gimp/libgimp/gimpimagemetadata.c
Jehan d493f0537f Issue #8900 and #9923: reimplementing GimpUnit as a proper class.
This fixes all our GObject Introspection issues with GimpUnit which was
both an enum and an int-derived type of user-defined units *completing*
the enum values. GIR clearly didn't like this!

Now GimpUnit is a proper class and units are unique objects, allowing to
compare them with an identity test (i.e. `unit == gimp_unit_pixel ()`
tells us if unit is the pixel unit or not), which makes it easy to use,
just like with int, yet adding also methods, making for nicer
introspected API.

As an aside, this also fixes #10738, by having all the built-in units
retrievable even if libgimpbase had not been properly initialized with
gimp_base_init().
I haven't checked in details how GIR works to introspect, but it looks
like it loads the library to inspect and runs functions, hence
triggering some CRITICALS because virtual methods (supposed to be
initialized with gimp_base_init() run by libgimp) are not set. This new
code won't trigger any critical because the vtable method are now not
necessary, at least for all built-in units.

Note that GimpUnit is still in libgimpbase. It could have been moved to
libgimp in order to avoid any virtual method table (since we need to
keep core and libgimp side's units in sync, PDB is required), but too
many libgimpwidgets widgets were already using GimpUnit. And technically
most of GimpUnit logic doesn't require PDB (only the creation/sync
part). This is one of the reasons why user-created GimpUnit list is
handled and stored differently from other types of objects.

Globally this simplifies the code a lot too and we don't need separate
implementations of various utils for core and libgimp, which means less
prone to errors.
2024-08-02 10:46:38 +02:00

