mirror of
https://gitlab.gnome.org/GNOME/gtk.git
synced 2024-11-14 12:41:07 +00:00
98e076b51e
This function is a (private) function to parse a GdkRGBA accoridng to the CSS specs. We should probably use it for gdk_rgba_parse(), but that would change the syntax we accept there... This also introduces a dependency of libgdk on libgtkcss. So far, no users for this function exist.
578 lines
15 KiB
C
578 lines
15 KiB
C
/* GDK - The GIMP Drawing Kit
|
||
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
|
||
*
|
||
* This library is free software; you can redistribute it and/or
|
||
* modify it under the terms of the GNU Lesser General Public
|
||
* License as published by the Free Software Foundation; either
|
||
* version 2 of the License, or (at your option) any later version.
|
||
*
|
||
* This library 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
|
||
* Lesser General Public License for more details.
|
||
*
|
||
* You should have received a copy of the GNU Lesser General Public
|
||
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
|
||
*/
|
||
|
||
/*
|
||
* Modified by the GTK+ Team and others 1997-2000. See the AUTHORS
|
||
* file for a list of people on the GTK+ Team. See the ChangeLog
|
||
* files for a list of changes. These files are distributed with
|
||
* GTK+ at ftp://ftp.gtk.org/pub/gtk/.
|
||
*/
|
||
|
||
#include "config.h"
|
||
|
||
#include "gdkrgbaprivate.h"
|
||
|
||
#include <string.h>
|
||
#include <errno.h>
|
||
#include <math.h>
|
||
|
||
#include "fallback-c89.c"
|
||
|
||
/**
|
||
* SECTION:rgba_colors
|
||
* @Short_description: RGBA colors
|
||
* @Title: RGBA Colors
|
||
*
|
||
* #GdkRGBA is a convenient way to pass rgba colors around.
|
||
* It’s based on cairo’s way to deal with colors and mirrors its behavior.
|
||
* All values are in the range from 0.0 to 1.0 inclusive. So the color
|
||
* (0.0, 0.0, 0.0, 0.0) represents transparent black and
|
||
* (1.0, 1.0, 1.0, 1.0) is opaque white. Other values will be clamped
|
||
* to this range when drawing.
|
||
*/
|
||
|
||
G_DEFINE_BOXED_TYPE (GdkRGBA, gdk_rgba,
|
||
gdk_rgba_copy, gdk_rgba_free)
|
||
|
||
/**
|
||
* GdkRGBA:
|
||
* @red: The intensity of the red channel from 0.0 to 1.0 inclusive
|
||
* @green: The intensity of the green channel from 0.0 to 1.0 inclusive
|
||
* @blue: The intensity of the blue channel from 0.0 to 1.0 inclusive
|
||
* @alpha: The opacity of the color from 0.0 for completely translucent to
|
||
* 1.0 for opaque
|
||
*
|
||
* A #GdkRGBA is used to represent a (possibly translucent)
|
||
* color, in a way that is compatible with cairo’s notion of color.
|
||
*/
|
||
|
||
/**
|
||
* gdk_rgba_copy:
|
||
* @rgba: a #GdkRGBA
|
||
*
|
||
* Makes a copy of a #GdkRGBA.
|
||
*
|
||
* The result must be freed through gdk_rgba_free().
|
||
*
|
||
* Returns: A newly allocated #GdkRGBA, with the same contents as @rgba
|
||
*/
|
||
GdkRGBA *
|
||
gdk_rgba_copy (const GdkRGBA *rgba)
|
||
{
|
||
return g_slice_dup (GdkRGBA, rgba);
|
||
}
|
||
|
||
/**
|
||
* gdk_rgba_free:
|
||
* @rgba: a #GdkRGBA
|
||
*
|
||
* Frees a #GdkRGBA created with gdk_rgba_copy()
|
||
*/
|
||
void
|
||
gdk_rgba_free (GdkRGBA *rgba)
|
||
{
|
||
g_slice_free (GdkRGBA, rgba);
|
||
}
|
||
|
||
/**
|
||
* gdk_rgba_is_clear:
|
||
* @rgba: a #GdkRGBA
|
||
*
|
||
* Checks if an @rgba value is transparent. That is, drawing with the value
|
||
* would not produce any change.
