gtk2/gtk/gtkcssimagefallback.c
Matthias Clasen 2e4b1e72f4 css: Support the image() notation
This lets us do fallback in case an image format is not
supported, and also lets us provide solid-color images.
We don't support image fragment notations.

See ttps://www.w3.org/TR/css3-images/#image-notation

https://bugzilla.gnome.org/show_bug.cgi?id=761318
2016-01-30 00:29:04 -05:00

256 lines
7.4 KiB
C

/*
* Copyright © 2016 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 2.1 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/>.
*
* Authors: Matthias Clasen <mclasen@redhat.com>
*/
#include "config.h"
#include "gtkcssimagefallbackprivate.h"
#include "gtkcssimagesurfaceprivate.h"
#include "gtkcsscolorvalueprivate.h"
#include "gtkcssrgbavalueprivate.h"
#include "gtkstyleproviderprivate.h"
G_DEFINE_TYPE (GtkCssImageFallback, _gtk_css_image_fallback, GTK_TYPE_CSS_IMAGE)
static int
gtk_css_image_fallback_get_width (GtkCssImage *image)
{
GtkCssImageFallback *fallback = GTK_CSS_IMAGE_FALLBACK (image);
if (fallback->used < 0)
return 0;
return _gtk_css_image_get_width (fallback->images[fallback->used]);
}
static int
gtk_css_image_fallback_get_height (GtkCssImage *image)
{
GtkCssImageFallback *fallback = GTK_CSS_IMAGE_FALLBACK (image);
if (fallback->used < 0)
return 0;
return _gtk_css_image_get_height (fallback->images[fallback->used]);
}
static double
gtk_css_image_fallback_get_aspect_ratio (GtkCssImage *image)
{
GtkCssImageFallback *fallback = GTK_CSS_IMAGE_FALLBACK (image);
if (fallback->used < 0)
return 1;
return _gtk_css_image_get_aspect_ratio (fallback->images[fallback->used]);
}
static void
gtk_css_image_fallback_draw (GtkCssImage *image,
cairo_t *cr,
double width,
double height)
{
GtkCssImageFallback *fallback = GTK_CSS_IMAGE_FALLBACK (image);
if (fallback->used < 0)
{
if (fallback->color)
gdk_cairo_set_source_rgba (cr, _gtk_css_rgba_value_get_rgba (fallback->color));
else
cairo_set_source_rgb (cr, 1, 0, 9);
cairo_rectangle (cr, 0, 0, width, height);
cairo_fill (cr);
}
else
_gtk_css_image_draw (fallback->images[fallback->used], cr, width, height);
}
static void
gtk_css_image_fallback_print (GtkCssImage *image,
GString *string)
{
GtkCssImageFallback *fallback = GTK_CSS_IMAGE_FALLBACK (image);
int i;
g_string_append (string, "image(");
for (i = 0; i < fallback->n_images; i++)
{
if (i > 0)
g_string_append (string, ",");
_gtk_css_image_print (fallback->images[i], string);
}
if (fallback->color)
{
g_string_append (string, ",");
_gtk_css_value_print (fallback->color, string);
}
g_string_append (string, ")");
}
static void
gtk_css_image_fallback_dispose (GObject *object)
{
GtkCssImageFallback *fallback = GTK_CSS_IMAGE_FALLBACK (object);
int i;
for (i = 0; i < fallback->n_images; i++)
g_object_unref (fallback->images[i]);
g_free (fallback->images);
fallback->images = NULL;
if (fallback->color)
{
_gtk_css_value_unref (fallback->color);
fallback->color = NULL;
}
G_OBJECT_CLASS (_gtk_css_image_fallback_parent_class)->dispose (object);
}
static GtkCssImage *
gtk_css_image_fallback_compute (GtkCssImage *image,
guint property_id,
GtkStyleProviderPrivate *provider,
GtkCssStyle *style,
GtkCssStyle *parent_style)
{
GtkCssImageFallback *fallback = GTK_CSS_IMAGE_FALLBACK (image);
GtkCssImageFallback *copy;
int i;
if (fallback->used < 0)
{
copy = g_object_new (_gtk_css_image_fallback_get_type (), NULL);
copy->n_images = fallback->n_images;
copy->images = g_new (GtkCssImage *, fallback->n_images);
for (i = 0; i < fallback->n_images; i++)
{
copy->images[i] = _gtk_css_image_compute (fallback->images[i],
property_id,
provider,
style,
parent_style);
/* Assume that failing to load an image leaves a 0x0 surface image */
if (GTK_IS_CSS_IMAGE_SURFACE (copy->images[i]) &&
_gtk_css_image_get_width (copy->images[i]) == 0 &&
_gtk_css_image_get_height (copy->images[i]) == 0)
continue;
if (copy->used < 0)
copy->used = i;
}
if (fallback->color)
copy->color = _gtk_css_value_compute (fallback->color,
property_id,
provider,
style,
parent_style);
else
copy->color = NULL;
return GTK_CSS_IMAGE (copy);
}
else
return g_object_ref (fallback);
}
static gboolean
gtk_css_image_fallback_parse (GtkCssImage *image,
GtkCssParser *parser)
{
GtkCssImageFallback *fallback = GTK_CSS_IMAGE_FALLBACK (image);
GPtrArray *images;
GtkCssImage *child;
if (!_gtk_css_parser_try (parser, "image", TRUE))
{
_gtk_css_parser_error (parser, "'image'");
return FALSE;
}
if (!_gtk_css_parser_try (parser, "(", TRUE))
{
_gtk_css_parser_error (parser,
"Expected '(' after 'image'");
return FALSE;
}
images = g_ptr_array_new_with_free_func (g_object_unref);
do
{
child = NULL;
if (_gtk_css_image_can_parse (parser))
child = _gtk_css_image_new_parse (parser);
if (child == NULL)
{
fallback->color = _gtk_css_color_value_parse (parser);
if (fallback->color)
break;
g_ptr_array_free (images, TRUE);
return FALSE;
}
g_ptr_array_add (images, child);
}
while ( _gtk_css_parser_try (parser, ",", TRUE));
if (!_gtk_css_parser_try (parser, ")", TRUE))
{
g_ptr_array_free (images, TRUE);
_gtk_css_parser_error (parser,
"Expected ')' at end of 'image'");
return FALSE;
}
fallback->n_images = images->len;
fallback->images = (GtkCssImage **) g_ptr_array_free (images, FALSE);
return TRUE;
}
static void
_gtk_css_image_fallback_class_init (GtkCssImageFallbackClass *klass)
{
GtkCssImageClass *image_class = GTK_CSS_IMAGE_CLASS (klass);
GObjectClass *object_class = G_OBJECT_CLASS (klass);
image_class->get_width = gtk_css_image_fallback_get_width;
image_class->get_height = gtk_css_image_fallback_get_height;
image_class->get_aspect_ratio = gtk_css_image_fallback_get_aspect_ratio;
image_class->draw = gtk_css_image_fallback_draw;
image_class->parse = gtk_css_image_fallback_parse;
image_class->compute = gtk_css_image_fallback_compute;
image_class->print = gtk_css_image_fallback_print;
object_class->dispose = gtk_css_image_fallback_dispose;
}
static void
_gtk_css_image_fallback_init (GtkCssImageFallback *image_fallback)
{
image_fallback->used = -1;
}