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/*
* Copyright 2009 John-Mark Bell <jmb@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/>.
*/
#ifndef NETSURF_CSS_UTILS_H_
#define NETSURF_CSS_UTILS_H_
#include <libcss/libcss.h>
#include "netsurf/css.h"
/** DPI of the screen, in fixed point units */
extern css_fixed nscss_screen_dpi;
/** Medium screen density for device viewing distance. */
extern css_fixed nscss_baseline_pixel_density;
/**
* Length conversion context data.
*/
typedef struct nscss_len_ctx {
/**
* Viewport width in px.
* Only used if unit is vh, vw, vi, vb, vmin, or vmax.
*/
int vw;
/**
* Viewport height in px.
* Only used if unit is vh, vw, vi, vb, vmin, or vmax.
*/
int vh;
/**
* Computed style for the document root element.
* May be NULL if unit is not rem, or rlh.
*/
const css_computed_style *root_style;
} nscss_len_ctx;
/**
* Convert an absolute CSS length to points.
*
* \param[in] ctx Length conversion context.
* \param[in] length Absolute CSS length.
* \param[in] unit Unit of the length.
* \return length in points
*/
css_fixed nscss_len2pt(
const nscss_len_ctx *ctx,
css_fixed length,
css_unit unit);
/**
* Convert a CSS length to pixels.
*
* \param[in] ctx Length conversion context.
* \param[in] length Length to convert.
* \param[in] unit Corresponding unit.
* \param[in] style Computed style applying to length.
* May be NULL if unit is not em, ex, cap, ch, or ic.
* \return length in pixels
*/
css_fixed nscss_len2px(
const nscss_len_ctx *ctx,
css_fixed length,
css_unit unit,
const css_computed_style *style);
/**
* Convert css pixels to physical pixels.
*
* \param[in] css_pixels Length in css pixels.
* \return length in physical pixels
*/
static inline css_fixed nscss_pixels_css_to_physical(
css_fixed css_pixels)
{
return FDIV(FMUL(css_pixels, nscss_screen_dpi),
nscss_baseline_pixel_density);
}
/**
* Convert physical pixels to css pixels.
*
* \param[in] physical_pixels Length in physical pixels.
* \return length in css pixels
*/
static inline css_fixed nscss_pixels_physical_to_css(
css_fixed physical_pixels)
{
return FDIV(FMUL(physical_pixels, nscss_baseline_pixel_density),
nscss_screen_dpi);
}
/**
* Temporary helper wrappers for for libcss computed style getter, while
* we don't support flexbox related property values.
*/
static inline uint8_t ns_computed_display(
const css_computed_style *style, bool root)
{
uint8_t value = css_computed_display(style, root);
if (value == CSS_DISPLAY_FLEX) {
return CSS_DISPLAY_BLOCK;
} else if (value == CSS_DISPLAY_INLINE_FLEX) {
return CSS_DISPLAY_INLINE_BLOCK;
}
return value;
}
static inline uint8_t ns_computed_display_static(
const css_computed_style *style)
{
uint8_t value = css_computed_display_static(style);
if (value == CSS_DISPLAY_FLEX) {
return CSS_DISPLAY_BLOCK;
} else if (value == CSS_DISPLAY_INLINE_FLEX) {
return CSS_DISPLAY_INLINE_BLOCK;
}
return value;
}
static inline uint8_t ns_computed_min_height(
const css_computed_style *style,
css_fixed *length, css_unit *unit)
{
uint8_t value = css_computed_min_height(style, length, unit);
if (value == CSS_MIN_HEIGHT_AUTO) {
value = CSS_MIN_HEIGHT_SET;
*length = 0;
*unit = CSS_UNIT_PX;
}
return value;
}
static inline uint8_t ns_computed_min_width(
const css_computed_style *style,
css_fixed *length, css_unit *unit)
{
uint8_t value = css_computed_min_width(style, length, unit);
if (value == CSS_MIN_WIDTH_AUTO) {
value = CSS_MIN_WIDTH_SET;
*length = 0;
*unit = CSS_UNIT_PX;
}
return value;
}
#endif
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