gtk2/gtk/deprecated/gtkgradient.c
2014-02-07 13:32:47 -05:00

552 lines
16 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* 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, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#define GDK_DISABLE_DEPRECATION_WARNINGS
#include "gtkgradientprivate.h"
#include "gtkcsscolorvalueprivate.h"
#include "gtkcssrgbavalueprivate.h"
#include "gtkstylecontextprivate.h"
#include "gtkstyleproperties.h"
#include "gtksymboliccolorprivate.h"
/**
* SECTION:gtkgradient
* @Short_description: Gradients
* @Title: GtkGradient
*
* GtkGradient is a boxed type that represents a gradient.
* It is the result of parsing a
* [gradient expression][gtkcssprovider-gradients].
* To obtain the gradient represented by a GtkGradient, it has to
* be resolved with gtk_gradient_resolve(), which replaces all
* symbolic color references by the colors they refer to (in a given
* context) and constructs a #cairo_pattern_t value.
*
* It is not normally necessary to deal directly with #GtkGradients,
* since they are mostly used behind the scenes by #GtkStyleContext and
* #GtkCssProvider.
*
* #GtkGradient is deprecated. It was used internally by GTKs CSS engine
* to represent gradients. As its handling is not conforming to modern
* web standards, it is not used anymore. If you want to use gradients in
* your own code, please use Cairo directly.
*/
G_DEFINE_BOXED_TYPE (GtkGradient, gtk_gradient,
gtk_gradient_ref, gtk_gradient_unref)
typedef struct ColorStop ColorStop;
struct ColorStop
{
gdouble offset;
GtkSymbolicColor *color;
};
struct _GtkGradient
{
gdouble x0;
gdouble y0;
gdouble x1;
gdouble y1;
gdouble radius0;
gdouble radius1;
GArray *stops;
guint ref_count;
};
/**
* gtk_gradient_new_linear:
* @x0: X coordinate of the starting point
* @y0: Y coordinate of the starting point
* @x1: X coordinate of the end point
* @y1: Y coordinate of the end point
*
* Creates a new linear gradient along the line defined by (x0, y0) and (x1, y1). Before using the gradient
* a number of stop colors must be added through gtk_gradient_add_color_stop().
*
* Returns: A newly created #GtkGradient
*
* Since: 3.0
*
* Deprecated: 3.8: #GtkGradient is deprecated.
**/
GtkGradient *
gtk_gradient_new_linear (gdouble x0,
gdouble y0,
gdouble x1,
gdouble y1)
{
GtkGradient *gradient;
gradient = g_slice_new (GtkGradient);
gradient->stops = g_array_new (FALSE, FALSE, sizeof (ColorStop));
gradient->x0 = x0;
gradient->y0 = y0;
gradient->x1 = x1;
gradient->y1 = y1;
gradient->radius0 = 0;
gradient->radius1 = 0;
gradient->ref_count = 1;
return gradient;
}
/**
* gtk_gradient_new_radial:
* @x0: X coordinate of the start circle
* @y0: Y coordinate of the start circle
* @radius0: radius of the start circle
* @x1: X coordinate of the end circle
* @y1: Y coordinate of the end circle
* @radius1: radius of the end circle
*
* Creates a new radial gradient along the two circles defined by (x0, y0, radius0) and
* (x1, y1, radius1). Before using the gradient a number of stop colors must be added
* through gtk_gradient_add_color_stop().
*
* Returns: A newly created #GtkGradient
*
* Since: 3.0
*
* Deprecated: 3.8: #GtkGradient is deprecated.
