Creates a binding between source_property on source and target_property
on target.
Whenever the source_property is changed the target_property is
updated using the same value. For instance:
g_object_bind_property (action, "active", widget, "sensitive", 0);
Will result in the "sensitive" property of the widget #GObject instance to be updated with the same value of the "active" property of the action #GObject instance.
If flags contains %G_BINDING_BIDIRECTIONAL then the binding will be mutual:
if target_property on target changes then the source_property on source
will be updated as well.
The binding will automatically be removed when either the source or the
target instances are finalized. To remove the binding without affecting the
source and the target you can just call g_object_unref() on the returned
#GBinding instance.
Removing the binding by calling g_object_unref() on it must only be done if
the binding, source and target are only used from a single thread and it
is clear that both source and target outlive the binding. Especially it
is not safe to rely on this if the binding, source or target can be
finalized from different threads. Keep another reference to the binding and
use g_binding_unbind() instead to be on the safe side.
A #GObject can have multiple bindings.
the property on source to bind
the target #GObject
the property on target to bind
flags to pass to #GBinding
Creates a binding between source_property on source and target_property
on target, allowing you to set the transformation functions to be used by
the binding.
This function is the language bindings friendly version of g_object_bind_property_full(), using #GClosures instead of function pointers.
the property on source to bind
the target #GObject
the property on target to bind
flags to pass to #GBinding
a #GClosure wrapping the transformation function from the source to the target, or %NULL to use the default
a #GClosure wrapping the transformation function from the target to the source, or %NULL to use the default
Removes all tags for all domains (EXIF, IPTC, and XMP).
This is a composite clear method that will clear a number of fields. See #gexiv2_metadata_get_comment for more information.
Clears all EXIF metadata from the loaded image.
Clears all IPTC metadata from the loaded image.
Removes the Exiv2 tag from the metadata object.
The Exiv2 Tag Reference can be found at
Exiv2 tag
Clears all XMP metadata from the loaded image.
Removes all GPS metadata from the loaded image
Removes the EXIF thumbnail from the loaded image.
This function is intended for #GObject implementations to re-enforce a [floating][floating-ref] object reference. Doing this is seldom required: all #GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling g_object_ref_sink().
Destroys the #GExiv2Metadata object and frees all associated memory.
Increases the freeze count on object. If the freeze count is
non-zero, the emission of "notify" signals on object is
stopped. The signals are queued until the freeze count is decreased
to zero. Duplicate notifications are squashed so that at most one
#GObject::notify signal is emitted for each property modified while the
object is frozen.
This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.
Load only an EXIF buffer, typically stored in a JPEG's APP1 segment.
A buffer containing the data to be read
This function does not work and will be removed in a future release.
Encode the XMP packet as a %NULL-terminated string.
One of #GExiv2XmpFormatFlags
The padding (FIXME: Add documentation)
A composite accessor that uses the first available metadata field from a list of well-known locations to find the photo's comment (or description).
MWG guidelines refer to these as
These fields are:
For fine-grained control, it's recommended to use Exiv2 tags directly rather than this method, which is more useful for quick or casual use.
Gets a named field from the objects table of associations (see g_object_set_data()).
name of the key for that association
Fetch EXIF tag represented by a fraction. nom will contain the numerator,
den the denominator of the fraction on successful return.
The tag you want the rational value for
Query self for a list of available EXIF tags
Get the thumbnail stored in the EXIF data of self
Returns the exposure time in seconds (shutter speed,
See
See
Convenience function to query the altitude stored in the GPS tags of the image
Convenience function to query all available GPS information at once.
Query the latitude stored in the GPS tags of self
Query the longitude stored in the GPS tags of self
Query self for a list of available IPTC tags
See
Composite accessor to query the pixel with stored in the metadata. This might differ from the height of image that is available through gexiv2_metadata_get_pixel_height()
Composite accessor to query the pixel with stored in the metadata. This might differ from the width of image that is available through gexiv2_metadata_get_pixel_width()
Query mime type of currently loaded image.
