renderer.c

一个很有名的浏览器

	if (tag) {
		tag->x = x;
		tag->y = y;
		memcpy(tag->name, t, tag_len + 1);
		add_to_list(document->tags, tag);
		if ((void *) renderer_context.last_tag_for_newline == &document->tags)
			renderer_context.last_tag_for_newline = tag;
	}
}


static void
put_chars_conv(struct part *part, unsigned char *chars, int charslen)
{
	assert(part && chars && charslen);
	if_assert_failed return;

	if (format.style.attr & AT_GRAPHICS) {
		put_chars(part, chars, charslen);
		return;
	}

	convert_string(renderer_context.convert_table, chars, charslen,
	               CSM_DEFAULT, NULL, (void (*)(void *, unsigned char *, int)) put_chars, part);
}

static inline void
put_link_number(struct part *part)
{
	unsigned char s[64];
	unsigned char *fl = format.link;
	unsigned char *ft = format.target;
	unsigned char *fi = format.image;
	struct form_control *ff = format.form;
	int slen = 0;

	format.link = format.target = format.image = NULL;
	format.form = NULL;

	s[slen++] = '[';
	ulongcat(s, &slen, part->link_num, sizeof(s) - 3, 0);
	s[slen++] = ']';
	s[slen] = '\0';

	renderer_context.nosearchable = 1;
	put_chars(part, s, slen);
	renderer_context.nosearchable = 0;

	if (ff && ff->type == FC_TEXTAREA) line_break(part);

	/* We might have ended up on a new line after the line breaking
	 * or putting the link number chars. */
	if (part->cx == -1) part->cx = par_format.leftmargin;

	format.link = fl;
	format.target = ft;
	format.image = fi;
	format.form = ff;
}

#define assert_link_variable(old, new) \
	assertm(!(old), "Old link value [%s]. New value [%s]", old, new);

static inline void
init_link_state_info(unsigned char *link, unsigned char *target,
		     unsigned char *image, struct form_control *form)
{
	assert_link_variable(renderer_context.link_state_info.image, image);
	assert_link_variable(renderer_context.link_state_info.target, target);
	assert_link_variable(renderer_context.link_state_info.link, link);

	renderer_context.link_state_info.link = null_or_stracpy(link);
	renderer_context.link_state_info.target = null_or_stracpy(target);
	renderer_context.link_state_info.image = null_or_stracpy(image);
	renderer_context.link_state_info.form = format.form;
}

static inline void
done_link_state_info(void)
{
	mem_free_if(renderer_context.link_state_info.link);
	mem_free_if(renderer_context.link_state_info.target);
	mem_free_if(renderer_context.link_state_info.image);
	memset(&renderer_context.link_state_info, 0,
	       sizeof(renderer_context.link_state_info));
}

static inline void
process_link(struct part *part, enum link_state link_state,
	     unsigned char *chars, int charslen)
{
	struct link *link;
	int x_offset = 0;

	switch (link_state) {
	case LINK_STATE_SAME: {
		unsigned char *name;

		if (!part->document) return;

		assertm(part->document->nlinks > 0, "no link");
		if_assert_failed return;

		link = &part->document->links[part->document->nlinks - 1];

		name = get_link_name(link);
		if (name) {
			unsigned char *new_name;

			new_name = straconcat(name, chars, NULL);
			if (new_name) {
				mem_free(name);
				link->data.name = new_name;
			}
		}

		/* FIXME: Concatenating two adjectent <a> elements to a single
		 * link is broken since we lose the event handlers for the
		 * second one.  OTOH simply appending them here won't fly since
		 * we may get here multiple times for even a single link. We
		 * will probably need some SP_ for creating a new link or so.
		 * --pasky */

		break;
	}

	case LINK_STATE_NEW:
		part->link_num++;

		init_link_state_info(format.link, format.target,
				     format.image, format.form);
		if (!part->document) return;

		/* Trim leading space from the link text */
		while (x_offset < charslen && chars[x_offset] <= ' ')
			x_offset++;

		if (x_offset) {
			charslen -= x_offset;
			chars += x_offset;
		}

		link = new_link(part->document, part->link_num,
				chars, charslen);
		if (!link) return;

		break;

	case LINK_STATE_NONE:
	default:
		INTERNAL("bad link_state %i", (int) link_state);
		return;
	}

