nscolour.c

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/*
 * Copyright 2020 Michael Drake <tlsa@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
 * NetSurf UI colours (implementation).
 *
 * Builds common colours used throughout NetSurf's interface.
 */
 
#include <stdio.h>
#include <assert.h>
#include <stddef.h>
#include <stdbool.h>
 
#include "netsurf/inttypes.h"
#include "netsurf/plot_style.h"
 
#include "utils/errors.h"
#include "utils/nscolour.h"
#include "desktop/system_colour.h"
 
colour nscolours[NSCOLOUR__COUNT];
 
/**
 * Set some colours up from a couple of system colour entries.
 *
 * \param[in]  name_bg    Name of choices string for background colour lookup.
 * \param[in]  name_fg    Name of choices string for foreground colour lookup.
 * \param[in]  bg_num     Numerator for background adjustment ratio.
 * \param[in]  bg_den     Denominator for backfground adjustment ratio.
 * \param[out] bg         Returns the background colour.
 * \param[out] bg_hover   Returns the hovered background colour.
 * \param[out] fg         Returns the foreground colour.
 * \param[out] fg_subtle  Returns the subtle foreground colour.
 * \param[out] fg_faded   Returns the faded foreground colour.
 * \param[out] fg_good    Returns the good foreground colour.
 * \param[out] fg_bad     Returns the bad foreground colour.
 * \param[out] border     Returns the border colour.
 */
static nserror nscolour__get(
                const char *name_bg,
                const char *name_fg,
                unsigned bg_num,
                unsigned bg_den,
                colour *bg,
                colour *bg_hover,
                colour *fg,
                colour *fg_subtle,
                colour *fg_faded,
                colour *fg_good,
                colour *fg_bad,
                colour *border)
{
        nserror res;
        bool dark_mode;
        colour bg_sys;
 
        assert(name_bg != NULL);
        assert(name_fg != NULL);
        assert(bg != NULL);
        assert(fg != NULL);
 
        /* user configured background colour */
        res = ns_system_colour_char(name_bg, &bg_sys);
        if (res != NSERROR_OK) {
                return res;
        }
 
        /* user configured foreground colour */
        res = ns_system_colour_char(name_fg, fg);
        if (res != NSERROR_OK) {
                return res;
        }
 
        /* if there is a valid background fraction apply it */
        if (bg_num < bg_den) {
                *bg = mix_colour(bg_sys, *fg, 255 * bg_num / bg_den);
        } else {
                *bg = bg_sys;
        }
 
        dark_mode = colour_lightness(*fg) > colour_lightness(*bg);
 
        if (bg_hover != NULL) {
                *bg_hover = dark_mode ?
                                half_lighten_colour(*bg) :
                                half_darken_colour(*bg);
        }
 
        if (fg_subtle != NULL) {
                *fg_subtle = mix_colour(*fg, *bg, 255 * 25 / 32);
        }
 
        if (fg_faded != NULL) {
                *fg_faded = mix_colour(*fg, *bg, 255 * 20 / 32);
        }
 
        if (fg_good != NULL) {
                *fg_good = colour_engorge_component(*fg, !dark_mode,
                                PLOT_COLOUR_COMPONENT_GREEN);
        }
 
        if (fg_bad != NULL) {
                *fg_bad = colour_engorge_component(*fg, !dark_mode,
                                PLOT_COLOUR_COMPONENT_RED);
        }
 
        if (border != NULL) {
                *border = mix_colour(*fg, bg_sys, 255 * 8 / 32);
        }
 
        return NSERROR_OK;
}
 
/* Exported interface, documented in utils/nscolour.h */
nserror nscolour_update(void)
{
        nserror res;
 
        res = nscolour__get("Window", "WindowText", 16, 16,
                        &nscolours[NSCOLOUR_WIN_EVEN_BG],
                        &nscolours[NSCOLOUR_WIN_EVEN_BG_HOVER],
                        &nscolours[NSCOLOUR_WIN_EVEN_FG],
                        &nscolours[NSCOLOUR_WIN_EVEN_FG_SUBTLE],
                        &nscolours[NSCOLOUR_WIN_EVEN_FG_FADED],
                        &nscolours[NSCOLOUR_WIN_EVEN_FG_GOOD],
                        &nscolours[NSCOLOUR_WIN_EVEN_FG_BAD],
                        &nscolours[NSCOLOUR_WIN_EVEN_BORDER]);
        if (res != NSERROR_OK) {
                return res;
        }
 
