (unit == CSS_UNIT_PCT) {
*frac += FIXTOINT(FDIV(value, F_100));
} else {
*fixed += FIXTOINT(nscss_len2px(len_ctx,
value, unit, style));
}
}
}
/**
* Calculate minimum and maximum width of a table.
*
* \param table box of type TABLE
* \param font_func Font functions
* \param content The HTML content we are laying out.
* \post table->min_width and table->max_width filled in,
* 0 <= table->min_width <= table->max_width
*/
static void layout_minmax_table(struct box *table,
const struct gui_layout_table *font_func,
const html_content *content)
{
unsigned int i, j;
int border_spacing_h = 0;
int table_min = 0, table_max = 0;
int extra_fixed = 0;
float extra_frac = 0;
struct column *col;
struct box *row_group, *row, *cell;
enum css_width_e wtype;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
/* check if the widths have already been calculated */
if (table->max_width != UNKNOWN_MAX_WIDTH)
return;
if (table_calculate_column_types(&content->len_ctx, table) == false) {
NSLOG(netsurf, WARNING,
"Could not establish table column types.");
return;
}
col = table->col;
/* start with 0 except for fixed-width columns */
for (i = 0; i != table->columns; i++) {
if (col[i].type == COLUMN_WIDTH_FIXED)
col[i].min = col[i].max = col[i].width;
else
col[i].min = col[i].max = 0;
}
/* border-spacing is used in the separated borders model */
if (css_computed_border_collapse(table->style) ==
CSS_BORDER_COLLAPSE_SEPARATE) {
css_fixed h = 0, v = 0;
css_unit hu = CSS_UNIT_PX, vu = CSS_UNIT_PX;
css_computed_border_spacing(table->style, &h, &hu, &v, &vu);
border_spacing_h = FIXTOINT(nscss_len2px(&content->len_ctx,
h, hu, table->style));
}
/* 1st pass: consider cells with colspan 1 only */
for (row_group = table->children; row_group; row_group =row_group->next)
for (row = row_group->children; row; row = row->next)
for (cell = row->children; cell; cell = cell->next) {
assert(cell->type == BOX_TABLE_CELL);
assert(cell->style);
/** TODO: Handle colspan="0" correctly.
* It's currently converted to 1 in box normaisation */
assert(cell->columns != 0);
if (cell->columns != 1)
continue;
layout_minmax_block(cell, font_func, content);
i = cell->start_column;
if (col[i].positioned)
continue;
/* update column min, max widths using cell widths */
if (col[i].min < cell->min_width)
col[i].min = cell->min_width;
if (col[i].max < cell->max_width)
col[i].max = cell->max_width;
}
/* 2nd pass: cells which span multiple columns */
for (row_group = table->children; row_group; row_group =row_group->next)
for (row = row_group->children; row; row = row->next)
for (cell = row->children; cell; cell = cell->next) {
unsigned int flexible_columns = 0;
int min = 0, max = 0, fixed_width = 0, extra;
if (cell->columns == 1)
continue;
layout_minmax_block(cell, font_func, content);
i = cell->start_column;
/* find min width so far of spanned columns, and count
* number of non-fixed spanned columns and total fixed width */
for (j = 0; j != cell->columns; j++) {
min += col[i + j].min;
if (col[i + j].type == COLUMN_WIDTH_FIXED)
fixed_width += col[i + j].width;
else
flexible_columns++;
}
min += (cell->columns - 1) * border_spacing_h;
/* distribute extra min to spanned columns */
if (min < cell->min_width) {
if (flexible_columns == 0) {
extra = 1 + (cell->min_width - min) /
cell->columns;
for (j = 0; j != cell->columns; j++) {
col[i + j].min += extra;
if (col[i + j].max < col[i + j].min)
col[i + j].max = col[i + j].min;
}
} else {
extra = 1 + (cell->min_width - min) /
flexible_columns;
for (j = 0; j != cell->columns; j++) {
if (col[i + j].type !=
COLUMN_WIDTH_FIXED) {
col[i + j].min += extra;
if (col[i + j].max <
col[i + j].min)
col[i + j].max =
col[i + j].min;
}
}
}
}
/* find max width so far of spanned columns */
for (j = 0; j != cell->columns; j++)
max += col[i + j].max;
max += (cell->columns - 1) * border_spacing_h;
/* distribute extra max to spanned columns */
if (max < cell->max_width && flexible_columns) {
extra = 1 + (cell->max_width - max) / flexible_columns;
for (j = 0; j != cell->columns; j++)
if (col[i + j].type != COLUMN_WIDTH_FIXED)
col[i + j].max += extra;
}
}
for (i = 0; i != table->columns; i++) {
if (col[i].max < col[i].min) {
box_dump(stderr, table, 0, true);
assert(0);
}
table_min += col[i].min;
table_max += col[i].max;
}
/* fixed width takes priority, unless it is too narrow */
wtype = css_computed_width(table->style, &value, &unit);
if (wtype == CSS_WIDTH_SET && unit != CSS_UNIT_PCT) {
int width = FIXTOINT(nscss_len2px(&content->len_ctx,
value, unit, table->style));
if (table_min < width)
table_min = width;
if (table_max < width)
table_max = width;
}
/* add margins, border, padding to min, max widths */
calculate_mbp_width(&content->len_ctx,
table->style, LEFT, true, true, true,
&extra_fixed, &extra_frac);
calculate_mbp_width(&content->len_ctx,
table->style, RIGHT, true, true, true,
&extra_fixed, &extra_frac);
if (extra_fixed < 0)
extra_fixed = 0;
if (extra_frac < 0)
extra_frac = 0;
if (1.0 <= extra_frac)
extra_frac = 0.9;
table->min_width = (table_min + extra_fixed) / (1.0 - extra_frac);
table->max_width = (table_max + extra_fixed) / (1.0 - extra_frac);
table->min_width += (table->columns + 1) * border_spacing_h;
table->max_width += (table->columns + 1) * border_spacing_h;
assert(0 <= table->min_width && table->min_width <= table->max_width);
}
/**
* Helper to check if a box has percentage max width.
*
* \param[in] b Box to check.
* \return true iff box has percnetage max width.
*/
static inline bool box_has_percentage_max_width(struct box *b)
{
css_unit unit = CSS_UNIT_PX;
enum css_max_width_e type;
css_fixed value = 0;
assert(b != NULL);
type = css_computed_max_width(b->style, &value, &unit);
return ((type == CSS_MAX_WIDTH_SET) && (unit == CSS_UNIT_PCT));
}
/**
* Calculate minimum and maximum width of a line.
*
* \param first a box in an inline container
* \param line_min updated to minimum width of line starting at first
* \param line_max updated to maximum width of line starting at first
* \param first_line true iff this is the first line in the inline container
* \param line_has_height updated to true or false, depending on line
* \param font_func Font functions.
* \return first box in next line, or 0 if no more lines
* \post 0 <= *line_min <= *line_max
*/
static struct box *
layout_minmax_line(struct box *first,
int *line_min,
int *line_max,
bool first_line,
bool *line_has_height,
const struct gui_layout_table *font_func,
const html_content *content)
{
int min = 0, max = 0, width, height, fixed;
float frac;
size_t i, j;
struct box *b;
struct box *block;
plot_font_style_t fstyle;
bool no_wrap;
assert(first->parent);
assert(first->parent->parent);
assert(first->parent->parent->style);
block = first->parent->parent;
no_wrap = (css_computed_white_space(block->style) ==
CSS_WHITE_SPACE_NOWRAP ||
css_computed_white_space(block->style) ==
CSS_WHITE_SPACE_PRE);
*line_has_height = false;
/* corresponds to the pass 1 loop in layout_line() */
for (b = first; b; b = b->next) {
enum css_width_e wtype;
enum css_height_e htype;
enum css_box_sizing_e bs;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
assert(b->type == BOX_INLINE || b->type == BOX_INLINE_BLOCK ||
b->type == BOX_FLOAT_LEFT ||
b->type == BOX_FLOAT_RIGHT ||
b->type == BOX_BR || b->type == BOX_TEXT ||
b->type == BOX_INLINE_END);
NSLOG(layout, DEBUG, "%p: min %i, max %i", b, min, max);
if (b->type == BOX_BR) {
b = b->next;
break;
}
if (b->type == BOX_FLOAT_LEFT || b->type == BOX_FLOAT_RIGHT) {
assert(b->children);
if (b->children->type == BOX_BLOCK)
layout_minmax_block(b->children, font_func,
content);
else
layout_minmax_table(b->children, font_func,
content);
b->min_width = b->children->min_width;
b->max_width = b->children->max_width;
if (min < b->min_width)
min = b->min_width;
max += b->max_width;
continue;
}
if (b->type == BOX_INLINE_BLOCK) {
layout_minmax_block(b, font_func, content);
if (min < b->min_width)
min = b->min_width;
max += b->max_width;
if (b->flags & HAS_HEIGHT)
*line_has_height = true;
continue;
}
assert(b->style);
font_plot_style_from_css(&content->len_ctx, b->style, &fstyle);
if (b->type == BOX_INLINE && !b->object &&
!(b->flags & REPLACE_DIM) &&
!(b->flags & IFRAME)) {
fixed = frac = 0;
calculate_mbp_width(&content->len_ctx,
b->style, LEFT, true, true, true,
&fixed, &frac);
if (!b->inline_end)
calculate_mbp_width(&content->len_ctx,
b->style, RIGHT,
true, true, true,
&fixed, &frac);
if (0 < fixed)
max += fixed;
*line_has_height = true;
/* \todo update min width, consider fractional extra */
} else if (b->type == BOX_INLINE_END) {
fixed = frac = 0;
calculate_mbp_width(&content->len_ctx,
b->inline_end->style, RIGHT,
true, true, true,
&fixed, &frac);
if (0 < fixed)
max += fixed;
if (b->next) {
if (b->space == UNKNOWN_WIDTH) {
font_func->width(&fstyle, " ", 1,
&b->space);
}
max += b->space;
}
*line_has_height = true;
continue;
}
if (!b->object && !(b->flags & IFRAME) && !b->gadget &&
!(b->flags & REPLACE_DIM)) {
/* inline non-replaced, 10.3.1 and 10.6.1 */
bool no_wrap_box;
if (!b->text)
continue;
no_wrap_box = (css_computed_white_space(b->style) ==
CSS_WHITE_SPACE_NOWRAP ||
css_computed_white_space(b->style) ==
CSS_WHITE_SPACE_PRE);
if (b->width == UNKNOWN_WIDTH) {
/** \todo handle errors */
/* If it's a select element, we must use the
* width of the widest option text */
if (b->parent->parent->gadget &&
b->parent->parent->gadget->type
== GADGET_SELECT) {
int opt_maxwidth = 0;
struct form_option *o;
for (o = b->parent->parent->gadget->
data.select.items; o;
o = o->next) {
int opt_width;
font_func->width(&fstyle,
o->text,
strlen(o->text),
&opt_width);
if (opt_maxwidth < opt_width)
opt_maxwidth =opt_width;
}
b->width = opt_maxwidth;
if (nsoption_bool(core_select_menu))
b->width += SCROLLBAR_WIDTH;
} else {
font_func->width(&fstyle, b->text,
b->length, &b->width);
b->flags |= MEASURED;
}
}
max += b->width;
if (b->next) {
if (b->space == UNKNOWN_WIDTH) {
font_func->width(&fstyle, " ", 1,
&b->space);
}
max += b->space;
}
if (no_wrap) {
/* Don't wrap due to block style,
* so min is the same as max */
min = max;
} else if (no_wrap_box) {
/* This inline box can't be wrapped,
* for min, consider box's width */
if (min < b->width)
min = b->width;
} else if (b->parent->flags & NEED_MIN) {
/* If we care what the minimum width is,
* calculate it. (It's only needed if we're
* shrinking-to-fit.) */
/* min = widest single word */
i = 0;
do {
for (j = i; j != b->length &&
b->text[j] != ' '; j++)
;
font_func->width(&fstyle, b->text + i,
j - i, &width);
if (min < width)
min = width;
i = j + 1;
} while (j != b->length);
}
*line_has_height = true;
continue;
}
/* inline replaced, 10.3.2 and 10.6.2 */
assert(b->style);
/* calculate box width */
wtype = css_computed_width(b->style, &value, &unit);
bs = css_computed_box_sizing(block->style);
if (wtype == CSS_WIDTH_SET) {
if (unit == CSS_UNIT_PCT) {
width = AUTO;
} else {
width = FIXTOINT(nscss_len2px(&content->len_ctx,
value, unit, b->style));
if (bs == CSS_BOX_SIZING_BORDER_BOX) {
fixed = frac = 0;
calculate_mbp_width(&content->len_ctx,
block->style, LEFT,
false, true, true,
&fixed, &frac);
calculate_mbp_width(&content->len_ctx,
block->style, RIGHT,
false, true, true,
&fixed, &frac);
if (width < fixed) {
width = fixed;
}
}
if (width < 0)
width = 0;
}
} else {
width = AUTO;
}
/* height */
htype = css_computed_height(b->style, &value, &unit);
if (htype == CSS_HEIGHT_SET) {
height = FIXTOINT(nscss_len2px(&content->len_ctx,
value, unit, b->style));
} else {
height = AUTO;
}
if (b->object || (b->flags & REPLACE_DIM)) {
if (b->object) {
int temp_height = height;
layout_get_object_dimensions(b,
&width, &temp_height,
INT_MIN, INT_MAX,
INT_MIN, INT_MAX);
}
fixed = frac = 0;
if (bs == CSS_BOX_SIZING_BORDER_BOX) {
calculate_mbp_width(&content->len_ctx,
b->style, LEFT,
true, false, false,
&fixed, &frac);
calculate_mbp_width(&content->len_ctx,
b->style, RIGHT,
true, false, false,
&fixed, &frac);
} else {
calculate_mbp_width(&content->len_ctx,
b->style, LEFT,
true, true, true,
&fixed, &frac);
calculate_mbp_width(&content->len_ctx,
b->style, RIGHT,
true, true, true,
&fixed, &frac);
}
if (0 < width + fixed)
width += fixed;
} else if (b->flags & IFRAME) {
/* TODO: handle percentage widths properly */
if (width == AUTO)
width = 400;
fixed = frac = 0;
if (bs == CSS_BOX_SIZING_BORDER_BOX) {
calculate_mbp_width(&content->len_ctx,
b->style, LEFT,
true, false, false,
&fixed, &frac);
calculate_mbp_width(&content->len_ctx,
b->style, RIGHT,
true, false, false,
&fixed, &frac);
} else {
calculate_mbp_width(&content->len_ctx,
b->style, LEFT,
true, true, true,
&fixed, &frac);
calculate_mbp_width(&content->len_ctx,
b->style, RIGHT,
true, true, true,
&fixed, &frac);
}
if (0 < width + fixed)
width += fixed;
} else {
/* form control with no object */
if (width == AUTO)
width = FIXTOINT(nscss_len2px(
&content->len_ctx,
INTTOFIX(1), CSS_UNIT_EM,
b->style));
}
if (min < width && !box_has_percentage_max_width(b))
min = width;
if (width > 0)
max += width;
*line_has_height = true;
}
if (first_line) {
/* todo: handle percentage values properly */
/* todo: handle text-indent interaction with floats */
int text_indent = layout_text_indent(&content->len_ctx,
first->parent->parent->style, 100);
min = (min + text_indent < 0) ? 0 : min + text_indent;
max = (max + text_indent < 0) ? 0 : max + text_indent;
}
*line_min = min;
*line_max = max;
NSLOG(layout, DEBUG, "line_min %i, line_max %i", min, max);
assert(b != first);
assert(0 <= *line_min);
assert(*line_min <= *line_max);
return b;
}
/**
* Calculate minimum and maximum width of an inline container.
*
* \param inline_container box of type INLINE_CONTAINER
* \param[out] has_height set to true if container has height
* \param font_func Font functions.
* \post inline_container->min_width and inline_container->max_width filled in,
* 0 <= inline_container->min_width <= inline_container->max_width
*/
static void
layout_minmax_inline_container(struct box *inline_container,
bool *has_height,
const struct gui_layout_table *font_func,
const html_content *content)
{
struct box *child;
int line_min = 0, line_max = 0;
int min = 0, max = 0;
bool first_line = true;
bool line_has_height;
assert(inline_container->type == BOX_INLINE_CONTAINER);
/* check if the widths have already been calculated */
if (inline_container->max_width != UNKNOWN_MAX_WIDTH)
return;
*has_height = false;
for (child = inline_container->children; child; ) {
child = layout_minmax_line(child, &line_min, &line_max,
first_line, &line_has_height, font_func,
content);
if (min < line_min)
min = line_min;
if (max < line_max)
max = line_max;
first_line = false;
*has_height |= line_has_height;
}
inline_container->min_width = min;
inline_container->max_width = max;
assert(0 <= inline_container->min_width &&
inline_container->min_width <=
inline_container->max_width);
}
/**
* Calculate minimum and maximum width of a block.
*
* \param block box of type BLOCK, INLINE_BLOCK, or TABLE_CELL
* \param font_func font functions
* \param content The HTML content being layed out.
