Returns a new rsvg handle. Must be freed with [methodGObject.Object.unref]. This
handle can be used to load an image.
The preferred way of loading SVG data into the returned [classRsvg.Handle] is with
[methodRsvg.Handle.read_stream_sync].
The deprecated way of loading SVG data is with [methodRsvg.Handle.write] and
[methodRsvg.Handle.close]; note that these require buffering the entire file
internally, and for this reason it is better to use the stream functions:
[ctorRsvg.Handle.new_from_stream_sync], [methodRsvg.Handle.read_stream_sync], or
[ctorRsvg.Handle.new_from_gfile_sync].
After loading the [classRsvg.Handle] with data, you can render it using Cairo or get
a GdkPixbuf from it. When finished, free the handle with [methodGObject.Object.unref]. No
more than one image can be loaded with one handle.
Note that this function creates an [classRsvg.Handle] with no flags set. If you
require any of [flagsRsvg.HandleFlags] to be set, use any of
[ctorRsvg.Handle.new_with_flags], [ctorRsvg.Handle.new_from_stream_sync], or
[ctorRsvg.Handle.new_from_gfile_sync].
Base URI, to be used to resolve relative references for resources. See the section "Security and locations of referenced files" for details.
SVG's description.
Horizontal resolution in dots per inch.
Horizontal resolution in dots per inch.
Exact width, in pixels, of the rendered SVG before calling the size callback
as specified by [methodRsvg.Handle.set_size_callback].
Exact height, in pixels, of the rendered SVG before calling the size callback
as specified by [methodRsvg.Handle.set_size_callback].
Flags from [flagsRsvg.HandleFlags].
Height, in pixels, of the rendered SVG after calling the size callback
as specified by [methodRsvg.Handle.set_size_callback].
SVG's metadata
SVG's title.
Width, in pixels, of the rendered SVG after calling the size callback
as specified by [methodRsvg.Handle.set_size_callback].
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
This is used after calling [methodRsvg.Handle.write] to indicate that there is no more data
to consume, and to start the actual parsing of the SVG document. The only reason to
call this function is if you use use [methodRsvg.Handle.write] to feed data into the handle;
if you use the other methods like [ctorRsvg.Handle.new_from_file] or
[methodRsvg.Handle.read_stream_sync], then you do not need to call this function.
This will return TRUE if the loader closed successfully and the
SVG data was parsed correctly. Note that handle isn't freed until
[methodGObject.Object.unref] is called.
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().
Frees handle.
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.
Gets the base uri for this [classRsvg.Handle].
Gets a named field from the objects table of associations (see g_object_set_data()).
name of the key for that association
Get the SVG's size. Do not call from within the size_func callback, because an infinite loop will occur.
This function depends on the [classRsvg.Handle]'s DPI to compute dimensions in
pixels, so you should call [methodRsvg.Handle.set_dpi] beforehand.
Get the size of a subelement of the SVG file. Do not call from within the size_func callback, because an infinite loop will occur.
This function depends on the [classRsvg.Handle]'s DPI to compute dimensions in
pixels, so you should call [methodRsvg.Handle.set_dpi] beforehand.
Element IDs should look like an URL fragment identifier; for example, pass
#foo (hash foo) to get the geometry of the element that
has an id="foo" attribute.
An element's id within the SVG, starting with "#" (a single hash character), for example, #layer1. This notation corresponds to a URL's fragment ID. Alternatively, pass NULL to use the whole SVG.
Computes the ink rectangle and logical rectangle of a single SVG element.
While rsvg_handle_get_geometry_for_layer computes the geometry of an SVG element subtree with
its transformation matrix, this other function will compute the element's geometry
as if it were being rendered under an identity transformation by itself. That is,
the resulting geometry is as if the element got extracted by itself from the SVG.
This function is the counterpart to rsvg_handle_render_element.
Element IDs should look like an URL fragment identifier; for example, pass
#foo (hash foo) to get the geometry of the element that
has an id="foo" attribute.
The "ink rectangle" is the bounding box that would be painted for fully- stroked and filled elements.
The "logical rectangle" just takes into account the unstroked paths and text outlines.
Note that these bounds are not minimum bounds; for example, clipping paths are not taken into account.