The EXIF Orientation field
Get the
Get the
An image may have stored one or more previews, often of different qualities, sometimes of different image formats than the containing image. This call returns the properties of all previews Exiv2 finds within the loaded image. Use #gexiv2_metadata_get_preview_image to load a particular preview into memory.
Gets a property of an object.
The value can be:
In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling g_value_unset().
Note that g_object_get_property() is really intended for language bindings, g_object_get() is much more convenient for C programming.
the name of the property to get
return location for the property value
This function gets back user data pointers stored via g_object_set_qdata().
A #GQuark, naming the user data pointer
Query self whether it supports writing EXIF metadata.
Query self whether it supports writing IPTC metadata.
Query self whether it supports writing XMP metadata.
An interpreted string is one fit for user display. It may display units or use formatting appropriate to the type of data the tag holds.
Tags that support multiple values are returned as a single string, with elements separated by ", ".
The Exiv2 Tag Reference can be found at
Exiv2 tag name
The Exiv2 Tag Reference can be found at
Exiv2 tag name
The Exiv2 Tag Reference can be found at
In case of error, a GLib warning will be logged. Use instead gexiv2_metadata_try_get_tag_multiple() if you want to avoid this and control if and how the error is outputted.
Exiv2 tag name
The Exiv2 Tag Reference can be found at
Tags that support multiple values may bereturned as a single byte array, with records separated by 4x INFORMATION SEPARATOR FOUR (ASCII 0x1c)
Exiv2 tag name
The Exiv2 Tag Reference can be found at
Tags that support multiple values are returned as a single string, with elements separated by ", ".
In case of error, a GLib warning will be logged. Use instead gexiv2_metadata_try_get_tag_string() if you want to avoid this and control if and how the error is outputted.
Exiv2 tag name
Gets n_properties properties for an object.
Obtained properties will be set to values. All properties must be valid.
Warnings will be emitted and undefined behaviour may result if invalid
properties are passed in.
the names of each property to get
the values of each property to get
The Exiv2 Tag Reference can be found at
Exiv2 tag
Checks whether object has a [floating][floating-ref] reference.
Emits a "notify" signal for the property property_name on object.
When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.
Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.
the name of a property installed on the class of object.
Emits a "notify" signal for the property specified by pspec on object.
This function omits the property name lookup, hence it is faster than g_object_notify().
One way to avoid using g_object_notify() from within the class that registered the properties, and using g_object_notify_by_pspec() instead, is to store the GParamSpec used with g_object_class_install_property() inside a static array, e.g.:
enum
{
PROP_0,
PROP_FOO,
PROP_LAST
};
static GParamSpec *properties[PROP_LAST];
static void
my_object_class_init (MyObjectClass *klass)
{
properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
0, 100,
50,
G_PARAM_READWRITE);
g_object_class_install_property (gobject_class,
PROP_FOO,
properties[PROP_FOO]);
}
and then notify a change on the "foo" property with:
g_object_notify_by_pspec (self, properties[PROP_FOO]);
the #GParamSpec of a property installed on the class of object.
The buffer must be an image format supported by Exiv2.
A buffer containing the data to be read
The file must be an image format supported by Exiv2.
Path to the file you want to open
Increase the reference count of object, and possibly remove the
[floating][floating-ref] reference, if object has a floating reference.
In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.
Since GLib 2.56, the type of object will be propagated to the return type
under the same conditions as for g_object_ref().
Releases all references to other objects. This can be used to break reference cycles.
This function should only be called from object system implementations.
Saves the metadata to the specified using an XMP sidecar file.
Path to the file you want to save to.
Saves the metadata to the specified file by reading the file into memory,copying this object's metadata into the image, then writing the image back out.
Path to the file you want to save to.
