static void measure_word(fz_context *ctx, fz_html_flow *node, float em)
{
const char *s;
int c, g;
float w;
em = fz_from_css_number(node->style->font_size, em, em);
node->x = 0;
node->y = 0;
node->h = fz_from_css_number_scale(node->style->line_height, em, em, em);
w = 0;
s = node->text;
while (*s)
{
s += fz_chartorune(&c, s);
g = fz_encode_character(ctx, node->style->font, c);
if (g)
{
w += fz_advance_glyph(ctx, node->style->font, g) * em;
}
else
{
g = fz_encode_character(ctx, node->style->fallback, c);
w += fz_advance_glyph(ctx, node->style->fallback, g) * em;
}
}
node->w = w;
node->em = em;
}
static void
htdoc_layout(fz_context *ctx, fz_document *doc_, float w, float h, float em)
{
html_document *doc = (html_document*)doc_;
if (doc->box)
{
doc->page_margin[T] = fz_from_css_number(doc->box->style.margin[T], em, em);
doc->page_margin[B] = fz_from_css_number(doc->box->style.margin[B], em, em);
doc->page_margin[L] = fz_from_css_number(doc->box->style.margin[L], em, em);
doc->page_margin[R] = fz_from_css_number(doc->box->style.margin[R], em, em);
}
doc->page_w = w - doc->page_margin[L] - doc->page_margin[R];
doc->page_h = h - doc->page_margin[T] - doc->page_margin[B];
doc->em = em;
fz_layout_html(ctx, doc->box, doc->page_w, doc->page_h, doc->em);
}
static void
epub_layout(fz_context *ctx, fz_document *doc_, float w, float h, float em)
{
epub_document *doc = (epub_document*)doc_;
epub_chapter *ch;
printf("epub: laying out chapters.\n");
for (ch = doc->spine; ch; ch = ch->next)
{
ch->em = em;
ch->page_margin[T] = fz_from_css_number(ch->box->style.margin[T], em, em);
ch->page_margin[B] = fz_from_css_number(ch->box->style.margin[B], em, em);
ch->page_margin[L] = fz_from_css_number(ch->box->style.margin[L], em, em);
ch->page_margin[R] = fz_from_css_number(ch->box->style.margin[R], em, em);
ch->page_w = w - ch->page_margin[L] - ch->page_margin[R];
ch->page_h = h - ch->page_margin[T] - ch->page_margin[B];
fz_layout_html(ctx, ch->box, ch->page_w, ch->page_h, ch->em);
}
printf("epub: done.\n");
}
static float layout_block(fz_context *ctx, fz_html *box, fz_html *top, float em, float page_h, float vertical)
{
fz_html *child;
int first;
fz_css_style *style = &box->style;
float *margin = box->margin;
float *border = box->border;
float *padding = box->padding;
em = box->em = fz_from_css_number(style->font_size, em, em);
margin[0] = fz_from_css_number(style->margin[0], em, top->w);
margin[1] = fz_from_css_number(style->margin[1], em, top->w);
margin[2] = fz_from_css_number(style->margin[2], em, top->w);
margin[3] = fz_from_css_number(style->margin[3], em, top->w);
padding[0] = fz_from_css_number(style->padding[0], em, top->w);
padding[1] = fz_from_css_number(style->padding[1], em, top->w);
padding[2] = fz_from_css_number(style->padding[2], em, top->w);
padding[3] = fz_from_css_number(style->padding[3], em, top->w);
border[0] = style->border_style[0] ? fz_from_css_number(style->border_width[0], em, top->w) : 0;
border[1] = style->border_style[1] ? fz_from_css_number(style->border_width[1], em, top->w) : 0;
border[2] = style->border_style[2] ? fz_from_css_number(style->border_width[2], em, top->w) : 0;
border[3] = style->border_style[3] ? fz_from_css_number(style->border_width[3], em, top->w) : 0;
box->x = top->x + margin[L] + border[L] + padding[L];
box->w = top->w - (margin[L] + margin[R] + border[L] + border[R] + padding[L] + padding[R]);