* \post block->min_width and block->max_width filled in,
* 0 <= block->min_width <= block->max_width
*/
static void layout_minmax_block(
struct box *block,
const struct gui_layout_table *font_func,
const html_content *content)
{
struct box *child;
int min = 0, max = 0;
int extra_fixed = 0;
float extra_frac = 0;
enum css_width_e wtype = CSS_WIDTH_AUTO;
css_fixed width = 0;
css_unit wunit = CSS_UNIT_PX;
enum css_height_e htype = CSS_HEIGHT_AUTO;
css_fixed height = 0;
css_unit hunit = CSS_UNIT_PX;
enum css_box_sizing_e bs = CSS_BOX_SIZING_CONTENT_BOX;
bool child_has_height = false;
assert(block->type == BOX_BLOCK ||
block->type == BOX_INLINE_BLOCK ||
block->type == BOX_TABLE_CELL);
/* check if the widths have already been calculated */
if (block->max_width != UNKNOWN_MAX_WIDTH)
return;
if (block->style != NULL) {
wtype = css_computed_width(block->style, &width, &wunit);
htype = css_computed_height(block->style, &height, &hunit);
bs = css_computed_box_sizing(block->style);
}
/* set whether the minimum width is of any interest for this box */
if (((block->parent && (block->parent->type == BOX_FLOAT_LEFT ||
block->parent->type == BOX_FLOAT_RIGHT)) ||
block->type == BOX_INLINE_BLOCK) &&
wtype != CSS_WIDTH_SET) {
/* box shrinks to fit; need minimum width */
block->flags |= NEED_MIN;
} else if (block->type == BOX_TABLE_CELL) {
/* box shrinks to fit; need minimum width */
block->flags |= NEED_MIN;
} else if (block->parent && (block->parent->flags & NEED_MIN) &&
wtype != CSS_WIDTH_SET) {
/* box inside shrink-to-fit context; need minimum width */
block->flags |= NEED_MIN;
}
if (block->gadget && (block->gadget->type == GADGET_TEXTBOX ||
block->gadget->type == GADGET_PASSWORD ||
block->gadget->type == GADGET_FILE ||
block->gadget->type == GADGET_TEXTAREA) &&
block->style && wtype == CSS_WIDTH_AUTO) {
css_fixed size = INTTOFIX(10);
css_unit unit = CSS_UNIT_EM;
min = max = FIXTOINT(nscss_len2px(&content->len_ctx,
size, unit, block->style));
block->flags |= HAS_HEIGHT;
}
if (block->gadget && (block->gadget->type == GADGET_RADIO ||
block->gadget->type == GADGET_CHECKBOX) &&
block->style && wtype == CSS_WIDTH_AUTO) {
css_fixed size = INTTOFIX(1);
css_unit unit = CSS_UNIT_EM;
/* form checkbox or radio button
* if width is AUTO, set it to 1em */
min = max = FIXTOINT(nscss_len2px(&content->len_ctx,
size, unit, block->style));
block->flags |= HAS_HEIGHT;
}
if (block->object) {
if (content_get_type(block->object) == CONTENT_HTML) {
layout_minmax_block(html_get_box_tree(block->object),
font_func, content);
min = html_get_box_tree(block->object)->min_width;
max = html_get_box_tree(block->object)->max_width;
} else {
min = max = content_get_width(block->object);
}
block->flags |= HAS_HEIGHT;
} else if (block->flags & IFRAME) {
/** \todo do we need to know the min/max width of the iframe's
* content? */
block->flags |= HAS_HEIGHT;
} else {
/* recurse through children */
for (child = block->children; child; child = child->next) {
switch (child->type) {
case BOX_BLOCK:
layout_minmax_block(child, font_func,
content);
if (child->flags & HAS_HEIGHT)
child_has_height = true;
break;
case BOX_INLINE_CONTAINER:
if (block->flags & NEED_MIN)
child->flags |= NEED_MIN;
layout_minmax_inline_container(child,
&child_has_height, font_func,
content);
if (child_has_height &&
child ==
child->parent->children) {
block->flags |= MAKE_HEIGHT;
}
break;
case BOX_TABLE:
layout_minmax_table(child, font_func,
content);
/* todo: fix for zero height tables */
child_has_height = true;
child->flags |= MAKE_HEIGHT;
break;
default:
assert(0);
}
assert(child->max_width != UNKNOWN_MAX_WIDTH);
if (child->style &&
(css_computed_position(child->style) ==
CSS_POSITION_ABSOLUTE ||
css_computed_position(child->style) ==
CSS_POSITION_FIXED)) {
/* This child is positioned out of normal flow,
* so it will have no affect on width */
continue;
}
if (min < child->min_width)
min = child->min_width;
if (max < child->max_width)
max = child->max_width;
if (child_has_height)
block->flags |= HAS_HEIGHT;
}
}
if (max < min) {
box_dump(stderr, block, 0, true);
assert(0);
}
/* fixed width takes priority */
if (block->type != BOX_TABLE_CELL && wtype == CSS_WIDTH_SET &&
wunit != CSS_UNIT_PCT) {
min = max = FIXTOINT(nscss_len2px(&content->len_ctx,
width, wunit, block->style));
if (bs == CSS_BOX_SIZING_BORDER_BOX) {
int border_box_fixed = 0;
float border_box_frac = 0;
calculate_mbp_width(&content->len_ctx,
block->style, LEFT,
false, true, true,
&border_box_fixed, &border_box_frac);
calculate_mbp_width(&content->len_ctx,
block->style, RIGHT,
false, true, true,
&border_box_fixed, &border_box_frac);
if (min < border_box_fixed) {
min = max = border_box_fixed;
}
}
}
if (htype == CSS_HEIGHT_SET && hunit != CSS_UNIT_PCT &&
height > INTTOFIX(0)) {
block->flags |= MAKE_HEIGHT;
block->flags |= HAS_HEIGHT;
}
/* add margins, border, padding to min, max widths */
/* Note: we don't know available width here so percentage margin
* and paddings are wrong. */
if (bs == CSS_BOX_SIZING_BORDER_BOX && wtype == CSS_WIDTH_SET) {
/* Border and padding included in width, so just get margin */
calculate_mbp_width(&content->len_ctx,
block->style, LEFT, true, false, false,
&extra_fixed, &extra_frac);
calculate_mbp_width(&content->len_ctx,
block->style, RIGHT, true, false, false,
&extra_fixed, &extra_frac);
} else {
calculate_mbp_width(&content->len_ctx,
block->style, LEFT, true, true, true,
&extra_fixed, &extra_frac);
calculate_mbp_width(&content->len_ctx,
block->style, RIGHT, true, true, true,
&extra_fixed, &extra_frac);
}
if (extra_fixed < 0)
extra_fixed = 0;
if (extra_frac < 0)
extra_frac = 0;
if (1.0 <= extra_frac)
extra_frac = 0.9;
if (block->style != NULL &&
(css_computed_float(block->style) == CSS_FLOAT_LEFT ||
css_computed_float(block->style) == CSS_FLOAT_RIGHT)) {
/* floated boxs */
block->min_width = min + extra_fixed;
block->max_width = max + extra_fixed;
} else {
/* not floated */
block->min_width = (min + extra_fixed) / (1.0 - extra_frac);
block->max_width = (max + extra_fixed) / (1.0 - extra_frac);
}
assert(0 <= block->min_width && block->min_width <= block->max_width);
}
/**
* Adjust a specified width or height for the box-sizing property.
*
* This turns the specified dimension into a content-box dimension.
*
* \param len_ctx Length conversion context
* \param box gadget to adjust dimensions of
* \param available_width width of containing block
* \param setwidth set true if the dimension to be tweaked is a width,
* else set false for a height
* \param dimension current value for given width/height dimension.
* updated to new value after consideration of
* gadget properties.
*/
static void layout_handle_box_sizing(
const nscss_len_ctx *len_ctx,
struct box *box,
int available_width,
bool setwidth,
int *dimension)
{
enum css_box_sizing_e bs;
assert(box && box->style);
bs = css_computed_box_sizing(box->style);
if (bs == CSS_BOX_SIZING_BORDER_BOX) {
int orig = *dimension;
int fixed = 0;
float frac = 0;
calculate_mbp_width(len_ctx, box->style,
setwidth ? LEFT : TOP,
false, true, true, &fixed, &frac);
calculate_mbp_width(len_ctx, box->style,
setwidth ? RIGHT : BOTTOM,
false, true, true, &fixed, &frac);
orig -= frac * available_width + fixed;
*dimension = orig > 0 ? orig : 0;
}
}
/**
* Calculate width, height, and thickness of margins, paddings, and borders.
*
* \param len_ctx Length conversion context
* \param available_width width of containing block
* \param viewport_height height of viewport in pixels or -ve if unknown
* \param box current box
* \param style style giving width, height, margins, paddings,
* and borders
* \param width updated to width, may be NULL
* \param height updated to height, may be NULL
* \param max_width updated to max-width, may be NULL
* \param min_width updated to min-width, may be NULL
* \param max_height updated to max-height, may be NULL
* \param min_height updated to min-height, may be NULL
* \param margin filled with margins, may be NULL
* \param padding filled with paddings, may be NULL
* \param border filled with border widths, may be NULL
*/
static void
layout_find_dimensions(const nscss_len_ctx *len_ctx,
int available_width,
int viewport_height,
struct box *box,
const css_computed_style *style,
int *width,
int *height,
int *max_width,
int *min_width,
int *max_height,
int *min_height,
int margin[4],
int padding[4],
struct box_border border[4])
{
struct box *containing_block = NULL;
unsigned int i;
if (width) {
enum css_width_e wtype;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
wtype = css_computed_width(style, &value, &unit);
if (wtype == CSS_WIDTH_SET) {
if (unit == CSS_UNIT_PCT) {
*width = FPCT_OF_INT_TOINT(
value, available_width);
} else {
*width = FIXTOINT(nscss_len2px(len_ctx,
value, unit, style));
}
} else {
*width = AUTO;
}
if (*width != AUTO) {
layout_handle_box_sizing(len_ctx, box, available_width,
true, width);
}
}
if (height) {
enum css_height_e htype;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
htype = css_computed_height(style, &value, &unit);
if (htype == CSS_HEIGHT_SET) {
if (unit == CSS_UNIT_PCT) {
enum css_height_e cbhtype;
if (css_computed_position(box->style) ==
CSS_POSITION_ABSOLUTE &&
box->parent) {
/* Box is absolutely positioned */
assert(box->float_container);
containing_block = box->float_container;
} else if (box->float_container &&
css_computed_position(box->style) !=
CSS_POSITION_ABSOLUTE &&
(css_computed_float(box->style) ==
CSS_FLOAT_LEFT ||
css_computed_float(box->style) ==
CSS_FLOAT_RIGHT)) {
/* Box is a float */
assert(box->parent &&
box->parent->parent &&
box->parent->parent->parent);
containing_block =
box->parent->parent->parent;
} else if (box->parent && box->parent->type !=
BOX_INLINE_CONTAINER) {
/* Box is a block level element */
containing_block = box->parent;
} else if (box->parent && box->parent->type ==
BOX_INLINE_CONTAINER) {
/* Box is an inline block */
assert(box->parent->parent);
containing_block = box->parent->parent;
}
if (containing_block) {
css_fixed f = 0;
css_unit u = CSS_UNIT_PX;
cbhtype = css_computed_height(
containing_block->style,
&f, &u);
}
if (containing_block &&
containing_block->height != AUTO &&
(css_computed_position(box->style) ==
CSS_POSITION_ABSOLUTE ||
cbhtype == CSS_HEIGHT_SET)) {
/* Box is absolutely positioned or its
* containing block has a valid
* specified height.
* (CSS 2.1 Section 10.5) */
*height = FPCT_OF_INT_TOINT(value,
containing_block->height);
} else if ((!box->parent ||
!box->parent->parent) &&
viewport_height >= 0) {
/* If root element or it's child
* (HTML or BODY) */
*height = FPCT_OF_INT_TOINT(value,
viewport_height);
} else {
/* precentage height not permissible
* treat height as auto */
*height = AUTO;
}
} else {
*height = FIXTOINT(nscss_len2px(len_ctx,
value, unit, style));
}
} else {
*height = AUTO;
}
if (*height != AUTO) {
layout_handle_box_sizing(len_ctx, box, available_width,
false, height);
}
}
if (max_width) {
enum css_max_width_e type;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
type = css_computed_max_width(style, &value, &unit);
if (type == CSS_MAX_WIDTH_SET) {
if (unit == CSS_UNIT_PCT) {
*max_width = FPCT_OF_INT_TOINT(value,
available_width);
} else {
*max_width = FIXTOINT(nscss_len2px(len_ctx,
value, unit, style));
}
} else {
/* Inadmissible */
*max_width = -1;
}
if (*max_width != -1) {
layout_handle_box_sizing(len_ctx, box, available_width,
true, max_width);
}
}
if (min_width) {
enum css_min_width_e type;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
type = ns_computed_min_width(style, &value, &unit);
if (type == CSS_MIN_WIDTH_SET) {
if (unit == CSS_UNIT_PCT) {
*min_width = FPCT_OF_INT_TOINT(value,
available_width);
} else {
*min_width = FIXTOINT(nscss_len2px(len_ctx,
value, unit, style));
}
} else {
/* Inadmissible */
*min_width = 0;
}
if (*min_width != 0) {
layout_handle_box_sizing(len_ctx, box, available_width,
true, min_width);
}
}
if (max_height) {
enum css_max_height_e type;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
type = css_computed_max_height(style, &value, &unit);
if (type == CSS_MAX_HEIGHT_SET) {
if (unit == CSS_UNIT_PCT) {
/* TODO: handle percentage */
*max_height = -1;
} else {
*max_height = FIXTOINT(nscss_len2px(len_ctx,
value, unit, style));
}
} else {
/* Inadmissible */
*max_height = -1;
}
}
if (min_height) {
enum css_min_height_e type;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
type = ns_computed_min_height(style, &value, &unit);
if (type == CSS_MIN_HEIGHT_SET) {
if (unit == CSS_UNIT_PCT) {
/* TODO: handle percentage */
*min_height = 0;
} else {
*min_height = FIXTOINT(nscss_len2px(len_ctx,
value, unit, style));
}
} else {
/* Inadmissible */
*min_height = 0;
}
}
for (i = 0; i != 4; i++) {
if (margin) {
enum css_margin_e type = CSS_MARGIN_AUTO;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
type = margin_funcs[i](style, &value, &unit);
if (type == CSS_MARGIN_SET) {
if (unit == CSS_UNIT_PCT) {
margin[i] = FPCT_OF_INT_TOINT(value,
available_width);
} else {
margin[i] = FIXTOINT(nscss_len2px(
len_ctx,
value, unit, style));
}
} else {
margin[i] = AUTO;
}
}
if (padding) {
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
padding_funcs[i](style, &value, &unit);
if (unit == CSS_UNIT_PCT) {
padding[i] = FPCT_OF_INT_TOINT(value,
available_width);
} else {
padding[i] = FIXTOINT(nscss_len2px(len_ctx,
value, unit, style));
}
}
/* Table cell borders are populated in table.c */
if (border && box->type != BOX_TABLE_CELL) {
enum css_border_style_e bstyle = CSS_BORDER_STYLE_NONE;
css_color color = 0;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
border_width_funcs[i](style, &value, &unit);
bstyle = border_style_funcs[i](style);
border_color_funcs[i](style, &color);
border[i].style = bstyle;
border[i].c = color;
if (bstyle == CSS_BORDER_STYLE_HIDDEN ||
bstyle == CSS_BORDER_STYLE_NONE)
/* spec unclear: following Mozilla */
border[i].width = 0;
else
border[i].width = FIXTOINT(nscss_len2px(len_ctx,
value, unit, style));
/* Special case for border-collapse: make all borders
* on table/table-row-group/table-row zero width. */
if (css_computed_border_collapse(style) ==
CSS_BORDER_COLLAPSE_COLLAPSE &&
(box->type == BOX_TABLE ||
box->type == BOX_TABLE_ROW_GROUP ||
box->type == BOX_TABLE_ROW))
border[i].width = 0;
}
}
}
/**
* Find next block that current margin collapses to.
*
* \param len_ctx Length conversion context
* \param box box to start tree-order search from (top margin is included)
* \param block box responsible for current block fromatting context
* \param viewport_height height of viewport in px
* \param max_pos_margin updated to to maximum positive margin encountered
* \param max_neg_margin updated to to maximum negative margin encountered
* \return next box that current margin collapses to, or NULL if none.
*/
static struct box*
layout_next_margin_block(const nscss_len_ctx *len_ctx,
struct box *box,
struct box *block,
int viewport_height,
int *max_pos_margin,
int *max_neg_margin)
{
assert(block != NULL);
while (box != NULL) {
if (box->type == BOX_INLINE_CONTAINER || (box->style &&
(css_computed_position(box->style) !=
CSS_POSITION_ABSOLUTE &&
css_computed_position(box->style) !=
CSS_POSITION_FIXED))) {
/* Not positioned */
/* Get margins */
if (box->style) {
layout_find_dimensions(len_ctx,
box->parent->width,
viewport_height, box,
box->style,
NULL, NULL, NULL, NULL,
NULL, NULL, box->margin,
box->padding, box->border);
/* Apply top margin */
if (*max_pos_margin < box->margin[TOP])
*max_pos_margin = box->margin[TOP];
else if (*max_neg_margin < -box->margin[TOP])
*max_neg_margin = -box->margin[TOP];
}
/* Check whether box is the box current margin collapses
* to */
if (box->flags & MAKE_HEIGHT ||
box->border[TOP].width ||
box->padding[TOP] ||
(box->style &&
css_computed_overflow_y(box->style) !=
CSS_OVERFLOW_VISIBLE) ||
(box->type == BOX_INLINE_CONTAINER &&
!box_is_first_child(box))) {
/* Collapse to this box; return it */
return box;
}
}
/* Find next box */
if (box->type == BOX_BLOCK && !box->object && box->children &&
box->style &&
css_computed_overflow_y(box->style) ==
CSS_OVERFLOW_VISIBLE) {
/* Down into children. */
box = box->children;
} else {
if (!box->next) {
/* No more siblings:
* Go up to first ancestor with a sibling. */
do {
/* Apply bottom margin */
if (*max_pos_margin <
box->margin[BOTTOM])
*max_pos_margin =
box->margin[BOTTOM];
else if (*max_neg_margin <
-box->margin[BOTTOM])
*max_neg_margin =
-box->margin[BOTTOM];
box = box->parent;
} while (box != block && !box->next);
if (box == block) {
/* Margins don't collapse with stuff
* outside the block formatting context
*/
return block;
}
}
/* Apply bottom margin */
if (*max_pos_margin < box->margin[BOTTOM])
*max_pos_margin = box->margin[BOTTOM];
else if (*max_neg_margin < -box->margin[BOTTOM])
*max_neg_margin = -box->margin[BOTTOM];
/* To next sibling. */
box = box->next;
/* Get margins */
if (box->style) {
layout_find_dimensions(len_ctx,
box->parent->width,
viewport_height, box,
box->style,
NULL, NULL, NULL, NULL,
NULL, NULL, box->margin,
box->padding, box->border);
}
}
}
return NULL;
}
/**
* Find y coordinate which clears all floats on left and/or right.
*
* \param fl first float in float list
* \param clear type of clear
* \return y coordinate relative to ancestor box for floats
*/
static int layout_clear(struct box *fl, enum css_clear_e clear)
{
int y = 0;
for (; fl; fl = fl->next_float) {
if ((clear == CSS_CLEAR_LEFT || clear == CSS_CLEAR_BOTH) &&
fl->type == BOX_FLOAT_LEFT)
if (y < fl->y + fl->height)
y = fl->y + fl->height;
if ((clear == CSS_CLEAR_RIGHT || clear == CSS_CLEAR_BOTH) &&
fl->type == BOX_FLOAT_RIGHT)
if (y < fl->y + fl->height)
y = fl->y + fl->height;
}
return y;
}
/**
* Find left and right edges in a vertical range.
*
* \param fl first float in float list
* \param y0 start of y range to search
* \param y1 end of y range to search
* \param x0 start left edge, updated to available left edge
* \param x1 start right edge, updated to available right edge
* \param left returns float on left if present
* \param right returns float on right if present
*/
static void
find_sides(struct box *fl,
int y0, int y1,
int *x0, int *x1,
struct box **left,
struct box **right)
{
int fy0, fy1, fx0, fx1;
NSLOG(layout, DEBUG, "y0 %i, y1 %i, x0 %i, x1 %i", y0, y1, *x0, *x1);
*left = *right = 0;
for (; fl; fl = fl->next_float) {
fy1 = fl->y + fl->height;
if (fy1 < y0) {
/* Floats are sorted in order of decreasing bottom pos.
* Past here, all floats will be too high to concern us.
*/
return;
}
fy0 = fl->y;
if (y0 < fy1 && fy0 <= y1) {
if (fl->type == BOX_FLOAT_LEFT) {
fx1 = fl->x + fl->width;
if (*x0 < fx1) {
*x0 = fx1;
*left = fl;
}
} else {
fx0 = fl->x;
if (fx0 < *x1) {
*x1 = fx0;
*right = fl;
}
}
}
}
NSLOG(layout, DEBUG, "x0 %i, x1 %i, left %p, right %p", *x0, *x1,
*left, *right);
}
/**
* Solve the width constraint as given in CSS 2.1 section 10.3.3.
*
* \param box Box to solve constraint for
* \param available_width Max width available in pixels
* \param width Current box width
* \param lm Min left margin required to avoid floats in px.