393 lines
12 KiB
C

/* LIBGIMP - The GIMP Library
* Copyright (C) 1995-2000 Peter Mattis and Spencer Kimball
*
* gimpimagemetadata.c
*
* 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 3 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
* <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <string.h>
#include <sys/time.h>
#include <gexiv2/gexiv2.h>
#include "gimp.h"
#include "gimpimagemetadata.h"
#include "libgimp-intl.h"
static gchar * gimp_image_metadata_interpret_comment (gchar *comment);
static void gimp_image_metadata_rotate (GimpImage *image,
GExiv2Orientation orientation);
/* public functions */
/**
* gimp_image_metadata_load_prepare:
* @image: The image
* @mime_type: The loaded file's mime-type
* @file: The file to load the metadata from
* @error: Return location for error
*
* Loads and returns metadata from @file to be passed into
* gimp_image_metadata_load_finish().
*
* Returns: (transfer full): The file's metadata.
*
* Since: 2.10
*/
GimpMetadata *
gimp_image_metadata_load_prepare (GimpImage *image,
const gchar *mime_type,
GFile *file,
GError **error)
{
GimpMetadata *metadata;
g_return_val_if_fail (GIMP_IS_IMAGE (image), NULL);
g_return_val_if_fail (mime_type != NULL, NULL);
g_return_val_if_fail (G_IS_FILE (file), NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
metadata = gimp_metadata_load_from_file (file, error);
return metadata;
}
static gchar *
gimp_image_metadata_interpret_comment (gchar *comment)
{
/* Exiv2 can return unwanted text at the start of a comment
* taken from Exif.Photo.UserComment since 0.27.3.
* Let's remove that part and return NULL if there
* is nothing else left as comment. */
if (comment)
{
if (g_str_has_prefix (comment, "charset=Ascii "))
{
gchar *real_comment;
/* Skip "charset=Ascii " (length 14) to find the real comment */
real_comment = g_strdup (comment + 14);
g_free (comment);
comment = real_comment;
}
if (comment[0] == '\0')
{
/* Removing an empty comment.*/
g_free (comment);
return NULL;
}
}
return comment;
}
/**
* gimp_image_metadata_load_finish:
* @image: The image
* @mime_type: The loaded file's mime-type
* @metadata: The metadata to set on the image
* @flags: Flags to specify what of the metadata to apply to the image
*
* Applies the @metadata previously loaded with
* gimp_image_metadata_load_prepare() to the image, taking into account
* the passed @flags.
*
* Since: 3.0
*/
void
gimp_image_metadata_load_finish (GimpImage *image,
const gchar *mime_type,
GimpMetadata *metadata,
GimpMetadataLoadFlags flags)
{
g_return_if_fail (GIMP_IS_IMAGE (image));
g_return_if_fail (GEXIV2_IS_METADATA (metadata));
if (flags & GIMP_METADATA_LOAD_COMMENT)
{
gchar *comment;
GError *error = NULL;
comment = gexiv2_metadata_try_get_tag_interpreted_string (GEXIV2_METADATA (metadata),
"Exif.Photo.UserComment",
&error);
if (error)
{
/* XXX. Should this be rather a user-facing error? */
g_printerr ("%s: unreadable '%s' metadata tag: %s\n",
G_STRFUNC, "Exif.Photo.UserComment", error->message);
g_clear_error (&error);
}
else if (comment)
{
if (g_str_has_prefix (comment, "charset=InvalidCharsetId "))
{
GBytes *bytes = NULL;
/* The Exif metadata writer forgot to add the charset.
* Read the raw data and assume it's UTF-8. */
g_printerr ("Invalid charset for tag %s. Using raw data.\n",
"Exif.Photo.UserComment");
bytes = gexiv2_metadata_try_get_tag_raw (GEXIV2_METADATA (metadata),
"Exif.Photo.UserComment",
NULL);
if (bytes)
{
gsize size, strsize;
const gchar *data;
gchar *raw_comment;
data = g_bytes_get_data (bytes, &size);
raw_comment = g_new (gchar, size + 1 );
strsize = g_strlcpy (raw_comment, data, size + 1);
g_bytes_unref (bytes);
g_free (comment);
if (raw_comment && strsize > 0 &&
g_utf8_validate (raw_comment, size, NULL))
{
comment = raw_comment;
}
else
{
g_free (raw_comment);
comment = NULL;
}
/* Fix the tag in our metadata too, that way we don't have to
* check for this in other places. */
gexiv2_metadata_try_set_tag_string (GEXIV2_METADATA (metadata),
"Exif.Photo.UserComment",
comment,
NULL);
}
}
else
{
comment = gimp_image_metadata_interpret_comment (comment);
}
}
if (! comment)
{
comment = gexiv2_metadata_try_get_tag_interpreted_string (GEXIV2_METADATA (metadata),
"Exif.Image.ImageDescription",
&error);
if (error)
{