if (margin[T] > vertical)
margin[T] -= vertical;
else
margin[T] = 0;
if (padding[T] == 0 && border[T] == 0)
vertical += margin[T];
else
vertical = 0;
box->y = top->y + top->h + margin[T] + border[T] + padding[T];
box->h = 0;
first = 1;
for (child = box->down; child; child = child->next)
{
if (child->type == BOX_BLOCK)
{
vertical = layout_block(ctx, child, box, em, page_h, vertical);
if (first)
{
/* move collapsed parent/child top margins to parent */
margin[T] += child->margin[T];
box->y += child->margin[T];
child->margin[T] = 0;
first = 0;
}
box->h += child->h +
child->padding[T] + child->padding[B] +
child->border[T] + child->border[B] +
child->margin[T] + child->margin[B];
}
else if (child->type == BOX_BREAK)
{
box->h += fz_from_css_number_scale(style->line_height, em, em, em);
vertical = 0;
first = 0;
}
else if (child->type == BOX_FLOW)
{
layout_flow(ctx, child, box, em, page_h);
if (child->h > 0)
{
box->h += child->h;
vertical = 0;
first = 0;
}
}
}
/* reserve space for the list mark */
if (box->list_item && box->h == 0)
{
box->h += fz_from_css_number_scale(style->line_height, em, em, em);
vertical = 0;
}
if (box->h == 0)
{
if (margin[B] > vertical)
margin[B] -= vertical;
else
margin[B] = 0;
}
else
{
box->h -= vertical;
vertical = fz_max(margin[B], vertical);
margin[B] = vertical;
}
return vertical;
}
static void layout_flow(fz_context *ctx, fz_html *box, fz_html *top, float em, float page_h)
{
fz_html_flow *node, *line, *mark;
float line_w;
float indent;
int align;
int line_align;
em = fz_from_css_number(box->style.font_size, em, em);
indent = box->is_first_flow ? fz_from_css_number(top->style.text_indent, em, top->w) : 0;
align = top->style.text_align;
if (box->flow_dir == BIDI_RIGHT_TO_LEFT)
{
if (align == TA_LEFT)
align = TA_RIGHT;
else if (align == TA_RIGHT)
align = TA_LEFT;
}
box->x = top->x;
box->y = top->y + top->h;
box->w = top->w;
box->h = 0;
if (!box->flow_head)
return;
for (node = box->flow_head; node; node = node->next)
{
if (node->type == FLOW_IMAGE)
{
float w = 0, h = 0;
find_accumulated_margins(ctx, box, &w, &h);
measure_image(ctx, node, top->w - w, page_h - h);
}
else
{
measure_word(ctx, node, em);
}
}
/* start by skipping whitespace (and newline) at the beginning of tags */
node = box->flow_head;
if (node->type == FLOW_BREAK)
node = node->next;
while (node && node->type == FLOW_GLUE)
node = node->next;
mark = NULL;
line = node;
line_w = indent;
while (node)
{
switch (node->type)
{
case FLOW_WORD:
break;
case FLOW_IMAGE:
/* TODO: break before/after image */
mark = node;
break;
case FLOW_GLUE:
mark = node;
break;
case FLOW_BREAK:
line_align = align == TA_JUSTIFY ? TA_LEFT : align;
flush_line(ctx, box, page_h, top->w, line_align, indent, line, node);
indent = 0;
line = node->next;
line_w = 0;
mark = NULL;
break;
}
if (mark && line_w + node->w > top->w)
{
flush_line(ctx, box, page_h, top->w, align, indent, line, mark);
indent = 0;
node = mark;
while (node && node->type == FLOW_GLUE)
node = node->next;
line = node;
line_w = 0;
mark = NULL;
}
if (node)
{
line_w += node->w;
node = node->next;
}
}
if (line)
{
line_align = align == TA_JUSTIFY ? TA_LEFT : align;
flush_line(ctx, box, page_h, top->w, line_align, indent, line, NULL);
}
}
static void layout_block(fz_context *ctx, fz_html *box, fz_html *top, float em, float top_collapse_margin, float page_h)
{
fz_html *child;