You can pass NULL for the id if you want to measure all
the elements in the SVG, i.e. to measure everything from the
root element.
This operation is not constant-time, as it involves going through all the child elements.
An element's id within the SVG, starting with "#" (a single hash character), for example, #layer1. This notation corresponds to a URL's fragment ID. Alternatively, pass NULL to compute the geometry for the whole SVG.
Computes the ink rectangle and logical rectangle of an SVG element, or the whole SVG, as if the whole SVG were rendered to a specific viewport.
Element IDs should look like an URL fragment identifier; for example, pass
#foo (hash foo) to get the geometry of the element that
has an id="foo" attribute.
The "ink rectangle" is the bounding box that would be painted for fully-stroked and filled elements.
The "logical rectangle" just takes into account the unstroked paths and text outlines.
Note that these bounds are not minimum bounds; for example, clipping paths are not taken into account.
You can pass NULL for the id if you want to measure all
the elements in the SVG, i.e. to measure everything from the
root element.
This operation is not constant-time, as it involves going through all the child elements.
An element's id within the SVG, starting with "#" (a single hash character), for example, #layer1. This notation corresponds to a URL's fragment ID. Alternatively, pass NULL to compute the geometry for the whole SVG.
Viewport size at which the whole SVG would be fitted.
In simple terms, queries the width, height, and viewBox attributes in an SVG document.
If you are calling this function to compute a scaling factor to render the SVG,
consider simply using [methodRsvg.Handle.render_document] instead; it will do the
scaling computations automatically.
Before librsvg 2.54.0, the out_has_width and out_has_height arguments would be set to true or false
depending on whether the SVG document actually had width and height attributes, respectively.
However, since librsvg 2.54.0, width and height are now geometry
properties per the SVG2 specification; they
are not plain attributes. SVG2 made it so that the initial value of those properties
is auto, which is equivalent to specifing a value of 100%. In this sense, even SVG
documents which lack width or height attributes semantically have to make them
default to 100%. This is why since librsvg 2.54.0, out_has_width and
out_has_heigth are always returned as TRUE, since with SVG2 all documents have a
default width and height of 100%.
As an example, the following SVG element has a width of 100 pixels and a height of 400 pixels, but no viewBox. This
function will return those sizes in out_width and out_height, and set out_has_viewbox to FALSE.
<svg xmlns="http://www.w3.org/2000/svg" width="100" height="400">
Conversely, the following element has a viewBox, but no width or height. This function will
set out_has_viewbox to TRUE, and it will also set out_has_width and out_has_height to TRUE but
return both length values as 100%.
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 400">
Note that the RsvgLength return values have RsvgUnits in them; you should
not assume that they are always in pixels. For example, the following SVG element
will return width and height values whose units fields are RSVG_UNIT_MM.
<svg xmlns="http://www.w3.org/2000/svg" width="210mm" height="297mm">
API ordering: This function must be called on a fully-loaded handle. See
the section "API ordering" for details.
Panics: this function will panic if the handle is not fully-loaded.
Converts an SVG document's intrinsic dimensions to pixels, and returns the result.
This function is able to extract the size in pixels from an SVG document if the
document has both width and height attributes
with physical units (px, in, cm, mm, pt, pc) or font-based units (em, ex). For
physical units, the dimensions are normalized to pixels using the dots-per-inch (DPI)
value set previously with [methodRsvg.Handle.set_dpi]. For font-based units, this function
uses the computed value of the font-size property for the toplevel
<svg> element. In those cases, this function returns TRUE.
This function is not able to extract the size in pixels directly from the intrinsic
dimensions of the SVG document if the width or
height are in percentage units (or if they do not exist, in which
case the SVG spec mandates that they default to 100%), as these require a
FALSE.
For example, the following document fragment has intrinsic dimensions that will resolve to 20x30 pixels.
<svg xmlns="http://www.w3.org/2000/svg" width="20" height="30"/>
Similarly, if the DPI is set to 96, this document will resolve to 192×288 pixels (i.e. 96×2 × 96×3).