This is a composite setter that will set a number of fields to the supplied value. See #gexiv2_metadata_get_comment for more information.
Comment string to set. Must not be %NULL
Each object carries around a table of associations from strings to pointers. This function lets you set an association.
If the object already had an association with that name, the old association will be destroyed.
Internally, the key is converted to a #GQuark using g_quark_from_string().
This means a copy of key is kept permanently (even after object has been
finalized) — so it is recommended to only use a small, bounded set of values
for key in your program, to avoid the #GQuark storage growing unbounded.
name of the key
data to associate with that key
Set EXIF tag represented by a fraction, with nom being the numerator,
den the denominator of the fraction.
The Exiv2 tag
Rational numerator
Rational denominator
Sets or replaces the EXIF thumbnail with the image in the file
Path of image file
Convenience function to create a new set of simple GPS data. Warning: Will remove any other GPS information that is currently set. See gexiv2_metadata_update_gps_info() for just modifying the GPS data.
Longitude value to set or replace current value
Latitude value to set or replace current value
Altitude value to set or replace current value
Update the image's metadata with height
The width of the image as it should be put into the metadata.
Composite setter to update the image's metadata with width
The width of the image as it should be put into the metadata
The orientation must be valid and cannot be #GEXIV2_ORIENTATION_UNSPECIFIED.
The new #GExiv2Orientation for the image.
Sets a property on an object.
the name of the property to set
the value
The Exiv2 Tag Reference can be found at
Exiv2 tag name
The value to set or replace the existing value
The Exiv2 Tag Reference can be found at
All previous tag values are erased. For multiple value tags, each of the non %NULL
entries in values is stored. For single value tags, only the last non %NULL value
is assigned.
In case of error, a GLib warning will be logged. Use instead gexiv2_metadata_try_set_tag_multiple() if you want to avoid this and control if and how the error is outputted.
Exiv2 tag name
An array of values to set or replace the existing value(s)
The Exiv2 Tag Reference can be found at
If a tag supports multiple values, then value is added to any existing values. For single
value tags, value replaces the value.
In case of error, a GLib warning will be logged. Use instead gexiv2_metadata_try_set_tag_string() if you want to avoid this and control if and how the error is outputted.
Exiv2 tag name
The value to set or replace the existing value
The Exiv2 Tag Reference can be found at
Exiv2 tag name
The GExiv2StructureType specifying the type of structure
Remove a specified datum from the object's data associations, without invoking the association's destroy handler.
name of the key
This function gets back user data pointers stored via
g_object_set_qdata() and removes the data from object
without invoking its destroy() function (if any was
set).
Usually, calling this function is only required to update
user data pointers with a destroy notifier, for example:
void
object_add_to_user_list (GObject *object,
const gchar *new_string)
{
// the quark, naming the object data
GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
// retrieve the old string list
GList *list = g_object_steal_qdata (object, quark_string_list);
// prepend new string
list = g_list_prepend (list, g_strdup (new_string));
// this changed 'list', so we need to set it again
g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
}
static void
free_string_list (gpointer data)
{
GList *node, *list = data;
for (node = list; node; node = node->next)
g_free (node->data);
g_list_free (list);
}
Using g_object_get_qdata() in the above example, instead of g_object_steal_qdata() would have left the destroy function set, and thus the partial string list would have been freed upon g_object_set_qdata_full().
A #GQuark, naming the user data pointer
Reverts the effect of a previous call to
g_object_freeze_notify(). The freeze count is decreased on object
and when it reaches zero, queued "notify" signals are emitted.
Duplicate notifications for each property are squashed so that at most one #GObject::notify signal is emitted for each property, in the reverse order in which they have been queued.
It is an error to call this function when the freeze count is zero.
Removes the Exiv2 tag from the metadata object.
The Exiv2 Tag Reference can be found at
Exiv2 tag
Removes all GPS metadata from the loaded image
Removes the EXIF thumbnail from the loaded image.
