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/* GTK - The GIMP Toolkit
* Copyright (C) 2010 Carlos Garnacho <carlosg@gnome.org>
*
* 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.
*/
#include "config.h"
#include "gtksymboliccolor.h"
#include "gtkstyleproperties.h"
#include "gtkintl.h"
/**
* SECTION:gtksymboliccolor
* @Short_description: Symbolic colors
* @Title: GtkSymbolicColor
*
* GtkSymbolicColor is a boxed type that represents a symbolic color.
* It is the result of parsing a
* <link linkend="gtkcssprovider-symbolic-colors">color expression</link>.
* To obtain the color represented by a GtkSymbolicColor, it has to
* be resolved with gtk_symbolic_color_resolve(), which replaces all
* symbolic color references by the colors they refer to (in a given
* context) and evaluates mix, shade and other expressions, resulting
* in a #GdkRGBA value.
*
* It is not normally necessary to deal directly with #GtkSymbolicColors,
* since they are mostly used behind the scenes by #GtkStyleContext and
* #GtkCssProvider.
*/
G_DEFINE_BOXED_TYPE (GtkSymbolicColor, gtk_symbolic_color,
gtk_symbolic_color_ref, gtk_symbolic_color_unref)
/* Symbolic colors */
typedef enum {
COLOR_TYPE_LITERAL,
COLOR_TYPE_NAME,
COLOR_TYPE_SHADE,
COLOR_TYPE_ALPHA,
COLOR_TYPE_MIX
} ColorType;
struct _GtkSymbolicColor
{
ColorType type;
guint ref_count;
union
{
GdkRGBA color;
gchar *name;
struct
{
GtkSymbolicColor *color;
gdouble factor;
} shade, alpha;
struct
{
GtkSymbolicColor *color1;
GtkSymbolicColor *color2;
gdouble factor;
} mix;
};
};
/**
* gtk_symbolic_color_new_literal:
* @color: a #GdkRGBA
*
* Creates a symbolic color pointing to a literal color.
*
* Returns: a newly created #GtkSymbolicColor
*
* Since: 3.0
**/
GtkSymbolicColor *
gtk_symbolic_color_new_literal (const GdkRGBA *color)
{
GtkSymbolicColor *symbolic_color;
g_return_val_if_fail (color != NULL, NULL);
symbolic_color = g_slice_new0 (GtkSymbolicColor);
symbolic_color->type = COLOR_TYPE_LITERAL;
symbolic_color->color = *color;
symbolic_color->ref_count = 1;
return symbolic_color;
}
/**
* gtk_symbolic_color_new_name:
* @name: color name
*
* Creates a symbolic color pointing to an unresolved named
* color. See gtk_style_context_lookup_color() and
* gtk_style_properties_lookup_color().
*
* Returns: a newly created #GtkSymbolicColor
*
* Since: 3.0
**/
GtkSymbolicColor *
gtk_symbolic_color_new_name (const gchar *name)
{
GtkSymbolicColor *symbolic_color;
g_return_val_if_fail (name != NULL, NULL);
symbolic_color = g_slice_new0 (GtkSymbolicColor);
symbolic_color->type = COLOR_TYPE_NAME;
symbolic_color->name = g_strdup (name);
symbolic_color->ref_count = 1;
return symbolic_color;
}
/**
* gtk_symbolic_color_new_shade:
* @color: another #GtkSymbolicColor
* @factor: shading factor to apply to @color
*
* Creates a symbolic color defined as a shade of
* another color. A factor > 1.0 would resolve to
* a brighter color, while < 1.0 would resolve to
* a darker color.