<svg xmlns="http://www.w3.org/2000/svg" width="2in" height="3in"/>
The dimensions of the following documents cannot be resolved to pixels directly, and
this function would return FALSE for them:
<!-- Needs a viewport against which to compute the percentages. -->
<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%"/>
<!-- Does not have intrinsic width/height, just a 1:2 aspect ratio which
needs to be fitted within a viewport. -->
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 200"/>
Instead of querying an SVG document's size, applications are encouraged to render SVG
documents to a size chosen by the application, by passing a suitably-sized viewport to
[methodRsvg.Handle.render_document].
Returns the pixbuf loaded by handle. The pixbuf returned will be reffed, so
the caller of this function must assume that ref.
API ordering: This function must be called on a fully-loaded handle. See
the section "API ordering" for details.
This function depends on the [classRsvg.Handle]'s dots-per-inch value (DPI) to compute the
"natural size" of the document in pixels, so you should call [methodRsvg.Handle.set_dpi]
beforehand.
Creates a GdkPixbuf the same size as the entire SVG loaded into handle, but
only renders the sub-element that has the specified id (and all its
sub-sub-elements recursively). If id is NULL, this function renders the
whole SVG.
This function depends on the [classRsvg.Handle]'s dots-per-inch value (DPI) to compute the
"natural size" of the document in pixels, so you should call [methodRsvg.Handle.set_dpi]
beforehand.
If you need to render an image which is only big enough to fit a particular
sub-element of the SVG, consider using [methodRsvg.Handle.render_element].
Element IDs should look like an URL fragment identifier; for example, pass
#foo (hash foo) to get the geometry of the element that
has an id="foo" attribute.
API ordering: This function must be called on a fully-loaded handle. See
the section "API ordering" for details.
An element's id within the SVG, starting with "#" (a single hash character), for example, #layer1. This notation corresponds to a URL's fragment ID. Alternatively, pass NULL to use the whole SVG.
Get the position of a subelement of the SVG file. Do not call from within the size_func callback, because an infinite loop will occur.
This function depends on the [classRsvg.Handle]'s DPI to compute dimensions in
pixels, so you should call [methodRsvg.Handle.set_dpi] beforehand.
Element IDs should look like an URL fragment identifier; for example, pass
#foo (hash foo) to get the geometry of the element that
has an id="foo" attribute.
An element's id within the SVG, starting with "#" (a single hash character), for example, #layer1. This notation corresponds to a URL's fragment ID. Alternatively, pass %NULL to use the whole SVG.
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
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
Checks whether the element id exists in the SVG document.
Element IDs should look like an URL fragment identifier; for example, pass
#foo (hash foo) to get the geometry of the element that
has an id="foo" attribute.
An element's id within the SVG, starting with "#" (a single hash character), for example, #layer1. This notation corresponds to a URL's fragment ID.
Do not call this function. This is intended for librsvg's internal test suite only.
Whether to enable testing mode
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.
Reads stream and writes the data from it to handle.
Before calling this function, you may need to call [methodRsvg.Handle.set_base_uri]
or [methodRsvg.Handle.set_base_gfile] to set the "base file" for resolving
references to external resources. SVG elements like
<image> which reference external resources will be
resolved relative to the location you specify with those functions.
If cancellable is not NULL, then the operation can be cancelled by
triggering the cancellable object from another thread. If the
operation was cancelled, the error G_IO_ERROR_CANCELLED will be
returned.
a GInputStream
a GCancellable, or NULL
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().
Draws a loaded SVG handle to a Cairo context. Please try to use
[methodRsvg.Handle.render_document] instead, which allows you to pick the size
at which the document will be rendered.
Historically this function has picked a size by itself, based on the following rules:
If the SVG document has both width and height
attributes with physical units (px, in, cm, mm, pt, pc) or font-based units (em,
ex), the function computes the size directly based on the dots-per-inch (DPI) you
have configured with [methodRsvg.Handle.set_dpi]. This is the same approach as
[methodRsvg.Handle.get_intrinsic_size_in_pixels].
Otherwise, if there is a viewBox attribute and both
width and height are set to
100% (or if they don't exist at all and thus default to 100%),
the function uses the width and height of the viewBox as a pixel size. This
produces a rendered document with the correct aspect ratio.
Otherwise, this function computes the extents of every graphical object in the SVG document to find the total extents. This is moderately expensive, but no more expensive than rendering the whole document, for example.