Encode the XMP packet as a %NULL-terminated string.
One of #GExiv2XmpFormatFlags
The padding (FIXME: Add documentation)
A composite accessor that uses the first available metadata field from a list of well-known locations to find the photo's comment (or description).
MWG guidelines refer to these as
These fields are:
For fine-grained control, it's recommended to use Exiv2 tags directly rather than this method, which is more useful for quick or casual use.
Fetch EXIF tag represented by a fraction. nom will contain the numerator,
den the denominator of the fraction on successful return.
The tag you want the rational value for
Returns the exposure time in seconds (shutter speed,
See
See
Convenience function to query the altitude stored in the GPS tags of the image
Convenience function to query all available GPS information at once.
Query the latitude stored in the GPS tags of self
Query the longitude stored in the GPS tags of self
See
Composite accessor to query the pixel with stored in the metadata. This might differ from the height of image that is available through gexiv2_metadata_get_pixel_height()
Composite accessor to query the pixel with stored in the metadata. This might differ from the width of image that is available through gexiv2_metadata_get_pixel_width()
The EXIF Orientation field
An interpreted string is one fit for user display. It may display units or use formatting appropriate to the type of data the tag holds.
Tags that support multiple values are returned as a single string, with elements separated by ", ".
The Exiv2 Tag Reference can be found at
Exiv2 tag name
The Exiv2 Tag Reference can be found at
Exiv2 tag name
The Exiv2 Tag Reference can be found at
Exiv2 tag name
The Exiv2 Tag Reference can be found at
Tags that support multiple values may be returned as a single byte array, with records separated by 4x INFORMATION SEPARATOR FOUR (ASCII 0x1c)
Exiv2 tag name
The Exiv2 Tag Reference can be found at
Tags that support multiple values are returned as a single string, with elements separated by ", ".
Exiv2 tag name
The Exiv2 Tag Reference can be found at
Exiv2 tag
This is a composite setter that will set a number of fields to the supplied value. See #gexiv2_metadata_get_comment for more information.
Comment string to set. Must not be %NULL
Set EXIF tag represented by a fraction, with nom being the numerator,
den the denominator of the fraction.
The Exiv2 tag
Rational numerator
Rational denominator
Convenience function to create a new set of simple GPS data. Warning: Will remove any other GPS information that is currently set. See gexiv2_metadata_update_gps_info() for just modifying the GPS data.
Longitude value to set or replace current value
Latitude value to set or replace current value
Altitude value to set or replace current value
Update the image's metadata with height
The width of the image as it should be put into the metadata.
Composite setter to update the image's metadata with width
The width of the image as it should be put into the metadata
The orientation must be valid and cannot be #GEXIV2_ORIENTATION_UNSPECIFIED.
The new #GExiv2Orientation for the image.
The Exiv2 Tag Reference can be found at
Exiv2 tag name
The value to set or replace the existing value
The Exiv2 Tag Reference can be found at
All previous tag values are erased. For multiple value tags, each of the non %NULL
entries in values is stored. For single value tags, only the last non %NULL value
is assigned.
Exiv2 tag name
An array of values to set or replace the existing value(s)
If a tag supports multiple values, then value is added to any existing values. For single
tags, value replaces the value.
The Exiv2 Tag Reference can be found at
Exiv2 tag name
The value to set or replace the existing value
The Exiv2 Tag Reference can be found at
Exiv2 tag name
The GExiv2StructureType specifying the type of structure
The Exiv2 Tag Reference can be found at
Multiple value tags are Xmp tags of type "XmpAlt", "XmpBag", "XmpSeq" or "LangAlt", or Iptc tags marked as Repeatable (which can be of any Iptc type). There are no multiple value Exif tags.
An Exiv2 tag
Convenience function to update longitude, latitude and altitude at once.