* zero if not applicable
* \param rm Min right margin required to avoid floats in px.
* zero if not applicable
* \param max_width Box max-width ( -ve means no max-width to apply)
* \param min_width Box min-width ( <=0 means no min-width to apply)
* \return New box width
*
* \post \a box's left/right margins will be updated.
*/
static int
layout_solve_width(struct box *box,
int available_width,
int width,
int lm,
int rm,
int max_width,
int min_width)
{
bool auto_width = false;
/* Increase specified left/right margins */
if (box->margin[LEFT] != AUTO && box->margin[LEFT] < lm &&
box->margin[LEFT] >= 0)
box->margin[LEFT] = lm;
if (box->margin[RIGHT] != AUTO && box->margin[RIGHT] < rm &&
box->margin[RIGHT] >= 0)
box->margin[RIGHT] = rm;
/* Find width */
if (width == AUTO) {
int margin_left = box->margin[LEFT];
int margin_right = box->margin[RIGHT];
if (margin_left == AUTO) {
margin_left = lm;
}
if (margin_right == AUTO) {
margin_right = rm;
}
width = available_width -
(margin_left + box->border[LEFT].width +
box->padding[LEFT] + box->padding[RIGHT] +
box->border[RIGHT].width + margin_right);
width = width < 0 ? 0 : width;
auto_width = true;
}
if (max_width >= 0 && width > max_width) {
/* max-width is admissable and width exceeds max-width */
width = max_width;
auto_width = false;
}
if (min_width > 0 && width < min_width) {
/* min-width is admissable and width is less than max-width */
width = min_width;
auto_width = false;
}
/* Width was auto, and unconstrained by min/max width, so we're done */
if (auto_width) {
/* any other 'auto' become 0 or the minimum required values */
if (box->margin[LEFT] == AUTO) {
box->margin[LEFT] = lm;
}
if (box->margin[RIGHT] == AUTO) {
box->margin[RIGHT] = rm;
}
return width;
}
/* Width was not auto, or was constrained by min/max width
* Need to compute left/right margins */
/* HTML alignment (only applies to over-constrained boxes) */
if (box->margin[LEFT] != AUTO && box->margin[RIGHT] != AUTO &&
box->parent != NULL && box->parent->style != NULL) {
switch (css_computed_text_align(box->parent->style)) {
case CSS_TEXT_ALIGN_LIBCSS_RIGHT:
box->margin[LEFT] = AUTO;
box->margin[RIGHT] = 0;
break;
case CSS_TEXT_ALIGN_LIBCSS_CENTER:
box->margin[LEFT] = box->margin[RIGHT] = AUTO;
break;
case CSS_TEXT_ALIGN_LIBCSS_LEFT:
box->margin[LEFT] = 0;
box->margin[RIGHT] = AUTO;
break;
default:
/* Leave it alone; no HTML alignment */
break;
}
}
if (box->margin[LEFT] == AUTO && box->margin[RIGHT] == AUTO) {
/* make the margins equal, centering the element */
box->margin[LEFT] = box->margin[RIGHT] =
(available_width - lm - rm -
(box->border[LEFT].width + box->padding[LEFT] +
width + box->padding[RIGHT] +
box->border[RIGHT].width)) / 2;
if (box->margin[LEFT] < 0) {
box->margin[RIGHT] += box->margin[LEFT];
box->margin[LEFT] = 0;
}
box->margin[LEFT] += lm;
} else if (box->margin[LEFT] == AUTO) {
box->margin[LEFT] = available_width - lm -
(box->border[LEFT].width + box->padding[LEFT] +
width + box->padding[RIGHT] +
box->border[RIGHT].width + box->margin[RIGHT]);
box->margin[LEFT] = box->margin[LEFT] < lm
? lm : box->margin[LEFT];
} else {
/* margin-right auto or "over-constrained" */
box->margin[RIGHT] = available_width - rm -
(box->margin[LEFT] + box->border[LEFT].width +
box->padding[LEFT] + width +
box->padding[RIGHT] +
box->border[RIGHT].width);
}
return width;
}
/**
* Compute dimensions of box, margins, paddings, and borders for a block-level
* element.
*
* \param len_ctx Length conversion context
* \param available_width Max width available in pixels
* \param viewport_height Height of viewport in pixels or -ve if unknown
* \param lm min left margin required to avoid floats in px.
* zero if not applicable
* \param rm min right margin required to avoid floats in px.
* zero if not applicable
* \param box box to find dimensions of. updated with new width,
* height, margins, borders and paddings
*
* See CSS 2.1 10.3.3, 10.3.4, 10.6.2, and 10.6.3.
*/
static void
layout_block_find_dimensions(const nscss_len_ctx *len_ctx,
int available_width,
int viewport_height,
int lm,
int rm,
struct box *box)
{
int width, max_width, min_width;
int height, max_height, min_height;
int *margin = box->margin;
int *padding = box->padding;
struct box_border *border = box->border;
const css_computed_style *style = box->style;
layout_find_dimensions(len_ctx, available_width, viewport_height, box,
style, &width, &height, &max_width, &min_width,
&max_height, &min_height, margin, padding, border);
if (box->object && !(box->flags & REPLACE_DIM) &&
content_get_type(box->object) != CONTENT_HTML) {
/* block-level replaced element, see 10.3.4 and 10.6.2 */
layout_get_object_dimensions(box, &width, &height,
min_width, max_width, min_height, max_height);
}
box->width = layout_solve_width(box, available_width, width, lm, rm,
max_width, min_width);
box->height = height;
if (margin[TOP] == AUTO)
margin[TOP] = 0;
if (margin[BOTTOM] == AUTO)
margin[BOTTOM] = 0;
}
/**
* Manipulate a block's [RB]padding/height/width to accommodate scrollbars
*
* \param box Box to apply scrollbar space too. Must be BOX_BLOCK.
* \param which Which scrollbar to make space for. Must be RIGHT or BOTTOM.
*/
static void layout_block_add_scrollbar(struct box *box, int which)
{
enum css_overflow_e overflow_x, overflow_y;
assert(box->type == BOX_BLOCK && (which == RIGHT || which == BOTTOM));
if (box->style == NULL)
return;
overflow_x = css_computed_overflow_x(box->style);
overflow_y = css_computed_overflow_y(box->style);
if (which == BOTTOM &&
(overflow_x == CSS_OVERFLOW_SCROLL ||
overflow_x == CSS_OVERFLOW_AUTO ||
(box->object &&
content_get_type(box->object) == CONTENT_HTML))) {
/* make space for scrollbar, unless height is AUTO */
if (box->height != AUTO &&
(overflow_x == CSS_OVERFLOW_SCROLL ||
box_hscrollbar_present(box))) {
box->padding[BOTTOM] += SCROLLBAR_WIDTH;
}
} else if (which == RIGHT &&
(overflow_y == CSS_OVERFLOW_SCROLL ||
overflow_y == CSS_OVERFLOW_AUTO ||
(box->object &&
content_get_type(box->object) == CONTENT_HTML))) {
/* make space for scrollbars, unless width is AUTO */
enum css_height_e htype;
css_fixed height = 0;
css_unit hunit = CSS_UNIT_PX;
htype = css_computed_height(box->style, &height, &hunit);
if (which == RIGHT && box->width != AUTO &&
htype == CSS_HEIGHT_SET &&
(overflow_y == CSS_OVERFLOW_SCROLL ||
box_vscrollbar_present(box))) {
box->width -= SCROLLBAR_WIDTH;
box->padding[RIGHT] += SCROLLBAR_WIDTH;
}
}
}
/**
* Moves the children of a box by a specified amount
*
* \param box top of tree of boxes
* \param x the amount to move children by horizontally
* \param y the amount to move children by vertically
*/
static void layout_move_children(struct box *box, int x, int y)
{
assert(box);
for (box = box->children; box; box = box->next) {
box->x += x;
box->y += y;
}
}
/**
* Layout a table.
*
* \param table table to layout
* \param available_width width of containing block
* \param content memory pool for any new boxes
* \return true on success, false on memory exhaustion
*/
static bool layout_table(struct box *table, int available_width,
html_content *content)
{
unsigned int columns = table->columns; /* total columns */
unsigned int i;
unsigned int *row_span;
int *excess_y;
int table_width, min_width = 0, max_width = 0;
int required_width = 0;
int x, remainder = 0, count = 0;
int table_height = 0;
int min_height = 0;
int *xs; /* array of column x positions */
int auto_width;
int spare_width;
int relative_sum = 0;
int border_spacing_h = 0, border_spacing_v = 0;
int spare_height;
int positioned_columns = 0;
struct box *containing_block = NULL;
struct box *c;
struct box *row;
struct box *row_group;
struct box **row_span_cell;
struct column *col;
const css_computed_style *style = table->style;
enum css_width_e wtype;
enum css_height_e htype;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
assert(table->type == BOX_TABLE);
assert(style);
assert(table->children && table->children->children);
assert(columns);
/* allocate working buffers */
col = malloc(columns * sizeof col[0]);
excess_y = malloc(columns * sizeof excess_y[0]);
row_span = malloc(columns * sizeof row_span[0]);
row_span_cell = malloc(columns * sizeof row_span_cell[0]);
xs = malloc((columns + 1) * sizeof xs[0]);
if (!col || !xs || !row_span || !excess_y || !row_span_cell) {
free(col);
free(excess_y);
free(row_span);
free(row_span_cell);
free(xs);
return false;
}
memcpy(col, table->col, sizeof(col[0]) * columns);
/* find margins, paddings, and borders for table and cells */
layout_find_dimensions(&content->len_ctx, available_width, -1, table,
style, 0, 0, 0, 0, 0, 0, table->margin, table->padding,
table->border);
for (row_group = table->children; row_group;
row_group = row_group->next) {
for (row = row_group->children; row; row = row->next) {
for (c = row->children; c; c = c->next) {
enum css_overflow_e overflow_x;
enum css_overflow_e overflow_y;
assert(c->style);
table_used_border_for_cell(
&content->len_ctx, c);
layout_find_dimensions(&content->len_ctx,
available_width, -1, c,
c->style, 0, 0, 0, 0, 0, 0,
0, c->padding, c->border);
overflow_x = css_computed_overflow_x(c->style);
overflow_y = css_computed_overflow_y(c->style);
if (overflow_x == CSS_OVERFLOW_SCROLL ||
overflow_x ==
CSS_OVERFLOW_AUTO) {
c->padding[BOTTOM] += SCROLLBAR_WIDTH;
}
if (overflow_y == CSS_OVERFLOW_SCROLL ||
overflow_y ==
CSS_OVERFLOW_AUTO) {
c->padding[RIGHT] += SCROLLBAR_WIDTH;
}
}
}
}
/* border-spacing is used in the separated borders model */
if (css_computed_border_collapse(style) ==
CSS_BORDER_COLLAPSE_SEPARATE) {
css_fixed h = 0, v = 0;
css_unit hu = CSS_UNIT_PX, vu = CSS_UNIT_PX;
css_computed_border_spacing(style, &h, &hu, &v, &vu);
border_spacing_h = FIXTOINT(nscss_len2px(&content->len_ctx,
h, hu, style));
border_spacing_v = FIXTOINT(nscss_len2px(&content->len_ctx,
v, vu, style));
}
/* find specified table width, or available width if auto-width */
wtype = css_computed_width(style, &value, &unit);
if (wtype == CSS_WIDTH_SET) {
if (unit == CSS_UNIT_PCT) {
table_width = FPCT_OF_INT_TOINT(value, available_width);
} else {
table_width =
FIXTOINT(nscss_len2px(&content->len_ctx,
value, unit, style));
}
/* specified width includes border */
table_width -= table->border[LEFT].width +
table->border[RIGHT].width;
table_width = table_width < 0 ? 0 : table_width;
auto_width = table_width;
} else {
table_width = AUTO;
auto_width = available_width -
((table->margin[LEFT] == AUTO ? 0 :
table->margin[LEFT]) +
table->border[LEFT].width +
table->padding[LEFT] +
table->padding[RIGHT] +
table->border[RIGHT].width +
(table->margin[RIGHT] == AUTO ? 0 :
table->margin[RIGHT]));
}
/* Find any table height specified within CSS/HTML */
htype = css_computed_height(style, &value, &unit);
if (htype == CSS_HEIGHT_SET) {
if (unit == CSS_UNIT_PCT) {
/* This is the minimum height for the table
* (see 17.5.3) */
if (css_computed_position(table->style) ==
CSS_POSITION_ABSOLUTE) {
/* Table is absolutely positioned */
assert(table->float_container);
containing_block = table->float_container;
} else if (table->float_container &&
css_computed_position(table->style) !=
CSS_POSITION_ABSOLUTE &&
(css_computed_float(table->style) ==
CSS_FLOAT_LEFT ||
css_computed_float(table->style) ==
CSS_FLOAT_RIGHT)) {
/* Table is a float */
assert(table->parent && table->parent->parent &&
table->parent->parent->parent);
containing_block =
table->parent->parent->parent;
} else if (table->parent && table->parent->type !=
BOX_INLINE_CONTAINER) {
/* Table is a block level element */
containing_block = table->parent;
} else if (table->parent && table->parent->type ==
BOX_INLINE_CONTAINER) {
/* Table is an inline block */
assert(table->parent->parent);
containing_block = table->parent->parent;
}
if (containing_block) {
css_fixed ignored = 0;
htype = css_computed_height(
containing_block->style,
&ignored, &unit);
}
if (containing_block &&
containing_block->height != AUTO &&
(css_computed_position(table->style) ==
CSS_POSITION_ABSOLUTE ||
htype == CSS_HEIGHT_SET)) {
/* Table is absolutely positioned or its
* containing block has a valid specified
* height. (CSS 2.1 Section 10.5) */
min_height = FPCT_OF_INT_TOINT(value,
containing_block->height);
}
} else {
/* This is the minimum height for the table
* (see 17.5.3) */
min_height = FIXTOINT(nscss_len2px(&content->len_ctx,
value, unit, style));
}
}
/* calculate width required by cells */
for (i = 0; i != columns; i++) {
NSLOG(layout, DEBUG,
"table %p, column %u: type %s, width %i, min %i, max %i",
table,
i,
((const char *[]){
"UNKNOWN",
"FIXED",
"AUTO",
"PERCENT",
"RELATIVE",
})[col[i].type],
col[i].width,
col[i].min,
col[i].max);
if (col[i].positioned) {
positioned_columns++;
continue;
} else if (col[i].type == COLUMN_WIDTH_FIXED) {
if (col[i].width < col[i].min)
col[i].width = col[i].max = col[i].min;
else
col[i].min = col[i].max = col[i].width;
required_width += col[i].width;
} else if (col[i].type == COLUMN_WIDTH_PERCENT) {
int width = col[i].width * auto_width / 100;
required_width += col[i].min < width ? width :
col[i].min;
} else
required_width += col[i].min;
NSLOG(layout, DEBUG, "required_width %i", required_width);
}
required_width += (columns + 1 - positioned_columns) *
border_spacing_h;
NSLOG(layout, DEBUG,
"width %i, min %i, max %i, auto %i, required %i", table_width,
table->min_width, table->max_width, auto_width, required_width);
if (auto_width < required_width) {
/* table narrower than required width for columns:
* treat percentage widths as maximums */
for (i = 0; i != columns; i++) {
if (col[i].type == COLUMN_WIDTH_RELATIVE)
continue;
if (col[i].type == COLUMN_WIDTH_PERCENT) {
col[i].max = auto_width * col[i].width / 100;
if (col[i].max < col[i].min)
col[i].max = col[i].min;
}
min_width += col[i].min;
max_width += col[i].max;
}
} else {
/* take percentages exactly */
for (i = 0; i != columns; i++) {
if (col[i].type == COLUMN_WIDTH_RELATIVE)
continue;
if (col[i].type == COLUMN_WIDTH_PERCENT) {
int width = auto_width * col[i].width / 100;
if (width < col[i].min)
width = col[i].min;
col[i].min = col[i].width = col[i].max = width;
col[i].type = COLUMN_WIDTH_FIXED;
}
min_width += col[i].min;
max_width += col[i].max;
}
}
/* allocate relative widths */
spare_width = auto_width;
for (i = 0; i != columns; i++) {
if (col[i].type == COLUMN_WIDTH_RELATIVE)
relative_sum += col[i].width;
else if (col[i].type == COLUMN_WIDTH_FIXED)
spare_width -= col[i].width;
else
spare_width -= col[i].min;
}
spare_width -= (columns + 1) * border_spacing_h;
if (relative_sum != 0) {
if (spare_width < 0)
spare_width = 0;
for (i = 0; i != columns; i++) {
if (col[i].type == COLUMN_WIDTH_RELATIVE) {
col[i].min = ceil(col[i].max =
(float) spare_width
* (float) col[i].width
/ relative_sum);
min_width += col[i].min;
max_width += col[i].max;
}
}
}
min_width += (columns + 1) * border_spacing_h;
max_width += (columns + 1) * border_spacing_h;
if (auto_width <= min_width) {
/* not enough space: minimise column widths */
for (i = 0; i < columns; i++) {
col[i].width = col[i].min;
}
table_width = min_width;
} else if (max_width <= auto_width) {
/* more space than maximum width */
if (table_width == AUTO) {
/* for auto-width tables, make columns max width */
for (i = 0; i < columns; i++) {
col[i].width = col[i].max;
}
table_width = max_width;
} else {
/* for fixed-width tables, distribute the extra space
* too */
unsigned int flexible_columns = 0;
for (i = 0; i != columns; i++)
if (col[i].type != COLUMN_WIDTH_FIXED)
flexible_columns++;
if (flexible_columns == 0) {
int extra = (table_width - max_width) / columns;
remainder = (table_width - max_width) -
(extra * columns);
for (i = 0; i != columns; i++) {
col[i].width = col[i].max + extra;
count -= remainder;
if (count < 0) {
col[i].width++;
count += columns;
}
}
} else {
int extra = (table_width - max_width) /
flexible_columns;
remainder = (table_width - max_width) -
(extra * flexible_columns);
for (i = 0; i != columns; i++)
if (col[i].type != COLUMN_WIDTH_FIXED) {
col[i].width = col[i].max +
extra;
count -= remainder;
if (count < 0) {
col[i].width++;
count += flexible_columns;
}
}
}
}
} else {
/* space between min and max: fill it exactly */
float scale = (float) (auto_width - min_width) /
(float) (max_width - min_width);
/* fprintf(stderr, "filling, scale %f\n", scale); */
for (i = 0; i < columns; i++) {
col[i].width = col[i].min + (int) (0.5 +
(col[i].max - col[i].min) * scale);
}
table_width = auto_width;
}
xs[0] = x = border_spacing_h;
for (i = 0; i != columns; i++) {
if (!col[i].positioned)
x += col[i].width + border_spacing_h;
xs[i + 1] = x;
row_span[i] = 0;
excess_y[i] = 0;
row_span_cell[i] = 0;
}
/* position cells */
table_height = border_spacing_v;
for (row_group = table->children; row_group;
row_group = row_group->next) {
int row_group_height = 0;
for (row = row_group->children; row; row = row->next) {
int row_height = 0;
htype = css_computed_height(row->style, &value, &unit);
if (htype == CSS_HEIGHT_SET && unit != CSS_UNIT_PCT) {
row_height = FIXTOINT(nscss_len2px(
&content->len_ctx,
value, unit, row->style));
}
for (c = row->children; c; c = c->next) {
assert(c->style);
c->width = xs[c->start_column + c->columns] -
xs[c->start_column] -
border_spacing_h -
c->border[LEFT].width -
c->padding[LEFT] -
c->padding[RIGHT] -
c->border[RIGHT].width;
c->float_children = 0;
c->cached_place_below_level = 0;
c->height = AUTO;
if (!layout_block_context(c, -1, content)) {
free(col);
free(excess_y);
free(row_span);
free(row_span_cell);
free(xs);
return false;
}
/* warning: c->descendant_y0 and
* c->descendant_y1 used as temporary storage
* until after vertical alignment is complete */
c->descendant_y0 = c->height;
c->descendant_y1 = c->padding[BOTTOM];
htype = css_computed_height(c->style,
&value, &unit);
if (htype == CSS_HEIGHT_SET &&
unit != CSS_UNIT_PCT) {
/* some sites use height="1" or similar
* to attempt to make cells as small as
* possible, so treat it as a minimum */
int h = FIXTOINT(nscss_len2px(
&content->len_ctx,
value, unit, c->style));
if (c->height < h)
c->height = h;
}
/* specified row height is treated as a minimum
*/
if (c->height < row_height)
c->height = row_height;
c->x = xs[c->start_column] +
c->border[LEFT].width;
c->y = c->border[TOP].width;
for (i = 0; i != c->columns; i++) {
row_span[c->start_column + i] = c->rows;
excess_y[c->start_column + i] =
c->border[TOP].width +
c->padding[TOP] +
c->height +
c->padding[BOTTOM] +
c->border[BOTTOM].width;
row_span_cell[c->start_column + i] = 0;
}
row_span_cell[c->start_column] = c;
c->padding[BOTTOM] = -border_spacing_v -
c->border[TOP].width -
c->padding[TOP] -
c->height -
c->border[BOTTOM].width;
}
for (i = 0; i != columns; i++)
if (row_span[i] != 0)
row_span[i]--;
else
row_span_cell[i] = 0;
if (row->next || row_group->next) {
/* row height is greatest excess of a cell
* which ends in this row */
for (i = 0; i != columns; i++)
if (row_span[i] == 0 && row_height <
excess_y[i])
row_height = excess_y[i];
} else {
/* except in the last row */
for (i = 0; i != columns; i++)
if (row_height < excess_y[i])
row_height = excess_y[i];
}
for (i = 0; i != columns; i++) {
if (row_height < excess_y[i])
excess_y[i] -= row_height;
else
excess_y[i] = 0;
if (row_span_cell[i] != 0)
row_span_cell[i]->padding[BOTTOM] +=
row_height +
border_spacing_v;
}
row->x = 0;
row->y = row_group_height;
row->width = table_width;
row->height = row_height;
row_group_height += row_height + border_spacing_v;
}
row_group->x = 0;
row_group->y = table_height;
row_group->width = table_width;
row_group->height = row_group_height;
table_height += row_group_height;
}
/* Table height is either the height of the contents, or specified
* height if greater */
table_height = max(table_height, min_height);
/** \todo distribute spare height over the row groups / rows / cells */
/* perform vertical alignment */
for (row_group = table->children; row_group;
row_group = row_group->next) {
for (row = row_group->children; row; row = row->next) {
for (c = row->children; c; c = c->next) {
enum css_vertical_align_e vertical_align;
/* unextended bottom padding is in
* c->descendant_y1, and unextended
* cell height is in c->descendant_y0 */
spare_height = (c->padding[BOTTOM] -
c->descendant_y1) +
(c->height - c->descendant_y0);
vertical_align = css_computed_vertical_align(
c->style, &value, &unit);
switch (vertical_align) {
case CSS_VERTICAL_ALIGN_SUB:
case CSS_VERTICAL_ALIGN_SUPER:
case CSS_VERTICAL_ALIGN_TEXT_TOP:
case CSS_VERTICAL_ALIGN_TEXT_BOTTOM:
case CSS_VERTICAL_ALIGN_SET:
case CSS_VERTICAL_ALIGN_BASELINE:
/* todo: baseline alignment, for now
* just use ALIGN_TOP */
case CSS_VERTICAL_ALIGN_TOP:
break;
case CSS_VERTICAL_ALIGN_MIDDLE:
c->padding[TOP] += spare_height / 2;
c->padding[BOTTOM] -= spare_height / 2;
layout_move_children(c, 0,
spare_height / 2);
break;
case CSS_VERTICAL_ALIGN_BOTTOM:
c->padding[TOP] += spare_height;
c->padding[BOTTOM] -= spare_height;
layout_move_children(c, 0,
spare_height);
break;
case CSS_VERTICAL_ALIGN_INHERIT:
assert(0);
break;
}
}
}
}
/* Top and bottom margins of 'auto' are set to 0. CSS2.1 10.6.3 */
if (table->margin[TOP] == AUTO)
table->margin[TOP] = 0;
if (table->margin[BOTTOM] == AUTO)
table->margin[BOTTOM] = 0;
free(col);
free(excess_y);
free(row_span);
free(row_span_cell);
free(xs);
table->width = table_width;
table->height = table_height;
return true;
}
/**
* Manimpulate box height according to CSS min-height and max-height properties
*
* \param len_ctx CSS length conversion context for document.
