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netsurf/render/layout.c
James Bursa f185bb4d0d [project @ 2003-09-09 21:43:44 by bursa] 
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svn path=/import/netsurf/; revision=278
2003-09-09 21:43:44 +00:00

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/*
* This file is part of NetSurf, http://netsurf.sourceforge.net/
* Licensed under the GNU General Public License,
* http://www.opensource.org/licenses/gpl-license
* Copyright 2003 James Bursa <bursa@users.sourceforge.net>
* Copyright 2003 Phil Mellor <monkeyson@users.sourceforge.net>
*/
#include <assert.h>
#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libxml/HTMLparser.h"
#include "netsurf/content/content.h"
#include "netsurf/css/css.h"
#ifdef riscos
#include "netsurf/desktop/gui.h"
#endif
#include "netsurf/render/box.h"
#include "netsurf/render/font.h"
#include "netsurf/render/layout.h"
#define NDEBUG
#include "netsurf/utils/log.h"
#include "netsurf/utils/utils.h"
/**
* internal functions
*/
static void layout_node(struct box * box, unsigned long width, struct box * cont,
unsigned long cx, unsigned long cy);
static void layout_block(struct box * box, unsigned long width, struct box * cont,
unsigned long cx, unsigned long cy);
static unsigned long layout_block_children(struct box * box, unsigned long width, struct box * cont,
unsigned long cx, unsigned long cy);
static void find_sides(struct box * fl, unsigned long y0, unsigned long y1,
unsigned long * x0, unsigned long * x1, struct box ** left, struct box ** right);
static void layout_inline_container(struct box * box, unsigned long width, struct box * cont,
unsigned long cx, unsigned long cy);
static signed long line_height(struct css_style * style);
static struct box * layout_line(struct box * first, unsigned long width, unsigned long * y,
unsigned long cy, struct box * cont);
static void place_float_below(struct box * c, unsigned long width, unsigned long y, struct box * cont);
static void layout_table(struct box * box, unsigned long width, struct box * cont,
unsigned long cx, unsigned long cy);
static void calculate_widths(struct box *box);
static void calculate_inline_container_widths(struct box *box);
static void calculate_table_widths(struct box *table);
/**
* layout algorithm
*/
/**
* layout_document -- calculate positions of boxes in a document
*
* doc root of document box tree
* width page width
*/
void layout_document(struct box * doc, unsigned long width)
{
struct box *box;
doc->float_children = 0;
layout_node(doc, width, doc, 0, 0);
for (box = doc->float_children; box != 0; box = box->next_float)
if (doc->height < box->y + box->height)
doc->height = box->y + box->height;
}
void layout_node(struct box * box, unsigned long width, struct box * cont,
unsigned long cx, unsigned long cy)
{
LOG(("box %p, width %lu, cont %p, cx %lu, cy %lu", box, width, cont, cx, cy));
gui_multitask();
switch (box->type) {
case BOX_BLOCK:
layout_block(box, width, cont, cx, cy);
break;
case BOX_INLINE_CONTAINER:
layout_inline_container(box, width, cont, cx, cy);
break;
case BOX_TABLE:
layout_table(box, width, cont, cx, cy);
break;
default:
assert(0);
}
}
/* TODO: change this to use style sheets */
int gadget_width(struct gui_gadget* gadget)
{
struct formoption* current;
int max;
/* should use wimp_textop via a gui wrapper for these */
switch (gadget->type)
{
case GADGET_CHECKBOX:
case GADGET_RADIO:
return 22;
case GADGET_TEXTBOX:
return gadget->data.textbox.size * 8;
case GADGET_PASSWORD:
return gadget->data.password.size * 8;
case GADGET_ACTIONBUTTON:
return strlen(gadget->data.actionbutt.label) * 8 + 16;
case GADGET_IMAGE:
return gadget->data.image.width;
case GADGET_SELECT:
current = gadget->data.select.items;
max = 32;
while (current != NULL)
{
if (strlen(current->text) * 8 + 16 > max)
