From a399aa40d960ca8414870bc9e5c4125ca0b20344 Mon Sep 17 00:00:00 2001
From: Tor Andersson <tor.andersson@artifex.com>
Date: Mon, 11 May 2015 17:15:11 +0200
Subject: epub: Handle white-space property.
Add 'break' nodes to flow list for forced line breaks.
---
source/html/html-layout.c | 235 +++++++++++++++++++++++++++++-----------------
1 file changed, 147 insertions(+), 88 deletions(-)
(limited to 'source/html')
diff --git a/source/html/html-layout.c b/source/html/html-layout.c
index da4dbe76..35c70fba 100644
--- a/source/html/html-layout.c
+++ b/source/html/html-layout.c
@@ -64,17 +64,17 @@ static fz_html_flow *add_flow(fz_context *ctx, fz_html *top, fz_css_style *style
return flow;
}
-static void add_flow_space(fz_context *ctx, fz_html *top, fz_css_style *style)
+static void add_flow_glue(fz_context *ctx, fz_html *top, fz_css_style *style, const char *text, int expand)
{
- fz_html_flow *flow;
-
- /* delete space at the beginning of the line */
- if (!top->flow_head)
- return;
+ fz_html_flow *flow = add_flow(ctx, top, style, FLOW_GLUE);
+ flow->text = (char*)text;
+ flow->expand = expand;
+}
- flow = add_flow(ctx, top, style, FLOW_GLUE);
- flow->text = " ";
- flow->broken_text = "";
+static void add_flow_break(fz_context *ctx, fz_html *top, fz_css_style *style)
+{
+ fz_html_flow *flow = add_flow(ctx, top, style, FLOW_BREAK);
+ flow->text = "";
}
static void add_flow_word(fz_context *ctx, fz_html *top, fz_css_style *style, const char *a, const char *b)
@@ -87,26 +87,78 @@ static void add_flow_word(fz_context *ctx, fz_html *top, fz_css_style *style, co
static void add_flow_image(fz_context *ctx, fz_html *top, fz_css_style *style, fz_image *img)
{
- fz_html_flow *flow = add_flow(ctx, top, style, FLOW_IMAGE);
+ fz_html_flow *flow;
+ add_flow_glue(ctx, top, style, "", 0);
+ flow = add_flow(ctx, top, style, FLOW_IMAGE);
flow->image = fz_keep_image(ctx, img);
+ add_flow_glue(ctx, top, style, "", 0);
}
static void generate_text(fz_context *ctx, fz_html *box, const char *text)
{
- fz_html *flow = box;
+ fz_html *flow;
+
+ int collapse; /* collapse sequences of white space */
+ int bsp; /* allow breaks at white space */
+ int bnl; /* force breaks at newline characters */
+
+ flow = box;
while (flow->type != BOX_FLOW)
flow = flow->up;
+ switch (box->style.white_space)
+ {
+ default:
+ case WS_NORMAL:
+ collapse = 1;
+ bsp = 1;
+ bnl = 0;
+ break;
+ case WS_PRE:
+ collapse = 0;
+ bsp = 0;
+ bnl = 1;
+ break;
+ case WS_NOWRAP:
+ collapse = 1;
+ bsp = 0;
+ bnl = 0;
+ break;
+ case WS_PRE_WRAP:
+ collapse = 0;
+ bsp = 1;
+ bnl = 1;
+ break;
+ case WS_PRE_LINE:
+ collapse = 1;
+ bsp = 1;
+ bnl = 1;
+ break;
+ }
+
while (*text)
{
- if (iswhite(*text))
+ if (bnl && (*text == '\n' || *text == '\r'))
{
- ++text;
- while (iswhite(*text))
- ++text;
- add_flow_space(ctx, flow, &box->style);
+ if (text[0] == '\r' && text[1] == '\n')
+ text += 2;
+ else
+ text += 1;
+ add_flow_break(ctx, flow, &box->style);
}
- if (*text)
+ else if (iswhite(*text))
+ {
+ const char *mark = text++;
+ if (collapse)
+ while (iswhite(*text))
+ ++text;
+ /* TODO: tabs */
+ if (bsp)
+ add_flow_glue(ctx, flow, &box->style, " ", 1);
+ else
+ add_flow_word(ctx, flow, &box->style, mark, text);
+ }
+ else
{
const char *mark = text++;
while (*text && !iswhite(*text))
@@ -294,9 +346,19 @@ static void generate_boxes(fz_context *ctx, fz_html_font_set *set, fz_archive *z
if (!strcmp(tag, "br"))
{
- box = new_box(ctx);
- fz_apply_css_style(ctx, set, &box->style, &match);
- top = insert_break_box(ctx, box, top);
+ if (top->type == BOX_INLINE)
+ {
+ fz_html *flow = top;
+ while (flow->type != BOX_FLOW)
+ flow = flow->up;
+ add_flow_break(ctx, flow, &top->style);
+ }
+ else
+ {
+ box = new_box(ctx);
+ fz_apply_css_style(ctx, set, &box->style, &match);
+ top = insert_break_box(ctx, box, top);
+ }
}
else if (!strcmp(tag, "img"))