g_printerr ("%s: unreadable '%s' metadata tag: %s\n",
G_STRFUNC, "Exif.Image.ImageDescription", error->message);
g_clear_error (&error);
}
}
if (comment)
{
GimpParasite *parasite;
parasite = gimp_parasite_new ("gimp-comment",
GIMP_PARASITE_PERSISTENT,
strlen (comment) + 1,
comment);
g_free (comment);
gimp_image_attach_parasite (image, parasite);
gimp_parasite_free (parasite);
}
}
if (flags & GIMP_METADATA_LOAD_RESOLUTION)
{
gdouble xres;
gdouble yres;
GimpUnit *unit;
if (gimp_metadata_get_resolution (metadata, &xres, &yres, &unit))
{
gimp_image_set_resolution (image, xres, yres);
gimp_image_set_unit (image, unit);
}
}
if (! (flags & GIMP_METADATA_LOAD_ORIENTATION))
{
gexiv2_metadata_try_set_orientation (GEXIV2_METADATA (metadata),
GEXIV2_ORIENTATION_NORMAL,
NULL);
}
if (flags & GIMP_METADATA_LOAD_COLORSPACE)
{
GimpColorProfile *profile = gimp_image_get_color_profile (image);
/* only look for colorspace information from metadata if the
* image didn't contain an embedded color profile
*/
if (! profile)
{
GimpMetadataColorspace colorspace;
colorspace = gimp_metadata_get_colorspace (metadata);
switch (colorspace)
{
case GIMP_METADATA_COLORSPACE_UNSPECIFIED:
case GIMP_METADATA_COLORSPACE_UNCALIBRATED:
case GIMP_METADATA_COLORSPACE_SRGB:
/* use sRGB, a NULL profile will do the right thing */
break;
case GIMP_METADATA_COLORSPACE_ADOBERGB:
profile = gimp_color_profile_new_rgb_adobe ();
break;
}
if (profile)
gimp_image_set_color_profile (image, profile);
}
if (profile)
g_object_unref (profile);
}
gimp_image_set_metadata (image, metadata);
}
/**
* gimp_image_metadata_load_thumbnail:
* @file: A #GFile image
* @error: Return location for error message
*
* Retrieves a thumbnail from metadata if present.
*
* Returns: (transfer none) (nullable): a #GimpImage of the @file thumbnail.
*
* Since: 2.10
*/
GimpImage *
gimp_image_metadata_load_thumbnail (GFile *file,
GError **error)
{
GimpMetadata *metadata;
GInputStream *input_stream;
GdkPixbuf *pixbuf;
guint8 *thumbnail_buffer;
gint thumbnail_size;
GimpImage *image = NULL;
g_return_val_if_fail (G_IS_FILE (file), NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
metadata = gimp_metadata_load_from_file (file, error);
if (! metadata)
return NULL;
if (! gexiv2_metadata_get_exif_thumbnail (GEXIV2_METADATA (metadata),
&thumbnail_buffer,
&thumbnail_size))
{
g_object_unref (metadata);
return NULL;
}
input_stream = g_memory_input_stream_new_from_data (thumbnail_buffer,
thumbnail_size,
(GDestroyNotify) g_free);
pixbuf = gdk_pixbuf_new_from_stream (input_stream, NULL, error);
g_object_unref (input_stream);
if (pixbuf)
{
GimpLayer *layer;
image = gimp_image_new (gdk_pixbuf_get_width (pixbuf),
gdk_pixbuf_get_height (pixbuf),
GIMP_RGB);
gimp_image_undo_disable (image);
layer = gimp_layer_new_from_pixbuf (image, _("Background"),
pixbuf,
100.0,
gimp_image_get_default_new_layer_mode (image),
0.0, 0.0);
g_object_unref (pixbuf);
gimp_image_insert_layer (image, layer, NULL, 0);
gimp_image_metadata_rotate (image,
gexiv2_metadata_try_get_orientation (GEXIV2_METADATA (metadata), NULL));
}
g_object_unref (metadata);
return image;
}
/* private functions */
static void
gimp_image_metadata_rotate (GimpImage *image,
GExiv2Orientation orientation)
{
switch (orientation)
{
case GEXIV2_ORIENTATION_UNSPECIFIED:
case GEXIV2_ORIENTATION_NORMAL: /* standard orientation, do nothing */
break;
case GEXIV2_ORIENTATION_HFLIP:
gimp_image_flip (image, GIMP_ORIENTATION_HORIZONTAL);
break;
case GEXIV2_ORIENTATION_ROT_180:
gimp_image_rotate (image, GIMP_ROTATE_DEGREES180);
break;
case GEXIV2_ORIENTATION_VFLIP:
gimp_image_flip (image, GIMP_ORIENTATION_VERTICAL);
break;
case GEXIV2_ORIENTATION_ROT_90_HFLIP: /* flipped diagonally around '\' */
gimp_image_rotate (image, GIMP_ROTATE_DEGREES90);
gimp_image_flip (image, GIMP_ORIENTATION_HORIZONTAL);
break;
case GEXIV2_ORIENTATION_ROT_90: /* 90 CW */
gimp_image_rotate (image, GIMP_ROTATE_DEGREES90);
break;
case GEXIV2_ORIENTATION_ROT_90_VFLIP: /* flipped diagonally around '/' */
gimp_image_rotate (image, GIMP_ROTATE_DEGREES90);
gimp_image_flip (image, GIMP_ORIENTATION_VERTICAL);
break;
case GEXIV2_ORIENTATION_ROT_270: /* 90 CCW */
gimp_image_rotate (image, GIMP_ROTATE_DEGREES270);
break;
default: /* shouldn't happen */
break;
}
}