|
||
*
|
||
* Returns: %TRUE if the @rgba is clear
|
||
*/
|
||
gboolean
|
||
gdk_rgba_is_clear (const GdkRGBA *rgba)
|
||
{
|
||
return rgba->alpha < ((double) 0x00ff / (double) 0xffff);
|
||
}
|
||
|
||
/**
|
||
* gdk_rgba_is_opaque:
|
||
* @rgba: a #GdkRGBA
|
||
*
|
||
* Checks if an @rgba value is opaque. That is, drawing with the value
|
||
* will not retain any results from previous contents.
|
||
*
|
||
* Returns: %TRUE if the @rgba is opaque
|
||
*/
|
||
gboolean
|
||
gdk_rgba_is_opaque (const GdkRGBA *rgba)
|
||
{
|
||
return rgba->alpha > ((double)0xff00 / (double)0xffff);
|
||
}
|
||
|
||
#define SKIP_WHITESPACES(s) while (*(s) == ' ') (s)++;
|
||
|
||
/* Parses a single color component from a rgb() or rgba() specification
|
||
* according to CSS3 rules. Compared to exact CSS3 parsing we are liberal
|
||
* in what we accept as follows:
|
||
*
|
||
* - For non-percentage values, we accept floats in the range 0-255
|
||
* not just [0-9]+ integers
|
||
* - For percentage values we accept any float, not just
|
||
* [ 0-9]+ | [0-9]* “.” [0-9]+
|
||
* - We accept mixed percentages and non-percentages in a single
|
||
* rgb() or rgba() specification.
|
||
*/
|
||
static gboolean
|
||
parse_rgb_value (const gchar *str,
|
||
gchar **endp,
|
||
gdouble *number)
|
||
{
|
||
const char *p;
|
||
|
||
*number = g_ascii_strtod (str, endp);
|
||
if (errno == ERANGE || *endp == str ||
|
||
isinf (*number) || isnan (*number))
|
||
return FALSE;
|
||
|
||
p = *endp;
|
||
|
||
SKIP_WHITESPACES (p);
|
||
|
||
if (*p == '%')
|
||
{
|
||
*endp = (char *)(p + 1);
|
||
*number = CLAMP(*number / 100., 0., 1.);
|
||
}
|
||
else
|
||
{
|
||
*number = CLAMP(*number / 255., 0., 1.);
|
||
}
|
||
|
||
return TRUE;
|
||
}
|
||
|
||
/**
|
||
* gdk_rgba_parse:
|
||
* @rgba: the #GdkRGBA to fill in
|
||
* @spec: the string specifying the color
|
||
*
|
||
* Parses a textual representation of a color, filling in
|
||
* the @red, @green, @blue and @alpha fields of the @rgba #GdkRGBA.
|
||
*
|
||
* The string can be either one of:
|
||
* - A standard name (Taken from the X11 rgb.txt file).
|
||
* - A hexadecimal value in the form “\#rgb”, “\#rrggbb”,
|
||
* “\#rrrgggbbb” or ”\#rrrrggggbbbb”
|
||
* - A RGB color in the form “rgb(r,g,b)” (In this case the color will
|
||
* have full opacity)
|
||
* - A RGBA color in the form “rgba(r,g,b,a)”
|
||
*
|
||
* Where “r”, “g”, “b” and “a” are respectively the red, green, blue and
|
||
* alpha color values. In the last two cases, “r”, “g”, and “b” are either integers
|
||
* in the range 0 to 255 or percentage values in the range 0% to 100%, and
|
||
* a is a floating point value in the range 0 to 1.