* \param box block to modify with any min-height or max-height
* \param container containing block for absolutely positioned elements, or
* NULL for non absolutely positioned elements.
* \return whether the height has been changed
*/
static bool layout_apply_minmax_height(
const nscss_len_ctx *len_ctx,
struct box *box,
struct box *container)
{
int h;
struct box *containing_block = NULL;
bool updated = false;
/* Find containing block for percentage heights */
if (box->style != NULL && css_computed_position(box->style) ==
CSS_POSITION_ABSOLUTE) {
/* Box is absolutely positioned */
assert(container);
containing_block = container;
} else if (box->float_container && box->style != NULL &&
(css_computed_float(box->style) == CSS_FLOAT_LEFT ||
css_computed_float(box->style) == CSS_FLOAT_RIGHT)) {
/* Box is a float */
assert(box->parent && box->parent->parent &&
box->parent->parent->parent);
containing_block = box->parent->parent->parent;
} else if (box->parent && box->parent->type != BOX_INLINE_CONTAINER) {
/* Box is a block level element */
containing_block = box->parent;
} else if (box->parent && box->parent->type == BOX_INLINE_CONTAINER) {
/* Box is an inline block */
assert(box->parent->parent);
containing_block = box->parent->parent;
}
if (box->style) {
enum css_height_e htype = CSS_HEIGHT_AUTO;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
if (containing_block) {
htype = css_computed_height(containing_block->style,
&value, &unit);
}
/* max-height */
if (css_computed_max_height(box->style, &value, &unit) ==
CSS_MAX_HEIGHT_SET) {
if (unit == CSS_UNIT_PCT) {
if (containing_block &&
containing_block->height != AUTO &&
(css_computed_position(box->style) ==
CSS_POSITION_ABSOLUTE ||
htype == CSS_HEIGHT_SET)) {
/* Box is absolutely positioned or its
* containing block has a valid
* specified height. (CSS 2.1
* Section 10.5) */
h = FPCT_OF_INT_TOINT(value,
containing_block->height);
if (h < box->height) {
box->height = h;
updated = true;
}
}
} else {
h = FIXTOINT(nscss_len2px(len_ctx,
value, unit, box->style));
if (h < box->height) {
box->height = h;
updated = true;
}
}
}
/* min-height */
if (ns_computed_min_height(box->style, &value, &unit) ==
CSS_MIN_HEIGHT_SET) {
if (unit == CSS_UNIT_PCT) {
if (containing_block &&
containing_block->height != AUTO &&
(css_computed_position(box->style) ==
CSS_POSITION_ABSOLUTE ||
htype == CSS_HEIGHT_SET)) {
/* Box is absolutely positioned or its
* containing block has a valid
* specified height. (CSS 2.1
* Section 10.5) */
h = FPCT_OF_INT_TOINT(value,
containing_block->height);
if (h > box->height) {
box->height = h;
updated = true;
}
}
} else {
h = FIXTOINT(nscss_len2px(len_ctx,
value, unit, box->style));
if (h > box->height) {
box->height = h;
updated = true;
}
}
}
}
return updated;
}
/**
* Layout a block which contains an object.
*
* \param block box of type BLOCK, INLINE_BLOCK, TABLE, or TABLE_CELL
* \return true on success, false on memory exhaustion
*/
static bool layout_block_object(struct box *block)
{
assert(block);
assert(block->type == BOX_BLOCK ||
block->type == BOX_INLINE_BLOCK ||
block->type == BOX_TABLE ||
block->type == BOX_TABLE_CELL);
assert(block->object);
NSLOG(layout, DEBUG, "block %p, object %p, width %i", block,
hlcache_handle_get_url(block->object), block->width);
if (content_get_type(block->object) == CONTENT_HTML) {
content_reformat(block->object, false, block->width, 1);
} else {
/* Non-HTML objects */
/* this case handled already in
* layout_block_find_dimensions() */
}
return true;
}
/**
* Insert a float into a container.
*
* \param cont block formatting context block, used to contain float
* \param b box to add to float
*
* This sorts floats in order of descending bottom edges.
*/
static void add_float_to_container(struct box *cont, struct box *b)
{
struct box *box = cont->float_children;
int b_bottom = b->y + b->height;
assert(b->type == BOX_FLOAT_LEFT || b->type == BOX_FLOAT_RIGHT);
if (box == NULL) {
/* No other float children */
b->next_float = NULL;
cont->float_children = b;
return;
} else if (b_bottom >= box->y + box->height) {
/* Goes at start of list */
b->next_float = cont->float_children;
cont->float_children = b;
} else {
struct box *prev = NULL;
while (box != NULL && b_bottom < box->y + box->height) {
prev = box;
box = box->next_float;
}
if (prev != NULL) {
b->next_float = prev->next_float;
prev->next_float = b;
}
}
}
/**
* Split a text box.
*
* \param content memory pool for any new boxes
* \param fstyle style for text in text box
* \param split_box box with text to split
* \param new_length new length for text in split_box, after splitting
* \param new_width new width for text in split_box, after splitting
* \return true on success, false on memory exhaustion
*
* A new box is created and inserted into the box tree after split_box,
* containing the text after new_length excluding the initial space character.
*/
static bool
layout_text_box_split(html_content *content,
plot_font_style_t *fstyle,
struct box *split_box,
size_t new_length,
int new_width)
{
int space_width = split_box->space;
struct box *c2;
const struct gui_layout_table *font_func = content->font_func;
bool space = (split_box->text[new_length] == ' ');
int used_length = new_length + (space ? 1 : 0);
if ((space && space_width == 0) || space_width == UNKNOWN_WIDTH) {
/* We're need to add a space, and we don't know how big
* it's to be, OR we have a space of unknown width anyway;
* Calculate space width */
font_func->width(fstyle, " ", 1, &space_width);
}
if (split_box->space == UNKNOWN_WIDTH)
split_box->space = space_width;
if (!space)
space_width = 0;
/* Create clone of split_box, c2 */
c2 = talloc_memdup(content->bctx, split_box, sizeof *c2);
if (!c2)
return false;
c2->flags |= CLONE;
/* Set remaining text in c2 */
c2->text += used_length;
/* Set c2 according to the remaining text */
c2->width -= new_width + space_width;
c2->flags &= ~MEASURED; /* width has been estimated */
c2->length = split_box->length - used_length;
/* Update split_box for its reduced text */
split_box->width = new_width;
split_box->flags |= MEASURED;
split_box->length = new_length;
split_box->space = space_width;
/* Insert c2 into box list */
c2->next = split_box->next;
split_box->next = c2;
c2->prev = split_box;
if (c2->next)
c2->next->prev = c2;
else
c2->parent->last = c2;
NSLOG(layout, DEBUG,
"split_box %p len: %" PRIsizet " \"%.*s\"",
split_box,
split_box->length,
(int)split_box->length,
split_box->text);
NSLOG(layout, DEBUG,
" new_box %p len: %" PRIsizet " \"%.*s\"",
c2,
c2->length,
(int)c2->length,
c2->text);
return true;
}
/**
* Compute dimensions of box, margins, paddings, and borders for a floating
* element using shrink-to-fit. Also used for inline-blocks.
*
* \param len_ctx CSS length conversion context for document.
* \param available_width Max width available in pixels
* \param style Box's style
* \param box Box for which to find dimensions
* Box margins, borders, paddings, width and
* height are updated.
*/
static void
layout_float_find_dimensions(
const nscss_len_ctx *len_ctx,
int available_width,
const css_computed_style *style,
struct box *box)
{
int width, height, max_width, min_width, max_height, min_height;
int *margin = box->margin;
int *padding = box->padding;
struct box_border *border = box->border;
enum css_overflow_e overflow_x = css_computed_overflow_x(style);
enum css_overflow_e overflow_y = css_computed_overflow_y(style);
int scrollbar_width_x =
(overflow_x == CSS_OVERFLOW_SCROLL ||
overflow_x == CSS_OVERFLOW_AUTO) ?
SCROLLBAR_WIDTH : 0;
int scrollbar_width_y =
(overflow_y == CSS_OVERFLOW_SCROLL ||
overflow_y == CSS_OVERFLOW_AUTO) ?
SCROLLBAR_WIDTH : 0;
layout_find_dimensions(len_ctx, available_width, -1, box, style,
&width, &height, &max_width, &min_width,
&max_height, &min_height, margin, padding, border);
if (margin[LEFT] == AUTO)
margin[LEFT] = 0;
if (margin[RIGHT] == AUTO)
margin[RIGHT] = 0;
if (box->gadget == NULL) {
padding[RIGHT] += scrollbar_width_y;
padding[BOTTOM] += scrollbar_width_x;
}
if (box->object && !(box->flags & REPLACE_DIM) &&
content_get_type(box->object) != CONTENT_HTML) {
/* Floating replaced element, with intrinsic width or height.
* See 10.3.6 and 10.6.2 */
layout_get_object_dimensions(box, &width, &height,
min_width, max_width, min_height, max_height);
} else if (box->gadget && (box->gadget->type == GADGET_TEXTBOX ||
box->gadget->type == GADGET_PASSWORD ||
box->gadget->type == GADGET_FILE ||
box->gadget->type == GADGET_TEXTAREA)) {
css_fixed size = 0;
css_unit unit = CSS_UNIT_EM;
/* Give sensible dimensions to gadgets, with auto width/height,
* that don't shrink to fit contained text. */
assert(box->style);
if (box->gadget->type == GADGET_TEXTBOX ||
box->gadget->type == GADGET_PASSWORD ||
box->gadget->type == GADGET_FILE) {
if (width == AUTO) {
size = INTTOFIX(10);
width = FIXTOINT(nscss_len2px(len_ctx,
size, unit, box->style));
}
if (box->gadget->type == GADGET_FILE &&
height == AUTO) {
size = FLTTOFIX(1.5);
height = FIXTOINT(nscss_len2px(len_ctx,
size, unit, box->style));
}
}
if (box->gadget->type == GADGET_TEXTAREA) {
if (width == AUTO) {
size = INTTOFIX(10);
width = FIXTOINT(nscss_len2px(len_ctx,
size, unit, box->style));
}
if (height == AUTO) {
size = INTTOFIX(4);
height = FIXTOINT(nscss_len2px(len_ctx,
size, unit, box->style));
}
}
} else if (width == AUTO) {
/* CSS 2.1 section 10.3.5 */
width = min(max(box->min_width, available_width),
box->max_width);
/* width includes margin, borders and padding */
if (width == available_width) {
width -= box->margin[LEFT] + box->border[LEFT].width +
box->padding[LEFT] +
box->padding[RIGHT] +
box->border[RIGHT].width +
box->margin[RIGHT];
} else {
/* width was obtained from a min_width or max_width
* value, so need to use the same method for calculating
* mbp as was used in layout_minmax_block() */
int fixed = 0;
float frac = 0;
calculate_mbp_width(len_ctx, box->style, LEFT,
true, true, true, &fixed, &frac);
calculate_mbp_width(len_ctx, box->style, RIGHT,
true, true, true, &fixed, &frac);
if (fixed < 0)
fixed = 0;
width -= fixed;
}
if (max_width >= 0 && width > max_width) width = max_width;
if (min_width > 0 && width < min_width) width = min_width;
} else {
if (max_width >= 0 && width > max_width) width = max_width;
if (min_width > 0 && width < min_width) width = min_width;
width -= scrollbar_width_y;
}
box->width = width;
box->height = height;
if (margin[TOP] == AUTO)
margin[TOP] = 0;
if (margin[BOTTOM] == AUTO)
margin[BOTTOM] = 0;
}
/**
* Layout the contents of a float or inline block.
*
* \param b float or inline block box
* \param width available width
* \param content memory pool for any new boxes
* \return true on success, false on memory exhaustion
*/
static bool layout_float(struct box *b, int width, html_content *content)
{
assert(b->type == BOX_TABLE || b->type == BOX_BLOCK ||
b->type == BOX_INLINE_BLOCK);
layout_float_find_dimensions(&content->len_ctx, width, b->style, b);
if (b->type == BOX_TABLE) {
if (!layout_table(b, width, content))
return false;
if (b->margin[LEFT] == AUTO)
b->margin[LEFT] = 0;
if (b->margin[RIGHT] == AUTO)
b->margin[RIGHT] = 0;
if (b->margin[TOP] == AUTO)
b->margin[TOP] = 0;
if (b->margin[BOTTOM] == AUTO)
b->margin[BOTTOM] = 0;
} else
return layout_block_context(b, -1, content);
return true;
}
/**
* Position a float in the first available space.
*
* \param c float box to position
* \param width available width
* \param cx x coordinate relative to cont to place float right of
* \param y y coordinate relative to cont to place float below
* \param cont ancestor box which defines horizontal space, for floats
*/
static void
place_float_below(struct box *c, int width, int cx, int y, struct box *cont)
{
int x0, x1, yy;
struct box *left;
struct box *right;
yy = y > cont->cached_place_below_level ?
y : cont->cached_place_below_level;
NSLOG(layout, DEBUG,
"c %p, width %i, cx %i, y %i, cont %p", c,
width, cx, y, cont);
do {
y = yy;
x0 = cx;
x1 = cx + width;
find_sides(cont->float_children, y, y + c->height, &x0, &x1,
&left, &right);
if (left != 0 && right != 0) {
yy = (left->y + left->height <
right->y + right->height ?
left->y + left->height :
right->y + right->height);
} else if (left == 0 && right != 0) {
yy = right->y + right->height;
} else if (left != 0 && right == 0) {
yy = left->y + left->height;
}
} while ((left != 0 || right != 0) && (c->width > x1 - x0));
if (c->type == BOX_FLOAT_LEFT) {
c->x = x0;
} else {
c->x = x1 - c->width;
}
c->y = y;
cont->cached_place_below_level = y;
}
/**
* Calculate line height from a style.