*
* Returns: A newly created #GtkSymbolicColor
*
* Since: 3.0
**/
GtkSymbolicColor *
gtk_symbolic_color_new_shade (GtkSymbolicColor *color,
gdouble factor)
{
GtkSymbolicColor *symbolic_color;
g_return_val_if_fail (color != NULL, NULL);
symbolic_color = g_slice_new0 (GtkSymbolicColor);
symbolic_color->type = COLOR_TYPE_SHADE;
symbolic_color->shade.color = gtk_symbolic_color_ref (color);
symbolic_color->shade.factor = factor;
symbolic_color->ref_count = 1;
return symbolic_color;
}
/**
* gtk_symbolic_color_new_alpha:
* @color: another #GtkSymbolicColor
* @factor: factor to apply to @color alpha
*
* Creates a symbolic color by modifying the relative alpha
* value of @color. A factor < 1.0 would resolve to a more
* transparent color, while > 1.0 would resolve to a more
* opaque color.
*
* Returns: A newly created #GtkSymbolicColor
*
* Since: 3.0
**/
GtkSymbolicColor *
gtk_symbolic_color_new_alpha (GtkSymbolicColor *color,
gdouble factor)
{
GtkSymbolicColor *symbolic_color;
g_return_val_if_fail (color != NULL, NULL);
symbolic_color = g_slice_new0 (GtkSymbolicColor);
symbolic_color->type = COLOR_TYPE_ALPHA;
symbolic_color->alpha.color = gtk_symbolic_color_ref (color);
symbolic_color->alpha.factor = factor;
symbolic_color->ref_count = 1;
return symbolic_color;
}
/**
* gtk_symbolic_color_new_mix:
* @color1: color to mix
* @color2: another color to mix
* @factor: mix factor
*
* Creates a symbolic color defined as a mix of another
* two colors. a mix factor of 0 would resolve to @color1,
* while a factor of 1 would resolve to @color2.
*
* Returns: A newly created #GtkSymbolicColor
*
* Since: 3.0
**/
GtkSymbolicColor *
gtk_symbolic_color_new_mix (GtkSymbolicColor *color1,
GtkSymbolicColor *color2,
gdouble factor)
{
GtkSymbolicColor *symbolic_color;
g_return_val_if_fail (color1 != NULL, NULL);
g_return_val_if_fail (color1 != NULL, NULL);
symbolic_color = g_slice_new0 (GtkSymbolicColor);
symbolic_color->type = COLOR_TYPE_MIX;
symbolic_color->mix.color1 = gtk_symbolic_color_ref (color1);
symbolic_color->mix.color2 = gtk_symbolic_color_ref (color2);
symbolic_color->mix.factor = factor;
symbolic_color->ref_count = 1;
return symbolic_color;
}
/**
* gtk_symbolic_color_ref:
* @color: a #GtkSymbolicColor
*
* Increases the reference count of @color
*
* Returns: the same @color
*
* Since: 3.0
**/
GtkSymbolicColor *
gtk_symbolic_color_ref (GtkSymbolicColor *color)
{
g_return_val_if_fail (color != NULL, NULL);
color->ref_count++;
return color;
}
/**
* gtk_symbolic_color_unref:
* @color: a #GtkSymbolicColor
*
* Decreases the reference count of @color, freeing its memory if the
* reference count reaches 0.
