netsurf/monkey/font.c
2013-05-28 14:16:10 +01:00

109 lines
3.4 KiB
C

/*
* Copyright 2011 Daniel Silverstone <dsilvers@digital-scurf.org>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* NetSurf is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "css/css.h"
#include "render/font.h"
#include "utils/nsoption.h"
#include "utils/utf8.h"
static bool nsfont_width(const plot_font_style_t *fstyle,
const char *string, size_t length,
int *width)
{
*width = (fstyle->size * utf8_bounded_length(string, length)) / FONT_SIZE_SCALE;
return true;
}
/**
* Find the position in a string where an x coordinate falls.
*
* \param fstyle style for this text
* \param string UTF-8 string to measure
* \param length length of string
* \param x x coordinate to search for
* \param char_offset updated to offset in string of actual_x, [0..length]
* \param actual_x updated to x coordinate of character closest to x
* \return true on success, false on error and error reported
*/
static bool nsfont_position_in_string(const plot_font_style_t *fstyle,
const char *string, size_t length,
int x, size_t *char_offset, int *actual_x)
{
*char_offset = x / (fstyle->size / FONT_SIZE_SCALE);
if (*char_offset > length)
*char_offset = length;
*actual_x = *char_offset * (fstyle->size / FONT_SIZE_SCALE);
return true;
}
/**
* Find where to split a string to make it fit a width.
*
* \param fstyle style for this text
* \param string UTF-8 string to measure
* \param length length of string, in bytes
* \param x width available
* \param char_offset updated to offset in string of actual_x, [1..length]
* \param actual_x updated to x coordinate of character closest to x
* \return true on success, false on error and error reported
*
* On exit, char_offset indicates first character after split point.
*
* Note: char_offset of 0 should never be returned.
*
* Returns:
* char_offset giving split point closest to x, where actual_x <= x
* else
* char_offset giving split point closest to x, where actual_x > x
*
* Returning char_offset == length means no split possible
*/
static bool nsfont_split(const plot_font_style_t *fstyle,
const char *string, size_t length,
int x, size_t *char_offset, int *actual_x)
{
int c_off = *char_offset = x / (fstyle->size / FONT_SIZE_SCALE);
if (*char_offset > length) {
*char_offset = length;
} else {
while (*char_offset > 0) {
if (string[*char_offset] == ' ')
break;
(*char_offset)--;
}
if (*char_offset == 0) {
*char_offset = c_off;
while (*char_offset < length && string[*char_offset] != ' ') {
(*char_offset)++;
}
}
}
*actual_x = *char_offset * (fstyle->size / FONT_SIZE_SCALE);
return true;
}
const struct font_functions nsfont = {
nsfont_width,
nsfont_position_in_string,
nsfont_split
};