*/
static int line_height(
const nscss_len_ctx *len_ctx,
const css_computed_style *style)
{
enum css_line_height_e lhtype;
css_fixed lhvalue = 0;
css_unit lhunit = CSS_UNIT_PX;
css_fixed line_height;
assert(style);
lhtype = css_computed_line_height(style, &lhvalue, &lhunit);
if (lhtype == CSS_LINE_HEIGHT_NORMAL) {
/* Normal => use a constant of 1.3 * font-size */
lhvalue = FLTTOFIX(1.3);
lhtype = CSS_LINE_HEIGHT_NUMBER;
}
if (lhtype == CSS_LINE_HEIGHT_NUMBER ||
lhunit == CSS_UNIT_PCT) {
line_height = nscss_len2px(len_ctx,
lhvalue, CSS_UNIT_EM, style);
if (lhtype != CSS_LINE_HEIGHT_NUMBER)
line_height = FDIV(line_height, F_100);
} else {
assert(lhunit != CSS_UNIT_PCT);
line_height = nscss_len2px(len_ctx,
lhvalue, lhunit, style);
}
return FIXTOINT(line_height);
}
/**
* Position a line of boxes in inline formatting context.
*
* \param first box at start of line
* \param width available width on input, updated with actual width on output
* (may be incorrect if the line gets split?)
* \param y coordinate of top of line, updated on exit to bottom
* \param cx coordinate of left of line relative to cont
* \param cy coordinate of top of line relative to cont
* \param cont ancestor box which defines horizontal space, for floats
* \param indent apply any first-line indent
* \param has_text_children at least one TEXT in the inline_container
* \param next_box updated to first box for next line, or 0 at end
* \param content memory pool for any new boxes
* \return true on success, false on memory exhaustion
*/
static bool
layout_line(struct box *first,
int *width,
int *y,
int cx,
int cy,
struct box *cont,
bool indent,
bool has_text_children,
html_content *content,
struct box **next_box)
{
int height, used_height;
int x0 = 0;
int x1 = *width;
int x, h, x_previous;
int fy = cy;
struct box *left;
struct box *right;
struct box *b;
struct box *split_box = 0;
struct box *d;
struct box *br_box = 0;
bool move_y = false;
bool place_below = false;
int space_before = 0, space_after = 0;
unsigned int inline_count = 0;
unsigned int i;
const struct gui_layout_table *font_func = content->font_func;
plot_font_style_t fstyle;
NSLOG(layout, DEBUG,
"first %p, first->text '%.*s', width %i, y %i, cx %i, cy %i",
first,
(int)first->length,
first->text,
*width,
*y,
cx,
cy);
/* find sides at top of line */
x0 += cx;
x1 += cx;
find_sides(cont->float_children, cy, cy, &x0, &x1, &left, &right);
x0 -= cx;
x1 -= cx;
if (indent)
x0 += layout_text_indent(&content->len_ctx,
first->parent->parent->style, *width);
if (x1 < x0)
x1 = x0;
/* get minimum line height from containing block.
* this is the line-height if there are text children and also in the
* case of an initially empty text input */
if (has_text_children || first->parent->parent->gadget)
used_height = height = line_height(&content->len_ctx,
first->parent->parent->style);
else
/* inline containers with no text are usually for layout and
* look better with no minimum line-height */
used_height = height = 0;
/* pass 1: find height of line assuming sides at top of line: loop
* body executed at least once
* keep in sync with the loop in layout_minmax_line() */
NSLOG(layout, DEBUG, "x0 %i, x1 %i, x1 - x0 %i", x0, x1, x1 - x0);
for (x = 0, b = first; x <= x1 - x0 && b != 0; b = b->next) {
int min_width, max_width, min_height, max_height;
assert(b->type == BOX_INLINE || b->type == BOX_INLINE_BLOCK ||
b->type == BOX_FLOAT_LEFT ||
b->type == BOX_FLOAT_RIGHT ||
b->type == BOX_BR || b->type == BOX_TEXT ||
b->type == BOX_INLINE_END);
NSLOG(layout, DEBUG, "pass 1: b %p, x %i", b, x);
if (b->type == BOX_BR)
break;
if (b->type == BOX_FLOAT_LEFT || b->type == BOX_FLOAT_RIGHT)
continue;
if (b->type == BOX_INLINE_BLOCK &&
(css_computed_position(b->style) ==
CSS_POSITION_ABSOLUTE ||
css_computed_position(b->style) ==
CSS_POSITION_FIXED))
continue;
assert(b->style != NULL);
font_plot_style_from_css(&content->len_ctx, b->style, &fstyle);
x += space_after;
if (b->type == BOX_INLINE_BLOCK) {
if (b->max_width != UNKNOWN_WIDTH)
if (!layout_float(b, *width, content))
return false;
h = b->border[TOP].width + b->padding[TOP] + b->height +
b->padding[BOTTOM] +
b->border[BOTTOM].width;
if (height < h)
height = h;
x += b->margin[LEFT] + b->border[LEFT].width +
b->padding[LEFT] + b->width +
b->padding[RIGHT] +
b->border[RIGHT].width +
b->margin[RIGHT];
space_after = 0;
continue;
}
if (b->type == BOX_INLINE) {
/* calculate borders, margins, and padding */
layout_find_dimensions(&content->len_ctx,
*width, -1, b, b->style, 0, 0, 0, 0,
0, 0, b->margin, b->padding, b->border);
for (i = 0; i != 4; i++)
if (b->margin[i] == AUTO)
b->margin[i] = 0;
x += b->margin[LEFT] + b->border[LEFT].width +
b->padding[LEFT];
if (b->inline_end) {
b->inline_end->margin[RIGHT] = b->margin[RIGHT];
b->inline_end->padding[RIGHT] =
b->padding[RIGHT];
b->inline_end->border[RIGHT] =
b->border[RIGHT];
} else {
x += b->padding[RIGHT] +
b->border[RIGHT].width +
b->margin[RIGHT];
}
} else if (b->type == BOX_INLINE_END) {
b->width = 0;
if (b->space == UNKNOWN_WIDTH) {
font_func->width(&fstyle, " ", 1, &b->space);
/** \todo handle errors */
}
space_after = b->space;
x += b->padding[RIGHT] + b->border[RIGHT].width +
b->margin[RIGHT];
continue;
}
if (!b->object && !(b->flags & IFRAME) && !b->gadget &&
!(b->flags & REPLACE_DIM)) {
/* inline non-replaced, 10.3.1 and 10.6.1 */
b->height = line_height(&content->len_ctx,
b->style ? b->style :
b->parent->parent->style);
if (height < b->height)
height = b->height;
if (!b->text) {
b->width = 0;
space_after = 0;
continue;
}
if (b->width == UNKNOWN_WIDTH) {
/** \todo handle errors */
/* If it's a select element, we must use the
* width of the widest option text */
if (b->parent->parent->gadget &&
b->parent->parent->gadget->type
== GADGET_SELECT) {
int opt_maxwidth = 0;
struct form_option *o;
for (o = b->parent->parent->gadget->
data.select.items; o;
o = o->next) {
int opt_width;
font_func->width(&fstyle,
o->text,
strlen(o->text),
&opt_width);
if (opt_maxwidth < opt_width)
opt_maxwidth =opt_width;
}
b->width = opt_maxwidth;
if (nsoption_bool(core_select_menu))
b->width += SCROLLBAR_WIDTH;
} else {
font_func->width(&fstyle, b->text,
b->length, &b->width);
b->flags |= MEASURED;
}
}
/* If the current text has not been measured (i.e. its
* width was estimated after splitting), and it fits on
* the line, measure it properly, so next box is placed
* correctly. */
if (b->text && (x + b->width < x1 - x0) &&
!(b->flags & MEASURED) &&
b->next) {
font_func->width(&fstyle, b->text,
b->length, &b->width);
b->flags |= MEASURED;
}
x += b->width;
if (b->space == UNKNOWN_WIDTH) {
font_func->width(&fstyle, " ", 1, &b->space);
/** \todo handle errors */
}
space_after = b->space;
continue;
}
space_after = 0;
/* inline replaced, 10.3.2 and 10.6.2 */
assert(b->style);
layout_find_dimensions(&content->len_ctx,
*width, -1, b, b->style,
&b->width, &b->height,
&max_width, &min_width,
&max_height, &min_height,
NULL, NULL, NULL);
if (b->object && !(b->flags & REPLACE_DIM)) {
layout_get_object_dimensions(b, &b->width, &b->height,
min_width, max_width,
min_height, max_height);
} else if (b->flags & IFRAME) {
/* TODO: should we look at the content dimensions? */
if (b->width == AUTO)
b->width = 400;
if (b->height == AUTO)
b->height = 300;
/* We reformat the iframe browser window to new
* dimensions in pass 2 */
} else {
/* form control with no object */
if (b->width == AUTO)
b->width = FIXTOINT(nscss_len2px(
&content->len_ctx, INTTOFIX(1),
CSS_UNIT_EM, b->style));
if (b->height == AUTO)
b->height = FIXTOINT(nscss_len2px(
&content->len_ctx, INTTOFIX(1),
CSS_UNIT_EM, b->style));
}
/* Reformat object to new box size */
if (b->object && content_get_type(b->object) == CONTENT_HTML &&
b->width !=
content_get_available_width(b->object)) {
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
enum css_height_e htype = css_computed_height(b->style,
&value, &unit);
content_reformat(b->object, false, b->width, b->height);
if (htype == CSS_HEIGHT_AUTO)
b->height = content_get_height(b->object);
}
if (height < b->height)
height = b->height;
x += b->width;
}
/* find new sides using this height */
x0 = cx;
x1 = cx + *width;
find_sides(cont->float_children, cy, cy + height, &x0, &x1,
&left, &right);
x0 -= cx;
x1 -= cx;
if (indent)
x0 += layout_text_indent(&content->len_ctx,
first->parent->parent->style, *width);
if (x1 < x0)
x1 = x0;
space_after = space_before = 0;
/* pass 2: place boxes in line: loop body executed at least once */
NSLOG(layout, DEBUG, "x0 %i, x1 %i, x1 - x0 %i", x0, x1, x1 - x0);
for (x = x_previous = 0, b = first; x <= x1 - x0 && b; b = b->next) {
NSLOG(layout, DEBUG, "pass 2: b %p, x %i", b, x);
if (b->type == BOX_INLINE_BLOCK &&
(css_computed_position(b->style) ==
CSS_POSITION_ABSOLUTE ||
css_computed_position(b->style) ==
CSS_POSITION_FIXED)) {
b->x = x + space_after;
} else if (b->type == BOX_INLINE ||
b->type == BOX_INLINE_BLOCK ||
b->type == BOX_TEXT ||
b->type == BOX_INLINE_END) {
assert(b->width != UNKNOWN_WIDTH);
x_previous = x;
x += space_after;
b->x = x;
if ((b->type == BOX_INLINE && !b->inline_end) ||
b->type == BOX_INLINE_BLOCK) {
b->x += b->margin[LEFT] + b->border[LEFT].width;
x = b->x + b->padding[LEFT] + b->width +
b->padding[RIGHT] +
b->border[RIGHT].width +
b->margin[RIGHT];
} else if (b->type == BOX_INLINE) {
b->x += b->margin[LEFT] + b->border[LEFT].width;
x = b->x + b->padding[LEFT] + b->width;
} else if (b->type == BOX_INLINE_END) {
b->height = b->inline_end->height;
x += b->padding[RIGHT] +
b->border[RIGHT].width +
b->margin[RIGHT];
} else {
x += b->width;
}
space_before = space_after;
if (b->object || b->flags & REPLACE_DIM ||
b->flags & IFRAME)
space_after = 0;
else if (b->text || b->type == BOX_INLINE_END) {
if (b->space == UNKNOWN_WIDTH) {
font_plot_style_from_css(
&content->len_ctx,
b->style, &fstyle);
/** \todo handle errors */
font_func->width(&fstyle, " ", 1,
&b->space);
}
space_after = b->space;
} else {
space_after = 0;
}
split_box = b;
move_y = true;
inline_count++;
} else if (b->type == BOX_BR) {
b->x = x;
b->width = 0;
br_box = b;
b = b->next;
split_box = 0;
move_y = true;
break;
} else {
/* float */
NSLOG(layout, DEBUG, "float %p", b);
d = b->children;
d->float_children = 0;
d->cached_place_below_level = 0;
b->float_container = d->float_container = cont;
if (!layout_float(d, *width, content))
return false;
NSLOG(layout, DEBUG,
"%p : %d %d",
d,
d->margin[TOP],
d->border[TOP].width);
d->x = d->margin[LEFT] + d->border[LEFT].width;
d->y = d->margin[TOP] + d->border[TOP].width;
b->width = d->margin[LEFT] + d->border[LEFT].width +
d->padding[LEFT] + d->width +
d->padding[RIGHT] +
d->border[RIGHT].width +
d->margin[RIGHT];
b->height = d->margin[TOP] + d->border[TOP].width +
d->padding[TOP] + d->height +
d->padding[BOTTOM] +
d->border[BOTTOM].width +
d->margin[BOTTOM];
if (b->width > (x1 - x0) - x)
place_below = true;
if (d->style && (css_computed_clear(d->style) ==
CSS_CLEAR_NONE ||
(css_computed_clear(d->style) ==
CSS_CLEAR_LEFT && left == 0) ||
(css_computed_clear(d->style) ==
CSS_CLEAR_RIGHT &&
right == 0) ||
(css_computed_clear(d->style) ==
CSS_CLEAR_BOTH &&
left == 0 && right == 0)) &&
(!place_below ||
(left == 0 && right == 0 && x == 0)) &&
cy >= cont->clear_level &&
cy >= cont->cached_place_below_level) {
/* + not cleared or,
* cleared and there are no floats to clear
* + fits without needing to be placed below or,
* this line is empty with no floats
* + current y, cy, is below the clear level
*
* Float affects current line */
if (b->type == BOX_FLOAT_LEFT) {
b->x = cx + x0;
if (b->width > 0)
x0 += b->width;
left = b;
} else {
b->x = cx + x1 - b->width;
if (b->width > 0)
x1 -= b->width;
right = b;
}
b->y = cy;
} else {
/* cleared or doesn't fit on line */
/* place below into next available space */
int fcy = (cy > cont->clear_level) ? cy :
cont->clear_level;
fcy = (fcy > cont->cached_place_below_level) ?
fcy :
cont->cached_place_below_level;
fy = (fy > fcy) ? fy : fcy;
fy = (fy == cy) ? fy + height : fy;
place_float_below(b, *width, cx, fy, cont);
fy = b->y;
if (d->style && (
(css_computed_clear(d->style) ==
CSS_CLEAR_LEFT && left != 0) ||
(css_computed_clear(d->style) ==
CSS_CLEAR_RIGHT &&
right != 0) ||
(css_computed_clear(d->style) ==
CSS_CLEAR_BOTH &&
(left != 0 || right != 0)))) {
/* to be cleared below existing
* floats */
if (b->type == BOX_FLOAT_LEFT)
b->x = cx;
else
b->x = cx + *width - b->width;
fcy = layout_clear(cont->float_children,
css_computed_clear(d->style));
if (fcy > cont->clear_level)
cont->clear_level = fcy;
if (b->y < fcy)
b->y = fcy;
}
if (b->type == BOX_FLOAT_LEFT)
left = b;
else
right = b;
}
add_float_to_container(cont, b);
split_box = 0;
}
}
if (x1 - x0 < x && split_box) {
/* the last box went over the end */
size_t split = 0;
int w;
bool no_wrap = css_computed_white_space(
split_box->style) == CSS_WHITE_SPACE_NOWRAP ||
css_computed_white_space(
split_box->style) == CSS_WHITE_SPACE_PRE;
x = x_previous;
if (!no_wrap &&
(split_box->type == BOX_INLINE ||
split_box->type == BOX_TEXT) &&
!split_box->object &&
!(split_box->flags & REPLACE_DIM) &&
!(split_box->flags & IFRAME) &&
!split_box->gadget && split_box->text) {
font_plot_style_from_css(&content->len_ctx,
split_box->style, &fstyle);
/** \todo handle errors */
font_func->split(&fstyle,
split_box->text,
split_box->length,
x1 - x0 - x - space_before,
&split,
&w);
}
/* split == 0 implies that text can't be split */
if (split == 0)
w = split_box->width;
NSLOG(layout, DEBUG,
"splitting: split_box %p \"%.*s\", spilt %"PRIsizet
", w %i, left %p, right %p, inline_count %u",
split_box,
(int)split_box->length,
split_box->text,
split,
w,
left,
right,
inline_count);
if ((split == 0 || x1 - x0 <= x + space_before + w) &&
!left && !right && inline_count == 1) {
/* first word of box doesn't fit, but no floats and
* first box on line so force in */
if (split == 0 || split == split_box->length) {
/* only one word in this box, or not text
* or white-space:nowrap */
b = split_box->next;
} else {
/* cut off first word for this line */
if (!layout_text_box_split(content, &fstyle,
split_box, split, w))
return false;
b = split_box->next;
}
x += space_before + w;
NSLOG(layout, DEBUG, "forcing");
} else if ((split == 0 || x1 - x0 <= x + space_before + w) &&
inline_count == 1) {
/* first word of first box doesn't fit, but a float is
* taking some of the width so move below it */
assert(left || right);
used_height = 0;
if (left) {
NSLOG(layout, DEBUG,
"cy %i, left->y %i, left->height %i",
cy,
left->y,
left->height);
used_height = left->y + left->height - cy + 1;
NSLOG(layout, DEBUG, "used_height %i",
used_height);
}
if (right && used_height <
right->y + right->height - cy + 1)
used_height = right->y + right->height - cy + 1;
if (used_height < 0)
used_height = 0;
b = split_box;
NSLOG(layout, DEBUG, "moving below float");
} else if (split == 0 || x1 - x0 <= x + space_before + w) {
/* first word of box doesn't fit so leave box for next
* line */
b = split_box;
NSLOG(layout, DEBUG, "leaving for next line");
} else {
/* fit as many words as possible */
assert(split != 0);
NSLOG(layout, DEBUG,
"'%.*s' %i %"PRIsizet" %i",
(int)split_box->length, split_box->text,
x1 - x0, split, w);
if (split != split_box->length) {
if (!layout_text_box_split(content, &fstyle,
split_box, split, w))
return false;
b = split_box->next;
}
x += space_before + w;
NSLOG(layout, DEBUG, "fitting words");
}
move_y = true;
}
/* set positions */
switch (css_computed_text_align(first->parent->parent->style)) {
case CSS_TEXT_ALIGN_RIGHT:
case CSS_TEXT_ALIGN_LIBCSS_RIGHT:
x0 = x1 - x;
break;
case CSS_TEXT_ALIGN_CENTER:
case CSS_TEXT_ALIGN_LIBCSS_CENTER:
x0 = (x0 + (x1 - x)) / 2;
break;
case CSS_TEXT_ALIGN_LEFT:
case CSS_TEXT_ALIGN_LIBCSS_LEFT:
case CSS_TEXT_ALIGN_JUSTIFY:
/* leave on left */
break;
case CSS_TEXT_ALIGN_DEFAULT:
/* None; consider text direction */
switch (css_computed_direction(first->parent->parent->style)) {
case CSS_DIRECTION_LTR:
/* leave on left */
break;
case CSS_DIRECTION_RTL:
x0 = x1 - x;
break;
}
break;
}
for (d = first; d != b; d = d->next) {
d->flags &= ~NEW_LINE;
if (d->type == BOX_INLINE_BLOCK &&
(css_computed_position(d->style) ==
CSS_POSITION_ABSOLUTE ||
css_computed_position(d->style) ==
CSS_POSITION_FIXED)) {
/* positioned inline-blocks:
* set static position (x,y) only, rest of positioning
* is handled later */
d->x += x0;
d->y = *y;
continue;
} else if ((d->type == BOX_INLINE &&
((d->object || d->gadget) == false) &&
!(d->flags & IFRAME) &&
!(d->flags & REPLACE_DIM)) ||
d->type == BOX_BR ||
d->type == BOX_TEXT ||
d->type == BOX_INLINE_END) {
/* regular (non-replaced) inlines */
d->x += x0;
d->y = *y - d->padding[TOP];
if (d->type == BOX_TEXT && d->height > used_height) {
/* text */
used_height = d->height;
}
} else if ((d->type == BOX_INLINE) ||
d->type == BOX_INLINE_BLOCK) {
/* replaced inlines and inline-blocks */
d->x += x0;
d->y = *y + d->border[TOP].width + d->margin[TOP];
h = d->margin[TOP] + d->border[TOP].width +
d->padding[TOP] + d->height +
d->padding[BOTTOM] +
d->border[BOTTOM].width +
d->margin[BOTTOM];
if (used_height < h)
used_height = h;
}
}
first->flags |= NEW_LINE;
assert(b != first || (move_y && 0 < used_height && (left || right)));
/* handle vertical-align by adjusting box y values */
/** \todo proper vertical alignment handling */
for (d = first; d != b; d = d->next) {
if ((d->type == BOX_INLINE && d->inline_end) ||
d->type == BOX_BR ||
d->type == BOX_TEXT ||
d->type == BOX_INLINE_END) {
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
switch (css_computed_vertical_align(d->style, &value,
&unit)) {
case CSS_VERTICAL_ALIGN_SUPER:
case CSS_VERTICAL_ALIGN_TOP:
case CSS_VERTICAL_ALIGN_TEXT_TOP:
/* already at top */
break;
case CSS_VERTICAL_ALIGN_SUB:
case CSS_VERTICAL_ALIGN_BOTTOM:
case CSS_VERTICAL_ALIGN_TEXT_BOTTOM:
d->y += used_height - d->height;
break;
default:
case CSS_VERTICAL_ALIGN_BASELINE:
d->y += 0.75 * (used_height - d->height);
break;
}
}
}
/* handle clearance for br */
if (br_box && css_computed_clear(br_box->style) != CSS_CLEAR_NONE) {
int clear_y = layout_clear(cont->float_children,
css_computed_clear(br_box->style));
if (used_height < clear_y - cy)
used_height = clear_y - cy;
}
if (move_y)
*y += used_height;
*next_box = b;
*width = x; /* return actual width */
return true;
}
/**
* Layout lines of text or inline boxes with floats.