*
* Since: 3.0
**/
void
gtk_symbolic_color_unref (GtkSymbolicColor *color)
{
g_return_if_fail (color != NULL);
color->ref_count--;
if (color->ref_count == 0)
{
switch (color->type)
{
case COLOR_TYPE_NAME:
g_free (color->name);
break;
case COLOR_TYPE_SHADE:
gtk_symbolic_color_unref (color->shade.color);
break;
case COLOR_TYPE_ALPHA:
gtk_symbolic_color_unref (color->alpha.color);
break;
case COLOR_TYPE_MIX:
gtk_symbolic_color_unref (color->mix.color1);
gtk_symbolic_color_unref (color->mix.color2);
break;
default:
break;
}
g_slice_free (GtkSymbolicColor, color);
}
}
static void
rgb_to_hls (gdouble *r,
gdouble *g,
gdouble *b)
{
gdouble min;
gdouble max;
gdouble red;
gdouble green;
gdouble blue;
gdouble h, l, s;
gdouble delta;
red = *r;
green = *g;
blue = *b;
if (red > green)
{
if (red > blue)
max = red;
else
max = blue;
if (green < blue)
min = green;
else
min = blue;
}
else
{
if (green > blue)
max = green;
else
max = blue;
if (red < blue)
min = red;
else
min = blue;
}
l = (max + min) / 2;
s = 0;
h = 0;
if (max != min)
{
if (l <= 0.5)
s = (max - min) / (max + min);
else
s = (max - min) / (2 - max - min);
delta = max -min;
if (red == max)
h = (green - blue) / delta;
else if (green == max)
h = 2 + (blue - red) / delta;
else if (blue == max)
h = 4 + (red - green) / delta;
h *= 60;
if (h < 0.0)
h += 360;
}
*r = h;
*g = l;
*b = s;
}
static void
hls_to_rgb (gdouble *h,
gdouble *l,
gdouble *s)
{
gdouble hue;
gdouble lightness;
gdouble saturation;
gdouble m1, m2;
gdouble r, g, b;
lightness = *l;
saturation = *s;
if (lightness <= 0.5)
m2 = lightness * (1 + saturation);
else
m2 = lightness + saturation - lightness * saturation;
m1 = 2 * lightness - m2;
if (saturation == 0)
{
*h = lightness;
*l = lightness;
*s = lightness;
}
else
{
hue = *h + 120;
while (hue > 360)
hue -= 360;
while (hue < 0)
hue += 360;
if (hue < 60)
r = m1 + (m2 - m1) * hue / 60;
else if (hue < 180)
r = m2;
else if (hue < 240)
r = m1 + (m2 - m1) * (240 - hue) / 60;
else
r = m1;
hue = *h;
while (hue > 360)
hue -= 360;
while (hue < 0)
hue += 360;
if (hue < 60)
g = m1 + (m2 - m1) * hue / 60;
else if (hue < 180)
g = m2;
else if (hue < 240)
g = m1 + (m2 - m1) * (240 - hue) / 60;
else
g = m1;
hue = *h - 120;
while (hue > 360)
hue -= 360;
while (hue < 0)
hue += 360;
if (hue < 60)
b = m1 + (m2 - m1) * hue / 60;
else if (hue < 180)
b = m2;
else if (hue < 240)
b = m1 + (m2 - m1) * (240 - hue) / 60;
else
b = m1;
*h = r;
*l = g;
*s = b;
}
}
static void
_shade_color (GdkRGBA *color,
gdouble factor)
{
GdkRGBA temp;
temp = *color;
rgb_to_hls (&temp.red, &temp.green, &temp.blue);
temp.green *= factor;
if (temp.green > 1.0)
temp.green = 1.0;
else if (temp.green < 0.0)
temp.green = 0.0;
temp.blue *= factor;
if (temp.blue > 1.0)
temp.blue = 1.0;
else if (temp.blue < 0.0)
temp.blue = 0.0;
hls_to_rgb (&temp.red, &temp.green, &temp.blue);
*color = temp;
}
/**
* gtk_symbolic_color_resolve:
* @color: a #GtkSymbolicColor
* @props: (allow-none): #GtkStyleProperties to use when resolving
* named colors, or %NULL
* @resolved_color: (out): return location for the resolved color
*
* If @color is resolvable, @resolved_color will be filled in
* with the resolved color, and %TRUE will be returned. Generally,
* if @color can't be resolved, it is due to it being defined on
* top of a named color that doesn't exist in @props.
*
* When @props is %NULL, resolving of named colors will fail, so if
* your @color is or references such a color, this function will
* return %FALSE.