max = strlen(current->text) * 8 + 16;
current = current->next;
}
return max;
case GADGET_TEXTAREA:
return gadget->data.textarea.cols * 8 + 8;
default:
assert(0);
}
return 0;
}
int gadget_height(struct gui_gadget* gadget)
{
switch (gadget->type)
{
case GADGET_CHECKBOX:
case GADGET_RADIO:
return 22;
case GADGET_TEXTBOX:
return 28;
case GADGET_PASSWORD:
return 28;
case GADGET_ACTIONBUTTON:
return 28;
case GADGET_IMAGE:
return gadget->data.image.height;
case GADGET_SELECT:
return 28; // * gadget->data.select.size;
case GADGET_TEXTAREA:
return gadget->data.textarea.rows * 16 + 8;
default:
assert(0);
}
return 0;
}
/**
* layout_block -- position block and recursively layout children
*
* box block box to layout
* width horizontal space available
* cont ancestor box which defines horizontal space, for inlines
* cx, cy box position relative to cont
*/
void layout_block(struct box * box, unsigned long width, struct box * cont,
unsigned long cx, unsigned long cy)
{
struct css_style * style = box->style;
assert(box->type == BOX_BLOCK);
assert(style != 0);
LOG(("box %p, width %lu, cont %p, cx %lu, cy %lu", box, width, cont, cx, cy));
switch (style->width.width) {
case CSS_WIDTH_LENGTH:
box->width = len(&style->width.value.length, style);
break;
case CSS_WIDTH_PERCENT:
box->width = width * style->width.value.percent / 100;
break;
case CSS_WIDTH_AUTO:
default:
/* take all available width */
box->width = width;
break;
}
box->height = layout_block_children(box, box->width, cont, cx, cy);
switch (style->height.height) {
case CSS_HEIGHT_LENGTH:
box->height = len(&style->height.length, style);
break;
case CSS_HEIGHT_AUTO:
default:
/* use the computed height */
break;
}
}
/**
* layout_block_children -- recursively layout block children
*
* (as above)
*/
unsigned long layout_block_children(struct box * box, unsigned long width, struct box * cont,
unsigned long cx, unsigned long cy)
{
struct box * c;
unsigned long y = 0;
assert(box->type == BOX_BLOCK || box->type == BOX_FLOAT_LEFT ||
box->type == BOX_FLOAT_RIGHT || box->type == BOX_TABLE_CELL);
LOG(("box %p, width %lu, cont %p, cx %lu, cy %lu", box, width, cont, cx, cy));
for (c = box->children; c != 0; c = c->next) {
if (c->style != 0 && c->style->clear != CSS_CLEAR_NONE) {
unsigned long x0, x1;
struct box * left, * right;
do {
x0 = cx;
x1 = cx + width;
find_sides(cont->float_children, cy + y, cy + y,
&x0, &x1, &left, &right);
if ((c->style->clear == CSS_CLEAR_LEFT || c->style->clear == CSS_CLEAR_BOTH)
&& left != 0)
y = left->y + left->height - cy + 1;
if ((c->style->clear == CSS_CLEAR_RIGHT || c->style->clear == CSS_CLEAR_BOTH)
&& right != 0)
if (cy + y < right->y + right->height + 1)
y = right->y + right->height - cy + 1;
} while ((c->style->clear == CSS_CLEAR_LEFT && left != 0) ||
(c->style->clear == CSS_CLEAR_RIGHT && right != 0) ||
(c->style->clear == CSS_CLEAR_BOTH && (left != 0 || right != 0)));
}
c->x = 0;
c->y = y;
layout_node(c, width, cont, cx, cy + y);
y = c->y + c->height;
if (box->width < c->width)
box->width = c->width;
}
return y;
}
/**
* find_sides -- find left and right margins
*
* fl first float in float list
* y0, y1 y range to search
* x1, x1 margins updated
* left float on left if present
* right float on right if present
*/
void find_sides(struct box * fl, unsigned long y0, unsigned long y1,
unsigned long * x0, unsigned long * x1, struct box ** left, struct box ** right)
{
/* fprintf(stderr, "find_sides: y0 %li y1 %li x0 %li x1 %li => ", y0, y1, *x0, *x1); */
*left = *right = 0;
for (; fl; fl = fl->next_float) {
if (y0 <= fl->y + fl->height && fl->y <= y1) {
if (fl->type == BOX_FLOAT_LEFT && *x0 < fl->x + fl->width) {
*x0 = fl->x + fl->width;
*left = fl;
} else if (fl->type == BOX_FLOAT_RIGHT && fl->x < *x1) {
*x1 = fl->x;
*right = fl;
}
}
}
/* fprintf(stderr, "x0 %li x1 %li left 0x%x right 0x%x\n", *x0, *x1, *left, *right); */