|
||
*
|
||
* Returns: %TRUE if the parsing succeeded
|
||
*/
|
||
gboolean
|
||
gdk_rgba_parse (GdkRGBA *rgba,
|
||
const gchar *spec)
|
||
{
|
||
gboolean has_alpha;
|
||
gdouble r, g, b, a;
|
||
gchar *str = (gchar *) spec;
|
||
gchar *p;
|
||
|
||
g_return_val_if_fail (spec != NULL, FALSE);
|
||
|
||
|
||
if (strncmp (str, "rgba", 4) == 0)
|
||
{
|
||
has_alpha = TRUE;
|
||
str += 4;
|
||
}
|
||
else if (strncmp (str, "rgb", 3) == 0)
|
||
{
|
||
has_alpha = FALSE;
|
||
a = 1;
|
||
str += 3;
|
||
}
|
||
else
|
||
{
|
||
PangoColor pango_color;
|
||
|
||
/* Resort on PangoColor for rgb.txt color
|
||
* map and '#' prefixed colors
|
||
*/
|
||
if (pango_color_parse (&pango_color, str))
|
||
{
|
||
if (rgba)
|
||
{
|
||
rgba->red = pango_color.red / 65535.;
|
||
rgba->green = pango_color.green / 65535.;
|
||
rgba->blue = pango_color.blue / 65535.;
|
||
rgba->alpha = 1;
|
||
}
|
||
|
||
return TRUE;
|
||
}
|
||
else
|
||
return FALSE;
|
||
}
|
||
|
||
SKIP_WHITESPACES (str);
|
||
|
||
if (*str != '(')
|
||
return FALSE;
|
||
|
||
str++;
|
||
|
||
/* Parse red */
|
||
SKIP_WHITESPACES (str);
|
||
if (!parse_rgb_value (str, &str, &r))
|
||
return FALSE;
|
||
SKIP_WHITESPACES (str);
|
||
|
||
if (*str != ',')
|
||
return FALSE;
|
||
|
||
str++;
|
||
|
||
/* Parse green */
|
||
SKIP_WHITESPACES (str);
|
||
if (!parse_rgb_value (str, &str, &g))
|
||
return FALSE;
|
||
SKIP_WHITESPACES (str);
|
||
|
||
if (*str != ',')
|
||
return FALSE;
|
||
|
||
str++;
|
||
|
||
/* Parse blue */
|
||
SKIP_WHITESPACES (str);
|
||
if (!parse_rgb_value (str, &str, &b))
|
||
return FALSE;
|
||
SKIP_WHITESPACES (str);
|
||
|
||
if (has_alpha)
|
||
{
|
||
if (*str != ',')
|
||
return FALSE;
|
||
|
||
str++;
|
||
|
||
SKIP_WHITESPACES (str);
|
||
a = g_ascii_strtod (str, &p);
|
||
if (errno == ERANGE || p == str ||
|
||
isinf (a) || isnan (a))
|
||
return FALSE;
|
||
str = p;
|
||
SKIP_WHITESPACES (str);
|
||
}
|
||
|
||
if (*str != ')')
|
||
return FALSE;
|
||
|
||
str++;
|
||
|
||
SKIP_WHITESPACES (str);
|
||
|
||
if (*str != '\0')
|
||
return FALSE;
|
||
|
||
if (rgba)
|
||
{
|
||
rgba->red = CLAMP (r, 0, 1);
|
||
rgba->green = CLAMP (g, 0, 1);
|
||
rgba->blue = CLAMP (b, 0, 1);
|
||
rgba->alpha = CLAMP (a, 0, 1);
|
||
}
|
||
|
||
return TRUE;
|
||
}
|
||
|
||
#undef SKIP_WHITESPACES
|
||
|
||
/**
|
||
* gdk_rgba_hash:
|
||
* @p: (type GdkRGBA): a #GdkRGBA pointer
|
||
*
|
||
* A hash function suitable for using for a hash
|
||
* table that stores #GdkRGBAs.
|
||
*
|
||
* Returns: The hash value for @p
|
||
*/
|
||
guint
|
||
gdk_rgba_hash (gconstpointer p)
|
||
{
|
||
const GdkRGBA *rgba = p;
|
||
|
||
return ((guint) (rgba->red * 65535) +
|
||
((guint) (rgba->green * 65535) << 11) +
|
||
((guint) (rgba->blue * 65535) << 22) +
|
||
((guint) (rgba->alpha * 65535) >> 6));
|
||
}
|
||
|
||
/**
|
||
* gdk_rgba_equal:
|
||
* @p1: (type GdkRGBA): a #GdkRGBA pointer
|
||
* @p2: (type GdkRGBA): another #GdkRGBA pointer
|
||
*
|
||
* Compares two RGBA colors.
|
||
*
|
||
* Returns: %TRUE if the two colors compare equal
|
||
*/
|
||
gboolean
|
||
gdk_rgba_equal (gconstpointer p1,
|
||
gconstpointer p2)
|
||
{
|
||
const GdkRGBA *rgba1, *rgba2;
|
||
|
||
rgba1 = p1;
|
||
rgba2 = p2;
|
||
|
||
if (rgba1->red == rgba2->red &&
|
||
rgba1->green == rgba2->green &&
|
||
rgba1->blue == rgba2->blue &&
|
||
rgba1->alpha == rgba2->alpha)
|
||
return TRUE;
|
||
|
||
return FALSE;
|
||
}
|
||
|
||
/**
|
||
* gdk_rgba_to_string:
|
||
* @rgba: a #GdkRGBA
|
||
*
|
||
* Returns a textual specification of @rgba in the form
|
||
* `rgb(r,g,b)` or
|
||
* `rgba(r g,b,a)`,
|
||
* where “r”, “g”, “b” and “a” represent the red, green,
|
||
* blue and alpha values respectively. “r”, “g”, and “b” are
|
||
* represented as integers in the range 0 to 255, and “a”
|
||
* is represented as a floating point value in the range 0 to 1.
