netsurf/render/font.h

95 lines
3.2 KiB
C

/*
* Copyright 2003 Phil Mellor <monkeyson@users.sourceforge.net>
* Copyright 2005 James Bursa <bursa@users.sourceforge.net>
* Copyright 2004 John Tytgat <joty@netsurf-browser.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/>.
*/
/** \file
* Font handling (interface).
*
* These functions provide font related services. They all work on UTF-8 strings
* with lengths given.
*
* Note that an interface to painting is not defined here. Painting is
* redirected through platform-dependent plotters anyway, so there is no gain in
* abstracting it here.
*/
#ifndef _NETSURF_RENDER_FONT_H_
#define _NETSURF_RENDER_FONT_H_
#include <stdbool.h>
#include <stddef.h>
#include "css/css.h"
#include "desktop/plot_style.h"
struct font_functions
{
/**
* Measure the width of a string.
*
* \param fstyle plot style for this text
* \param string UTF-8 string to measure
* \param length length of string, in bytes
* \param width updated to width of string[0..length)
* \return true on success, false on error and error reported
*/
bool (*font_width)(const plot_font_style_t *fstyle,
const char *string, size_t length,
int *width);
/**
* 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, in bytes
* \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
*/
bool (*font_position_in_string)(const plot_font_style_t *fstyle,
const char *string, size_t length,
int x, size_t *char_offset, int *actual_x);
/**
* 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, [0..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 == 0 ||
* string[char_offset] == ' ' ||
* char_offset == length]
*/
bool (*font_split)(const plot_font_style_t *fstyle,
const char *string, size_t length,
int x, size_t *char_offset, int *actual_x);
};
extern const struct font_functions nsfont;
void font_plot_style_from_css(const css_computed_style *css,
plot_font_style_t *fstyle);
#endif