*
* \param box inline container box
* \param width horizontal space available
* \param cont ancestor box which defines horizontal space, for floats
* \param cx box position relative to cont
* \param cy box position relative to cont
* \param content memory pool for any new boxes
* \return true on success, false on memory exhaustion
*/
static bool layout_inline_container(struct box *inline_container, int width,
struct box *cont, int cx, int cy, html_content *content)
{
bool first_line = true;
bool has_text_children;
struct box *c, *next;
int y = 0;
int curwidth,maxwidth = width;
assert(inline_container->type == BOX_INLINE_CONTAINER);
NSLOG(layout, DEBUG,
"inline_container %p, width %i, cont %p, cx %i, cy %i",
inline_container,
width,
cont,
cx,
cy);
has_text_children = false;
for (c = inline_container->children; c; c = c->next) {
bool is_pre = false;
if (c->style) {
enum css_white_space_e whitespace;
whitespace = css_computed_white_space(c->style);
is_pre = (whitespace == CSS_WHITE_SPACE_PRE ||
whitespace == CSS_WHITE_SPACE_PRE_LINE ||
whitespace == CSS_WHITE_SPACE_PRE_WRAP);
}
if ((!c->object && !(c->flags & REPLACE_DIM) &&
!(c->flags & IFRAME) &&
c->text && (c->length || is_pre)) ||
c->type == BOX_BR)
has_text_children = true;
}
/** \todo fix wrapping so that a box with horizontal scrollbar will
* shrink back to 'width' if no word is wider than 'width' (Or just set
* curwidth = width and have the multiword lines wrap to the min width)
*/
for (c = inline_container->children; c; ) {
NSLOG(layout, DEBUG, "c %p", c);
curwidth = inline_container->width;
if (!layout_line(c, &curwidth, &y, cx, cy + y, cont, first_line,
has_text_children, content, &next))
return false;
maxwidth = max(maxwidth,curwidth);
c = next;
first_line = false;
}
inline_container->width = maxwidth;
inline_container->height = y;
return true;
}
/**
* Layout a block formatting context.
*
* \param block BLOCK, INLINE_BLOCK, or TABLE_CELL to layout
* \param viewport_height Height of viewport in pixels or -ve if unknown
* \param content Memory pool for any new boxes
* \return true on success, false on memory exhaustion
*
* This function carries out layout of a block and its children, as described
* in CSS 2.1 9.4.1.
*/
static bool
layout_block_context(struct box *block,
int viewport_height,
html_content *content)
{
struct box *box;
int cx, cy; /**< current coordinates */
int max_pos_margin = 0;
int max_neg_margin = 0;
int y = 0;
int lm, rm;
struct box *margin_collapse = NULL;
bool in_margin = false;
css_fixed gadget_size;
css_unit gadget_unit; /* Checkbox / radio buttons */
assert(block->type == BOX_BLOCK ||
block->type == BOX_INLINE_BLOCK ||
block->type == BOX_TABLE_CELL);
assert(block->width != UNKNOWN_WIDTH);
assert(block->width != AUTO);
block->float_children = NULL;
block->cached_place_below_level = 0;
block->clear_level = 0;
/* special case if the block contains an object */
if (block->object) {
int temp_width = block->width;
if (!layout_block_object(block))
return false;
layout_get_object_dimensions(block, &temp_width,
&block->height, INT_MIN, INT_MAX,
INT_MIN, INT_MAX);
return true;
} else if (block->flags & REPLACE_DIM) {
return true;
}
/* special case if the block contains an radio button or checkbox */
if (block->gadget && (block->gadget->type == GADGET_RADIO ||
block->gadget->type == GADGET_CHECKBOX)) {
/* form checkbox or radio button
* if width or height is AUTO, set it to 1em */
gadget_unit = CSS_UNIT_EM;
gadget_size = INTTOFIX(1);
if (block->height == AUTO)
block->height = FIXTOINT(nscss_len2px(
&content->len_ctx, gadget_size,
gadget_unit, block->style));
}
box = block->children;
/* set current coordinates to top-left of the block */
cx = 0;
y = cy = block->padding[TOP];
if (box)
box->y = block->padding[TOP];
/* Step through the descendants of the block in depth-first order, but
* not into the children of boxes which aren't blocks. For example, if
* the tree passed to this function looks like this (box->type shown):
*
* block -> BOX_BLOCK
* BOX_BLOCK * (1)
* BOX_INLINE_CONTAINER * (2)
* BOX_INLINE
* BOX_TEXT
* ...
* BOX_BLOCK * (3)
* BOX_TABLE * (4)
* BOX_TABLE_ROW
* BOX_TABLE_CELL
* ...
* BOX_TABLE_CELL
* ...
* BOX_BLOCK * (5)
* BOX_INLINE_CONTAINER * (6)
* BOX_TEXT
* ...
* then the while loop will visit each box marked with *, setting box
* to each in the order shown. */
while (box) {
enum css_overflow_e overflow_x = CSS_OVERFLOW_VISIBLE;
enum css_overflow_e overflow_y = CSS_OVERFLOW_VISIBLE;
assert(box->type == BOX_BLOCK || box->type == BOX_TABLE ||
box->type == BOX_INLINE_CONTAINER);
/* Tables are laid out before being positioned, because the
* position depends on the width which is calculated in
* table layout. Blocks and inline containers are positioned
* before being laid out, because width is not dependent on
* content, and the position is required during layout for
* correct handling of floats.
*/
if (box->style &&
(css_computed_position(box->style) ==
CSS_POSITION_ABSOLUTE ||
css_computed_position(box->style) ==
CSS_POSITION_FIXED)) {
box->x = box->parent->padding[LEFT];
/* absolute positioned; this element will establish
* its own block context when it gets laid out later,
* so no need to look at its children now. */
goto advance_to_next_box;
}
/* If we don't know which box the current margin collapses
* through to, find out. Update the pos/neg margin values. */
if (margin_collapse == NULL) {
margin_collapse = layout_next_margin_block(
&content->len_ctx, box, block,
viewport_height,
&max_pos_margin, &max_neg_margin);
/* We have a margin that has not yet been applied. */
in_margin = true;
}
/* Clearance. */
y = 0;
if (box->style && css_computed_clear(box->style) !=
CSS_CLEAR_NONE)
y = layout_clear(block->float_children,
css_computed_clear(box->style));
/* Find box's overflow properties */
if (box->style) {
overflow_x = css_computed_overflow_x(box->style);
overflow_y = css_computed_overflow_y(box->style);
}
/* Blocks establishing a block formatting context get minimum
* left and right margins to avoid any floats. */
lm = rm = 0;
if (box->type == BOX_BLOCK || box->flags & IFRAME) {
if (!box->object && !(box->flags & IFRAME) &&
!(box->flags & REPLACE_DIM) &&
box->style &&
(overflow_x != CSS_OVERFLOW_VISIBLE ||
overflow_y != CSS_OVERFLOW_VISIBLE)) {
/* box establishes new block formatting context
* so available width may be diminished due to
* floats. */
int x0, x1, top;
struct box *left, *right;
top = cy + max_pos_margin - max_neg_margin;
top = (top > y) ? top : y;
x0 = cx;
x1 = cx + box->parent->width -
box->parent->padding[LEFT] -
box->parent->padding[RIGHT];
find_sides(block->float_children, top, top,
&x0, &x1, &left, &right);
/* calculate min required left & right margins
* needed to avoid floats */
lm = x0 - cx;
rm = cx + box->parent->width -
box->parent->padding[LEFT] -
box->parent->padding[RIGHT] -
x1;
}
layout_block_find_dimensions(&content->len_ctx,
box->parent->width,
viewport_height, lm, rm, box);
if (box->type == BOX_BLOCK && !(box->flags & IFRAME)) {
layout_block_add_scrollbar(box, RIGHT);
layout_block_add_scrollbar(box, BOTTOM);
}
} else if (box->type == BOX_TABLE) {
if (box->style != NULL) {
enum css_width_e wtype;
css_fixed width = 0;
css_unit unit = CSS_UNIT_PX;
wtype = css_computed_width(box->style, &width,
&unit);
if (wtype == CSS_WIDTH_AUTO) {
/* max available width may be
* diminished due to floats. */
int x0, x1, top;
struct box *left, *right;
top = cy + max_pos_margin -
max_neg_margin;
top = (top > y) ? top : y;
x0 = cx;
x1 = cx + box->parent->width -
box->parent->padding[LEFT] -
box->parent->padding[RIGHT];
find_sides(block->float_children,
top, top, &x0, &x1,
&left, &right);
/* calculate min required left & right
* margins needed to avoid floats */
lm = x0 - cx;
rm = cx + box->parent->width -
box->parent->padding[LEFT] -
box->parent->padding[RIGHT] -
x1;
}
}
if (!layout_table(box, box->parent->width - lm - rm,
content))
return false;
layout_solve_width(box, box->parent->width, box->width,
lm, rm, -1, -1);
}
/* Position box: horizontal. */
box->x = box->parent->padding[LEFT] + box->margin[LEFT] +
box->border[LEFT].width;
cx += box->x;
/* Position box: vertical. */
if (box->border[TOP].width) {
box->y += box->border[TOP].width;
cy += box->border[TOP].width;
}
/* Vertical margin */
if (((box->type == BOX_BLOCK && (box->flags & HAS_HEIGHT)) ||
box->type == BOX_TABLE ||
(box->type == BOX_INLINE_CONTAINER &&
!box_is_first_child(box)) ||
margin_collapse == box) &&
in_margin == true) {
/* Margin goes above this box. */
cy += max_pos_margin - max_neg_margin;
box->y += max_pos_margin - max_neg_margin;
/* Current margin has been applied. */
in_margin = false;
max_pos_margin = max_neg_margin = 0;
}
/* Handle clearance */
if (box->type != BOX_INLINE_CONTAINER &&
(y > 0) && (cy < y)) {
/* box clears something*/
box->y += y - cy;
cy = y;
}
/* Unless the box has an overflow style of visible, the box
* establishes a new block context. */
if (box->type == BOX_BLOCK && box->style &&
(overflow_x != CSS_OVERFLOW_VISIBLE ||
overflow_y != CSS_OVERFLOW_VISIBLE)) {
layout_block_context(box, viewport_height, content);
cy += box->padding[TOP];
if (box->height == AUTO) {
box->height = 0;
layout_block_add_scrollbar(box, BOTTOM);
}
cx -= box->x;
cy += box->height + box->padding[BOTTOM] +
box->border[BOTTOM].width;
y = box->y + box->padding[TOP] + box->height +
box->padding[BOTTOM] +
box->border[BOTTOM].width;
/* Skip children, because they are done in the new
* block context */
goto advance_to_next_box;
}
NSLOG(layout, DEBUG, "box %p, cx %i, cy %i", box, cx, cy);
/* Layout (except tables). */
if (box->object) {
if (!layout_block_object(box))
return false;
} else if (box->type == BOX_INLINE_CONTAINER) {
box->width = box->parent->width;
if (!layout_inline_container(box, box->width, block,
cx, cy, content))
return false;
} else if (box->type == BOX_TABLE) {
/* Move down to avoid floats if necessary. */
int x0, x1;
struct box *left, *right;
y = cy;
while (1) {
enum css_width_e wtype;
css_fixed width = 0;
css_unit unit = CSS_UNIT_PX;
wtype = css_computed_width(box->style,
&width, &unit);
x0 = cx;
x1 = cx + box->parent->width;
find_sides(block->float_children, y,
y + box->height,
&x0, &x1, &left, &right);
if (wtype == CSS_WIDTH_AUTO)
break;
if (box->width <= x1 - x0)
break;
if (!left && !right)
break;
else if (!left)
y = right->y + right->height + 1;
else if (!right)
y = left->y + left->height + 1;
else if (left->y + left->height <
right->y + right->height)
y = left->y + left->height + 1;
else
y = right->y + right->height + 1;
}
box->x += x0 - cx;
cx = x0;
box->y += y - cy;
cy = y;
}
/* Advance to next box. */
if (box->type == BOX_BLOCK && !box->object && !(box->iframe) &&
box->children) {
/* Down into children. */
if (box == margin_collapse) {
/* Current margin collapsed though to this box.
* Unset margin_collapse. */
margin_collapse = NULL;
}
y = box->padding[TOP];
box = box->children;
box->y = y;
cy += y;
continue;
} else if (box->type == BOX_BLOCK || box->object ||
box->flags & IFRAME)
cy += box->padding[TOP];
if (box->type == BOX_BLOCK && box->height == AUTO) {
box->height = 0;
layout_block_add_scrollbar(box, BOTTOM);
}
cy += box->height + box->padding[BOTTOM] +
box->border[BOTTOM].width;
cx -= box->x;
y = box->y + box->padding[TOP] + box->height +
box->padding[BOTTOM] +
box->border[BOTTOM].width;
advance_to_next_box:
if (!box->next) {
/* No more siblings:
* up to first ancestor with a sibling. */
do {
if (box == margin_collapse) {
/* Current margin collapsed though to
* this box. Unset margin_collapse. */
margin_collapse = NULL;
}
/* Apply bottom margin */
if (max_pos_margin < box->margin[BOTTOM])
max_pos_margin = box->margin[BOTTOM];
else if (max_neg_margin < -box->margin[BOTTOM])
max_neg_margin = -box->margin[BOTTOM];
box = box->parent;
if (box == block)
break;
/* Margin is invalidated if this is a box
* margins can't collapse through. */
if (box->type == BOX_BLOCK &&
box->flags & MAKE_HEIGHT) {
margin_collapse = NULL;
in_margin = false;
max_pos_margin = max_neg_margin = 0;
}
if (box->height == AUTO) {
box->height = y - box->padding[TOP];
if (box->type == BOX_BLOCK)
layout_block_add_scrollbar(box,
BOTTOM);
} else
cy += box->height -
(y - box->padding[TOP]);
/* Apply any min-height and max-height to
* boxes in normal flow */
if (box->style &&
css_computed_position(box->style) !=
CSS_POSITION_ABSOLUTE &&
layout_apply_minmax_height(
&content->len_ctx,
box, NULL)) {
/* Height altered */
/* Set current cy */
cy += box->height -
(y - box->padding[TOP]);
}
cy += box->padding[BOTTOM] +
box->border[BOTTOM].width;
cx -= box->x;
y = box->y + box->padding[TOP] + box->height +
box->padding[BOTTOM] +
box->border[BOTTOM].width;
} while (box->next == NULL);
if (box == block)
break;
}
/* To next sibling. */
if (box == margin_collapse) {
/* Current margin collapsed though to this box.
* Unset margin_collapse. */
margin_collapse = NULL;
}
if (max_pos_margin < box->margin[BOTTOM])
max_pos_margin = box->margin[BOTTOM];
else if (max_neg_margin < -box->margin[BOTTOM])
max_neg_margin = -box->margin[BOTTOM];
box = box->next;
box->y = y;
}
/* Account for bottom margin of last contained block */
cy += max_pos_margin - max_neg_margin;
/* Increase height to contain any floats inside (CSS 2.1 10.6.7). */
for (box = block->float_children; box; box = box->next_float) {
y = box->y + box->height + box->padding[BOTTOM] +
box->border[BOTTOM].width + box->margin[BOTTOM];
if (cy < y)
cy = y;
}
if (block->height == AUTO) {
block->height = cy - block->padding[TOP];
if (block->type == BOX_BLOCK)
layout_block_add_scrollbar(block, BOTTOM);
}
if (block->style && css_computed_position(block->style) !=
CSS_POSITION_ABSOLUTE) {
/* Block is in normal flow */
layout_apply_minmax_height(&content->len_ctx, block, NULL);
}
if (block->gadget &&
(block->gadget->type == GADGET_TEXTAREA ||
block->gadget->type == GADGET_PASSWORD ||
block->gadget->type == GADGET_TEXTBOX)) {
plot_font_style_t fstyle;
int ta_width = block->padding[LEFT] + block->width +
block->padding[RIGHT];
int ta_height = block->padding[TOP] + block->height +
block->padding[BOTTOM];
font_plot_style_from_css(&content->len_ctx,
block->style, &fstyle);
fstyle.background = NS_TRANSPARENT;
textarea_set_layout(block->gadget->data.text.ta,
&fstyle, ta_width, ta_height,
block->padding[TOP], block->padding[RIGHT],
block->padding[BOTTOM], block->padding[LEFT]);
}
return true;
}
/**
* Check a node's tag type.
*
* Assumes node is an HTML element.
*
* \param[in] node Node to ckeck tag type of.
* \param[in] type Tag type to test for.
* \return true if if node has given type, false otherwise.
*/
static inline bool
layout__check_element_type(
const dom_node *node,
dom_html_element_type type)
{
dom_html_element_type node_type;
dom_exception exc;
exc = dom_html_element_get_tag_type(node, &node_type);
if (exc != DOM_NO_ERR) {
return false;
}
return node_type == type;
}
/**
* Helper to get attribute value from a LI node.
