#[repr(transparent)]
pub struct Builder { /* private fields */ }
Expand description

A Builder reads XML descriptions of a user interface and instantiates the described objects.

To create a Builder from a user interface description, call from_file(), from_resource() or from_string().

In the (unusual) case that you want to add user interface descriptions from multiple sources to the same Builder you can call new() to get an empty builder and populate it by (multiple) calls to add_from_file(), add_from_resource() or add_from_string().

A Builder 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::Window::destroy() to get rid of them and all the widgets they contain.

The functions object() and 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::Window::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.

GtkBuilder UI Definitions

Builder parses textual descriptions of user interfaces which are specified in XML format. We refer to these descriptions as “GtkBuilder UI definitions” or just “UI definitions” if the context is clear.

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 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>”. 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 explicitly with the “type-func” attribute.

Objects may be given a name with the “id” attribute, which allows the application to retrieve them from the builder with object(). 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 ___ (three consecutive 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.

Builder 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_INPUT_HINT_EMOJI|GTK_INPUT_HINT_LOWERCASE”) and colors (in a format understood by gdk::RGBA::parse()).

GVariants can be specified in the format understood by g_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 expose_object(). In general, Builder 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, and optionally, “bind-property” and “bind-flags” to specify the source property and source binding flags respectively. Internally, Builder implements this using GBinding objects. For more information see g_object_bind_property().

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 content area of a Dialog). This can be achieved by setting the “internal-child” property of the <child> element to a true value. Note that Builder 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.

Signal handlers and function pointers

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. 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.

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 Unix, this is not necessary; applications should instead be compiled with the -Wl,–export-dynamic CFLAGS, and linked against gmodule-export-2.0.

A GtkBuilder UI Definition

<interface>
  <object class="GtkDialog" id="dialog1">
    <child internal-child="content_area">
      <object class="GtkBox" id="vbox1">
        <child internal-child="action_area">
          <object class="GtkBox" id="hbuttonbox1">
            <child>
              <object class="GtkButton" id="ok_button">
                <property name="label" translatable="yes">_Ok</property>
                <property name="use-underline">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 element gets parsed by the custom tag handler of the parent object, while a custom element in an element gets parsed by the custom tag handler of the object.

These XML fragments are explained in the documentation of the respective objects.

A <template> tag can be used to define a widget class’s components. See the GtkWidget documentation for details.

Implements

glib::ObjectExt

Implementations

Creates a new empty builder object.

This function is only useful if you intend to make multiple calls to add_from_file(), add_from_resource() or add_from_string() in order to merge multiple UI descriptions into a single builder.

Returns

a new (empty) Builder object

Parses the UI definition at @resource_path.

If there is an error locating the resource or parsing the description, then the program will be aborted.

resource_path

a GResource resource path

Returns

a Builder containing the described interface

Parses the UI definition in @string.

If @string is None-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.

string

a user interface (XML) description

length

the length of @string, or -1

Returns

a Builder containing the interface described by @string

Parses a resource file containing a UI definition and merges it with the current contents of @self.

This function is useful if you need to call set_current_object() to add user data to callbacks before loading GtkBuilder UI. Otherwise, you probably want from_resource() instead.

If an error occurs, 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().

resource_path

the path of the resource file to parse

Returns

true on success, false if an error occurred

Parses a string containing a UI definition and merges it with the current contents of @self.

This function is useful if you need to call set_current_object() to add user data to callbacks before loading Builder UI. Otherwise, you probably want from_string() instead.

Upon errors false will be returned and @error will be assigned a GError from the GTK_BUILDER_ERROR, G_MARKUP_ERROR or G_VARIANT_PARSE_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().

buffer

the string to parse

length

the length of @buffer (may be -1 if @buffer is nul-terminated)

Returns

true on success, false if an error occurred

Parses a file containing a UI definition building only the requested objects and merges them with the current contents of @self.