This function cannot deal with percentage-based units for width
and height because there is no viewport against which they could
be resolved; that is why it will compute the extents of objects in that case. This
is why we recommend that you use [methodRsvg.Handle.render_document] instead, which takes
in a viewport and follows the sizing policy from the web platform.
Drawing will occur with respect to the cr's current transformation: for example, if
the cr has a rotated current transformation matrix, the whole SVG will be rotated in
the rendered version.
This function depends on the [classRsvg.Handle]'s DPI to compute dimensions in
pixels, so you should call [methodRsvg.Handle.set_dpi] beforehand.
Note that cr must be a Cairo context that is not in an error state, that is,
cairo_status() must return CAIRO_STATUS_SUCCESS for it. Cairo can set a
context to be in an error state in various situations, for example, if it was
passed an invalid matrix or if it was created for an invalid surface.
Renders a single SVG element in the same place as for a whole SVG document (a "subset"
of the document). Please try to use [methodRsvg.Handle.render_layer] instead, which allows
you to pick the size at which the document with the layer will be rendered.
This is equivalent to [methodRsvg.Handle.render_cairo], but it renders only a single
element and its children, as if they composed an individual layer in the SVG.
Historically this function has picked a size for the whole document by itself, based on the following rules:
If the SVG document has both width and height
attributes with physical units (px, in, cm, mm, pt, pc) or font-based units (em,
ex), the function computes the size directly based on the dots-per-inch (DPI) you
have configured with [methodRsvg.Handle.set_dpi]. This is the same approach as
[methodRsvg.Handle.get_intrinsic_size_in_pixels].
Otherwise, if there is a viewBox attribute and both
width and height are set to
100% (or if they don't exist at all and thus default to 100%),
the function uses the width and height of the viewBox as a pixel size. This
produces a rendered document with the correct aspect ratio.
Otherwise, this function computes the extents of every graphical object in the SVG document to find the total extents. This is moderately expensive, but no more expensive than rendering the whole document, for example.
This function cannot deal with percentage-based units for width
and height because there is no viewport against which they could
be resolved; that is why it will compute the extents of objects in that case. This
is why we recommend that you use [methodRsvg.Handle.render_layer] instead, which takes
in a viewport and follows the sizing policy from the web platform.
Drawing will occur with respect to the cr's current transformation: for example, if
the cr has a rotated current transformation matrix, the whole SVG will be rotated in
the rendered version.
This function depends on the [classRsvg.Handle]'s DPI to compute dimensions in
pixels, so you should call [methodRsvg.Handle.set_dpi] beforehand.
Note that cr must be a Cairo context that is not in an error state, that is,
cairo_status() must return CAIRO_STATUS_SUCCESS for it. Cairo can set a
context to be in an error state in various situations, for example, if it was
passed an invalid matrix or if it was created for an invalid surface.
Element IDs should look like an URL fragment identifier; for example, pass
#foo (hash foo) to get the geometry of the element that
has an id="foo" attribute.
A Cairo context
An element's id within the SVG, starting with "#" (a single hash character), for example, #layer1. This notation corresponds to a URL's fragment ID. Alternatively, pass NULL to render the whole SVG.
Renders the whole SVG document fitted to a viewport.
The viewport gives the position and size at which the whole SVG document will be
rendered. The document is scaled proportionally to fit into this viewport.
The cr must be in a CAIRO_STATUS_SUCCESS state, or this function will not
render anything, and instead will return an error.
A Cairo context
Viewport size at which the whole SVG would be fitted.
Renders a single SVG element to a given viewport.
This function can be used to extract individual element subtrees and render them,
scaled to a given element_viewport. This is useful for applications which have
reusable objects in an SVG and want to render them individually; for example, an
SVG full of icons that are meant to be be rendered independently of each other.
Element IDs should look like an URL fragment identifier; for example, pass
#foo (hash foo) to get the geometry of the element that
has an id="foo" attribute.
You can pass NULL for the id if you want to render all
the elements in the SVG, i.e. to render everything from the
root element.
The element_viewport gives the position and size at which the named element will
be rendered. FIXME: mention proportional scaling.