*
* Returns: %TRUE if the color has been resolved
*
* Since: 3.0
**/
gboolean
gtk_symbolic_color_resolve (GtkSymbolicColor *color,
GtkStyleProperties *props,
GdkRGBA *resolved_color)
{
g_return_val_if_fail (color != NULL, FALSE);
g_return_val_if_fail (resolved_color != NULL, FALSE);
g_return_val_if_fail (props == NULL || GTK_IS_STYLE_PROPERTIES (props), FALSE);
switch (color->type)
{
case COLOR_TYPE_LITERAL:
*resolved_color = color->color;
return TRUE;
case COLOR_TYPE_NAME:
{
GtkSymbolicColor *named_color;
if (props == NULL)
return FALSE;
named_color = gtk_style_properties_lookup_color (props, color->name);
if (!named_color)
return FALSE;
return gtk_symbolic_color_resolve (named_color, props, resolved_color);
}
break;
case COLOR_TYPE_SHADE:
{
GdkRGBA shade;
if (!gtk_symbolic_color_resolve (color->shade.color, props, &shade))
return FALSE;
_shade_color (&shade, color->shade.factor);
*resolved_color = shade;
return TRUE;
}
break;
case COLOR_TYPE_ALPHA:
{
GdkRGBA alpha;
if (!gtk_symbolic_color_resolve (color->alpha.color, props, &alpha))
return FALSE;
*resolved_color = alpha;
resolved_color->alpha = CLAMP (alpha.alpha * color->alpha.factor, 0, 1);
return TRUE;
}
case COLOR_TYPE_MIX:
{
GdkRGBA color1, color2;
if (!gtk_symbolic_color_resolve (color->mix.color1, props, &color1))
return FALSE;
if (!gtk_symbolic_color_resolve (color->mix.color2, props, &color2))
return FALSE;
resolved_color->red = CLAMP (color1.red + ((color2.red - color1.red) * color->mix.factor), 0, 1);
resolved_color->green = CLAMP (color1.green + ((color2.green - color1.green) * color->mix.factor), 0, 1);
resolved_color->blue = CLAMP (color1.blue + ((color2.blue - color1.blue) * color->mix.factor), 0, 1);
resolved_color->alpha = CLAMP (color1.alpha + ((color2.alpha - color1.alpha) * color->mix.factor), 0, 1);
return TRUE;
}
break;
default:
g_assert_not_reached ();
}
return FALSE;
}
/**
* gtk_symbolic_color_to_string:
* @color: color to convert to a string
*
* Converts the given @color to a string representation. This is useful
* both for debugging and for serialization of strings. The format of
* the string may change between different versions of GTK, but it is
* guaranteed that the GTK css parser is able to read the string and
* create the same symbolic color from it.
*
* Returns: a new string representing @color
**/
char *
gtk_symbolic_color_to_string (GtkSymbolicColor *color)
{
char *s;
g_return_val_if_fail (color != NULL, NULL);
switch (color->type)
{
case COLOR_TYPE_LITERAL:
s = gdk_rgba_to_string (&color->color);
break;
case COLOR_TYPE_NAME:
s = g_strconcat ("@", color->name, NULL);
break;
case COLOR_TYPE_SHADE:
{
char *color_string = gtk_symbolic_color_to_string (color->shade.color);
char factor[G_ASCII_DTOSTR_BUF_SIZE];
g_ascii_dtostr (factor, sizeof (factor), color->shade.factor);
s = g_strdup_printf ("shade (%s, %s)", color_string, factor);
g_free (color_string);
}
break;
case COLOR_TYPE_ALPHA:
{
char *color_string = gtk_symbolic_color_to_string (color->shade.color);
char factor[G_ASCII_DTOSTR_BUF_SIZE];
g_ascii_dtostr (factor, sizeof (factor), color->alpha.factor);
s = g_strdup_printf ("alpha (%s, %s)", color_string, factor);
g_free (color_string);
}
break;
case COLOR_TYPE_MIX:
{
char *color_string1 = gtk_symbolic_color_to_string (color->mix.color1);
char *color_string2 = gtk_symbolic_color_to_string (color->mix.color2);
char factor[G_ASCII_DTOSTR_BUF_SIZE];
g_ascii_dtostr (factor, sizeof (factor), color->mix.factor);
s = g_strdup_printf ("mix (%s, %s, %s)", color_string1, color_string2, factor);
g_free (color_string1);
g_free (color_string2);
}
break;
default:
g_assert_not_reached ();
}
return s;
}