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A GtkBuilder is an auxiliary object that reads textual descriptions
of a user interface and instantiates the described objects. To create
a GtkBuilder from a user interface description, call
gtk_builder_new_from_file()
, gtk_builder_new_from_resource()
or
gtk_builder_new_from_string()
.
In the (unusual) case that you want to add user interface
descriptions from multiple sources to the same GtkBuilder you can
call gtk_builder_new()
to get an empty builder and populate it by
(multiple) calls to gtk_builder_add_from_file()
,
gtk_builder_add_from_resource()
or gtk_builder_add_from_string()
.
A GtkBuilder holds a reference to all objects that it has constructed
and drops these references when it is finalized. This finalization can
cause the destruction of non-widget objects or widgets which are not
contained in a toplevel window. For toplevel windows constructed by a
builder, it is the responsibility of the user to call gtk_widget_destroy()
to get rid of them and all the widgets they contain.
The functions gtk_builder_get_object()
and gtk_builder_get_objects()
can be used to access the widgets in the interface by the names assigned
to them inside the UI description. Toplevel windows returned by these
functions will stay around until the user explicitly destroys them
with gtk_widget_destroy()
. Other widgets will either be part of a
larger hierarchy constructed by the builder (in which case you should
not have to worry about their lifecycle), or without a parent, in which
case they have to be added to some container to make use of them.
Non-widget objects need to be reffed with g_object_ref()
to keep them
beyond the lifespan of the builder.
The function gtk_builder_connect_signals()
and variants thereof can be
used to connect handlers to the named signals in the description.
GtkBuilder parses textual descriptions of user interfaces which are specified
in an XML format which can be roughly described by the RELAX NG schema below.
We refer to these descriptions as GtkBuilder UI definitions
or just UI definitions if the context is clear. Do not
confuse GtkBuilder UI Definitions with
GtkUIManager UI Definitions, which are more
limited in scope. It is common to use .ui
as the filename extension for files containing GtkBuilder UI definitions.
FIXME: MISSING XINCLUDE CONTENT
The toplevel element is <interface>. It optionally takes a "domain"
attribute, which will make the builder look for translated strings using
dgettext()
in the domain specified. This can also be done by calling
gtk_builder_set_translation_domain()
on the builder. Objects are described by
<object> elements, which can contain <property> elements to set
properties, <signal> elements which connect signals to handlers, and
<child> elements, which describe child objects (most often widgets
inside a container, but also e.g. actions in an action group, or columns in a
tree model). A <child> element contains an <object> element which
describes the child object. The target toolkit version(s) are described by
<requires> elements, the "lib" attribute specifies the widget library
in question (currently the only supported value is "gtk+") and the "version"
attribute specifies the target version in the form
"<major>.<minor>". The builder will error out if the version
requirements are not met.
Typically, the specific kind of object represented by an <object>
element is specified by the "class" attribute. If the type has not been
loaded yet, GTK+ tries to find the
from the
class name by applying heuristics. This works in most cases, but if
necessary, it is possible to specify the name of the
_get_type()
explictly with the "type-func" attribute.
As a special case, GtkBuilder allows to use an object that has been
constructed by a GtkUIManager in another part of the UI definition by
specifying the id of the GtkUIManager in the "constructor" attribute and the
name of the object in the "id" attribute.
Objects must be given a name with the "id" attribute, which allows the
application to retrieve them from the builder with _get_type()
gtk_builder_get_object()
.
An id is also necessary to use the object as property value in other parts of
the UI definition.
Prior to 2.20, GtkBuilder was setting the "name" property of constructed widgets to the
"id" attribute. In GTK+ 2.20 or newer, you have to use gtk_buildable_get_name()
instead
of gtk_widget_get_name()
to obtain the "id", or set the "name" property in your UI
definition.
Setting properties of objects is pretty straightforward with the
<property> element: the "name" attribute specifies the name of the
property, and the content of the element specifies the value. If the
"translatable" attribute is set to a true value, GTK+ uses gettext()
(or
dgettext()
if the builder has a translation domain set) to find a translation
for the value. This happens before the value is parsed, so it can be used for
properties of any type, but it is probably most useful for string properties.
It is also possible to specify a context to disambiguate short strings, and
comments which may help the translators.
