gtk2/gtk/gtkcssimage.c
Benjamin Otte 27b9efbea2 cssimage: Fix size computation for -gtk-icontheme()
For images without a concrete size but with an aspect ratio, we took the
wrong code path.

(I even copied the documentation that said "Otherwise" but didn't put an
else clause there, go me!)
2014-07-23 18:51:26 +02:00

492 lines
14 KiB
C

/*
* Copyright © 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 2.1 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: Benjamin Otte <otte@gnome.org>
*/
#include "config.h"
#include "gtkcssimageprivate.h"
#include "gtkcsscomputedvaluesprivate.h"
/* for the types only */
#include "gtk/gtkcssimagecrossfadeprivate.h"
#include "gtk/gtkcssimagegradientprivate.h"
#include "gtk/gtkcssimageiconthemeprivate.h"
#include "gtk/gtkcssimagelinearprivate.h"
#include "gtk/gtkcssimageurlprivate.h"
#include "gtk/gtkcssimagescaledprivate.h"
#include "gtk/gtkcssimagewin32private.h"
G_DEFINE_ABSTRACT_TYPE (GtkCssImage, _gtk_css_image, G_TYPE_OBJECT)
static int
gtk_css_image_real_get_width (GtkCssImage *image)
{
return 0;
}
static int
gtk_css_image_real_get_height (GtkCssImage *image)
{
return 0;
}
static double
gtk_css_image_real_get_aspect_ratio (GtkCssImage *image)
{
int width, height;
width = _gtk_css_image_get_width (image);
height = _gtk_css_image_get_height (image);
if (width && height)
return (double) width / height;
else
return 0;
}
static GtkCssImage *
gtk_css_image_real_compute (GtkCssImage *image,
guint property_id,
GtkStyleProviderPrivate *provider,
int scale,
GtkCssComputedValues *values,
GtkCssComputedValues *parent_values,
GtkCssDependencies *dependencies)
{
return g_object_ref (image);
}
static gboolean
gtk_css_image_real_equal (GtkCssImage *image1,
GtkCssImage *image2)
{
return FALSE;
}
static GtkCssImage *
gtk_css_image_real_transition (GtkCssImage *start,
GtkCssImage *end,
guint property_id,
double progress)
{
if (progress <= 0.0)
return g_object_ref (start);
else if (progress >= 1.0)
return end ? g_object_ref (end) : NULL;
else
return _gtk_css_image_cross_fade_new (start, end, progress);
}
static void
_gtk_css_image_class_init (GtkCssImageClass *klass)
{
klass->get_width = gtk_css_image_real_get_width;
klass->get_height = gtk_css_image_real_get_height;
klass->get_aspect_ratio = gtk_css_image_real_get_aspect_ratio;
klass->compute = gtk_css_image_real_compute;
klass->equal = gtk_css_image_real_equal;
klass->transition = gtk_css_image_real_transition;
}
static void
_gtk_css_image_init (GtkCssImage *image)
{
}
int
_gtk_css_image_get_width (GtkCssImage *image)
{
GtkCssImageClass *klass;
g_return_val_if_fail (GTK_IS_CSS_IMAGE (image), 0);
klass = GTK_CSS_IMAGE_GET_CLASS (image);
return klass->get_width (image);
}
int
_gtk_css_image_get_height (GtkCssImage *image)
{
GtkCssImageClass *klass;
g_return_val_if_fail (GTK_IS_CSS_IMAGE (image), 0);
klass = GTK_CSS_IMAGE_GET_CLASS (image);
return klass->get_height (image);
}
double
_gtk_css_image_get_aspect_ratio (GtkCssImage *image)
{
GtkCssImageClass *klass;
g_return_val_if_fail (GTK_IS_CSS_IMAGE (image), 0);
klass = GTK_CSS_IMAGE_GET_CLASS (image);
return klass->get_aspect_ratio (image);
}
GtkCssImage *
_gtk_css_image_compute (GtkCssImage *image,
guint property_id,
GtkStyleProviderPrivate *provider,
int scale,
GtkCssComputedValues *values,
GtkCssComputedValues *parent_values,
GtkCssDependencies *dependencies)
{
GtkCssDependencies unused;
GtkCssImageClass *klass;
g_return_val_if_fail (GTK_IS_CSS_IMAGE (image), 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);
if (dependencies == NULL)
dependencies = &unused;
*dependencies = 0;
klass = GTK_CSS_IMAGE_GET_CLASS (image);