        res = nscolour__get("Window", "WindowText", 15, 16,
                        &nscolours[NSCOLOUR_WIN_ODD_BG],
                        &nscolours[NSCOLOUR_WIN_ODD_BG_HOVER],
                        &nscolours[NSCOLOUR_WIN_ODD_FG],
                        &nscolours[NSCOLOUR_WIN_ODD_FG_SUBTLE],
                        &nscolours[NSCOLOUR_WIN_ODD_FG_FADED],
                        &nscolours[NSCOLOUR_WIN_ODD_FG_GOOD],
                        &nscolours[NSCOLOUR_WIN_ODD_FG_BAD],
                        &nscolours[NSCOLOUR_WIN_ODD_BORDER]);
        if (res != NSERROR_OK) {
                return res;
        }
 
        res = nscolour__get("Highlight", "HighlightText", 16, 16,
                        &nscolours[NSCOLOUR_SEL_BG],
                        NULL,
                        &nscolours[NSCOLOUR_SEL_FG],
                        &nscolours[NSCOLOUR_SEL_FG_SUBTLE],
                        NULL,
                        NULL,
                        NULL,
                        NULL);
        if (res != NSERROR_OK) {
                return res;
        }
 
        res = ns_system_colour_char("Scrollbar",
                        &nscolours[NSCOLOUR_SCROLL_WELL]);
        if (res != NSERROR_OK) {
                return res;
        }
 
        res = nscolour__get("ButtonFace", "ButtonText", 16, 16,
                        &nscolours[NSCOLOUR_BUTTON_BG],
                        NULL,
                        &nscolours[NSCOLOUR_BUTTON_FG],
                        NULL,
                        NULL,
                        NULL,
                        NULL,
                        NULL);
        if (res != NSERROR_OK) {
                return res;
        }
 
        nscolours[NSCOLOUR_TEXT_INPUT_BG] =
                        colour_to_bw_nearest(nscolours[NSCOLOUR_WIN_EVEN_BG]);
        nscolours[NSCOLOUR_TEXT_INPUT_FG] =
                        colour_to_bw_nearest(nscolours[NSCOLOUR_WIN_EVEN_FG]);
        nscolours[NSCOLOUR_TEXT_INPUT_FG_SUBTLE] =
                        blend_colour(nscolours[NSCOLOUR_TEXT_INPUT_BG],
                                     nscolours[NSCOLOUR_TEXT_INPUT_FG]);
 
        return NSERROR_OK;
}
 
/* Exported interface, documented in utils/nscolour.h */
nserror nscolour_get_stylesheet(const char **stylesheet_out)
{
        static char buffer[640];
        int ret;
 
        assert(stylesheet_out != NULL);
 
        ret = snprintf(buffer, sizeof(buffer),
                        ".ns-odd-bg {\n"
                        "\tbackground-color: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-odd-bg-hover {\n"
                        "\tbackground-color: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-odd-fg {\n"
                        "\tcolor: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-odd-fg-subtle {\n"
                        "\tcolor: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-odd-fg-faded {\n"
                        "\tcolor: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-odd-fg-good {\n"
                        "\tcolor: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-odd-fg-bad {\n"
                        "\tcolor: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-even-bg {\n"
                        "\tbackground-color: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-even-bg-hover {\n"
                        "\tbackground-color: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-even-fg {\n"
                        "\tcolor: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-even-fg-subtle {\n"
                        "\tcolor: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-even-fg-faded {\n"
                        "\tcolor: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-even-fg-good {\n"
                        "\tcolor: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-even-fg-bad {\n"
                        "\tcolor: #%06"PRIx32";\n"
                        "}\n"
                        ".ns-border {\n"
                        "\tborder-color: #%06"PRIx32";\n"
                        "}\n",
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_ODD_BG]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_ODD_BG_HOVER]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_ODD_FG]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_ODD_FG_SUBTLE]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_ODD_FG_FADED]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_ODD_FG_GOOD]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_ODD_FG_BAD]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_EVEN_BG]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_EVEN_BG_HOVER]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_EVEN_FG]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_EVEN_FG_SUBTLE]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_EVEN_FG_FADED]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_EVEN_FG_GOOD]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_EVEN_FG_BAD]),
                        colour_rb_swap(nscolours[NSCOLOUR_WIN_EVEN_BORDER]));
        assert(ret > 0 && (size_t)ret < sizeof(buffer));
        if (ret < 0 || (size_t)ret >= sizeof(buffer)) {
                /* Error or buffer too small */
                return NSERROR_NOSPACE;
        }
 
        *stylesheet_out = buffer;
        return NSERROR_OK;
}