GtkBuilder can parse textual representations for the most common property
types: characters, strings, integers, floating-point numbers, booleans
(strings like "TRUE", "t", "yes", "y", "1" are interpreted as TRUE
, strings
like "FALSE, "f", "no", "n", "0" are interpreted as FALSE
), enumerations
(can be specified by their name, nick or integer value), flags (can be
specified by their name, nick, integer value, optionally combined with "|",
e.g. "GTK_VISIBLE|GTK_REALIZED") and colors (in a format understood by
gdk_color_parse()
). Pixbufs can be specified as a filename of an image file to load.
Objects can be referred to by their name and by default refer to objects declared
in the local xml fragment and objects exposed via gtk_builder_expose_object()
.
In general, GtkBuilder allows forward references to objects &mdash declared
in the local xml; an object doesn't have to be constructed before it can be referred to.
The exception to this rule is that an object has to be constructed before
it can be used as the value of a construct-only property.
Signal handlers are set up with the <signal> element. The "name"
attribute specifies the name of the signal, and the "handler" attribute
specifies the function to connect to the signal. By default, GTK+ tries to
find the handler using g_module_symbol()
, but this can be changed by passing
a custom GtkBuilderConnectFunc to gtk_builder_connect_signals_full()
. The
remaining attributes, "after", "swapped" and "object", have the same meaning
as the corresponding parameters of the g_signal_connect_object()
or
g_signal_connect_data()
functions. A "last_modification_time" attribute
is also allowed, but it does not have a meaning to the builder.
Sometimes it is necessary to refer to widgets which have implicitly been
constructed by GTK+ as part of a composite widget, to set properties on them
or to add further children (e.g. the vbox
of a GtkDialog). This can be
achieved by setting the "internal-child" propery of the <child> element
to a true value. Note that GtkBuilder still requires an <object>
element for the internal child, even if it has already been constructed.
A number of widgets have different places where a child can be added (e.g.
tabs vs. page content in notebooks). This can be reflected in a UI definition
by specifying the "type" attribute on a <child>. The possible values
for the "type" attribute are described in the sections describing the
widget-specific portions of UI definitions.
Example 9. A GtkBuilder UI Definition
<interface> <object class="GtkDialog" id="dialog1"> <child internal-child="vbox"> <object class="GtkVBox" id="vbox1"> <property name="border-width">10</property> <child internal-child="action_area"> <object class="GtkHButtonBox" id="hbuttonbox1"> <property name="border-width">20</property> <child> <object class="GtkButton" id="ok_button"> <property name="label">gtk-ok</property> <property name="use-stock">TRUE</property> <signal name="clicked" handler="ok_button_clicked"/> </object> </child> </object> </child> </object> </child> </object> </interface>
Beyond this general structure, several object classes define their own XML DTD fragments for filling in the ANY placeholders in the DTD above. Note that a custom element in a <child> element gets parsed by the custom tag handler of the parent object, while a custom element in an <object> element gets parsed by the custom tag handler of the object. These XML fragments are explained in the documentation of the respective objects, see GtkWidget, GtkLabel, GtkWindow, GtkContainer, GtkDialog, GtkCellLayout, GtkColorSelectionDialog, GtkFontSelectionDialog, GtkExpander, GtkFrame, GtkListStore, GtkTreeStore, GtkNotebook, GtkSizeGroup, GtkTreeView, GtkUIManager, GtkActionGroup. GtkMenuItem, GtkMenuToolButton, GtkAssistant, GtkScale, GtkComboBoxText, GtkRecentFilter, GtkFileFilter, GtkTextTagTable.
Additionally, since 3.10 a special <template> tag has been added to the format allowing one to define a widget class's components.
Apart from the language for UI descriptions that has been explained
in the previous section, GtkBuilder can also parse XML fragments
of GMenu markup. The resulting
GMenu object and its named submenus are available via
gtk_builder_get_object()
like other constructed objects.
void (*GtkBuilderConnectFunc) (GtkBuilder *builder
,GObject *object
,const gchar *signal_name
,const gchar *handler_name
,GObject *connect_object
,GConnectFlags flags
,gpointer user_data
);
This is the signature of a function used to connect signals. It is used
by the gtk_builder_connect_signals()
and gtk_builder_connect_signals_full()
methods. It is mainly intended for interpreted language bindings, but
could be useful where the programmer wants more control over the signal
connection process. Note that this function can only be called once,
subsequent calls will do nothing.
builder |
||
object |
object to connect a signal to |
|
signal_name |
name of the signal |
|
handler_name |
name of the handler |
|
connect_object |
a GObject, if non- |
|
flags |
GConnectFlags to use |
|
user_data |
user data |
Since 2.12
GtkBuilder *
gtk_builder_new (void
);
Creates a new empty builder object.