@@ -406,11 +468,12 @@ static void measure_word(fz_context *ctx, fz_html_flow *node, float em)
node->em = em;
}
-static float measure_line(fz_html_flow *node, fz_html_flow *end, float *baseline)
+static float measure_line(fz_html_flow *node, fz_html_flow *end, float *baseline, float *line_w)
{
- float max_a = 0, max_d = 0, h = 0;
+ float max_a = 0, max_d = 0, h = node->h;
while (node != end)
{
+ *line_w += node->w;
if (node->type == FLOW_IMAGE)
{
if (node->h > max_a)
@@ -444,7 +507,7 @@ static void layout_line(fz_context *ctx, float indent, float page_w, float line_
{
fz_html_flow *it;
for (it = node; it != end; it = it->next)
- if (it->type == FLOW_GLUE)
+ if (it->type == FLOW_GLUE && it->expand)
++n;
justify = slop / n;
}
@@ -474,37 +537,12 @@ static void layout_line(fz_context *ctx, float indent, float page_w, float line_
else
node->y = y + baseline + va;
x += node->w;
- if (node->type == FLOW_GLUE)
+ if (node->type == FLOW_GLUE && node->expand)
x += justify;
node = node->next;
}
}
-static fz_html_flow *find_next_glue(fz_html_flow *node, float *w)
-{
- while (node && node->type == FLOW_GLUE)
- {
- *w += node->w;
- node = node->next;
- }
- while (node && node->type != FLOW_GLUE)
- {
- *w += node->w;
- node = node->next;
- }
- return node;
-}
-
-static fz_html_flow *find_next_word(fz_html_flow *node, float *w)
-{
- while (node && node->type == FLOW_GLUE)
- {
- *w += node->w;
- node = node->next;
- }
- return node;
-}
-
static void find_accumulated_margins(fz_context *ctx, fz_html *box, float *w, float *h)
{
while (box)
@@ -518,16 +556,25 @@ static void find_accumulated_margins(fz_context *ctx, fz_html *box, float *w, fl
}
}
+static void flush_line(fz_context *ctx, fz_html *box, float page_h, float page_w, int align, float indent, fz_html_flow *a, fz_html_flow *b)
+{
+ float avail, line_h, line_w, baseline;
+ line_w = indent;
+ avail = page_h - fmodf(box->y + box->h, page_h);
+ line_h = measure_line(a, b, &baseline, &line_w);
+ if (line_h > avail)
+ box->h += avail;
+ layout_line(ctx, indent, page_w, line_w, align, a, b, box, baseline);
+ box->h += line_h;
+}
+
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;
+ fz_html_flow *node, *line, *mark;
float line_w;
float indent;
- float avail, line_h;
- float baseline;
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;
@@ -555,52 +602,63 @@ static void layout_flow(fz_context *ctx, fz_html *box, fz_html *top, float em, f
}
}
- line_start = find_next_word(box->flow_head, &glue_w);
- line_end = NULL;
+ /* 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;
- word_w = 0;
- word_start = line_start;
- while (word_start)
+
+ while (node)
{
- word_end = find_next_glue(word_start, &word_w);
- if (line_w + word_w <= top->w)
+ switch (node->type)
{
- line_w += word_w;
- glue_w = 0;
- line_end = word_end;
- word_start = find_next_word(word_end, &glue_w);
- word_w = glue_w;
+ 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;
}
- else
+
+ if (mark && line_w + node->w > top->w)
{
- 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;
+ 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;
- word_w = 0;
+ mark = NULL;
}
- }
- /* don't justify the last line of a paragraph */
- if (align == TA_JUSTIFY)
- align = TA_LEFT;
+ if (node)
+ {
+ line_w += node->w;
+ node = node->next;
+ }
+ }
- if (line_start)
+ if (line)
{
- 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;
+ line_align = align == TA_JUSTIFY ? TA_LEFT : align;
+ flush_line(ctx, box, page_h, top->w, line_align, indent, line, NULL);
}
}
@@ -1108,6 +1166,7 @@ fz_print_html_flow(fz_context *ctx, fz_html_flow *flow)
{
case FLOW_WORD: printf("%s", flow->text); break;
case FLOW_GLUE: printf(" "); break;
+ case FLOW_BREAK: printf("\\n"); break;
case FLOW_IMAGE: printf("[image]"); break;
}
flow = flow->next;
--
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