}
/**
* layout_inline_container -- layout lines of text or inline boxes with floats
*
* box inline container
* width horizontal space available
* cont ancestor box which defines horizontal space, for inlines
* cx, cy box position relative to cont
*/
void layout_inline_container(struct box * box, unsigned long width, struct box * cont,
unsigned long cx, unsigned long cy)
{
struct box * c;
unsigned long y = 0;
assert(box->type == BOX_INLINE_CONTAINER);
LOG(("box %p, width %lu, cont %p, cx %lu, cy %lu", box, width, cont, cx, cy));
for (c = box->children; c != 0; ) {
c = layout_line(c, width, &y, cy + y, cont);
}
box->width = width;
box->height = y;
}
signed long line_height(struct css_style * style)
{
assert(style != 0);
assert(style->line_height.size == CSS_LINE_HEIGHT_LENGTH ||
style->line_height.size == CSS_LINE_HEIGHT_ABSOLUTE ||
style->line_height.size == CSS_LINE_HEIGHT_PERCENT);
if (style->line_height.size == CSS_LINE_HEIGHT_LENGTH)
return len(&style->line_height.value.length, style);
else if (style->line_height.size == CSS_LINE_HEIGHT_ABSOLUTE)
return style->line_height.value.absolute * len(&style->font_size.value.length, 0);
else
return style->line_height.value.percent * len(&style->font_size.value.length, 0) / 100.0;
}
struct box * layout_line(struct box * first, unsigned long width, unsigned long * y,
unsigned long cy, struct box * cont)
{
unsigned long height;
unsigned long x0 = 0;
unsigned long x1 = width;
unsigned long x, h, x_previous;
struct box * left;
struct box * right;
struct box * b;
struct box * c;
struct box * d;
struct box * fl;
int move_y = 0;
unsigned int space_before = 0, space_after = 0;
/* fprintf(stderr, "layout_line: '%.*s' %li %li %li\n", first->length, first->text, width, *y, cy); */
/* find sides at top of line */
find_sides(cont->float_children, cy, cy, &x0, &x1, &left, &right);
/* get minimum line height from containing block */
height = line_height(first->parent->parent->style);
/* pass 1: find height of line assuming sides at top of line */
for (x = 0, b = first; x < x1 - x0 && b != 0; b = b->next) {
assert(b->type == BOX_INLINE || b->type == BOX_FLOAT_LEFT || b->type == BOX_FLOAT_RIGHT);
if (b->type == BOX_INLINE) {
if (b->object && b->style && b->style->height.height == CSS_HEIGHT_LENGTH)
h = len(&b->style->height.length, b->style);
else if (b->text)
h = line_height(b->style ? b->style : b->parent->parent->style);
else if (b->gadget != 0)
h = gadget_height(b->gadget);
else
h = 0;
b->height = h;
if (h > height) height = h;
if (b->object && b->style && b->style->width.width == CSS_WIDTH_LENGTH)
b->width = len(&b->style->width.value.length, b->style);
else if (b->object && b->style && b->style->width.width == CSS_WIDTH_PERCENT)
b->width = width * b->style->width.value.percent / 100;
else if (b->text) {
if (b->width == UNKNOWN_WIDTH)
b->width = font_width(b->font, b->text, b->length);
} else if (b->gadget != 0)
b->width = gadget_width(b->gadget);
else
b->width = 0;
if (b->text != 0)
x += b->width + b->space ? b->font->space_width : 0;
else
x += b->width;
}
}
/* find new sides using this height */
x0 = 0;
x1 = width;
find_sides(cont->float_children, cy, cy + height, &x0, &x1, &left, &right);
/* pass 2: place boxes in line */
for (x = x_previous = 0, b = first; x <= x1 - x0 && b != 0; b = b->next) {
if (b->type == BOX_INLINE) {
x_previous = x;
x += space_after;
b->x = x;
x += b->width;
space_before = space_after;
if (b->object)
space_after = 0;
else if (b->text)
space_after = b->space ? b->font->space_width : 0;
else
space_after = 0;
c = b;
move_y = 1;
/* fprintf(stderr, "layout_line: '%.*s' %li %li\n", b->length, b->text, xp, x); */
} else {
/* float */
unsigned long w = width;
d = b->children;
d->float_children = 0;
/* css_dump_style(b->style); */
if (d->style->width.width == CSS_WIDTH_AUTO) {