*
* \param[in] li_node DOM node for the LI element;
* \param[out] value_out Returns the value on success.
* \return true if node has value, otherwise false.
*/
static bool
layout__get_li_value(dom_node *li_node, dom_long *value_out)
{
dom_exception exc;
dom_long value;
bool has_value;
/** \todo
* dom_html_li_element_get_value() is rubbish and we can't tell
* a lack of value attribute or invalid value from a perfectly
* valid '-1'.
*
* This helps for the common case of no value. However we should
* fix libdom to have some kind of sane interface to get numerical
* attributes.
*/
exc = dom_element_has_attribute(li_node,
corestring_dom_value,
&has_value);
if (exc != DOM_NO_ERR || has_value == false) {
return false;
}
exc = dom_html_li_element_get_value(
(dom_html_li_element *)li_node,
&value);
if (exc != DOM_NO_ERR) {
return false;
}
*value_out = value;
return true;
}
/**
* Helper to get start attribute value from a OL node.
*
* \param[in] ol_node DOM node for the OL element;
* \param[out] start_out Returns the value on success.
* \return true if node has value, otherwise false.
*/
static bool
layout__get_ol_start(dom_node *ol_node, dom_long *start_out)
{
dom_exception exc;
dom_long start;
bool has_start;
/** \todo
* see layout__get_li_value().
*/
exc = dom_element_has_attribute(ol_node,
corestring_dom_start,
&has_start);
if (exc != DOM_NO_ERR || has_start == false) {
return false;
}
exc = dom_html_olist_element_get_start(
(dom_html_olist_element *)ol_node,
&start);
if (exc != DOM_NO_ERR) {
return false;
}
*start_out = start;
return true;
}
/**
* Helper to get reversed attribute value from a OL node.
*
* \param[in] ol_node DOM node for the OL element;
* \return true if node has reversed, otherwise false.
*/
static bool
layout__get_ol_reversed(dom_node *ol_node)
{
dom_exception exc;
bool has_reversed;
exc = dom_element_has_attribute(ol_node,
corestring_dom_reversed,
&has_reversed);
if (exc != DOM_NO_ERR) {
return false;
}
return has_reversed;
}
/**
* Get the number of list items for a list owner.
*
* \param[in] list_owner DOM node to count list items for.
* \param[in] count_out Returns list item count on success.
* \return true on success, otherwise false.
*/
static bool
layout__get_list_item_count(
dom_node *list_owner, int *count_out)
{
dom_html_element_type tag_type;
dom_exception exc;
dom_node *child;
int count;
if (list_owner == NULL) {
return false;
}
exc = dom_html_element_get_tag_type(list_owner, &tag_type);
if (exc != DOM_NO_ERR) {
return false;
}
if (tag_type != DOM_HTML_ELEMENT_TYPE_OL &&
tag_type != DOM_HTML_ELEMENT_TYPE_UL) {
return false;
}
exc = dom_node_get_first_child(list_owner, &child);
if (exc != DOM_NO_ERR) {
return false;
}
count = 0;
while (child != NULL) {
dom_node *temp_node;
if (layout__check_element_type(child,
DOM_HTML_ELEMENT_TYPE_LI)) {
struct box *child_box;
if (dom_node_get_user_data(child,
corestring_dom___ns_key_box_node_data,
&child_box) != DOM_NO_ERR) {
dom_node_unref(child);
return false;
}
if (child_box != NULL &&
child_box->list_marker != NULL) {
count++;
}
}
exc = dom_node_get_next_sibling(child, &temp_node);
dom_node_unref(child);
if (exc != DOM_NO_ERR) {
return false;
}
child = temp_node;
}
*count_out = count;
return true;
}
/**
* Handle list item counting, if this is a list owner box.
*
* \param[in] box Box to do list item counting for.
*/
static void
layout__ordered_list_count(
struct box *box)
{
dom_html_element_type tag_type;
dom_exception exc;
dom_node *child;
int step = 1;
int next;
if (box->node == NULL) {
return;
}
exc = dom_html_element_get_tag_type(box->node, &tag_type);
if (exc != DOM_NO_ERR) {
return;
}
if (tag_type != DOM_HTML_ELEMENT_TYPE_OL &&
tag_type != DOM_HTML_ELEMENT_TYPE_UL) {
return;
}
next = 1;
if (tag_type == DOM_HTML_ELEMENT_TYPE_OL) {
bool have_start = layout__get_ol_start(box->node, &next);
bool have_reversed = layout__get_ol_reversed(box->node);
if (have_reversed) {
step = -1;
}
if (!have_start && have_reversed) {
layout__get_list_item_count(box->node, &next);
}
}
exc = dom_node_get_first_child(box->node, &child);
if (exc != DOM_NO_ERR) {
return;
}
while (child != NULL) {
dom_node *temp_node;
if (layout__check_element_type(child,
DOM_HTML_ELEMENT_TYPE_LI)) {
struct box *child_box;
if (dom_node_get_user_data(child,
corestring_dom___ns_key_box_node_data,
&child_box) != DOM_NO_ERR) {
dom_node_unref(child);
return;
}
if (child_box != NULL &&
child_box->list_marker != NULL) {
dom_long value;
struct box *marker = child_box->list_marker;
if (layout__get_li_value(child, &value)) {
marker->list_value = value;
next = marker->list_value;
} else {
marker->list_value = next;
}
next += step;
}
}
exc = dom_node_get_next_sibling(child, &temp_node);
dom_node_unref(child);
if (exc != DOM_NO_ERR) {
return;
}
child = temp_node;
}
}
/**
* Set up the marker text for a numerical list item.
*
* \param[in] content The HTML content.
* \param[in] box The list item's main box.
*/
static void
layout__set_numerical_marker_text(
const html_content *content,
struct box *box)
{
struct box *marker = box->list_marker;
size_t counter_len;
css_error css_res;
enum {
/**
* initial length of a list marker buffer
*
* enough for 9,999,999,999,999,999,999 in decimal
* or five characters for 4-byte UTF-8.
*/
LIST_MARKER_SIZE = 20,
};
marker->text = talloc_array(content->bctx, char, LIST_MARKER_SIZE);
if (marker->text == NULL) {
return;
}
css_res = css_computed_format_list_style(box->style, marker->list_value,
marker->text, LIST_MARKER_SIZE, &counter_len);
if (css_res == CSS_OK) {
if (counter_len > LIST_MARKER_SIZE) {
/* Use computed size as marker did not fit in
* default allocation. */
marker->text = talloc_realloc(content->bctx,
marker->text,
char,
counter_len);
if (marker->text == NULL) {
return;
}
css_computed_format_list_style(box->style,
marker->list_value, marker->text,
counter_len, &counter_len);
}
marker->length = counter_len;
}
}
/**
* Find out if box's style represents a numerical list style type.
*
* \param[in] b Box with style to test.
* \return true if box has numerical list style type, false otherwise.
*/
static bool
layout__list_item_is_numerical(
const struct box *b)
{
enum css_list_style_type_e t = css_computed_list_style_type(b->style);
switch (t) {
case CSS_LIST_STYLE_TYPE_DISC: /* Fall through. */
case CSS_LIST_STYLE_TYPE_CIRCLE: /* Fall through. */
case CSS_LIST_STYLE_TYPE_SQUARE: /* Fall through. */
case CSS_LIST_STYLE_TYPE_NONE:
return false;
default:
return true;
}
}
/**
* Layout list markers.
*/
static void
layout_lists(const html_content *content, struct box *box)
{
struct box *child;
layout__ordered_list_count(box);
for (child = box->children; child; child = child->next) {
if (child->list_marker) {
struct box *marker = child->list_marker;
if (layout__list_item_is_numerical(child)) {
if (marker->text == NULL) {
layout__set_numerical_marker_text(
content, child);
}
}
if (marker->object) {
marker->width =
content_get_width(marker->object);
marker->x = -marker->width;
marker->height =
content_get_height(marker->object);
marker->y = (line_height(
&content->len_ctx,
marker->style) -
marker->height) / 2;
} else if (marker->text) {
if (marker->width == UNKNOWN_WIDTH) {
plot_font_style_t fstyle;
font_plot_style_from_css(
&content->len_ctx,
marker->style,
&fstyle);
content->font_func->width(&fstyle,
marker->text,
marker->length,
&marker->width);
marker->flags |= MEASURED;
}
marker->x = -marker->width;
marker->y = 0;
marker->height = line_height(
&content->len_ctx,
marker->style);
} else {
marker->x = 0;
marker->y = 0;
marker->width = 0;
marker->height = 0;
}
/* Gap between marker and content */
marker->x -= 4;
}
layout_lists(content, child);
}
}
/**
* Compute box offsets for a relatively or absolutely positioned box with
* respect to a box.
*
* \param len_ctx Length conversion context
* \param box box to compute offsets for
* \param containing_block box to compute percentages with respect to
* \param top updated to top offset, or AUTO
* \param right updated to right offset, or AUTO
* \param bottom updated to bottom offset, or AUTO
* \param left updated to left offset, or AUTO
*
* See CSS 2.1 9.3.2. containing_block must have width and height.
*/
static void
layout_compute_offsets(const nscss_len_ctx *len_ctx,
struct box *box,
struct box *containing_block,
int *top,
int *right,
int *bottom,
int *left)
{
uint32_t type;
css_fixed value = 0;
css_unit unit = CSS_UNIT_PX;
assert(containing_block->width != UNKNOWN_WIDTH &&
containing_block->width != AUTO &&
containing_block->height != AUTO);
/* left */
type = css_computed_left(box->style, &value, &unit);
if (type == CSS_LEFT_SET) {
if (unit == CSS_UNIT_PCT) {
*left = FPCT_OF_INT_TOINT(value,
containing_block->width);
} else {
*left = FIXTOINT(nscss_len2px(len_ctx,
value, unit, box->style));
}
} else {
*left = AUTO;
}
/* right */
type = css_computed_right(box->style, &value, &unit);
if (type == CSS_RIGHT_SET) {
if (unit == CSS_UNIT_PCT) {
*right = FPCT_OF_INT_TOINT(value,
containing_block->width);
} else {
*right = FIXTOINT(nscss_len2px(len_ctx,
value, unit, box->style));
}
} else {
*right = AUTO;
}
/* top */
type = css_computed_top(box->style, &value, &unit);
if (type == CSS_TOP_SET) {
if (unit == CSS_UNIT_PCT) {
*top = FPCT_OF_INT_TOINT(value,
containing_block->height);
} else {
*top = FIXTOINT(nscss_len2px(len_ctx,
value, unit, box->style));
}
} else {
*top = AUTO;
}
/* bottom */
type = css_computed_bottom(box->style, &value, &unit);
if (type == CSS_BOTTOM_SET) {
if (unit == CSS_UNIT_PCT) {
*bottom = FPCT_OF_INT_TOINT(value,
containing_block->height);
} else {
*bottom = FIXTOINT(nscss_len2px(len_ctx,
value, unit, box->style));
}
} else {
*bottom = AUTO;
}
}
/**
* Layout and position an absolutely positioned box.
*
* \param box absolute box to layout and position
* \param containing_block containing block
* \param cx position of box relative to containing_block
* \param cy position of box relative to containing_block
* \param content memory pool for any new boxes
* \return true on success, false on memory exhaustion
*/
static bool
layout_absolute(struct box *box,
struct box *containing_block,
int cx, int cy,
html_content *content)
{
int static_left, static_top; /* static position */
int top, right, bottom, left;
int width, height, max_width, min_width;
int *margin = box->margin;
int *padding = box->padding;
struct box_border *border = box->border;
int available_width = containing_block->width;
int space;
assert(box->type == BOX_BLOCK || box->type == BOX_TABLE ||
box->type == BOX_INLINE_BLOCK);
/* The static position is where the box would be if it was not
* absolutely positioned. The x and y are filled in by
* layout_block_context(). */
static_left = cx + box->x;
static_top = cy + box->y;
if (containing_block->type == BOX_BLOCK ||
containing_block->type == BOX_INLINE_BLOCK ||
containing_block->type == BOX_TABLE_CELL) {
/* Block level container => temporarily increase containing
* block dimensions to include padding (we restore this
* again at the end) */
containing_block->width += containing_block->padding[LEFT] +
containing_block->padding[RIGHT];
containing_block->height += containing_block->padding[TOP] +
containing_block->padding[BOTTOM];
} else {
/** \todo inline containers */
}
layout_compute_offsets(&content->len_ctx, box, containing_block,
&top, &right, &bottom, &left);
/* Pass containing block into layout_find_dimensions via the float
* containing block box member. This is unused for absolutely positioned
* boxes because a box can't be floated and absolutely positioned. */
box->float_container = containing_block;
layout_find_dimensions(&content->len_ctx, available_width, -1,
box, box->style, &width, &height,
&max_width, &min_width, 0, 0,
margin, padding, border);
box->float_container = NULL;
/* 10.3.7 */
NSLOG(layout, DEBUG,
"%i + %i + %i + %i + %i + %i + %i + %i + %i = %i",
left, margin[LEFT], border[LEFT].width, padding[LEFT], width,
padding[RIGHT], border[RIGHT].width, margin[RIGHT], right,
containing_block->width);
if (left == AUTO && width == AUTO && right == AUTO) {
if (margin[LEFT] == AUTO)
margin[LEFT] = 0;
if (margin[RIGHT] == AUTO)
margin[RIGHT] = 0;
left = static_left;
width = min(max(box->min_width, available_width),
box->max_width);
width -= box->margin[LEFT] + box->border[LEFT].width +
box->padding[LEFT] + box->padding[RIGHT] +
box->border[RIGHT].width + box->margin[RIGHT];
/* Adjust for {min|max}-width */
if (max_width >= 0 && width > max_width) width = max_width;
if (width < min_width) width = min_width;
right = containing_block->width -
left -
margin[LEFT] - border[LEFT].width - padding[LEFT] -
width -
padding[RIGHT] - border[RIGHT].width - margin[RIGHT];
} else if (left != AUTO && width != AUTO && right != AUTO) {
/* Adjust for {min|max}-width */
if (max_width >= 0 && width > max_width) width = max_width;
if (min_width > 0 && width < min_width) width = min_width;
if (margin[LEFT] == AUTO && margin[RIGHT] == AUTO) {
space = containing_block->width -
left - border[LEFT].width -
padding[LEFT] - width - padding[RIGHT] -
border[RIGHT].width - right;
if (space < 0) {
margin[LEFT] = 0;
margin[RIGHT] = space;
} else {
margin[LEFT] = margin[RIGHT] = space / 2;
}
} else if (margin[LEFT] == AUTO) {
margin[LEFT] = containing_block->width -
left - border[LEFT].width -
padding[LEFT] - width - padding[RIGHT] -
border[RIGHT].width - margin[RIGHT] -
right;
} else if (margin[RIGHT] == AUTO) {
margin[RIGHT] = containing_block->width -
left - margin[LEFT] -
border[LEFT].width -
padding[LEFT] - width - padding[RIGHT] -
border[RIGHT].width - right;
} else {
right = containing_block->width -
left - margin[LEFT] -
border[LEFT].width -
padding[LEFT] - width - padding[RIGHT] -
border[RIGHT].width - margin[RIGHT];
}
} else {
if (margin[LEFT] == AUTO)
margin[LEFT] = 0;
if (margin[RIGHT] == AUTO)
margin[RIGHT] = 0;
if (left == AUTO && width == AUTO && right != AUTO) {
available_width -= right;
width = min(max(box->min_width, available_width),
box->max_width);
width -= box->margin[LEFT] + box->border[LEFT].width +
box->padding[LEFT] + box->padding[RIGHT] +
box->border[RIGHT].width + box->margin[RIGHT];
/* Adjust for {min|max}-width */
if (max_width >= 0 && width > max_width)
width = max_width;
if (width < min_width)
width = min_width;
left = containing_block->width -
margin[LEFT] - border[LEFT].width -
padding[LEFT] - width - padding[RIGHT] -
border[RIGHT].width - margin[RIGHT] -
right;
} else if (left == AUTO && width != AUTO && right == AUTO) {
/* Adjust for {min|max}-width */
if (max_width >= 0 && width > max_width)
width = max_width;
if (min_width > 0 && width < min_width)
width = min_width;
left = static_left;
right = containing_block->width -
left - margin[LEFT] -
border[LEFT].width -
padding[LEFT] - width - padding[RIGHT] -
border[RIGHT].width - margin[RIGHT];
} else if (left != AUTO && width == AUTO && right == AUTO) {
available_width -= left;
width = min(max(box->min_width, available_width),
box->max_width);
width -= box->margin[LEFT] + box->border[LEFT].width +
box->padding[LEFT] + box->padding[RIGHT] +
box->border[RIGHT].width + box->margin[RIGHT];
/* Adjust for {min|max}-width */
if (max_width >= 0 && width > max_width)
width = max_width;
if (width < min_width)
width = min_width;
right = containing_block->width -
left - margin[LEFT] -
border[LEFT].width -
padding[LEFT] - width - padding[RIGHT] -
border[RIGHT].width - margin[RIGHT];
} else if (left == AUTO && width != AUTO && right != AUTO) {
/* Adjust for {min|max}-width */
if (max_width >= 0 && width > max_width)
width = max_width;
if (width < min_width)
width = min_width;
left = containing_block->width -
margin[LEFT] - border[LEFT].width -
padding[LEFT] - width - padding[RIGHT] -
border[RIGHT].width - margin[RIGHT] -
right;
} else if (left != AUTO && width == AUTO && right != AUTO) {
width = containing_block->width -
left - margin[LEFT] -
border[LEFT].width -
padding[LEFT] - padding[RIGHT] -
border[RIGHT].width - margin[RIGHT] -
right;
/* Adjust for {min|max}-width */
if (max_width >= 0 && width > max_width)
width = max_width;
if (width < min_width)
width = min_width;
} else if (left != AUTO && width != AUTO && right == AUTO) {
/* Adjust for {min|max}-width */
if (max_width >= 0 && width > max_width)
width = max_width;
if (width < min_width)
width = min_width;
right = containing_block->width -
left - margin[LEFT] -
border[LEFT].width -
padding[LEFT] - width - padding[RIGHT] -
border[RIGHT].width - margin[RIGHT];
}
}
NSLOG(layout, DEBUG,
"%i + %i + %i + %i + %i + %i + %i + %i + %i = %i",
left, margin[LEFT], border[LEFT].width, padding[LEFT], width,
padding[RIGHT], border[RIGHT].width, margin[RIGHT], right,
containing_block->width);
box->x = left + margin[LEFT] + border[LEFT].width - cx;
if (containing_block->type == BOX_BLOCK ||
containing_block->type == BOX_INLINE_BLOCK ||
containing_block->type == BOX_TABLE_CELL) {
/* Block-level ancestor => reset container's width */
containing_block->width -= containing_block->padding[LEFT] +
containing_block->padding[RIGHT];
} else {
/** \todo inline ancestors */
}
box->width = width;
box->height = height;
if (box->type == BOX_BLOCK || box->type == BOX_INLINE_BLOCK ||
box->object || box->flags & IFRAME) {
if (!layout_block_context(box, -1, content))
return false;
} else if (box->type == BOX_TABLE) {
/* layout_table also expects the containing block to be
* stored in the float_container field */
box->float_container = containing_block;
/* \todo layout_table considers margins etc. again */
if (!layout_table(box, width, content))
return false;
box->float_container = NULL;
layout_solve_width(box, box->parent->width, box->width, 0, 0,
-1, -1);
}
/* 10.6.4 */
NSLOG(layout, DEBUG,
"%i + %i + %i + %i + %i + %i + %i + %i + %i = %i",
top, margin[TOP], border[TOP].width, padding[TOP], height,
padding[BOTTOM], border[BOTTOM].width, margin[BOTTOM], bottom,
containing_block->height);
if (top == AUTO && height == AUTO && bottom == AUTO) {
top = static_top;
height = box->height;
if (margin[TOP] == AUTO)
margin[TOP] = 0;
if (margin[BOTTOM] == AUTO)
margin[BOTTOM] = 0;
bottom = containing_block->height -
top - margin[TOP] - border[TOP].width -
padding[TOP] - height - padding[BOTTOM] -
border[BOTTOM].width - margin[BOTTOM];
} else if (top != AUTO && height != AUTO && bottom != AUTO) {
if (margin[TOP] == AUTO && margin[BOTTOM] == AUTO) {
space = containing_block->height -
top - border[TOP].width - padding[TOP] -
height - padding[BOTTOM] -
border[BOTTOM].width - bottom;
margin[TOP] = margin[BOTTOM] = space / 2;
} else if (margin[TOP] == AUTO) {
margin[TOP] = containing_block->height -
top - border[TOP].width - padding[TOP] -
height - padding[BOTTOM] -
border[BOTTOM].width - margin[BOTTOM] -
bottom;
} else if (margin[BOTTOM] == AUTO) {
margin[BOTTOM] = containing_block->height -
top - margin[TOP] - border[TOP].width -
padding[TOP] - height -
padding[BOTTOM] - border[BOTTOM].width -
bottom;
} else {
bottom = containing_block->height -
top - margin[TOP] - border[TOP].width -
padding[TOP] - height -
padding[BOTTOM] - border[BOTTOM].width -
margin[BOTTOM];
}
} else {
if (margin[TOP] == AUTO)
margin[TOP] = 0;
if (margin[BOTTOM] == AUTO)
margin[BOTTOM] = 0;
if (top == AUTO && height == AUTO && bottom != AUTO) {
height = box->height;
top = containing_block->height -
margin[TOP] - border[TOP].width -
padding[TOP] - height -
padding[BOTTOM] - border[BOTTOM].width -
margin[BOTTOM] - bottom;
} else if (top == AUTO && height != AUTO && bottom == AUTO) {
top = static_top;
bottom = containing_block->height -
top - margin[TOP] - border[TOP].width -
padding[TOP] - height -
padding[BOTTOM] - border[BOTTOM].width -
margin[BOTTOM];
} else if (top != AUTO && height == AUTO && bottom == AUTO) {
height = box->height;
bottom = containing_block->height -
top - margin[TOP] - border[TOP].width -
padding[TOP] - height -
padding[BOTTOM] - border[BOTTOM].width -
margin[BOTTOM];
} else if (top == AUTO && height != AUTO && bottom != AUTO) {
top = containing_block->height -
margin[TOP] - border[TOP].width -
padding[TOP] - height -
padding[BOTTOM] - border[BOTTOM].width -
margin[BOTTOM] - bottom;
} else if (top != AUTO && height == AUTO && bottom != AUTO) {
height = containing_block->height -
top - margin[TOP] - border[TOP].width -
padding[TOP] - padding[BOTTOM] -
border[BOTTOM].width - margin[BOTTOM] -
bottom;
} else if (top != AUTO && height != AUTO && bottom == AUTO) {
bottom = containing_block->height -
top - margin[TOP] - border[TOP].width -
padding[TOP] - height -
padding[BOTTOM] - border[BOTTOM].width -
margin[BOTTOM];
}
}
NSLOG(layout, DEBUG,
"%i + %i + %i + %i + %i + %i + %i + %i + %i = %i",
top, margin[TOP], border[TOP].width, padding[TOP], height,
padding[BOTTOM], border[BOTTOM].width, margin[BOTTOM], bottom,
containing_block->height);
box->y = top + margin[TOP] + border[TOP].width - cy;
if (containing_block->type == BOX_BLOCK ||
containing_block->type == BOX_INLINE_BLOCK ||
containing_block->type == BOX_TABLE_CELL) {
/* Block-level ancestor => reset container's height */
containing_block->height -= containing_block->padding[TOP] +
containing_block->padding[BOTTOM];
} else {
/** \todo Inline ancestors */
}
box->height = height;
layout_apply_minmax_height(&content->len_ctx, box, containing_block);
return true;
}
/**
* Recursively layout and position absolutely positioned boxes.