This function is only useful if you intend to make multiple calls to
gtk_builder_add_from_file()
, gtk_builder_add_from_resource()
or
gtk_builder_add_from_string()
in order to merge multiple UI
descriptions into a single builder.
Most users will probably want to use gtk_builder_new_from_file()
,
gtk_builder_new_from_resource()
or gtk_builder_new_from_string()
.
Since 2.12
GtkBuilder *
gtk_builder_new_from_file (const gchar *filename
);
Builds the GtkBuilder UI definition
in the file filename
.
If there is an error opening the file or parsing the description then the program will be aborted. You should only ever attempt to parse user interface descriptions that are shipped as part of your program.
Since 3.10
GtkBuilder *
gtk_builder_new_from_resource (const gchar *resource_path
);
Builds the GtkBuilder UI definition
at resource_path
.
If there is an error locating the resurce or parsing the description then the program will be aborted.
Since 3.10
GtkBuilder * gtk_builder_new_from_string (const gchar *string
,gssize length
);
Builds the user interface described by string
(in the GtkBuilder UI definition format).
If string
is NULL
-terminated then length
should be -1. If length
is not -1 then it is the length of string
.
If there is an error parsing string
then the program will be
aborted. You should not attempt to parse user interface description
from untrusted sources.
Since 3.10
void gtk_builder_add_callback_symbol (GtkBuilder *builder
,const gchar *callback_name
,GCallback callback_symbol
);
Adds the callback_symbol
to the scope of builder
under the given callback_name
.
Using this function overrides the behavior of gtk_builder_connect_signals()
for any callback symbols that are added. Using this method allows for better
encapsulation as it does not require that callback symbols be declared in
the global namespace.
builder |
||
callback_name |
The name of the callback, as expected in the XML |
|
callback_symbol |
The callback pointer. |
[scope async] |
Since 3.10
void gtk_builder_add_callback_symbols (GtkBuilder *builder
,const gchar *first_callback_name
,GCallback first_callback_symbol
,...
);
A convenience function to add many callbacks instead of calling
gtk_builder_add_callback_symbol()
for each symbol.
builder |
||
first_callback_name |
The name of the callback, as expected in the XML |
|
first_callback_symbol |
The callback pointer. |
[scope async] |
... |
A list of callback name and callback symbol pairs terminated with |
Since 3.10
GCallback gtk_builder_lookup_callback_symbol (GtkBuilder *builder
,const gchar *callback_name
);
Fetches a symbol previously added to builder
with gtk_builder_add_callback_symbols()
This function is intended for possible use in language bindings
or for any case that one might be cusomizing signal connections
using gtk_builder_connect_signals_full()
Since 3.10
guint gtk_builder_add_from_file (GtkBuilder *builder
,const gchar *filename
,GError **error
);
Parses a file containing a GtkBuilder
UI definition and merges it with the current contents of builder
.
Most users will probably want to use gtk_builder_new_from_file()
.
Upon errors 0 will be returned and error
will be assigned a
GError from the GTK_BUILDER_ERROR, G_MARKUP_ERROR or G_FILE_ERROR
domain.
It's not really reasonable to attempt to handle failures of this
call. You should not use this function with untrusted files (ie:
files that are not part of your application). Broken GtkBuilder
files can easily crash your program, and it's possible that memory
was leaked leading up to the reported failure. The only reasonable
thing to do when an error is detected is to call g_error()
.
builder |
||
filename |
the name of the file to parse |
|
error |
return location for an error, or |
[allow-none] |
Since 2.12
guint gtk_builder_add_from_resource (GtkBuilder *builder
,const gchar *resource_path
,GError **error
);
Parses a resource file containing a GtkBuilder
UI definition and merges it with the current contents of builder
.
Most users will probably want to use gtk_builder_new_from_resource()
.
Upon errors 0 will be returned and error
will be assigned a
GError from the GTK_BUILDER_ERROR, G_MARKUP_ERROR or G_RESOURCE_ERROR
domain.