A Cairo context
An element's id within the SVG, starting with "#" (a single hash character), for example, #layer1. This notation corresponds to a URL's fragment ID. Alternatively, pass NULL to render the whole SVG document tree.
Viewport size in which to fit the element
Renders a single SVG element in the same place as for a whole SVG document.
The viewport gives the position and size at which the whole SVG document would be
rendered. The document is scaled proportionally to fit into this viewport; hence the
individual layer may be smaller than this.
This is equivalent to [methodRsvg.Handle.render_document], but it renders only a
single element and its children, as if they composed an individual layer in
the SVG. The element is rendered with the same transformation matrix as it
has within the whole SVG document. Applications can use this to re-render a
single element and repaint it on top of a previously-rendered document, for
example.
Element IDs should look like an URL fragment identifier; for example, pass
#foo (hash foo) to get the geometry of the element that
has an id="foo" attribute.
You can pass NULL for the id if you want to render all
the elements in the SVG, i.e. to render everything from the
root element.
A Cairo context
An element's id within the SVG, starting with "#" (a single hash character), for example, #layer1. This notation corresponds to a URL's fragment ID. Alternatively, pass NULL to render the whole SVG document tree.
Viewport size at which the whole SVG would be fitted.
Releases all references to other objects. This can be used to break reference cycles.
This function should only be called from object system implementations.
Set the base URI for this SVG.
Note: This function may only be called before [methodRsvg.Handle.write] or
[methodRsvg.Handle.read_stream_sync] have been called.
The base uri
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
Sets the DPI at which the handle will be rendered. Common values are
75, 90, and 300 DPI.
Passing a number <= 0 to dpi will reset the DPI to whatever the default
value happens to be, but since [idrsvg_set_default_dpi] is deprecated, please
do not pass values <= 0 to this function.
Dots Per Inch (i.e. as Pixels Per Inch)
Sets the DPI at which the handle will be rendered. Common values are
75, 90, and 300 DPI.
Passing a number <= 0 to dpi will reset the DPI to whatever the default
value happens to be, but since [idrsvg_set_default_dpi_x_y] is deprecated,
please do not pass values <= 0 to this function.
Dots Per Inch (i.e. Pixels Per Inch)
Dots Per Inch (i.e. Pixels Per Inch)
Sets a property on an object.
the name of the property to set
the value
Sets the sizing function for the handle, which can be used to override the
size that librsvg computes for SVG images. The size_func is called from the
following functions:
Rsvg.Handle.get_dimensions]Rsvg.Handle.get_dimensions_sub]Rsvg.Handle.get_position_sub]Rsvg.Handle.render_cairo]Rsvg.Handle.render_cairo_sub]Librsvg computes the size of the SVG being rendered, and passes it to the
size_func, which may then modify these values to set the final size of the
generated image.
A sizing function, or NULL
Sets a CSS stylesheet to use for an SVG document.
The css_len argument is mandatory; this function will not compute the length
of the css string. This is because a provided stylesheet, which the calling
program could read from a file, can have nul characters in it.
During the CSS cascade, the specified stylesheet will be used with a "User" origin.
Note that import rules will not be resolved, except for data: URLs.
String with CSS data; must be valid UTF-8.
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.
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.
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.
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
Loads the next count bytes of the image. You can call this function multiple
times until the whole document is consumed; then you must call [methodRsvg.Handle.close]
to actually parse the document.
Before calling this function for the first time, you may need to call
[methodRsvg.Handle.set_base_uri] or [methodRsvg.Handle.set_base_gfile] to set the "base
file" for resolving references to external resources. SVG elements like
<image> which reference external resources will be
resolved relative to the location you specify with those functions.
pointer to svg data
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
Returns a new rsvg handle. Must be freed with [methodGObject.Object.unref]. This
handle can be used to load an image.
The preferred way of loading SVG data into the returned [classRsvg.Handle] is with
[methodRsvg.Handle.read_stream_sync].
The deprecated way of loading SVG data is with [methodRsvg.Handle.write] and
[methodRsvg.Handle.close]; note that these require buffering the entire file
internally, and for this reason it is better to use the stream functions:
[ctorRsvg.Handle.new_from_stream_sync], [methodRsvg.Handle.read_stream_sync], or
[ctorRsvg.Handle.new_from_gfile_sync].