return klass->compute (image, property_id, provider, scale, values, parent_values, dependencies);
}
GtkCssImage *
_gtk_css_image_transition (GtkCssImage *start,
GtkCssImage *end,
guint property_id,
double progress)
{
GtkCssImageClass *klass;
g_return_val_if_fail (start == NULL || GTK_IS_CSS_IMAGE (start), NULL);
g_return_val_if_fail (end == NULL || GTK_IS_CSS_IMAGE (end), NULL);
progress = CLAMP (progress, 0.0, 1.0);
if (start == NULL)
{
if (end == NULL)
return NULL;
else
{
start = end;
end = NULL;
progress = 1.0 - progress;
}
}
klass = GTK_CSS_IMAGE_GET_CLASS (start);
return klass->transition (start, end, property_id, progress);
}
gboolean
_gtk_css_image_equal (GtkCssImage *image1,
GtkCssImage *image2)
{
GtkCssImageClass *klass;
g_return_val_if_fail (image1 == NULL || GTK_IS_CSS_IMAGE (image1), FALSE);
g_return_val_if_fail (image2 == NULL || GTK_IS_CSS_IMAGE (image2), FALSE);
if (image1 == image2)
return TRUE;
if (image1 == NULL || image2 == NULL)
return FALSE;
if (G_OBJECT_TYPE (image1) != G_OBJECT_TYPE (image2))
return FALSE;
klass = GTK_CSS_IMAGE_GET_CLASS (image1);
return klass->equal (image1, image2);
}
void
_gtk_css_image_draw (GtkCssImage *image,
cairo_t *cr,
double width,
double height)
{
GtkCssImageClass *klass;
g_return_if_fail (GTK_IS_CSS_IMAGE (image));
g_return_if_fail (cr != NULL);
g_return_if_fail (width > 0);
g_return_if_fail (height > 0);
cairo_save (cr);
klass = GTK_CSS_IMAGE_GET_CLASS (image);
klass->draw (image, cr, width, height);
cairo_restore (cr);
}
void
_gtk_css_image_print (GtkCssImage *image,
GString *string)
{
GtkCssImageClass *klass;
g_return_if_fail (GTK_IS_CSS_IMAGE (image));
g_return_if_fail (string != NULL);
klass = GTK_CSS_IMAGE_GET_CLASS (image);
klass->print (image, string);
}
/* Applies the algorithm outlined in
* http://dev.w3.org/csswg/css3-images/#default-sizing
*/
void
_gtk_css_image_get_concrete_size (GtkCssImage *image,
double specified_width,
double specified_height,
double default_width,
double default_height,
double *concrete_width,
double *concrete_height)
{
double image_width, image_height, image_aspect;
g_return_if_fail (GTK_IS_CSS_IMAGE (image));
g_return_if_fail (specified_width >= 0);
g_return_if_fail (specified_height >= 0);
g_return_if_fail (default_width > 0);
g_return_if_fail (default_height > 0);
g_return_if_fail (concrete_width != NULL);
g_return_if_fail (concrete_height != NULL);
/* If the specified size is a definite width and height,
* the concrete object size is given that width and height.
*/
if (specified_width && specified_height)
{
*concrete_width = specified_width;
*concrete_height = specified_height;
return;
}
image_width = _gtk_css_image_get_width (image);
image_height = _gtk_css_image_get_height (image);
image_aspect = _gtk_css_image_get_aspect_ratio (image);
/* If the specified size has neither a definite width nor height,
* and has no additional contraints, the dimensions of the concrete
* object size are calculated as follows:
*/
if (specified_width == 0.0 && specified_height == 0.0)
{
/* If the object has only an intrinsic aspect ratio,
* the concrete object size must have that aspect ratio,
* and additionally be as large as possible without either
* its height or width exceeding the height or width of the
* default object size.
*/
if (image_aspect > 0 && image_width == 0 && image_height == 0)
{
if (image_aspect * default_height > default_width)
{
*concrete_width = default_height * image_aspect;
*concrete_height = default_height;
}
else
{
*concrete_width = default_width;
*concrete_height = default_width / image_aspect;
}
}
else
{
/* Otherwise, the width and height of the concrete object
* size is the same as the object's intrinsic width and
* intrinsic height, if they exist.