It's not really reasonable to attempt to handle failures of this
call. The only reasonable thing to do when an error is detected is
to call g_error()
.
builder |
||
resource_path |
the path of the resource file to parse |
|
error |
return location for an error, or |
[allow-none] |
Since 3.4
guint gtk_builder_add_from_string (GtkBuilder *builder
,const gchar *buffer
,gsize length
,GError **error
);
Parses a string containing a GtkBuilder
UI definition and merges it with the current contents of builder
.
Most users will probably want to use gtk_builder_new_from_string()
.
Upon errors 0 will be returned and error
will be assigned a
GError from the GTK_BUILDER_ERROR or G_MARKUP_ERROR domain.
It's not really reasonable to attempt to handle failures of this
call. The only reasonable thing to do when an error is detected is
to call g_error()
.
builder |
||
buffer |
the string to parse |
|
length |
the length of |
|
error |
return location for an error, or |
[allow-none] |
Since 2.12
guint gtk_builder_add_objects_from_file (GtkBuilder *builder
,const gchar *filename
,gchar **object_ids
,GError **error
);
Parses a file containing a GtkBuilder
UI definition building only the requested objects and merges
them with the current contents of builder
.
Upon errors 0 will be returned and error
will be assigned a
GError from the GTK_BUILDER_ERROR, G_MARKUP_ERROR or G_FILE_ERROR
domain.
If you are adding an object that depends on an object that is not
its child (for instance a GtkTreeView that depends on its
GtkTreeModel), you have to explicitely list all of them in object_ids
.
builder |
||
filename |
the name of the file to parse |
|
object_ids |
nul-terminated array of objects to build. |
[array zero-terminated=1][element-type utf8] |
error |
return location for an error, or |
[allow-none] |
Since 2.14
guint gtk_builder_add_objects_from_string (GtkBuilder *builder
,const gchar *buffer
,gsize length
,gchar **object_ids
,GError **error
);
Parses a string containing a GtkBuilder
UI definition building only the requested objects and merges
them with the current contents of builder
.
Upon errors 0 will be returned and error
will be assigned a
GError from the GTK_BUILDER_ERROR or G_MARKUP_ERROR domain.
If you are adding an object that depends on an object that is not
its child (for instance a GtkTreeView that depends on its
GtkTreeModel), you have to explicitely list all of them in object_ids
.
builder |
||
buffer |
the string to parse |
|
length |
the length of |
|
object_ids |
nul-terminated array of objects to build. |
[array zero-terminated=1][element-type utf8] |
error |
return location for an error, or |
[allow-none] |
Since 2.14
guint gtk_builder_add_objects_from_resource (GtkBuilder *builder
,const gchar *resource_path
,gchar **object_ids
,GError **error
);
Parses a resource file containing a GtkBuilder
UI definition building only the requested objects and merges
them with the current contents of builder
.
Upon errors 0 will be returned and error
will be assigned a
GError from the GTK_BUILDER_ERROR, G_MARKUP_ERROR or G_RESOURCE_ERROR
domain.
If you are adding an object that depends on an object that is not
its child (for instance a GtkTreeView that depends on its
GtkTreeModel), you have to explicitely list all of them in object_ids
.
builder |
||
resource_path |
the path of the resource file to parse |
|
object_ids |
nul-terminated array of objects to build. |
[array zero-terminated=1][element-type utf8] |
error |
return location for an error, or |
[allow-none] |
Since 3.4
GObject * gtk_builder_get_object (GtkBuilder *builder
,const gchar *name
);
Gets the object named name
. Note that this function does not
increment the reference count of the returned object.
Since 2.12
GSList *
gtk_builder_get_objects (GtkBuilder *builder
);
Gets all objects that have been constructed by builder
. Note that
this function does not increment the reference counts of the returned
objects.
a newly-allocated GSList containing all the objects
constructed by the GtkBuilder instance. It should be freed by
g_slist_free()
.
[element-type GObject][transfer container]
Since 2.12
void gtk_builder_expose_object (GtkBuilder *builder
,const gchar *name
,GObject *object
);
Add object
to the builder
object pool so it can be referenced just like any
other object built by builder.
Since 3.8
void gtk_builder_connect_signals (GtkBuilder *builder
,gpointer user_data
);
This method is a simpler variation of gtk_builder_connect_signals_full()
.