After loading the [classRsvg.Handle] with data, you can render it using Cairo or get
a GdkPixbuf from it. When finished, free the handle with [methodGObject.Object.unref]. No
more than one image can be loaded with one handle.
Note that this function creates an [classRsvg.Handle] with no flags set. If you
require any of [flagsRsvg.HandleFlags] to be set, use any of
[ctorRsvg.Handle.new_with_flags], [ctorRsvg.Handle.new_from_stream_sync], or
[ctorRsvg.Handle.new_from_gfile_sync].
Loads the SVG specified by data. Note that this function creates an
[classRsvg.Handle] without a base URL, and without any [flagsRsvg.HandleFlags]. If you
need these, use [ctorRsvg.Handle.new_from_stream_sync] instead by creating
a [classGio.MemoryInputStream] from your data.
The SVG data
Loads the SVG specified by file_name. Note that this function, like
[ctorRsvg.Handle.new], does not specify any loading flags for the resulting
handle. If you require the use of [flagsRsvg.HandleFlags], use
[ctorRsvg.Handle.new_from_gfile_sync].
The file name to load, or a URI.
Creates a new [classRsvg.Handle] for file.
This function sets the "base file" of the handle to be file itself, so SVG
elements like <image> which reference external
resources will be resolved relative to the location of file.
If cancellable is not NULL, then the operation can be cancelled by
triggering the cancellable object from another thread. If the
operation was cancelled, the error G_IO_ERROR_CANCELLED will be
returned in error.
a GFile
flags from [flagsRsvg.HandleFlags]
a GCancellable, or NULL
Creates a new [classRsvg.Handle] for stream.
This function sets the "base file" of the handle to be base_file if
provided. SVG elements like <image> which reference
external resources will be resolved relative to the location of base_file.
If cancellable is not NULL, then the operation can be cancelled by
triggering the cancellable object from another thread. If the
operation was cancelled, the error G_IO_ERROR_CANCELLED will be
returned in error.
a GInputStream
a GFile, or NULL
flags from [flagsRsvg.HandleFlags]
a GCancellable, or NULL
Creates a new [classRsvg.Handle] with flags flags. After calling this function,
you can feed the resulting handle with SVG data by using
[methodRsvg.Handle.read_stream_sync].
flags from [flagsRsvg.HandleFlags]
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
[class
Rsvg.Handle] loads an SVG document into memory.This is the main entry point into the librsvg library. An [class
Rsvg.Handle] is an object that represents SVG data in memory. Your program creates an [classRsvg.Handle] from an SVG file, or from a memory buffer that contains SVG data, or in the most general form, from aGInputStreamthat will provide SVG data.Librsvg can load SVG images and render them to Cairo surfaces, using a mixture of SVG's static mode and secure static mode. Librsvg does not do animation nor scripting, and can load references to external data only in some situations; see below.
Librsvg supports reading SVG 1.1 data, and is gradually adding support for features in SVG 2. Librsvg also supports SVGZ files, which are just an SVG stream compressed with the GZIP algorithm.
The "base file" and resolving references to external files
When you load an SVG, librsvg needs to know the location of the "base file" for it. This is so that librsvg can determine the location of referenced entities. For example, say you have an SVG in
/foo/bar/foo.svgand that it has an image element like this:In this case, librsvg needs to know the location of the toplevel
/foo/bar/foo.svgso that it can generate the appropriate reference to/foo/bar/resources/foo.png.Security and locations of referenced files
When processing an SVG, librsvg will only load referenced files if they are in the same directory as the base file, or in a subdirectory of it. That is, if the base file is
/foo/bar/baz.svg, then librsvg will only try to load referenced files (from SVG's<image>element, for example, or from content included through XML entities) if those files are in/foo/bar/*or in/foo/bar/*\/.../*. This is so that malicious SVG files cannot include files that are in a directory above.The full set of rules for deciding which URLs may be loaded is as follows; they are applied in order. A referenced URL will not be loaded as soon as one of these rules fails:
All
data:URLs may be loaded. These are sometimes used to include raster image data, encoded as base-64, directly in an SVG file.All other URL schemes in references require a base URL. For example, this means that if you load an SVG with [ctor
Rsvg.Handle.new_from_data] without calling [methodRsvg.Handle.set_base_uri], then any referenced files will not be allowed (e.g. raster images to be loaded from other files will not work).If referenced URLs are absolute, rather than relative, then they must have the same scheme as the base URL. For example, if the base URL has a
filescheme, then all URL references inside the SVG must also have thefilescheme, or be relative references which will be resolved against the base URL.If referenced URLs have a
resourcescheme, that is, if they are included into your binary program with GLib's resource mechanism, they are allowed to be loaded (provided that the base URL is also aresource, per the previous rule).Otherwise, non-
fileschemes are not allowed. For example, librsvg will not loadhttpresources, to keep malicious SVG data from "phoning home".A relative URL must resolve to the same directory as the base URL, or to one of its subdirectories. Librsvg will canonicalize filenames, by removing ".." path components and resolving symbolic links, to decide whether files meet these conditions.