* If the concrete object size is still missing a width or
* height, and the object has an intrinsic aspect ratio,
* the missing dimension is calculated from the present
* dimension and the intrinsic aspect ratio.
* Otherwise, the missing dimension is taken from the default
* object size.
*/
if (image_width)
*concrete_width = image_width;
else if (image_aspect)
*concrete_width = image_height * image_aspect;
else
*concrete_width = default_width;
if (image_height)
*concrete_height = image_height;
else if (image_aspect)
*concrete_height = image_width / image_aspect;
else
*concrete_height = default_height;
}
return;
}
/* If the specified size has only a width or height, but not both,
* then the concrete object size is given that specified width or height.
* The other dimension is calculated as follows:
* If the object has an intrinsic aspect ratio, the missing dimension of
* the concrete object size is calculated using the intrinsic aspect-ratio
* and the present dimension.
* Otherwise, if the missing dimension is present in the object's intrinsic
* dimensions, the missing dimension is taken from the object's intrinsic
* dimensions.
* Otherwise, the missing dimension of the concrete object size is taken
* from the default object size.
*/
if (specified_width)
{
*concrete_width = specified_width;
if (image_aspect)
*concrete_height = specified_width / image_aspect;
else if (image_height)
*concrete_height = image_height;
else
*concrete_height = default_height;
}
else
{
*concrete_height = specified_height;
if (image_aspect)
*concrete_width = specified_height * image_aspect;
else if (image_width)
*concrete_width = image_width;
else
*concrete_width = default_width;
}
}
cairo_surface_t *
_gtk_css_image_get_surface (GtkCssImage *image,
cairo_surface_t *target,
int surface_width,
int surface_height)
{
cairo_surface_t *result;
cairo_t *cr;
g_return_val_if_fail (GTK_IS_CSS_IMAGE (image), NULL);
g_return_val_if_fail (surface_width > 0, NULL);
g_return_val_if_fail (surface_height > 0, NULL);
if (target)
{
result = cairo_surface_create_similar (target,
CAIRO_CONTENT_COLOR_ALPHA,
surface_width,
surface_height);
}
else
result = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
surface_width,
surface_height);
cr = cairo_create (result);
_gtk_css_image_draw (image, cr, surface_width, surface_height);
cairo_destroy (cr);
return result;
}
static GType
gtk_css_image_get_parser_type (GtkCssParser *parser)
{
static const struct {
const char *prefix;
GType (* type_func) (void);
} image_types[] = {
{ "url", _gtk_css_image_url_get_type },
{ "-gtk-gradient", _gtk_css_image_gradient_get_type },
{ "-gtk-icontheme", _gtk_css_image_icon_theme_get_type },
{ "-gtk-scaled", _gtk_css_image_scaled_get_type },
{ "-gtk-win32-theme-part", _gtk_css_image_win32_get_type },
{ "linear-gradient", _gtk_css_image_linear_get_type },
{ "repeating-linear-gradient", _gtk_css_image_linear_get_type },
{ "cross-fade", _gtk_css_image_cross_fade_get_type }
};
guint i;
for (i = 0; i < G_N_ELEMENTS (image_types); i++)
{
if (_gtk_css_parser_has_prefix (parser, image_types[i].prefix))
return image_types[i].type_func ();
}
return G_TYPE_INVALID;
}
/**
* _gtk_css_image_can_parse:
* @parser: a css parser
*
* Checks if the parser can potentially parse the given stream as an
* image from looking at the first token of @parser. This is useful for
* implementing shorthand properties. A successful parse of an image
* can not be guaranteed.
*
* Returns: %TURE if it looks like an image.
**/
gboolean
_gtk_css_image_can_parse (GtkCssParser *parser)
{
return gtk_css_image_get_parser_type (parser) != G_TYPE_INVALID;
}
GtkCssImage *
_gtk_css_image_new_parse (GtkCssParser *parser)
{
GtkCssImageClass *klass;
GtkCssImage *image;
GType image_type;
g_return_val_if_fail (parser != NULL, NULL);
image_type = gtk_css_image_get_parser_type (parser);
if (image_type == G_TYPE_INVALID)
{
_gtk_css_parser_error (parser, "Not a valid image");
return NULL;
}
image = g_object_new (image_type, NULL);
klass = GTK_CSS_IMAGE_GET_CLASS (image);
if (!klass->parse (image, parser))
{
g_object_unref (image);
return NULL;
}
return image;
}