/* either a float with no width specified (contravenes standard)
* or we don't know the width for some reason, eg. image not loaded */
calculate_widths(b);
if (d->max_width < width)
w = d->max_width;
else
w = d->min_width;
}
layout_node(d, w, d, 0, 0);
/* increase height to contain any floats inside */
for (fl = d->float_children; fl != 0; fl = fl->next_float)
if (d->height < fl->y + fl->height)
d->height = fl->y + fl->height;
d->x = d->y = 0;
b->width = d->width;
b->height = d->height;
if (b->width < (x1 - x0) - x || (left == 0 && right == 0 && x == 0)) {
/* fits next to this line, or this line is empty with no floats */
if (b->type == BOX_FLOAT_LEFT) {
b->x = x0;
x0 += b->width;
left = b;
} else {
b->x = x1 - b->width;
x1 -= b->width;
right = b;
}
b->y = cy;
/* fprintf(stderr, "layout_line: float fits %li %li, edges %li %li\n", */
/* b->x, b->y, x0, x1); */
} else {
/* doesn't fit: place below */
place_float_below(b, width, cy + height + 1, cont);
/* fprintf(stderr, "layout_line: float doesn't fit %li %li\n", b->x, b->y); */
}
b->next_float = cont->float_children;
cont->float_children = b;
}
}
if (x1 - x0 < x) {
/* the last box went over the end */
char * space = 0;
unsigned int w;
struct box * c2;
x = x_previous;
if (!c->object && c->text)
space = strchr(c->text, ' ');
if (space != 0 && c->length <= (unsigned int) (space - c->text))
/* space after end of string */
space = 0;
/* space != 0 implies c->text != 0 */
if (space == 0)
w = c->width;
else
w = font_width(c->font, c->text, (unsigned int) (space - c->text));
if (x1 - x0 <= x + space_before + w && left == 0 && right == 0 && c == first) {
/* first word doesn't fit, but no floats and first on line so force in */
if (space == 0) {
/* only one word in this box or not text */
b = c->next;
} else {
/* cut off first word for this line */
c2 = memcpy(xcalloc(1, sizeof(struct box)), c, sizeof(struct box));
c2->text = xstrdup(space + 1);
c2->length = c->length - ((space + 1) - c->text);
c2->width = UNKNOWN_WIDTH;
c2->clone = 1;
c->length = space - c->text;
c->width = w;
c->space = 1;
c2->next = c->next;
c->next = c2;
b = c2;
}
x += space_before + w;
/* fprintf(stderr, "layout_line: overflow, forcing\n"); */
} else if (x1 - x0 <= x + space_before + w) {
/* first word doesn't fit, but full width not available so leave for later */
b = c;
/* fprintf(stderr, "layout_line: overflow, leaving\n"); */
} else {
/* fit as many words as possible */
assert(space != 0);
space = font_split(c->font, c->text, c->length,
x1 - x0 - x - space_before, &w);
LOG(("'%.*s' %lu %u (%c) %u", (int) c->length, c->text,
(unsigned long) (x1 - x0), space - c->text, *space, w));
assert(space != c->text);
c2 = memcpy(xcalloc(1, sizeof(struct box)), c, sizeof(struct box));
c2->text = xstrdup(space + 1);
c2->length = c->length - ((space + 1) - c->text);
c2->width = UNKNOWN_WIDTH;
c2->clone = 1;
c->length = space - c->text;
c->width = w;
c->space = 1;
c2->next = c->next;
c->next = c2;
b = c2;
x += space_before + w;
/* fprintf(stderr, "layout_line: overflow, fit\n"); */
}
move_y = 1;
}
/* set positions */
switch (first->parent->parent->style->text_align) {
case CSS_TEXT_ALIGN_RIGHT: x0 = x1 - x; break;
case CSS_TEXT_ALIGN_CENTER: x0 = (x0 + (x1 - x)) / 2; break;
default: break; /* leave on left */
}
for (d = first; d != b; d = d->next) {
if (d->type == BOX_INLINE) {
d->x += x0;
d->y = *y;
}
}
if (move_y) *y += height + 1;
return b;
}
void place_float_below(struct box * c, unsigned long width, unsigned long y, struct box * cont)
{
unsigned long x0, x1, yy = y;
struct box * left;
struct box * right;
do {
y = yy;
x0 = 0;
x1 = width;
find_sides(cont->float_children, y, y, &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) + 1;
} else if (left == 0 && right != 0) {
yy = right->y + right->height + 1;
} else if (left != 0 && right == 0) {
yy = left->y + left->height + 1;
}