Loading an SVG with GIO
This is the easiest and most resource-efficient way of loading SVG data into an [class
Rsvg.Handle].If you have a
GFilethat stands for an SVG file, you can simply call [ctorRsvg.Handle.new_from_gfile_sync] to load an [classRsvg.Handle] from it.Alternatively, if you have a
GInputStream, you can use [ctorRsvg.Handle.new_from_stream_sync].Both of those methods allow specifying a
GCancellable, so the loading process can be cancelled from another thread.Loading an SVG from memory
If you already have SVG data in a byte buffer in memory, you can create a memory input stream with [ctor
Gio.MemoryInputStream.new_from_data] and feed that to [ctorRsvg.Handle.new_from_stream_sync].Note that in this case, it is important that you specify the base_file for the in-memory SVG data. Librsvg uses the base_file to resolve links to external content, like raster images.
Loading an SVG without GIO
You can load an [class
Rsvg.Handle] from a simple filename or URI with [ctorRsvg.Handle.new_from_file]. Note that this is a blocking operation; there is no way to cancel it if loading a remote URI takes a long time. Also, note that this method does not let you specify [flagsRsvg.HandleFlags].Otherwise, loading an SVG without GIO is not recommended, since librsvg will need to buffer your entire data internally before actually being able to parse it. The deprecated way of doing this is by creating a handle with [ctor
Rsvg.Handle.new] or [ctorRsvg.Handle.new_with_flags], and then using [methodRsvg.Handle.write] and [methodRsvg.Handle.close] to feed the handle with SVG data. Still, please try to use the GIO stream functions instead.Resolution of the rendered image (dots per inch, or DPI)
SVG images can contain dimensions like "
5cm" or "2pt" that must be converted from physical units into device units. To do this, librsvg needs to know the actual dots per inch (DPI) of your target device. You can call [methodRsvg.Handle.set_dpi] or [methodRsvg.Handle.set_dpi_x_y] on an [classRsvg.Handle] to set the DPI before rendering it.Rendering
The preferred way to render a whole SVG document is to use [method
Rsvg.Handle.render_document]. Please see its documentation for details.API ordering
Due to the way the librsvg API evolved over time, an [class
Rsvg.Handle] object is available for use as soon as it is constructed. However, not all of its methods can be called at any time. For example, an [classRsvg.Handle] just constructed with [ctorRsvg.Handle.new] is not loaded yet, and it does not make sense to call [methodRsvg.Handle.render_document] on it just at that point.The documentation for the available methods in [class
Rsvg.Handle] may mention that a particular method is only callable on a "fully loaded handle". This means either:The handle was loaded with [method
Rsvg.Handle.write] and [methodRsvg.Handle.close], and those functions returned no errors.The handle was loaded with [method
Rsvg.Handle.read_stream_sync] and that function returned no errors.Before librsvg 2.46, the library did not fully verify that a handle was in a fully loaded state for the methods that require it. To preserve compatibility with old code which inadvertently called the API without checking for errors, or which called some methods outside of the expected order, librsvg will just emit a
g_critical()message in those cases.New methods introduced in librsvg 2.46 and later will check for the correct ordering, and panic if they are called out of order. This will abort the program as if it had a failed assertion.