|
||
*
|
||
* These string forms are string forms that are supported by
|
||
* the CSS3 colors module, and can be parsed by gdk_rgba_parse().
|
||
*
|
||
* Note that this string representation may lose some
|
||
* precision, since “r”, “g” and “b” are represented as 8-bit
|
||
* integers. If this is a concern, you should use a
|
||
* different representation.
|
||
*
|
||
* Returns: A newly allocated text string
|
||
*/
|
||
gchar *
|
||
gdk_rgba_to_string (const GdkRGBA *rgba)
|
||
{
|
||
if (rgba->alpha > 0.999)
|
||
{
|
||
return g_strdup_printf ("rgb(%d,%d,%d)",
|
||
(int)(0.5 + CLAMP (rgba->red, 0., 1.) * 255.),
|
||
(int)(0.5 + CLAMP (rgba->green, 0., 1.) * 255.),
|
||
(int)(0.5 + CLAMP (rgba->blue, 0., 1.) * 255.));
|
||
}
|
||
else
|
||
{
|
||
gchar alpha[G_ASCII_DTOSTR_BUF_SIZE];
|
||
|
||
g_ascii_formatd (alpha, G_ASCII_DTOSTR_BUF_SIZE, "%g", CLAMP (rgba->alpha, 0, 1));
|
||
|
||
return g_strdup_printf ("rgba(%d,%d,%d,%s)",
|
||
(int)(0.5 + CLAMP (rgba->red, 0., 1.) * 255.),
|
||
(int)(0.5 + CLAMP (rgba->green, 0., 1.) * 255.),
|
||
(int)(0.5 + CLAMP (rgba->blue, 0., 1.) * 255.),
|
||
alpha);
|
||
}
|
||
}
|
||
|
||
static gboolean
|
||
parse_color_channel_value (GtkCssParser *parser,
|
||
double *value,
|
||
gboolean is_percentage)
|
||
{
|
||
if (is_percentage)
|
||
{
|
||
if (!gtk_css_parser_consume_percentage (parser, value))
|
||
return FALSE;
|
||
|
||
*value = CLAMP (*value, 0.0, 100.0) / 100.0;
|
||
return TRUE;
|
||
}
|
||
else
|
||
{
|
||
if (!gtk_css_parser_consume_number (parser, value))
|
||
return FALSE;
|
||
|
||
*value = CLAMP (*value, 0.0, 255.0) / 255.0;
|
||
return TRUE;
|
||
}
|
||
}
|
||
|
||
static guint
|
||
parse_color_channel (GtkCssParser *parser,
|
||
guint arg,
|
||
gpointer data)
|
||
{
|
||
GdkRGBA *rgba = data;
|
||
|
||
switch (arg)
|
||
{
|
||
case 0:
|
||
/* We abuse rgba->alpha to store if we use percentages or numbers */
|
||
if (gtk_css_token_is (gtk_css_parser_get_token (parser), GTK_CSS_TOKEN_PERCENTAGE))
|
||
rgba->alpha = 1.0;
|
||
else
|
||
rgba->alpha = 0.0;
|
||
|
||
if (!parse_color_channel_value (parser, &rgba->red, rgba->alpha != 0.0))
|
||
return 0;
|
||
return 1;
|
||
|
||
case 1:
|
||
if (!parse_color_channel_value (parser, &rgba->green, rgba->alpha != 0.0))
|
||
return 0;
|
||
return 1;
|
||
|
||
case 2:
|
||
if (!parse_color_channel_value (parser, &rgba->blue, rgba->alpha != 0.0))
|
||
return 0;
|
||
return 1;
|
||
|
||
case 3:
|
||
if (!gtk_css_parser_consume_number (parser, &rgba->alpha))
|
||
return 0;
|
||
|
||
rgba->alpha = CLAMP (rgba->alpha, 0.0, 1.0);
|
||
return 1;
|
||
|
||
default:
|
||
g_assert_not_reached ();
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
static gboolean
|
||
rgba_init_chars (GdkRGBA *rgba,
|
||
const char s[8])
|
||
{
|
||
guint i;
|
||
|
||
for (i = 0; i < 8; i++)
|
||
{
|
||
if (!g_ascii_isxdigit (s[i]))
|
||
return FALSE;
|
||
}
|
||
|
||
