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 Builder.newFromFile, Builder.newFromResource or Builder.newFromString.
In the (unusual) case that you want to add user interface descriptions from multiple sources to the same GtkBuilder you can call Builder.new to get an empty builder and populate it by (multiple) calls to Builder.addFromFile, Builder.addFromResource or Builder.addFromString.
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 Widget.destroy to get rid of them and all the widgets they contain.
The functions Builder.getObject and Builder.getObjects 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 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 Builder.connectSignals 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][XML-UI], which are more limited in scope. It is common to use .ui as the filename extension for files containing GtkBuilder UI definitions.
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 Builder.setTranslationDomain 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 get_type() function 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() function explictly with the "type-func" attribute. As a special case, GtkBuilder allows to use an object that has been constructed by a gtk.UIManager in another part of the UI definition by specifying the id of the gtk.UIManager in the “constructor” attribute and the name of the object in the “id” attribute.
Objects may be given a name with the “id” attribute, which allows the application to retrieve them from the builder with Builder.getObject. An id is also necessary to use the object as property value in other parts of the UI definition. GTK+ reserves ids starting and ending with ___ (3 underscores) for its own purposes.
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_rgba_parse()).
GVariants can be specified in the format understood by Variant.parse, and 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 Builder.exposeObject. In general, GtkBuilder allows forward references to objects — 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.
It is also possible to bind a property value to another object's property value using the attributes "bind-source" to specify the source object of the binding, "bind-property" to specify the source property and optionally "bind-flags" to specify the binding flags Internally builder implement this using GBinding objects. For more information see g_object_bind_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 Module.symbol, but this can be changed by passing a custom GtkBuilderConnectFunc to Builder.connectSignalsFull. 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 gtk.Dialog). 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.
|[ <interface> <object class="GtkDialog" id="dialog1"> <child internal-child="vbox"> <object class="GtkBox" id="vbox1"> <property name="border-width">10</property> <child internal-child="action_area"> <object class="GtkButtonBox" 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. Additionally, since 3.10 a special <template> tag has been added to the format allowing one to define a widget class’s components. See the [GtkWidget documentation][composite-templates] for details.
Sets our main struct and passes it to the parent class.
Creates a new builder object. Since 2.12
Builds the [GtkBuilder UI definition][BUILDER-UI] in the file filename.
Adds the callback_symbol to the scope of builder under the given callback_name.
Parses a file containing a [GtkBuilder UI definition][BUILDER-UI] and merges it with the current contents of builder.
Parses a resource file containing a [GtkBuilder UI definition][BUILDER-UI] and merges it with the current contents of builder.
Parses a string containing a [GtkBuilder UI definition][BUILDER-UI] and merges it with the current contents of builder.
Parses a file containing a [GtkBuilder UI definition][BUILDER-UI] building only the requested objects and merges them with the current contents of builder.
Parses a resource file containing a [GtkBuilder UI definition][BUILDER-UI] building only the requested objects and merges them with the current contents of builder.
Parses a string containing a [GtkBuilder UI definition][BUILDER-UI] building only the requested objects and merges them with the current contents of builder.
This method is a simpler variation of Builder.connectSignalsFull. It uses symbols explicitly added to builder with prior calls to Builder.addCallbackSymbol. In the case that symbols are not explicitly added; it uses glib.Module’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.
This function can be thought of the interpreted language binding version of Builder.connectSignals, except that it does not require GModule to function correctly.
Add object to the builder object pool so it can be referenced just like any other object built by builder.
Main private entry point for building composite container components from template XML.
Gets the gtk.Application associated with the builder.
Get the main Gtk struct
Gets the object named name. Note that this function does not increment the reference count of the returned object.
Gets all objects that have been constructed by builder. Since 2.12
the main Gtk struct as a void*
Gets the translation domain of builder.
Fetches a symbol previously added to builder with Builder.addCallbackSymbols
Sets the application associated with builder.
Sets the translation domain of builder. See translation-domain.
This function demarshals a value from a string. This function calls Value.init on the value argument, so it need not be initialised beforehand.
the main Gtk struct
the main Gtk struct
Get the main Gtk struct
the main Gtk struct as a void*
Gets a D Object from the objects table of associations.
The notify signal is emitted on an object when one of its properties has been changed. Note that getting this signal doesn't guarantee that the value of the property has actually changed, it may also be emitted when the setter for the property is called to reinstate the previous value.
Find the gobject.ParamSpec 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().
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 gobject.ParamSpec, but normally ObjectClass.overrideProperty 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.
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().
Increases the reference count of the object by one and sets a callback to be called when all other references to the object are dropped, or when this is already the last reference to the object and another reference is established.
Adds a weak reference from weak_pointer to object to indicate that the pointer located at weak_pointer_location is only valid during the lifetime of object. When the object is finalized, weak_pointer will be set to NULL.
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:
Complete version of g_object_bind_property().
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 is a variant of g_object_get_data() which returns a 'duplicate' of the value. dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object.
This is a variant of g_object_get_qdata() which returns a 'duplicate' of the value. dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object.
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 notify signal is emitted for each property modified while the object is frozen.
Gets a named field from the objects table of associations (see g_object_set_data()).
Gets a property of an object.
This function gets back user data pointers stored via g_object_set_qdata().
Gets properties of an object.
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.
Checks whether object has a floating[floating-ref] reference.
Emits a "notify" signal for the property property_name on object.
Emits a "notify" signal for the property specified by pspec on object.
Increases the reference count of object.
Increase the reference count of object, and possibly remove the floating[floating-ref] reference, if object has a floating reference.
Removes a reference added with g_object_add_toggle_ref(). The reference count of the object is decreased by one.
Removes a weak reference from object that was previously added using g_object_add_weak_pointer(). The weak_pointer_location has to match the one used with g_object_add_weak_pointer().
Compares the user data for the key key on object with oldval, and if they are the same, replaces oldval with newval.
Compares the user data for the key quark on object with oldval, and if they are the same, replaces oldval with newval.
Releases all references to other objects. This can be used to break reference cycles.
Each object carries around a table of associations from strings to pointers. This function lets you set an association.
Like g_object_set_data() except it adds notification for when the association is destroyed, either by setting it to a different value or when the object is destroyed.
Sets a property on an object.
This sets an opaque, named pointer on an object. The name is specified through a GQuark (retrived e.g. via g_quark_from_static_string()), and the pointer can be gotten back from the object with g_object_get_qdata() until the object is finalized. Setting a previously set user data pointer, overrides (frees) the old pointer set, using NULL as pointer essentially removes the data stored.
This function works like g_object_set_qdata(), but in addition, a void (*destroy) (gpointer) function may be specified which is called with data as argument when the object is finalized, or the data is being overwritten by a call to g_object_set_qdata() with the same quark.
Sets properties on an object.
Sets n_properties properties for an object. Properties to be set will be taken from values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.
Remove a specified datum from the object's data associations, without invoking the association's destroy handler.
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:
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.
Decreases the reference count of object. When its reference count drops to 0, the object is finalized (i.e. its memory is freed).
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 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.
Adds a weak reference callback to an object. Weak references are used for notification when an object is finalized. They are called "weak references" because they allow you to safely hold a pointer to an object without calling g_object_ref() (g_object_ref() adds a strong reference, that is, forces the object to stay alive).
Removes a weak reference callback to an object.
Clears a reference to a GObject