	/* Add new canvas positions to the link. */
	if (realloc_points(link, link->npoints + charslen)) {
		struct point *point = &link->points[link->npoints];
		int x = X(part->cx) + x_offset;
		int y = Y(part->cy);

		link->npoints += charslen;

		for (; charslen > 0; charslen--, point++, x++) {
			point->x = x;
			point->y = y;
		}
	}
}

static inline enum link_state
get_link_state(void)
{
	enum link_state state;

	if (!(format.link || format.image || format.form)) {
		state = LINK_STATE_NONE;

	} else if ((renderer_context.link_state_info.link
		    || renderer_context.link_state_info.image
		    || renderer_context.link_state_info.form)
		   && !xstrcmp(format.link, renderer_context.link_state_info.link)
		   && !xstrcmp(format.target, renderer_context.link_state_info.target)
		   && !xstrcmp(format.image, renderer_context.link_state_info.image)
		   && format.form == renderer_context.link_state_info.form) {

		return LINK_STATE_SAME;

	} else {
		state = LINK_STATE_NEW;
	}

	done_link_state_info();

	return state;
}

void
process_hidden_link(struct part *part)
{
	enum link_state state = get_link_state();

	process_link(part, state, NULL, 0);
}

#define is_drawing_subs_or_sups() \
	((format.style.attr & AT_SUBSCRIPT && global_doc_opts->display_subs) \
	 || (format.style.attr & AT_SUPERSCRIPT && global_doc_opts->display_sups))

static inline int
html_has_non_space_chars(unsigned char *chars, int charslen)
{
	int pos = 0;

	while (pos < charslen)
		if (!isspace(chars[pos++]))
			return 1;

	return 0;
}

void
put_chars(struct part *part, unsigned char *chars, int charslen)
{
	enum link_state link_state;
	int update_after_subscript = renderer_context.did_subscript;

	assert(part);
	if_assert_failed return;

	assert(chars && charslen);
	if_assert_failed return;

	/* If we are not handling verbatim aligning and we are at the begining
	 * of a line trim whitespace. */
	if (part->cx == -1) {
		/* If we are not handling verbatim aligning trim leading
		 * whitespaces. */
		if (!html_is_preformatted()) {
			while (charslen && *chars == ' ') {
				chars++;
				charslen--;
			}

			if (charslen < 1) return;
		}

		part->cx = par_format.leftmargin;
	}

	/* For preformatted html always update 'the last tag' so we never end
	 * up moving tags to the wrong line (Fixes bug 324). For all other html
	 * it is moved only when the line being rendered carry some real
	 * non-whitespace content. */
	if (html_is_preformatted()
	    || html_has_non_space_chars(chars, charslen)) {
		renderer_context.last_tag_for_newline = (void *) &part->document->tags;
	}

	int_lower_bound(&part->box.height, part->cy + 1);

	link_state = get_link_state();

	if (link_state == LINK_STATE_NEW) {
		int x_offset = 0;

		/* Don't add inaccessible links. It seems to be caused
		 * by the parser putting a space char after stuff like
		 * <img>-tags or comments wrapped in <a>-tags. See bug
		 * 30 for test case. */
		while (x_offset < charslen && chars[x_offset] <= ' ')
			x_offset++;

		/* For pure spaces reset the link state */
		if (x_offset == charslen)
			link_state = LINK_STATE_NONE;
		else if (global_doc_opts->num_links_display)
			put_link_number(part);
	}

	set_hline(part, chars, charslen, link_state);

	if (link_state != LINK_STATE_NONE) {
		/* We need to update the current @link_state because <sub> and
		 * <sup> tags will output to the canvas using an inner
		 * put_chars() call which results in their process_link() call
		 * will ``update'' the @link_state. */
		if (link_state == LINK_STATE_NEW
		    && (is_drawing_subs_or_sups()
			|| update_after_subscript != renderer_context.did_subscript)) {
			link_state = get_link_state();
		}

		process_link(part, link_state, chars, charslen);
	}

	if (renderer_context.nowrap
	    && part->cx + charslen > overlap(par_format))
		return;

	part->cx += charslen;
	renderer_context.nobreak = 0;

	if (!html_is_preformatted()) {
		while (part->cx > overlap(par_format)
		       && part->cx > par_format.leftmargin) {
			int x = split_line(part);

			if (!x) break;
			if (part->document)
				align_line(part, part->cy - 1, 0);
			renderer_context.nobreak = x - 1;
		}
	}

	assert(charslen > 0);
	part->xa += charslen;
	int_lower_bound(&part->max_width, part->xa
			+ par_format.leftmargin + par_format.rightmargin
			- (chars[charslen - 1] == ' '
			   && !html_is_preformatted()));
	return;