rgba->red = (g_ascii_xdigit_value (s[0]) * 16 + g_ascii_xdigit_value (s[1])) / 255.0;
|
||
rgba->green = (g_ascii_xdigit_value (s[2]) * 16 + g_ascii_xdigit_value (s[3])) / 255.0;
|
||
rgba->blue = (g_ascii_xdigit_value (s[4]) * 16 + g_ascii_xdigit_value (s[5])) / 255.0;
|
||
rgba->alpha = (g_ascii_xdigit_value (s[6]) * 16 + g_ascii_xdigit_value (s[7])) / 255.0;
|
||
|
||
return TRUE;
|
||
}
|
||
|
||
gboolean
|
||
gdk_rgba_parser_parse (GtkCssParser *parser,
|
||
GdkRGBA *rgba)
|
||
{
|
||
const GtkCssToken *token;
|
||
|
||
token = gtk_css_parser_get_token (parser);
|
||
if (gtk_css_token_is_function (token, "rgb"))
|
||
{
|
||
if (!gtk_css_parser_consume_function (parser, 3, 3, parse_color_channel, rgba))
|
||
return FALSE;
|
||
|
||
rgba->alpha = 1.0;
|
||
return TRUE;
|
||
}
|
||
else if (gtk_css_token_is_function (token, "rgba"))
|
||
{
|
||
return gtk_css_parser_consume_function (parser, 4, 4, parse_color_channel, rgba);
|
||
}
|
||
else if (gtk_css_token_is (token, GTK_CSS_TOKEN_HASH_ID) ||
|
||
gtk_css_token_is (token, GTK_CSS_TOKEN_HASH_UNRESTRICTED))
|
||
{
|
||
const char *s = token->string.string;
|
||
|
||
switch (strlen (s))
|
||
{
|
||
case 3:
|
||
if (!rgba_init_chars (rgba, (char[8]) {s[0], s[0], s[1], s[1], s[2], s[2], 'F', 'F' }))
|
||
{
|
||
gtk_css_parser_error_value (parser, "Hash code is not a valid hex color.");
|
||
return FALSE;
|
||
}
|
||
break;
|
||
|
||
case 4:
|
||
if (!rgba_init_chars (rgba, (char[8]) {s[0], s[0], s[1], s[1], s[2], s[2], s[3], s[3] }))
|
||
{
|
||
gtk_css_parser_error_value (parser, "Hash code is not a valid hex color.");
|
||
return FALSE;
|
||
}
|
||
break;
|
||
|
||
case 6:
|
||
if (!rgba_init_chars (rgba, (char[8]) {s[0], s[1], s[2], s[3], s[4], s[5], 'F', 'F' }))
|
||
{
|
||
gtk_css_parser_error_value (parser, "Hash code is not a valid hex color.");
|
||
return FALSE;
|
||
}
|
||
break;
|
||
|
||
case 8:
|
||
if (!rgba_init_chars (rgba, s))
|
||
{
|
||
gtk_css_parser_error_value (parser, "Hash code is not a valid hex color.");
|
||
return FALSE;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
gtk_css_parser_error_value (parser, "Hash code is not a valid hex color.");
|
||
return FALSE;
|
||
break;
|
||
}
|
||
|
||
gtk_css_parser_consume_token (parser);
|
||
return TRUE;
|
||
}
|
||
else if (gtk_css_token_is (token, GTK_CSS_TOKEN_IDENT))
|
||
{
|
||
if (gtk_css_token_is_ident (token, "transparent"))
|
||
{
|
||
*rgba = (GdkRGBA) { 0, 0, 0, 0 };
|
||
}
|
||
else if (gdk_rgba_parse (rgba, token->string.string))
|
||
{
|
||
/* everything's fine */
|
||
}
|
||
else
|
||
{
|
||
gtk_css_parser_error_syntax (parser, "\"%s\" is not a valid color name.", token->string.string);
|
||
return FALSE;
|
||
}
|
||
|
||
gtk_css_parser_consume_token (parser);
|
||
return TRUE;
|
||
}
|
||
else
|
||
{
|
||
gtk_css_parser_error_syntax (parser, "Expected a valid color.");
|
||
return FALSE;
|
||
}
|
||
}
|
||
|