**/
GtkGradient *
gtk_gradient_new_radial (gdouble x0,
gdouble y0,
gdouble radius0,
gdouble x1,
gdouble y1,
gdouble radius1)
{
GtkGradient *gradient;
gradient = g_slice_new (GtkGradient);
gradient->stops = g_array_new (FALSE, FALSE, sizeof (ColorStop));
gradient->x0 = x0;
gradient->y0 = y0;
gradient->x1 = x1;
gradient->y1 = y1;
gradient->radius0 = radius0;
gradient->radius1 = radius1;
gradient->ref_count = 1;
return gradient;
}
/**
* gtk_gradient_add_color_stop:
* @gradient: a #GtkGradient
* @offset: offset for the color stop
* @color: color to use
*
* Adds a stop color to @gradient.
*
* Since: 3.0
*
* Deprecated: 3.8: #GtkGradient is deprecated.
**/
void
gtk_gradient_add_color_stop (GtkGradient *gradient,
gdouble offset,
GtkSymbolicColor *color)
{
ColorStop stop;
g_return_if_fail (gradient != NULL);
stop.offset = offset;
stop.color = gtk_symbolic_color_ref (color);
g_array_append_val (gradient->stops, stop);
}
/**
* gtk_gradient_ref:
* @gradient: a #GtkGradient
*
* Increases the reference count of @gradient.
*
* Returns: The same @gradient
*
* Since: 3.0
*
* Deprecated: 3.8: #GtkGradient is deprecated.
**/
GtkGradient *
gtk_gradient_ref (GtkGradient *gradient)
{
g_return_val_if_fail (gradient != NULL, NULL);
gradient->ref_count++;
return gradient;
}
/**
* gtk_gradient_unref:
* @gradient: a #GtkGradient
*
* Decreases the reference count of @gradient, freeing its memory
* if the reference count reaches 0.
*
* Since: 3.0
*
* Deprecated: 3.8: #GtkGradient is deprecated.
**/
void
gtk_gradient_unref (GtkGradient *gradient)
{
g_return_if_fail (gradient != NULL);
gradient->ref_count--;
if (gradient->ref_count == 0)
{
guint i;
for (i = 0; i < gradient->stops->len; i++)
{
ColorStop *stop;
stop = &g_array_index (gradient->stops, ColorStop, i);
gtk_symbolic_color_unref (stop->color);
}
g_array_free (gradient->stops, TRUE);
g_slice_free (GtkGradient, gradient);
}
}
/**
* gtk_gradient_resolve:
* @gradient: a #GtkGradient
* @props: #GtkStyleProperties to use when resolving named colors
* @resolved_gradient: (out): return location for the resolved pattern
*
* If @gradient is resolvable, @resolved_gradient will be filled in
* with the resolved gradient as a cairo_pattern_t, and %TRUE will
* be returned. Generally, if @gradient cant be resolved, it is
* due to it being defined on top of a named color that doesn't
* exist in @props.
*
* Returns: %TRUE if the gradient has been resolved
*
* Since: 3.0
*
* Deprecated: 3.8: #GtkGradient is deprecated.
**/
gboolean
gtk_gradient_resolve (GtkGradient *gradient,
GtkStyleProperties *props,
cairo_pattern_t **resolved_gradient)
{
cairo_pattern_t *pattern;
guint i;
g_return_val_if_fail (gradient != NULL, FALSE);
g_return_val_if_fail (GTK_IS_STYLE_PROPERTIES (props), FALSE);
g_return_val_if_fail (resolved_gradient != NULL, FALSE);
if (gradient->radius0 == 0 && gradient->radius1 == 0)