*
* \param box tree of boxes to layout
* \param containing_block current containing block
* \param cx position of box relative to containing_block
* \param cy position of box relative to containing_block
* \param content memory pool for any new boxes
* \return true on success, false on memory exhaustion
*/
static bool
layout_position_absolute(struct box *box,
struct box *containing_block,
int cx, int cy,
html_content *content)
{
struct box *c;
for (c = box->children; c; c = c->next) {
if ((c->type == BOX_BLOCK || c->type == BOX_TABLE ||
c->type == BOX_INLINE_BLOCK) &&
(css_computed_position(c->style) ==
CSS_POSITION_ABSOLUTE ||
css_computed_position(c->style) ==
CSS_POSITION_FIXED)) {
if (!layout_absolute(c, containing_block,
cx, cy, content))
return false;
if (!layout_position_absolute(c, c, 0, 0, content))
return false;
} else if (c->style && css_computed_position(c->style) ==
CSS_POSITION_RELATIVE) {
if (!layout_position_absolute(c, c, 0, 0, content))
return false;
} else {
int px, py;
if (c->style && (css_computed_float(c->style) ==
CSS_FLOAT_LEFT ||
css_computed_float(c->style) ==
CSS_FLOAT_RIGHT)) {
/* Float x/y coords are relative to nearest
* ansestor with float_children, rather than
* relative to parent. Need to get x/y relative
* to parent */
struct box *p;
px = c->x;
py = c->y;
for (p = box->parent; p && !p->float_children;
p = p->parent) {
px -= p->x;
py -= p->y;
}
} else {
/* Not a float, so box x/y coords are relative
* to parent */
px = c->x;
py = c->y;
}
if (!layout_position_absolute(c, containing_block,
cx + px, cy + py, content))
return false;
}
}
return true;
}
/**
* Compute a box's relative offset as per CSS 2.1 9.4.3
*
* \param len_ctx Length conversion context
* \param box Box to compute relative offsets for.
* \param x Receives relative offset in x.
* \param y Receives relative offset in y.
*/
static void layout_compute_relative_offset(
const nscss_len_ctx *len_ctx,
struct box *box,
int *x,
int *y)
{
int left, right, top, bottom;
struct box *containing_block;
assert(box && box->parent && box->style &&
css_computed_position(box->style) ==
CSS_POSITION_RELATIVE);
if (box->float_container &&
(css_computed_float(box->style) == CSS_FLOAT_LEFT ||
css_computed_float(box->style) == CSS_FLOAT_RIGHT)) {
containing_block = box->float_container;
} else {
containing_block = box->parent;
}
layout_compute_offsets(len_ctx, box, containing_block,
&top, &right, &bottom, &left);
if (left == AUTO && right == AUTO)
left = right = 0;
else if (left == AUTO)
/* left is auto => computed = -right */
left = -right;
else if (right == AUTO)
/* right is auto => computed = -left */
right = -left;
else {
/* over constrained => examine direction property
* of containing block */
if (containing_block->style &&
css_computed_direction(
containing_block->style) ==
CSS_DIRECTION_RTL) {
/* right wins */
left = -right;
} else {
/* assume LTR in all other cases */
right = -left;
}
}
assert(left == -right);
if (top == AUTO && bottom == AUTO) {
top = bottom = 0;
} else if (top == AUTO) {
top = -bottom;
} else {
/* bottom is AUTO, or neither are AUTO */
bottom = -top;
}
NSLOG(layout, DEBUG, "left %i, right %i, top %i, bottom %i", left,
right, top, bottom);
*x = left;
*y = top;
}
/**
* Adjust positions of relatively positioned boxes.
*
* \param len_ctx Length conversion context
* \param root box to adjust the position of
* \param fp box which forms the block formatting context for children of
* "root" which are floats
* \param fx x offset due to intervening relatively positioned boxes
* between current box, "root", and the block formatting context
* box, "fp", for float children of "root"
* \param fy y offset due to intervening relatively positioned boxes
* between current box, "root", and the block formatting context
* box, "fp", for float children of "root"
*/
static void
layout_position_relative(
const nscss_len_ctx *len_ctx,
struct box *root,
struct box *fp,
int fx,
int fy)
{
struct box *box; /* for children of "root" */
struct box *fn; /* for block formatting context box for children of
* "box" */
struct box *fc; /* for float children of the block formatting context,
* "fp" */
int x, y; /* for the offsets resulting from any relative
* positioning on the current block */
int fnx, fny; /* for affsets which apply to flat children of "box" */
/**\todo ensure containing box is large enough after moving boxes */
assert(root);
/* Normal children */
for (box = root->children; box; box = box->next) {
if (box->type == BOX_TEXT)
continue;
/* If relatively positioned, get offsets */
if (box->style && css_computed_position(box->style) ==
CSS_POSITION_RELATIVE)
layout_compute_relative_offset(
len_ctx, box, &x, &y);
else
x = y = 0;
/* Adjust float coordinates.
* (note float x and y are relative to their block formatting
* context box and not their parent) */
if (box->style && (css_computed_float(box->style) ==
CSS_FLOAT_LEFT ||
css_computed_float(box->style) ==
CSS_FLOAT_RIGHT) &&
(fx != 0 || fy != 0)) {
/* box is a float and there is a float offset to
* apply */
for (fc = fp->float_children; fc; fc = fc->next_float) {
if (box == fc->children) {
/* Box is floated in the block
* formatting context block, fp.
* Apply float offsets. */
box->x += fx;
box->y += fy;
fx = fy = 0;
}
}
}
if (box->float_children) {
fn = box;
fnx = fny = 0;
} else {
fn = fp;
fnx = fx + x;
fny = fy + y;
}
/* recurse first */
layout_position_relative(len_ctx, box, fn, fnx, fny);
/* Ignore things we're not interested in. */
if (!box->style || (box->style &&
css_computed_position(box->style) !=
CSS_POSITION_RELATIVE))
continue;
box->x += x;
box->y += y;
/* Handle INLINEs - their "children" are in fact
* the sibling boxes between the INLINE and
* INLINE_END boxes */
if (box->type == BOX_INLINE && box->inline_end) {
struct box *b;
for (b = box->next; b && b != box->inline_end;
b = b->next) {
b->x += x;
b->y += y;
}
}
}
}
/**
* Find a box's bounding box relative to itself, i.e. the box's border edge box
*
* \param len_ctx Length conversion context
* \param box box find bounding box of
* \param desc_x0 updated to left of box's bbox
* \param desc_y0 updated to top of box's bbox
* \param desc_x1 updated to right of box's bbox
* \param desc_y1 updated to bottom of box's bbox
*/
static void
layout_get_box_bbox(
const nscss_len_ctx *len_ctx,
struct box *box,
int *desc_x0, int *desc_y0,
int *desc_x1, int *desc_y1)
{
*desc_x0 = -box->border[LEFT].width;
*desc_y0 = -box->border[TOP].width;
*desc_x1 = box->padding[LEFT] + box->width + box->padding[RIGHT] +
box->border[RIGHT].width;
*desc_y1 = box->padding[TOP] + box->height + box->padding[BOTTOM] +
box->border[BOTTOM].width;
/* To stop the top of text getting clipped when css line-height is
* reduced, we increase the top of the descendant bbox. */
if (box->type == BOX_BLOCK && box->style != NULL &&
css_computed_overflow_y(box->style) ==
CSS_OVERFLOW_VISIBLE &&
box->object == NULL) {
css_fixed font_size = 0;
css_unit font_unit = CSS_UNIT_PT;
int text_height;
css_computed_font_size(box->style, &font_size, &font_unit);
text_height = nscss_len2px(len_ctx, font_size, font_unit,
box->style);
text_height = FIXTOINT(text_height * 3 / 4);
*desc_y0 = (*desc_y0 < -text_height) ? *desc_y0 : -text_height;
}
}
/**
* Apply changes to box descendant_[xy][01] values due to given child.
*
* \param len_ctx Length conversion context
* \param box box to update
* \param child a box, which may affect box's descendant bbox
* \param off_x offset to apply to child->x coord to treat as child of box
* \param off_y offset to apply to child->y coord to treat as child of box
*/
static void
layout_update_descendant_bbox(
const nscss_len_ctx *len_ctx,
struct box *box,
struct box *child,
int off_x,
int off_y)
{
int child_desc_x0, child_desc_y0, child_desc_x1, child_desc_y1;
/* get coordinates of child relative to box */
int child_x = child->x - off_x;
int child_y = child->y - off_y;
bool html_object = (child->object &&
content_get_type(child->object) == CONTENT_HTML);
enum css_overflow_e overflow_x = CSS_OVERFLOW_VISIBLE;
enum css_overflow_e overflow_y = CSS_OVERFLOW_VISIBLE;
if (child->style != NULL) {
overflow_x = css_computed_overflow_x(child->style);
overflow_y = css_computed_overflow_y(child->style);
}
/* Get child's border edge */
layout_get_box_bbox(len_ctx, child,
&child_desc_x0, &child_desc_y0,
&child_desc_x1, &child_desc_y1);
if (overflow_x == CSS_OVERFLOW_VISIBLE &&
html_object == false) {
/* get child's descendant bbox relative to box */
child_desc_x0 = child->descendant_x0;
child_desc_x1 = child->descendant_x1;
}
if (overflow_y == CSS_OVERFLOW_VISIBLE &&
html_object == false) {
/* get child's descendant bbox relative to box */
child_desc_y0 = child->descendant_y0;
child_desc_y1 = child->descendant_y1;
}
child_desc_x0 += child_x;
child_desc_y0 += child_y;
child_desc_x1 += child_x;
child_desc_y1 += child_y;
/* increase box's descendant bbox to contain descendants */
if (child_desc_x0 < box->descendant_x0)
box->descendant_x0 = child_desc_x0;
if (child_desc_y0 < box->descendant_y0)
box->descendant_y0 = child_desc_y0;
if (box->descendant_x1 < child_desc_x1)
box->descendant_x1 = child_desc_x1;
if (box->descendant_y1 < child_desc_y1)
box->descendant_y1 = child_desc_y1;
}
/**
* Recursively calculate the descendant_[xy][01] values for a laid-out box tree
* and inform iframe browser windows of their size and position.
*
* \param len_ctx Length conversion context
* \param box tree of boxes to update
*/
static void layout_calculate_descendant_bboxes(
const nscss_len_ctx *len_ctx,
struct box *box)
{
struct box *child;
assert(box->width != UNKNOWN_WIDTH);
assert(box->height != AUTO);
/* assert((box->width >= 0) && (box->height >= 0)); */
/* Initialise box's descendant box to border edge box */
layout_get_box_bbox(len_ctx, box,
&box->descendant_x0, &box->descendant_y0,
&box->descendant_x1, &box->descendant_y1);
/* Extend it to contain HTML contents if box is replaced */
if (box->object && content_get_type(box->object) == CONTENT_HTML) {
if (box->descendant_x1 < content_get_width(box->object))
box->descendant_x1 = content_get_width(box->object);
if (box->descendant_y1 < content_get_height(box->object))
box->descendant_y1 = content_get_height(box->object);
}
if (box->iframe != NULL) {
int x, y;
box_coords(box, &x, &y);
browser_window_set_position(box->iframe, x, y);
browser_window_set_dimensions(box->iframe,
box->width, box->height);
browser_window_reformat(box->iframe, true,
box->width, box->height);
}
if (box->type == BOX_INLINE || box->type == BOX_TEXT)
return;
if (box->type == BOX_INLINE_END) {
box = box->inline_end;
for (child = box->next; child;
child = child->next) {
if (child->type == BOX_FLOAT_LEFT ||
child->type == BOX_FLOAT_RIGHT)
continue;
layout_update_descendant_bbox(len_ctx, box, child,
box->x, box->y);
if (child == box->inline_end)
break;
}
return;
}
if (box->flags & REPLACE_DIM)
/* Box's children aren't displayed if the box is replaced */
return;
for (child = box->children; child; child = child->next) {
if (child->type == BOX_FLOAT_LEFT ||
child->type == BOX_FLOAT_RIGHT)
continue;
layout_calculate_descendant_bboxes(len_ctx, child);
if (box->style && css_computed_overflow_x(box->style) ==
CSS_OVERFLOW_HIDDEN &&
css_computed_overflow_y(box->style) ==
CSS_OVERFLOW_HIDDEN)
continue;
layout_update_descendant_bbox(len_ctx, box, child, 0, 0);
}
for (child = box->float_children; child; child = child->next_float) {
assert(child->type == BOX_FLOAT_LEFT ||
child->type == BOX_FLOAT_RIGHT);
layout_calculate_descendant_bboxes(len_ctx, child);
layout_update_descendant_bbox(len_ctx, box, child, 0, 0);
}
if (box->list_marker) {
child = box->list_marker;
layout_calculate_descendant_bboxes(len_ctx, child);
layout_update_descendant_bbox(len_ctx, box, child, 0, 0);
}
}
/* exported function documented in html/layout.h */
bool layout_document(html_content *content, int width, int height)
{
bool ret;
struct box *doc = content->layout;
const struct gui_layout_table *font_func = content->font_func;
NSLOG(layout, DEBUG, "Doing layout to %ix%i of %s",
width, height, nsurl_access(content_get_url(
&content->base)));
layout_minmax_block(doc, font_func, content);
layout_block_find_dimensions(&content->len_ctx,
width, height, 0, 0, doc);
doc->x = doc->margin[LEFT] + doc->border[LEFT].width;
doc->y = doc->margin[TOP] + doc->border[TOP].width;
width -= doc->margin[LEFT] + doc->border[LEFT].width +
doc->padding[LEFT] + doc->padding[RIGHT] +
doc->border[RIGHT].width + doc->margin[RIGHT];
if (width < 0) {
width = 0;
}
doc->width = width;
ret = layout_block_context(doc, height, content);
/* make <html> and <body> fill available height */
if (doc->y + doc->padding[TOP] + doc->height + doc->padding[BOTTOM] +
doc->border[BOTTOM].width + doc->margin[BOTTOM] <
height) {
doc->height = height - (doc->y + doc->padding[TOP] +
doc->padding[BOTTOM] +
doc->border[BOTTOM].width +
doc->margin[BOTTOM]);
if (doc->children)
doc->children->height = doc->height -
(doc->children->margin[TOP] +
doc->children->border[TOP].width +
doc->children->padding[TOP] +
doc->children->padding[BOTTOM] +
doc->children->border[BOTTOM].width +
doc->children->margin[BOTTOM]);
}
layout_lists(content, doc);
layout_position_absolute(doc, doc, 0, 0, content);
layout_position_relative(&content->len_ctx, doc, doc, 0, 0);
layout_calculate_descendant_bboxes(&content->len_ctx, doc);
return ret;
}
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