} 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;
}
/**
* layout a table
*/
void layout_table(struct box * table, unsigned long width, struct box * cont,
unsigned long cx, unsigned long cy)
{
unsigned int columns = table->columns; /* total columns */
unsigned long table_width, max_width = 0;
unsigned long x;
unsigned long table_height = 0;
unsigned long *xs; /* array of column x positions */
unsigned int i;
unsigned int *row_span, *excess_y, min;
unsigned long x0;
unsigned long x1;
unsigned long cy1;
struct box *left;
struct box *right;
struct box *c;
struct box *row;
struct box *row_group;
struct box **row_span_cell;
struct box *fl;
assert(table->type == BOX_TABLE);
assert(table->style != 0);
assert(table->children != 0 && table->children->children != 0);
LOG(("table %p, width %lu, cont %p, cx %lu, cy %lu", table, width, cont, cx, cy));
calculate_table_widths(table);
/* find table width */
switch (table->style->width.width) {
case CSS_WIDTH_LENGTH:
table_width = len(&table->style->width.value.length, table->style);
break;
case CSS_WIDTH_PERCENT:
table_width = width * table->style->width.value.percent / 100;
break;
case CSS_WIDTH_AUTO:
default:
table_width = width;
break;
}
LOG(("width %lu, min %lu, max %lu", table_width, table->min_width, table->max_width));
/* percentage width columns give an upper bound if possible */
for (i = 0; i < table->columns; i++) {
if (table->col[i].type == COLUMN_WIDTH_PERCENT) {
table->col[i].max = width * table->col[i].width / 100;
if (table->col[i].max < table->col[i].min)
table->col[i].max = table->col[i].min;
}
max_width += table->col[i].max;
}
if (table_width <= table->min_width) {
/* not enough space: minimise column widths */
for (i = 0; i < table->columns; i++) {
table->col[i].width = table->col[i].min;
}
table_width = table->min_width;
} else if (max_width <= table_width) {
/* more space than maximum width */
if (table->style->width.width == CSS_WIDTH_AUTO) {
/* for auto-width tables, make columns max width */
for (i = 0; i < table->columns; i++) {
table->col[i].width = table->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 != table->columns; i++)
if (table->col[i].type != COLUMN_WIDTH_FIXED)
flexible_columns++;
if (flexible_columns == 0) {
unsigned long extra = (table_width - max_width) / table->columns;
for (i = 0; i != table->columns; i++)
table->col[i].width = table->col[i].max + extra;
} else {
unsigned long extra = (table_width - max_width) / flexible_columns;
for (i = 0; i != table->columns; i++)
if (table->col[i].type != COLUMN_WIDTH_FIXED)
table->col[i].width = table->col[i].max + extra;
}
}
} else {
/* space between min and max: fill it exactly */
float scale = (float) (table_width - table->min_width) /
(float) (max_width - table->min_width);
/* fprintf(stderr, "filling, scale %f\n", scale); */
for (i = 0; i < table->columns; i++) {
table->col[i].width = table->col[i].min +
(table->col[i].max - table->col[i].min) * scale;
}
}
xs = xcalloc(columns + 1, sizeof(*xs));
row_span = xcalloc(columns, sizeof(row_span[0]));
excess_y = xcalloc(columns, sizeof(excess_y[0]));
row_span_cell = xcalloc(columns, sizeof(row_span_cell[0]));
xs[0] = x = 0;
for (i = 0; i != columns; i++) {
x += table->col[i].width;
xs[i + 1] = x;
row_span[i] = 0;
excess_y[i] = 0;
row_span_cell[i] = 0;
}
/* position cells */
for (row_group = table->children; row_group != 0; row_group = row_group->next) {
unsigned long row_group_height = 0;
for (row = row_group->children; row != 0; row = row->next) {
unsigned long row_height = 0;
for (c = row->children; c != 0; c = c->next) {
assert(c->style != 0);
c->width = xs[c->start_column + c->columns] - xs[c->start_column];
c->float_children = 0;
c->height = layout_block_children(c, c->width, c, 0, 0);
if (c->style->height.height == CSS_HEIGHT_LENGTH) {
/* some sites use height="1" or similar to attempt
