forked from AuroraMiddleware/gtk
d2b64a1db2
CSS3 defines a somewhat odd syntax for rgba() colors - the rgb values are integers from 0 to 255 or percentages and the a value is a float from 0 to 1. To avoid increasing the total amount of confusion in the world, make gdk_rgb_to_string() and gdk_rgb_parse() follow this syntax rather than using floats for r, g, and b. https://bugzilla.gnome.org/show_bug.cgi?id=633762
331 lines
7.7 KiB
C
331 lines
7.7 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, write to the
|
|
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
* Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
/*
|
|
* 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 "gdkrgba.h"
|
|
#include <string.h>
|
|
|
|
/**
|
|
* SECTION:rgba_colors
|
|
* @Short_description: RGBA colors
|
|
* @Title: RGBA Colors
|
|
*/
|
|
|
|
G_DEFINE_BOXED_TYPE (GdkRGBA, gdk_rgba,
|
|
gdk_rgba_copy, gdk_rgba_free)
|
|
|
|
/**
|
|
* gdk_rgba_copy:
|
|
* @rgba: a #GdkRGBA
|
|
*
|
|
* Makes a copy of a #GdkRGBA structure, the result must be freed
|
|
* through gdk_rgba_free().
|
|
*
|
|
* Returns: A newly allocated #GdkRGBA
|
|
**/
|
|
GdkRGBA *
|
|
gdk_rgba_copy (GdkRGBA *rgba)
|
|
{
|
|
GdkRGBA *copy;
|
|
|
|
copy = g_slice_new (GdkRGBA);
|
|
copy->red = rgba->red;
|
|
copy->green = rgba->green;
|
|
copy->blue = rgba->blue;
|
|
copy->alpha = rgba->alpha;
|
|
|
|
return copy;
|
|
}
|
|
|
|
/**
|
|
* gdk_rgba_free:
|
|
* @rgba: a #GdkRGBA
|
|
*
|
|
* Frees a #GdkRGBA struct created with gdk_rgba_copy()
|
|
**/
|
|
void
|
|
gdk_rgba_free (GdkRGBA *rgba)
|
|
{
|
|
g_slice_free (GdkRGBA, rgba);
|
|
}
|
|
|
|
#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 double
|
|
parse_rgb_value (const char *str,
|
|
char **endp)
|
|
{
|
|
double number;
|
|
const char *p;
|
|
|
|
number = g_ascii_strtod (str, endp);
|
|
|
|
p = *endp;
|
|
|
|
SKIP_WHITESPACES (p);
|
|
|
|
if (*p == '%')
|
|
{
|
|
*endp = (char *)(p + 1);
|
|
return CLAMP(number / 100., 0., 1.);
|
|
}
|
|
else
|
|
{
|
|
return CLAMP(number / 255., 0., 1.);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gdk_rgba_parse:
|
|
* @spec: the string specifying the color
|
|
* @rgba: the #GdkRGBA struct to fill in
|
|
*
|
|
* Parses a textual representation of a color, filling in
|
|
* the <structfield>red</structfield>, <structfield>green</structfield>,
|
|
* <structfield>blue</structfield> and <structfield>alpha</structfield>
|
|
* fields of the @rgba struct.
|
|
*
|
|
* The string can be either one of:
|
|
* <itemizedlist>
|
|
* <listitem>
|
|
* A standard name (Taken from the X11 rgb.txt file).
|
|
* </listitem>
|
|
* <listitem>
|
|
* A hex value in the form '#rgb' '#rrggbb' '#rrrgggbbb' or '#rrrrggggbbbb'
|
|
* </listitem>
|
|
* <listitem>
|
|
* A RGB color in the form 'rgb(r,g,b)' (In this case the color will
|
|
* have full opacity)
|
|
* </listitem>
|
|
* <listitem>
|
|
* A RGBA color in the form 'rgba(r,g,b,a)'
|
|
* </listitem>
|
|
* </itemizedlist>
|
|
*
|
|
* 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 precentage 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 (const gchar *spec,
|
|
GdkRGBA *rgba)
|
|
{
|
|
gboolean has_alpha;
|
|
gdouble r, g, b, a;
|
|
gchar *str = (gchar *) spec;
|
|
|
|
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);
|
|
r = parse_rgb_value (str, &str);
|
|
SKIP_WHITESPACES (str);
|
|
|
|
if (*str != ',')
|
|
return FALSE;
|
|
|
|
str++;
|
|
|
|
/* Parse green */
|
|
SKIP_WHITESPACES (str);
|
|
g = parse_rgb_value (str, &str);
|
|
SKIP_WHITESPACES (str);
|
|
|
|
if (*str != ',')
|
|
return FALSE;
|
|
|
|
str++;
|
|
|
|
/* Parse blue */
|
|
SKIP_WHITESPACES (str);
|
|
b = parse_rgb_value (str, &str);
|
|
SKIP_WHITESPACES (str);
|
|
|
|
if (has_alpha)
|
|
{
|
|
if (*str != ',')
|
|
return FALSE;
|
|
|
|
str++;
|
|
|
|
SKIP_WHITESPACES (str);
|
|
a = g_ascii_strtod (str, &str);
|
|
SKIP_WHITESPACES (str);
|
|
}
|
|
|
|
if (*str != ')')
|
|
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: a #GdkRGBA pointer.
|
|
*
|
|
* A hash function suitable for using for a hash
|
|
* table that stores #GdkRGBA<!-- -->s.
|
|
*
|
|
* Return value: The hash function applied to @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: a #GdkRGBA pointer.
|
|
* @p2: another #GdkRGBA pointer.
|
|
*
|
|
* Compares two RGBA colors.
|
|
*
|
|
* Return value: %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 <literal>rgb
|
|
* (r, g, b)</literal> or <literal>rgba (r, g, b, a)</literal>,
|
|
* where 'r', 'g', 'b' and 'a' represent the red, green, blue and alpha values
|
|
* respectively. r, g, and b are integers in the range 0 to 255, and a
|
|
* is a floating point value in the range 0 to 1.
|
|
*
|
|
* (These string forms are string forms those supported by the CSS3 colors module)
|
|
*
|
|
* 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_dtostr (alpha, G_ASCII_DTOSTR_BUF_SIZE, 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);
|
|
}
|
|
}
|