gtk2/gtk/gtkcssrgbavalue.c

130 lines
3.6 KiB
C
Raw Normal View History

/* GTK - The GIMP Toolkit
* Copyright (C) 2011 Red Hat, Inc.
*
* 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/>.
*/
#include "config.h"
#include "gtkcssrgbavalueprivate.h"
#include "gtkcssstylepropertyprivate.h"
#include "gtkstylecontextprivate.h"
struct _GtkCssValue {
GTK_CSS_VALUE_BASE
GdkRGBA rgba;
};
static void
gtk_css_value_rgba_free (GtkCssValue *value)
{
g_slice_free (GtkCssValue, value);
}
static GtkCssValue *
gtk_css_value_rgba_compute (GtkCssValue *value,
guint property_id,
GtkStyleProvider *provider,
GtkCssStyle *style,
GtkCssStyle *parent_style)
{
return _gtk_css_value_ref (value);
}
static gboolean
gtk_css_value_rgba_equal (const GtkCssValue *rgba1,
const GtkCssValue *rgba2)
{
return gdk_rgba_equal (&rgba1->rgba, &rgba2->rgba);
}
static inline double
transition (double start,
double end,
double progress)
{
return start + (end - start) * progress;
}
static GtkCssValue *
gtk_css_value_rgba_transition (GtkCssValue *start,
GtkCssValue *end,
guint property_id,
double progress)
{
GdkRGBA result;
progress = CLAMP (progress, 0, 1);
result.alpha = transition (start->rgba.alpha, end->rgba.alpha, progress);
if (result.alpha <= 0.0)
{
result.red = result.green = result.blue = 0.0;
}
else
{
result.red = transition (start->rgba.red * start->rgba.alpha,
end->rgba.red * end->rgba.alpha,
progress) / result.alpha;
result.green = transition (start->rgba.green * start->rgba.alpha,
end->rgba.green * end->rgba.alpha,
progress) / result.alpha;
result.blue = transition (start->rgba.blue * start->rgba.alpha,
end->rgba.blue * end->rgba.alpha,
progress) / result.alpha;
}
return _gtk_css_rgba_value_new_from_rgba (&result);
}
static void
gtk_css_value_rgba_print (const GtkCssValue *rgba,
GString *string)
{
char *s = gdk_rgba_to_string (&rgba->rgba);
g_string_append (string, s);
g_free (s);
}
static const GtkCssValueClass GTK_CSS_VALUE_RGBA = {
gtk_css_value_rgba_free,
gtk_css_value_rgba_compute,
gtk_css_value_rgba_equal,
gtk_css_value_rgba_transition,
NULL,
NULL,
gtk_css_value_rgba_print
};
GtkCssValue *
_gtk_css_rgba_value_new_from_rgba (const GdkRGBA *rgba)
{
GtkCssValue *value;
g_return_val_if_fail (rgba != NULL, NULL);
value = _gtk_css_value_new (GtkCssValue, &GTK_CSS_VALUE_RGBA);
value->rgba = *rgba;
return value;
}
const GdkRGBA *
_gtk_css_rgba_value_get_rgba (const GtkCssValue *rgba)
{
g_return_val_if_fail (rgba->class == &GTK_CSS_VALUE_RGBA, NULL);
return &rgba->rgba;
}