pattern = cairo_pattern_create_linear (gradient->x0, gradient->y0,
gradient->x1, gradient->y1);
else
pattern = cairo_pattern_create_radial (gradient->x0, gradient->y0,
gradient->radius0,
gradient->x1, gradient->y1,
gradient->radius1);
for (i = 0; i < gradient->stops->len; i++)
{
ColorStop *stop;
GdkRGBA color;
stop = &g_array_index (gradient->stops, ColorStop, i);
if (!gtk_symbolic_color_resolve (stop->color, props, &color))
{
cairo_pattern_destroy (pattern);
return FALSE;
}
cairo_pattern_add_color_stop_rgba (pattern, stop->offset,
color.red, color.green,
color.blue, color.alpha);
}
*resolved_gradient = pattern;
return TRUE;
}
cairo_pattern_t *
_gtk_gradient_resolve_full (GtkGradient *gradient,
GtkStyleProviderPrivate *provider,
GtkCssComputedValues *values,
GtkCssComputedValues *parent_values,
GtkCssDependencies *dependencies)
{
cairo_pattern_t *pattern;
guint i;
g_return_val_if_fail (gradient != NULL, NULL);
g_return_val_if_fail (GTK_IS_STYLE_PROVIDER (provider), NULL);
g_return_val_if_fail (GTK_IS_CSS_COMPUTED_VALUES (values), NULL);
g_return_val_if_fail (parent_values == NULL || GTK_IS_CSS_COMPUTED_VALUES (parent_values), NULL);
g_return_val_if_fail (*dependencies == 0, NULL);
if (gradient->radius0 == 0 && gradient->radius1 == 0)
pattern = cairo_pattern_create_linear (gradient->x0, gradient->y0,
gradient->x1, gradient->y1);
else
pattern = cairo_pattern_create_radial (gradient->x0, gradient->y0,
gradient->radius0,
gradient->x1, gradient->y1,
gradient->radius1);
for (i = 0; i < gradient->stops->len; i++)
{
ColorStop *stop;
GtkCssValue *val;
GdkRGBA rgba;
GtkCssDependencies stop_deps;
stop = &g_array_index (gradient->stops, ColorStop, i);
/* if color resolving fails, assume transparency */
val = _gtk_css_color_value_resolve (_gtk_symbolic_color_get_css_value (stop->color),
provider,
_gtk_css_computed_values_get_value (values, GTK_CSS_PROPERTY_COLOR),
GTK_CSS_DEPENDS_ON_COLOR,
&stop_deps,
NULL);
if (val)
{
rgba = *_gtk_css_rgba_value_get_rgba (val);
*dependencies = _gtk_css_dependencies_union (*dependencies, stop_deps);
_gtk_css_value_unref (val);
}
else
{
rgba.red = rgba.green = rgba.blue = rgba.alpha = 0.0;
}
cairo_pattern_add_color_stop_rgba (pattern, stop->offset,
rgba.red, rgba.green,
rgba.blue, rgba.alpha);
}
return pattern;
}
static void
append_number (GString *str,
double d,
const char *zero,
const char *half,
const char *one)
{
if (zero && d == 0.0)
g_string_append (str, zero);
else if (half && d == 0.5)
g_string_append (str, half);
else if (one && d == 1.0)
g_string_append (str, one);
else
{
char buf[G_ASCII_DTOSTR_BUF_SIZE];
g_ascii_dtostr (buf, sizeof (buf), d);
g_string_append (str, buf);
}
}
/**
* gtk_gradient_to_string:
* @gradient: the gradient to print
*
* Creates a string representation for @gradient that is suitable
* for using in GTK CSS files.
*
* Returns: A string representation for @gradient
*
* Deprecated: 3.8: #GtkGradient is deprecated.