Longitude value to set or replace current value
Latitude value to set or replace current value
Altitude value to set or replace current value
Decreases the reference count of object. When its reference count
drops to 0, the object is finalized (i.e. its memory is freed).
If the pointer to the #GObject may be reused in future (for example, if it is an instance variable of another object), it is recommended to clear the pointer to %NULL rather than retain a dangling pointer to a potentially invalid #GObject instance. Use g_clear_object() for this.
Convenience function to update longitude, latitude and altitude at once.
Longitude value to set or replace current value
Latitude value to set or replace current value
Altitude value to set or replace current value
This function essentially limits the life time of the closure to
the life time of the object. That is, when the object is finalized,
the closure is invalidated by calling g_closure_invalidate() on
it, in order to prevent invocations of the closure with a finalized
(nonexisting) object. Also, g_object_ref() and g_object_unref() are
added as marshal guards to the closure, to ensure that an extra
reference count is held on object during invocation of the
closure. Usually, this function will be called on closures that
use this object as closure data.
#GClosure to watch
The Exiv2 Tag Reference can be found at
An Exiv2 tag
The Exiv2 Tag Reference can be found at
An Exiv2 tag
The names of the various Exiv2 tag types can be found at Exiv2::TypeId,
The Exiv2 Tag Reference can be found at
An Exiv2 tag
Find the #GParamSpec with the given name for an
interface. Generally, the interface vtable passed in as g_iface
will be the default vtable from g_type_default_interface_ref(), or,
if you know the interface has already been loaded,
g_type_default_interface_peek().
any interface vtable for the interface, or the default vtable for the interface
name of a property to look up.
Add a property to an interface; this is only useful for interfaces that are added to GObject-derived types. Adding a property to an interface forces all objects classes with that interface to have a compatible property. The compatible property could be a newly created #GParamSpec, but normally g_object_class_override_property() will be used so that the object class only needs to provide an implementation and inherits the property description, default value, bounds, and so forth from the interface property.
This function is meant to be called from the interface's default
vtable initialization function (the class_init member of
#GTypeInfo.) It must not be called after after class_init has
been called for any object types implementing this interface.
If pspec is a floating reference, it will be consumed.
any interface vtable for the interface, or the default vtable for the interface.
the #GParamSpec for the new property
Lists the properties of an interface.Generally, the interface
vtable passed in as g_iface will be the default vtable from
g_type_default_interface_ref(), or, if you know the interface has
already been loaded, g_type_default_interface_peek().
any interface vtable for the interface, or the default vtable for the interface
The Exiv2 Tag Reference can be found at
An Exiv2 tag
The Exiv2 Tag Reference can be found at
An Exiv2 tag
The Exiv2 Tag Reference can be found at
An Exiv2 tag
Creates a new instance of a #GObject subtype and sets its properties.
Construction parameters (see %G_PARAM_CONSTRUCT, %G_PARAM_CONSTRUCT_ONLY) which are not explicitly specified are set to their default values.
the type id of the #GObject subtype to instantiate
an array of #GParameter
The Exiv2 Tag Reference can be found at
An Exiv2 tag
The Exiv2 Tag Reference can be found at
An Exiv2 tag
The names of the various Exiv2 tag types can be found at Exiv2::TypeId,
The Exiv2 Tag Reference can be found at
An Exiv2 tag
An object holding all the Exiv2 metadata. Previews, if present, are also available.
As gexiv2 is only a wrapper around Exiv2, it's better to read its documentation to understand the full scope of what it offers:
In particular, rather than providing a getter/setter method pair for every metadata value available for images (of which there are thousands), Exiv2 uses a dotted addressing scheme. For example, to access a photo's EXIF Orientation field, the caller passes to Exiv2 "Exif.Photo.Orientation". Thesetags (in Exiv2 parlance) are key to using Exiv2 (and
therefore gexiv2) to its fullest.
A full reference for all supported Exiv2 tags can be found at