float box_collapse_margin;
int prev_br;
float *margin = box->margin;
float *border = box->border;
float *padding = box->padding;
em = fz_from_css_number(box->style.font_size, em, em);
margin[0] = fz_from_css_number(box->style.margin[0], em, top->w);
margin[1] = fz_from_css_number(box->style.margin[1], em, top->w);
margin[2] = fz_from_css_number(box->style.margin[2], em, top->w);
margin[3] = fz_from_css_number(box->style.margin[3], em, top->w);
padding[0] = fz_from_css_number(box->style.padding[0], em, top->w);
padding[1] = fz_from_css_number(box->style.padding[1], em, top->w);
padding[2] = fz_from_css_number(box->style.padding[2], em, top->w);
padding[3] = fz_from_css_number(box->style.padding[3], em, top->w);
if (box->style.border_style)
{
border[0] = fz_from_css_number(box->style.border_width[0], em, top->w);
border[1] = fz_from_css_number(box->style.border_width[1], em, top->w);
border[2] = fz_from_css_number(box->style.border_width[2], em, top->w);
border[3] = fz_from_css_number(box->style.border_width[3], em, top->w);
}
else
border[0] = border[1] = border[2] = border[3] = 0;
if (padding[T] == 0 && border[T] == 0)
box_collapse_margin = margin[T];
else
box_collapse_margin = 0;
if (margin[T] > top_collapse_margin)
margin[T] -= top_collapse_margin;
else
margin[T] = 0;
box->x = top->x + margin[L] + border[L] + padding[L];
box->y = top->y + top->h + margin[T] + border[T] + padding[T];
box->w = top->w - (margin[L] + margin[R] + border[L] + border[R] + padding[L] + padding[R]);
box->h = 0;
prev_br = 0;
for (child = box->down; child; child = child->next)
{
if (child->type == BOX_BLOCK)
{
layout_block(ctx, child, box, em, box_collapse_margin, page_h);
box->h += child->h +
child->padding[T] + child->padding[B] +
child->border[T] + child->border[B] +
child->margin[T] + child->margin[B];
box_collapse_margin = child->margin[B];
prev_br = 0;
}
else if (child->type == BOX_BREAK)
{
/* TODO: interaction with page breaks */
if (prev_br)
box->h += fz_from_css_number_scale(box->style.line_height, em, em, em);
prev_br = 1;
}
else if (child->type == BOX_FLOW)
{
layout_flow(ctx, child, box, em, page_h);
if (child->h > 0)
{
box->h += child->h;
box_collapse_margin = 0;
prev_br = 0;
}
}
}
if (padding[B] == 0 && border[B] == 0)
{
if (margin[B] > 0)
{
box->h -= box_collapse_margin;
if (margin[B] < box_collapse_margin)
margin[B] = box_collapse_margin;
}
}
}
static void layout_flow(fz_context *ctx, fz_html *box, fz_html *top, float em, float page_h)
{
fz_html_flow *node, *line_start, *word_start, *word_end, *line_end;
float glue_w;
float word_w;
float line_w;
float indent;
float avail, line_h;
float baseline;
int align;
em = fz_from_css_number(box->style.font_size, em, em);
indent = box->is_first_flow ? fz_from_css_number(top->style.text_indent, em, top->w) : 0;
align = top->style.text_align;
box->x = top->x;
box->y = top->y + top->h;
box->w = top->w;
box->h = 0;
if (!box->flow_head)
return;
for (node = box->flow_head; node; node = node->next)
if (node->type == FLOW_IMAGE)
measure_image(ctx, node, top->w, page_h);
else
measure_word(ctx, node, em);
line_start = find_next_word(box->flow_head, &glue_w);
line_end = NULL;
line_w = indent;
word_w = 0;
word_start = line_start;
while (word_start)
{
word_end = find_next_glue(word_start, &word_w);
if (line_w + word_w <= top->w)
{
line_w += word_w;
glue_w = 0;
line_end = word_end;
word_start = find_next_word(word_end, &glue_w);