**/
char *
gtk_gradient_to_string (GtkGradient *gradient)
{
GString *str;
guint i;
g_return_val_if_fail (gradient != NULL, NULL);
str = g_string_new ("-gtk-gradient (");
if (gradient->radius0 == 0 && gradient->radius1 == 0)
{
g_string_append (str, "linear, ");
append_number (str, gradient->x0, "left", "center", "right");
g_string_append_c (str, ' ');
append_number (str, gradient->y0, "top", "center", "bottom");
g_string_append (str, ", ");
append_number (str, gradient->x1, "left", "center", "right");
g_string_append_c (str, ' ');
append_number (str, gradient->y1, "top", "center", "bottom");
}
else
{
g_string_append (str, "radial, ");
append_number (str, gradient->x0, "left", "center", "right");
g_string_append_c (str, ' ');
append_number (str, gradient->y0, "top", "center", "bottom");
g_string_append (str, ", ");
append_number (str, gradient->radius0, NULL, NULL, NULL);
g_string_append (str, ", ");
append_number (str, gradient->x1, "left", "center", "right");
g_string_append_c (str, ' ');
append_number (str, gradient->y1, "top", "center", "bottom");
g_string_append (str, ", ");
append_number (str, gradient->radius1, NULL, NULL, NULL);
}
for (i = 0; i < gradient->stops->len; i++)
{
ColorStop *stop;
char *s;
stop = &g_array_index (gradient->stops, ColorStop, i);
g_string_append (str, ", ");
if (stop->offset == 0.0)
g_string_append (str, "from (");
else if (stop->offset == 1.0)
g_string_append (str, "to (");
else
{
g_string_append (str, "color-stop (");
append_number (str, stop->offset, NULL, NULL, NULL);
g_string_append (str, ", ");
}
s = gtk_symbolic_color_to_string (stop->color);
g_string_append (str, s);
g_free (s);
g_string_append (str, ")");
}
g_string_append (str, ")");
return g_string_free (str, FALSE);
}
static GtkGradient *
gtk_gradient_fade (GtkGradient *gradient,
double opacity)
{
GtkGradient *faded;
guint i;
faded = g_slice_new (GtkGradient);
faded->stops = g_array_new (FALSE, FALSE, sizeof (ColorStop));
faded->x0 = gradient->x0;
faded->y0 = gradient->y0;
faded->x1 = gradient->x1;
faded->y1 = gradient->y1;
faded->radius0 = gradient->radius0;
faded->radius1 = gradient->radius1;
faded->ref_count = 1;
for (i = 0; i < gradient->stops->len; i++)
{
GtkSymbolicColor *color;
ColorStop *stop;
stop = &g_array_index (gradient->stops, ColorStop, i);
color = gtk_symbolic_color_new_alpha (stop->color, opacity);
gtk_gradient_add_color_stop (faded, stop->offset, color);
gtk_symbolic_color_unref (color);
}
return faded;
}
GtkGradient *
_gtk_gradient_transition (GtkGradient *start,
GtkGradient *end,
guint property_id,
double progress)
{
GtkGradient *gradient;
guint i;
g_return_val_if_fail (start != NULL, NULL);
if (end == NULL)
return gtk_gradient_fade (start, 1.0 - CLAMP (progress, 0.0, 1.0));
if (start->stops->len != end->stops->len)
return NULL;
/* check both are radial/linear */
if ((start->radius0 == 0 && start->radius1 == 0) != (end->radius0 == 0 && end->radius1 == 0))
return NULL;
gradient = g_slice_new (GtkGradient);
gradient->stops = g_array_new (FALSE, FALSE, sizeof (ColorStop));
gradient->x0 = (1 - progress) * start->x0 + progress * end->x0;
gradient->y0 = (1 - progress) * start->y0 + progress * end->y0;
gradient->x1 = (1 - progress) * start->x1 + progress * end->x1;
gradient->y1 = (1 - progress) * start->y1 + progress * end->y1;
gradient->radius0 = (1 - progress) * start->radius0 + progress * end->radius0;
gradient->radius1 = (1 - progress) * start->radius1 + progress * end->radius1;
gradient->ref_count = 1;
for (i = 0; i < start->stops->len; i++)
{
ColorStop *start_stop, *end_stop;
GtkSymbolicColor *color;
double offset;
start_stop = &g_array_index (start->stops, ColorStop, i);
end_stop = &g_array_index (end->stops, ColorStop, i);
offset = (1 - progress) * start_stop->offset + progress * end_stop->offset;
color = gtk_symbolic_color_new_mix (start_stop->color,
end_stop->color,
progress);
gtk_gradient_add_color_stop (gradient, offset, color);
gtk_symbolic_color_unref (color);
}
return gradient;
}