It uses symbols explicitly added to builder
with prior calls to
gtk_builder_add_callback_symbol()
. In the case that symbols are not
explicitly added; it uses GModule's introspective features (by opening the module NULL
)
to look at the application's symbol table. From here it tries to match
the signal handler names given in the interface description with
symbols in the application and connects the signals. Note that this
function can only be called once, subsequent calls will do nothing.
Note that unless gtk_builder_add_callback_symbol()
is called for
all signal callbacks which are referenced by the loaded XML, this
function will require that GModule be supported on the platform.
If you rely on GModule support to lookup callbacks in the symbol table, the following details should be noted:
When compiling applications for Windows, you must declare signal callbacks with G_MODULE_EXPORT, or they will not be put in the symbol table. On Linux and Unices, this is not necessary; applications should instead be compiled with the -Wl,--export-dynamic CFLAGS, and linked against gmodule-export-2.0.
Since 2.12
void gtk_builder_connect_signals_full (GtkBuilder *builder
,GtkBuilderConnectFunc func
,gpointer user_data
);
This function can be thought of the interpreted language binding
version of gtk_builder_connect_signals()
, except that it does not
require GModule to function correctly.
builder |
||
func |
the function used to connect the signals. |
[scope call] |
user_data |
arbitrary data that will be passed to the connection function |
Since 2.12
void gtk_builder_set_translation_domain (GtkBuilder *builder
,const gchar *domain
);
Sets the translation domain of builder
.
See “translation-domain”.
Since 2.12
const gchar *
gtk_builder_get_translation_domain (GtkBuilder *builder
);
Gets the translation domain of builder
.
the translation domain. This string is owned by the builder object and must not be modified or freed.
Since 2.12
GType gtk_builder_get_type_from_name (GtkBuilder *builder
,const char *type_name
);
Looks up a type by name, using the virtual function that GtkBuilder has for that purpose. This is mainly used when implementing the GtkBuildable interface on a type.
Since 2.12
gboolean gtk_builder_value_from_string (GtkBuilder *builder
,GParamSpec *pspec
,const gchar *string
,GValue *value
,GError **error
);
This function demarshals a value from a string. This function
calls g_value_init()
on the value
argument, so it need not be
initialised beforehand.
This function can handle char, uchar, boolean, int, uint, long, ulong, enum, flags, float, double, string, GdkColor, GdkRGBA and GtkAdjustment type values. Support for GtkWidget type values is still to come.
Upon errors FALSE
will be returned and error
will be assigned a
GError from the GTK_BUILDER_ERROR domain.
builder |
||
pspec |
the GParamSpec for the property |
|
string |
the string representation of the value |
|
value |
the GValue to store the result in. |
[out] |
error |
return location for an error, or |
[allow-none] |
Since 2.12
gboolean gtk_builder_value_from_string_type (GtkBuilder *builder
,GType type
,const gchar *string
,GValue *value
,GError **error
);
Like gtk_builder_value_from_string()
, this function demarshals
a value from a string, but takes a GType instead of GParamSpec.
This function calls g_value_init()
on the value
argument, so it
need not be initialised beforehand.
Upon errors FALSE
will be returned and error
will be assigned a
GError from the GTK_BUILDER_ERROR domain.
Since 2.12
#define GTK_BUILDER_WARN_INVALID_CHILD_TYPE(object, type)
This macro should be used to emit a warning about and unexpected type
value
in a GtkBuildable add_child implementation.
Error codes that identify various errors that can occur while using GtkBuilder.
A type-func attribute didn't name a function that returns a GType. |
||
The input contained a tag that GtkBuilder can't handle. |
||
An attribute that is required by GtkBuilder was missing. |
||
GtkBuilder found an attribute that it doesn't understand. |
||
GtkBuilder found a tag that it doesn't understand. |
||
A required property value was missing. |
||
GtkBuilder couldn't parse some attribute value. |
||
The input file requires a newer version of GTK+. |
||
An object id occurred twice. |
||
A specified object type is of the same type or derived from the type of the composite class being extended with builder XML. |
||
The wrong type was specified in a composite class's template XML |
“translation-domain”
property“translation-domain” gchar *
The translation domain used when translating property values that
have been marked as translatable in interface descriptions.
If the translation domain is NULL
, GtkBuilder uses gettext()
,
otherwise g_dgettext()
.
Flags: Read / Write
Default value: NULL
Since 2.12