gtk2/gtk/gtkcolorchooser.c

263 lines
7.8 KiB
C

/* GTK - The GIMP Toolkit
*
* Copyright (C) 2012, 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 "gtkcolorchooser.h"
#include "gtkcolorchooserprivate.h"
#include "gtkintl.h"
#include "gtktypebuiltins.h"
#include "gtkprivate.h"
/**
* SECTION:gtkcolorchooser
* @Short_description: Interface implemented by widgets for choosing colors
* @Title: GtkColorChooser
* @See_also: #GtkColorChooserDialog, #GtkColorChooserWidget, #GtkColorButton
*
* #GtkColorChooser is an interface that is implemented by widgets
* for choosing colors. Depending on the situation, colors may be
* allowed to have alpha (translucency).
*
* In GTK+, the main widgets that implement this interface are
* #GtkColorChooserWidget, #GtkColorChooserDialog and #GtkColorButton.
*
* Since: 3.4
*/
enum
{
COLOR_ACTIVATED,
LAST_SIGNAL
};
static guint signals[LAST_SIGNAL];
G_DEFINE_INTERFACE (GtkColorChooser, gtk_color_chooser, G_TYPE_OBJECT);
static void
gtk_color_chooser_default_init (GtkColorChooserInterface *iface)
{
/**
* GtkColorChooser:rgba:
*
* The ::rgba property contains the currently selected color,
* as a #GdkRGBA struct. The property can be set to change
* the current selection programmatically.
*
* Since: 3.4
*/
g_object_interface_install_property (iface,
g_param_spec_boxed ("rgba",
P_("Color"),
P_("Current color, as a GdkRGBA"),
GDK_TYPE_RGBA,
GTK_PARAM_READWRITE));
/**
* GtkColorChooser:use-alpha:
*
* When ::use-alpha is %TRUE, colors may have alpha (translucency)
* information. When it is %FALSE, the #GdkRGBA struct obtained
* via the #GtkColorChooser:rgba property will be forced to have
* alpha == 1.
*
* Implementations are expected to show alpha by rendering the color
* over a non-uniform background (like a checkerboard pattern).
*
* Since: 3.4
*/
g_object_interface_install_property (iface,
g_param_spec_boolean ("use-alpha",
P_("Use alpha"),
P_("Whether alpha should be shown"),
TRUE,
GTK_PARAM_READWRITE));
/**
* GtkColorChooser::color-activated:
* @chooser: the object which received the signal
* @color: the color
*
* Emitted when a color is activated from the color chooser.
* This usually happens when the user clicks a color swatch,
* or a color is selected and the user presses one of the keys
* Space, Shift+Space, Return or Enter.
*
* Since: 3.4
*/
signals[COLOR_ACTIVATED] =
g_signal_new ("color-activated",
GTK_TYPE_COLOR_CHOOSER,
G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (GtkColorChooserInterface, color_activated),
NULL, NULL,
NULL,
G_TYPE_NONE,
1, GDK_TYPE_RGBA);
}
void
_gtk_color_chooser_color_activated (GtkColorChooser *chooser,
const GdkRGBA *color)
{
g_signal_emit (chooser, signals[COLOR_ACTIVATED], 0, color);
}
/**
* gtk_color_chooser_get_rgba:
* @chooser: a #GtkColorChooser
* @color: return location for the color
*
* Gets the currently-selected color.
*
* Since: 3.4
*/
void
gtk_color_chooser_get_rgba (GtkColorChooser *chooser,
GdkRGBA *color)
{
g_return_if_fail (GTK_IS_COLOR_CHOOSER (chooser));
GTK_COLOR_CHOOSER_GET_IFACE (chooser)->get_rgba (chooser, color);
}
/**
* gtk_color_chooser_set_rgba:
* @chooser: a #GtkColorChooser
* @color: the new color
*
* Sets the color.
*
* Since: 3.4
*/
void
gtk_color_chooser_set_rgba (GtkColorChooser *chooser,
const GdkRGBA *color)
{
g_return_if_fail (GTK_IS_COLOR_CHOOSER (chooser));
g_return_if_fail (color != NULL);
GTK_COLOR_CHOOSER_GET_IFACE (chooser)->set_rgba (chooser, color);
}
/**
* gtk_color_chooser_get_use_alpha:
* @chooser: a #GtkColorChooser
*
* Returns whether the color chooser shows the alpha channel.
*
* Returns: %TRUE if the color chooser uses the alpha channel,
* %FALSE if not
*
* Since: 3.4
*/
gboolean
gtk_color_chooser_get_use_alpha (GtkColorChooser *chooser)
{
gboolean use_alpha;
g_return_val_if_fail (GTK_IS_COLOR_CHOOSER (chooser), TRUE);
g_object_get (chooser, "use-alpha", &use_alpha, NULL);
return use_alpha;
}
/**
* gtk_color_chooser_set_use_alpha:
* @chooser: a #GtkColorChooser
* @use_alpha: %TRUE if color chooser should use alpha channel, %FALSE if not
*
* Sets whether or not the color chooser should use the alpha channel.
*
* Since: 3.4
*/
void
gtk_color_chooser_set_use_alpha (GtkColorChooser *chooser,
gboolean use_alpha)
{
g_return_if_fail (GTK_IS_COLOR_CHOOSER (chooser));
g_object_set (chooser, "use-alpha", use_alpha, NULL);
}
/**
* gtk_color_chooser_add_palette:
* @chooser: a #GtkColorChooser
* @horizontal: %TRUE if the palette should be displayed in rows,
* %FALSE for columns
* @colors_per_line: the number of colors to show in each row/column
* @n_colors: the total number of elements in @colors
* @colors: (allow-none) (array length=n_colors): the colors of the palette, or %NULL
*
* Adds a palette to the color chooser. If @horizontal is %TRUE,
* the colors are grouped in rows, with @colors_per_line colors
* in each row. If @horizontal is %FALSE, the colors are grouped
* in columns instead.
*
* The default color palette of #GtkColorChooserWidget has
* 27 colors, organized in columns of 3 colors. The default gray
* palette has 9 grays in a single row.
*
* The layout of the color chooser widget works best when the
* palettes have 9-10 columns.
*
* Calling this function is called for the first time has the
* side effect of removing the default color and gray palettes
* from the color chooser.
*
* If @colors is %NULL, removes all previously added palettes.
*
* Since: 3.4
*/
void
gtk_color_chooser_add_palette (GtkColorChooser *chooser,
gboolean horizontal,
gint colors_per_line,
gint n_colors,
GdkRGBA *colors)
{
g_return_if_fail (GTK_IS_COLOR_CHOOSER (chooser));
if (GTK_COLOR_CHOOSER_GET_IFACE (chooser)->add_palette)
GTK_COLOR_CHOOSER_GET_IFACE (chooser)->add_palette (chooser, horizontal, colors_per_line, n_colors, colors);
}
cairo_pattern_t *
_gtk_color_chooser_get_checkered_pattern (void)
{
/* need to respect pixman's stride being a multiple of 4 */
static unsigned char data[8] = { 0xFF, 0x00, 0x00, 0x00,
0x00, 0xFF, 0x00, 0x00 };
static cairo_surface_t *checkered = NULL;
cairo_pattern_t *pattern;
if (checkered == NULL)
checkered = cairo_image_surface_create_for_data (data,
CAIRO_FORMAT_A8,
2, 2, 4);
pattern = cairo_pattern_create_for_surface (checkered);
cairo_pattern_set_extend (pattern, CAIRO_EXTEND_REPEAT);
cairo_pattern_set_filter (pattern, CAIRO_FILTER_NEAREST);
return pattern;
}