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/*
netrik -- The ANTRIK Internet Viewer
Copyright (C) Olaf D. Buddenhagen AKA antrik, et al (see AUTHORS)
Published under the GNU GPL; see LICENSE for details.
*/
/*
* items.c -- helper functions for handling the page structure tree
*
* (C) 2003 antrik
*
* These functions help in retrieving some common data from the item tree.
*/
#include <assert.h>
#include "items.h"
/* Get the starting position of a specific line inside a text block.
* The line number is relative to the page, not the text item. */
int line_start(item, line)
const struct Item *item;
int line;
{
const struct String *string=item->data.string; /* current string */
const int string_line=line-item->y_start; /* current line number relatively to beginning of text block */
int start;
assert(line >= item->y_start);
assert(line < item->y_end);
if(string_line) /* not first line of text block */
start=string->line_table[string_line-1]; /* start of desired line */
else /* first line */
start=0;
return start;
}
/* Get the ending position of a specific line inside a text block.
* The line number is relative to the page, not the text item. */
int line_end(item, line)
const struct Item *item;
int line;
{
const struct String *string=item->data.string; /* current string */
const int string_line=line-item->y_start; /* current line number relatively to beginning of text block */
int end;
assert(line >= item->y_start);
assert(line < item->y_end);
if(line<item->y_end-1) /* not last line of text block */
end=string->line_table[string_line]; /* start of next(!) line is end of the desired one */
else /* last line */
end=string->div[string->div_count-1].end; /* string end */
if((unsigned)string->text[end-1]<=' ') /* discard blanks/newlines at line end */
if(line_start(item, line) < end) /* unless empty line, meaning the blank doesn't belong to this line */
--end;
return end;
}
/* Get starting x position (column) of a specific (possibly centered) line from
* a text block. (Returned in page coordinates.) The line number is relative to
* the page, not the text item. */
int line_pos(item, line)
const struct Item *item;
int line;
{
int pos;
if(item->center==0) /* normal */
pos=item->x_start; /* just return item position (no offset) */
else /* centered */
pos=item->x_start + ((item->x_end-item->x_start) - (line_end(item, line)-line_start(item,line))) / 2; /* offset=(block width-line width)/2 */
return pos;
}
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