word_w = glue_w;
}
else
{
avail = page_h - fmodf(box->y + box->h, page_h);
line_h = measure_line(line_start, line_end, &baseline);
if (line_h > avail)
box->h += avail;
layout_line(ctx, indent, top->w, line_w, align, line_start, line_end, box, baseline);
box->h += line_h;
word_start = find_next_word(line_end, &glue_w);
line_start = word_start;
line_end = NULL;
indent = 0;
line_w = 0;
word_w = 0;
}
}
/* don't justify the last line of a paragraph */
if (align == TA_JUSTIFY)
align = TA_LEFT;
if (line_start)
{
avail = page_h - fmodf(box->y + box->h, page_h);
line_h = measure_line(line_start, line_end, &baseline);
if (line_h > avail)
box->h += avail;
layout_line(ctx, indent, top->w, line_w, align, line_start, line_end, box, baseline);
box->h += line_h;
}
}
static fz_css_color
color_from_value(fz_css_value *value, fz_css_color initial)
{
if (!value)
return initial;
if (value->type == CSS_HASH)
{
int r, g, b;
size_t n = strlen(value->data);
if (n == 3)
{
r = tohex(value->data[0]) * 16 + tohex(value->data[0]);
g = tohex(value->data[1]) * 16 + tohex(value->data[1]);
b = tohex(value->data[2]) * 16 + tohex(value->data[2]);
}
else if (n == 6)
{
r = tohex(value->data[0]) * 16 + tohex(value->data[1]);
g = tohex(value->data[2]) * 16 + tohex(value->data[3]);
b = tohex(value->data[4]) * 16 + tohex(value->data[5]);
}
else
{
r = g = b = 0;
}
return make_color(r, g, b, 255);
}
if (value->type == '(' && !strcmp(value->data, "rgb"))
{
fz_css_value *vr, *vg, *vb;
int r, g, b;
vr = value->args;
vg = vr && vr->next ? vr->next->next : NULL; /* skip the ',' nodes */
vb = vg && vg->next ? vg->next->next : NULL; /* skip the ',' nodes */
r = fz_from_css_number(number_from_value(vr, 0, N_NUMBER), 255, 255);
g = fz_from_css_number(number_from_value(vg, 0, N_NUMBER), 255, 255);
b = fz_from_css_number(number_from_value(vb, 0, N_NUMBER), 255, 255);
return make_color(r, g, b, 255);
}
if (value->type == CSS_KEYWORD)
{
if (!strcmp(value->data, "transparent"))
return make_color(0, 0, 0, 0);
if (!strcmp(value->data, "maroon"))
return make_color(0x80, 0x00, 0x00, 255);
if (!strcmp(value->data, "red"))
return make_color(0xFF, 0x00, 0x00, 255);
if (!strcmp(value->data, "orange"))
return make_color(0xFF, 0xA5, 0x00, 255);
if (!strcmp(value->data, "yellow"))
return make_color(0xFF, 0xFF, 0x00, 255);
if (!strcmp(value->data, "olive"))
return make_color(0x80, 0x80, 0x00, 255);
if (!strcmp(value->data, "purple"))
return make_color(0x80, 0x00, 0x80, 255);
if (!strcmp(value->data, "fuchsia"))
return make_color(0xFF, 0x00, 0xFF, 255);
if (!strcmp(value->data, "white"))
return make_color(0xFF, 0xFF, 0xFF, 255);
if (!strcmp(value->data, "lime"))
return make_color(0x00, 0xFF, 0x00, 255);
if (!strcmp(value->data, "green"))
return make_color(0x00, 0x80, 0x00, 255);
if (!strcmp(value->data, "navy"))
return make_color(0x00, 0x00, 0x80, 255);
if (!strcmp(value->data, "blue"))
return make_color(0x00, 0x00, 0xFF, 255);
if (!strcmp(value->data, "aqua"))
return make_color(0x00, 0xFF, 0xFF, 255);
if (!strcmp(value->data, "teal"))
return make_color(0x00, 0x80, 0x80, 255);
if (!strcmp(value->data, "black"))
return make_color(0x00, 0x00, 0x00, 255);
if (!strcmp(value->data, "silver"))
return make_color(0xC0, 0xC0, 0xC0, 255);
if (!strcmp(value->data, "gray"))
return make_color(0x80, 0x80, 0x80, 255);
return make_color(0, 0, 0, 255);
}
return initial;
}