}

#undef overlap

void
line_break(struct part *part)
{
	struct tag *tag;

	assert(part);
	if_assert_failed return;

	int_lower_bound(&part->box.width, part->cx + par_format.rightmargin);

	if (renderer_context.nobreak) {
		renderer_context.nobreak = 0;
		part->cx = -1;
		part->xa = 0;
		return;
	}

	if (!part->document || !part->document->data) goto end;

	if (!realloc_lines(part->document, part->box.height + part->cy + 1))
		return;

	if (part->cx > par_format.leftmargin && LEN(part->cy) > part->cx - 1
	    && POS(part->cx - 1, part->cy).data == ' ') {
		del_chars(part, part->cx - 1, part->cy);
		part->cx--;
	}

	if (part->cx > 0) align_line(part, part->cy, 1);

	for (tag = renderer_context.last_tag_for_newline;
	     tag && (void *) tag != &part->document->tags;
	     tag = tag->prev) {
		tag->x = X(0);
		tag->y = Y(part->cy + 1);
	}

end:
	part->cy++;
	part->cx = -1;
	part->xa = 0;
   	memset(part->spaces, 0, part->spaces_len);
}

static void
html_special_form(struct part *part, struct form *form)
{
	assert(part && form);
	if_assert_failed return;

	if (!part->document) {
		done_form(form);
		return;
	}

	if (!list_empty(part->document->forms)) {
		struct form *nform;

		/* Make sure the new form ``claims'' its slice of the form range
		 * maintained in the form_num and form_end variables. */
		foreach (nform, part->document->forms) {
			if (form->form_num < nform->form_num
			    || nform->form_end < form->form_num)
				continue;

			/* First check if the form has identical form numbers.
			 * That should only be the case when the form being
			 * added is in fact the same form in which case it
			 * should be dropped. The fact that this can happen
			 * suggests that the table renderering can be confused.
			 * See bug 647 for a test case. */
			if (nform->form_num == form->form_num
			    && nform->form_end == form->form_end) {
				done_form(form);
				return;
			}

			/* The form start is inside an already added form, so
			 * partition the space of the existing form and get
			 * |old|new|. */
			nform->form_end = form->form_num - 1;
			assertm(nform->form_num <= nform->form_end,
				"[%d:%d] [%d:%d]", nform->form_num, nform->form_end,
				form->form_num, form->form_end);
			break;
		}
	} else {
		/* If it is the first form make sure it eats the whole form
		 * range. */
#if 0
		/* Disabled because in tables the parse order may lead to a
		 * later form being parsed before a preceeding one causing the
		 * wrong order if we set it to zero. Let's hope it doesn't break
		 * anything else. */
		form->form_num = 0;
#endif
	}

	add_to_list(part->document->forms, form);
}

static void
html_special_form_control(struct part *part, struct form_control *fc)
{
	struct form *form;

	assert(part && fc);
	if_assert_failed return;

	if (!part->document) {
		done_form_control(fc);
		mem_free(fc);
		return;
	}

	fc->g_ctrl_num = renderer_context.g_ctrl_num++;

	/* We don't want to recode hidden fields. */
	if (fc->type == FC_TEXT || fc->type == FC_PASSWORD ||
	    fc->type == FC_TEXTAREA) {
		unsigned char *dv = convert_string(renderer_context.convert_table,
						   fc->default_value,
						   strlen(fc->default_value),
						   CSM_QUERY, NULL, NULL, NULL);

		if (dv) mem_free_set(&fc->default_value, dv);
	}

	if (list_empty(part->document->forms)) {
		/* No forms encountered yet, that means a homeless form
		 * control. Generate a dummy form for those Flying
		 * Dutchmans. */
		form = init_form();
		form->form_num = 0;
		add_to_list(part->document->forms, form);
	}
	/* Attach this form control to the last form encountered. */
	form = part->document->forms.next;
	fc->form = form;
	add_to_list(form->items, fc);
}

/* Reparents form items based on position in the source. */
void
check_html_form_hierarchy(struct part *part)
{
	struct document *document = part->document;
	INIT_LIST_HEAD(form_controls);
	struct form *form;
	struct form_control *fc, *next;

	if (list_empty(document->forms))
		return;