* to make cells as small as possible, so treat
* it as a minimum */
unsigned long h = len(&c->style->height.length, c->style);
if (c->height < h)
c->height = h;
}
/* increase height to contain any floats inside */
for (fl = c->float_children; fl != 0; fl = fl->next_float)
if (c->height < fl->y + fl->height)
c->height = fl->y + fl->height;
c->x = xs[c->start_column];
c->y = 0;
for (i = 0; i != c->columns; i++) {
row_span[c->start_column + i] = c->rows;
excess_y[c->start_column + i] = c->height;
row_span_cell[c->start_column + i] = 0;
}
row_span_cell[c->start_column] = c;
c->height = 0;
}
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]->height += row_height;
}
row->x = 0;
row->y = row_group_height;
row->width = table_width;
row->height = row_height;
row_group_height += row_height;
}
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;
}
xfree(row_span_cell);
xfree(excess_y);
xfree(row_span);
xfree(xs);
table->width = table_width;
table->height = table_height;
/* find sides and move table down if it doesn't fit in available width */
cy1 = cy;
while (1) {
x0 = 0;
x1 = width;
find_sides(cont->float_children, cy1, cy1 + table_height,
&x0, &x1, &left, &right);
if (table_width <= x1 - x0)
break;
if (left == 0 && right == 0)
break;
/* move down to the next place where the space may increase */
if (left == 0)
cy1 = right->y + right->height + 1;
else if (right == 0)
cy1 = left->y + left->height + 1;
else if (left->y + left->height < right->y + right->height)
cy1 = left->y + left->height + 1;
else
cy1 = right->y + right->height + 1;
}
table->x = x0;
table->y += cy1 - cy;
}
/**
* find min, max widths required by boxes
*/
void calculate_widths(struct box *box)
{
struct box *child;
unsigned long min = 0, max = 0, width;
assert(box->type == BOX_TABLE_CELL ||
box->type == BOX_BLOCK ||
box->type == BOX_FLOAT_LEFT || box->type == BOX_FLOAT_RIGHT);
/* check if the widths have already been calculated */
if (box->max_width != UNKNOWN_MAX_WIDTH)
return;
for (child = box->children; child != 0; child = child->next) {
switch (child->type) {
case BOX_BLOCK:
case BOX_TABLE:
if (child->style->width.width == CSS_WIDTH_LENGTH) {
width = len(&child->style->width.value.length,
child->style);
if (min < width) min = width;
if (max < width) max = width;
} else {
if (child->type == BOX_TABLE)
calculate_table_widths(child);
else
calculate_widths(child);
if (min < child->min_width) min = child->min_width;
if (max < child->max_width) max = child->max_width;
}
break;
case BOX_INLINE_CONTAINER:
calculate_inline_container_widths(child);
if (min < child->min_width) min = child->min_width;
if (max < child->max_width) max = child->max_width;
break;
default:
break;
}
}
box->min_width = min;
box->max_width = max;
}
void calculate_inline_container_widths(struct box *box)
{
struct box *child;
unsigned long min = 0, max = 0, width;
char *word, *space;
for (child = box->children; child != 0; child = child->next) {
switch (child->type) {
case BOX_INLINE:
if (child->object) {
if (child->style->width.width == CSS_WIDTH_LENGTH) {
child->width = len(&child->style->width.value.length,
child->style);
max += child->width;
if (min < child->width)
min = child->width;
}
} else if (child->text) {
/* max = all one line */
child->width = font_width(child->font,
child->text, child->length);
max += child->width;
/* TODO: add spaces */
/* min = widest word */
for (word = child->text,
space = strchr(child->text, ' ');
space != 0;
word = space + 1,
space = strchr(word, ' ')) {
width = font_width(child->font, word,
(unsigned int) (space - word));
if (min < width) min = width;
}
width = font_width(child->font, word, strlen(word));
if (min < width) min = width;
} else if (child->gadget) {
child->width = gadget_width(child->gadget);
max += child->width;
if (min < child->width)
min = child->width;
}
break;
case BOX_FLOAT_LEFT:
case BOX_FLOAT_RIGHT:
if (child->style != 0 &&
child->style->width.width == CSS_WIDTH_LENGTH) {
width = len(&child->style->width.value.length,
child->style);
if (min < width) min = width;
if (max < width) max = width;
} else {
calculate_widths(child);
if (min < child->min_width) min = child->min_width;
if (max < child->max_width) max = child->max_width;
}
break;
default:
assert(0);
}
}
box->min_width = min;
box->max_width = max;
}
void calculate_table_widths(struct box *table)
{
unsigned int i, pass;
struct box *row_group, *row, *cell;
unsigned long width, min_width = 0, max_width = 0;
struct column *col;
LOG(("table %p, columns %u", table, table->columns));
/* check if the widths have already been calculated */
if (table->max_width != UNKNOWN_MAX_WIDTH)
return;
if (table->col)
col = table->col;
else
col = xcalloc(table->columns, sizeof(*col));
assert(table->children != 0 && table->children->children != 0);
for (pass = 0; pass != 2; pass++) {
for (row_group = table->children; row_group != 0; row_group = row_group->next) {
assert(row_group->type == BOX_TABLE_ROW_GROUP);
for (row = row_group->children; row != 0; row = row->next) {
assert(row->type == BOX_TABLE_ROW);
for (cell = row->children; cell != 0; cell = cell->next) {
unsigned int j, flexible_columns = 0;
unsigned long min = 0, max = 0, extra;
/* consider cells with colspan 1 in 1st pass, rest
* in 2nd pass */
if ((pass == 0 && cell->columns != 1) ||
(pass == 1 && cell->columns == 1))
continue;
assert(cell->type == BOX_TABLE_CELL);
assert(cell->style != 0);
calculate_widths(cell);
i = cell->start_column;
/* find min, max width so far of spanned columns */
for (j = 0; j != cell->columns; j++) {
min += col[i + j].min;
max += col[i + j].max;
}
/* use specified width if colspan == 1 */
if (col[i].type != COLUMN_WIDTH_FIXED &&
cell->style->width.width == CSS_WIDTH_LENGTH &&
cell->columns == 1) {
width = len(&cell->style->width.value.length,
cell->style);
if (width < cell->min_width)
width = cell->min_width;
col[i].type = COLUMN_WIDTH_FIXED;
if (min < width)
/* specified width greater than min => use it */
col[i].width = col[i].max = max = col[i].min = min = width;
else
/* specified width not big enough => use min */
col[i].width = col[i].max = max = min;
continue;
}
else if (col[i].type == COLUMN_WIDTH_UNKNOWN) {
if (cell->style->width.width == CSS_WIDTH_PERCENT) {
col[i].type = COLUMN_WIDTH_PERCENT;
col[i].width = cell->style->width.value.percent;
} else if (cell->style->width.width == CSS_WIDTH_AUTO) {
col[i].type = COLUMN_WIDTH_AUTO;
}
}
for (j = 0; j != cell->columns; j++) {
if (col[i + j].type != COLUMN_WIDTH_FIXED)
flexible_columns++;
}
/* distribute extra width to spanned columns */
if (min < cell->min_width) {
if (flexible_columns == 0) {
extra = 1 + (cell->min_width - min)
/ cell->columns;
max = 0;
for (j = 0; j != cell->columns; j++) {
col[i + j].min += extra;
if (col[i + j].width < col[i + j].min)
col[i + j].width = col[i + j].min;
if (col[i + j].max < col[i + j].min)
col[i + j].max = col[i + j].min;
max += col[i + j].max;
}
} else {
extra = 1 + (cell->min_width - min)
/ flexible_columns;
max = 0;
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;
max += col[i + j].max;
}
}
}
}
if (max < cell->max_width) {
if (flexible_columns == 0) {
extra = 1 + (cell->max_width - max)
/ cell->columns;
for (j = 0; j != cell->columns; j++)
col[i + j].max += extra;
} else {
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++) {
LOG(("col %u, type %i, min %lu, max %lu, width %lu",
i, col[i].type, col[i].min, col[i].max, col[i].width));
assert(col[i].min <= col[i].max);
min_width += col[i].min;
max_width += col[i].max;
}
table->min_width = min_width;
table->max_width = max_width;
table->col = col;
LOG(("min_width %lu, max_width %lu", min_width, max_width));
}
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