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 TreeView that depends on its TreeModel), you have to explicitly list all of them in @object_ids.

filename

the name of the file to parse

object_ids

nul-terminated array of objects to build

Returns

true on success, false if an error occurred

Parses a resource file containing a UI definition, building only the requested objects and merges them with the current contents of @self.

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 TreeView that depends on its TreeModel), you have to explicitly list all of them in @object_ids.

resource_path

the path of the resource file to parse

object_ids

nul-terminated array of objects to build

Returns

true on success, false if an error occurred

Parses a string containing a UI definition, building only the requested objects and merges them with the current contents of @self.

Upon errors false 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 TreeView that depends on its TreeModel), you have to explicitly list all of them in @object_ids.

buffer

the string to parse

length

the length of @buffer (may be -1 if @buffer is nul-terminated)

object_ids

nul-terminated array of objects to build

Returns

true on success, false if an error occurred

Creates a closure to invoke the function called @function_name.

This is using the create_closure() implementation of @self’s BuilderScope.

If no closure could be created, None will be returned and @error will be set.

function_name

name of the function to look up

flags

closure creation flags

object

Object to create the closure with

Returns

A new closure for invoking @function_name

Add @object to the @self object pool so it can be referenced just like any other object built by builder.

Only a single object may be added using @name. However, it is not an error to expose the same object under multiple names. gtk_builder_get_object() may be used to determine if an object has already been added with @name.

name

the name of the object exposed to the builder

object

the object to expose

Main private entry point for building composite components from template XML.

Most likely you do not need to call this function in applications as templates are handled by Widget.

object

the object that is being extended

template_type

the type that the template is for

buffer

the string to parse

length

the length of @buffer (may be -1 if @buffer is nul-terminated)

Returns

A positive value on success, 0 if an error occurred

Gets all objects that have been constructed by @self.

Note that this function does not increment the reference counts of the returned objects.

Returns

a newly-allocated GSList containing all the objects constructed by the GtkBuilder instance. It should be freed by g_slist_free()

Gets the scope in use that was set via gtk_builder_set_scope().

Returns

the current scope

Gets the translation domain of @self.

Returns

the translation domain

Looks up a type by name.

This is using the virtual function that Builder has for that purpose. This is mainly used when implementing the Buildable interface on a type.

type_name

type name to lookup

Returns

the GType found for @type_name or G_TYPE_INVALID if no type was found

Sets the current object for the @self.

The current object can be thought of as the this object that the builder is working for and will often be used as the default object when an object is optional.

WidgetExt::init_template() for example will set the current object to the widget the template is inited for. For functions like from_resource(), the current object will be None.

current_object

the new current object

Sets the scope the builder should operate in.

If @scope is None, a new Gtk::BuilderCScope will be created.

scope

the scope to use

Sets the translation domain of @self.

domain

the translation domain

Demarshals a value from a string.

This function calls g_value_init() on the @value argument, so it need not be initialised beforehand.

Can handle char, uchar, boolean, int, uint, long, ulong, enum, flags, float, double, string, gdk::RGBA and Adjustment type values.

Upon errors false will be returned and @error will be assigned a GError from the GTK_BUILDER_ERROR domain.

pspec

the GParamSpec for the property

string

the string representation of the value

Returns

true on success

value

the GValue to store the result in

Demarshals a value from a string.

Unlike value_from_string(), this function takes a GType instead of GParamSpec.

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.

type_

the GType of the value

string

the string representation of the value

Returns

true on success

value

the GValue to store the result in

Parses the 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.

filename

filename of user interface description file

Returns

a Builder containing the described interface

Gets the current object set via gtk_builder_set_current_object().

Returns

the current object

Gets the object named @name.

Note that this function does not increment the reference count of the returned object.

name

name of object to get

Returns

the object named @name

Parses a file containing a UI definition and merges it with the current contents of @self.

This function is useful if you need to call set_current_object()) to add user data to callbacks before loading GtkBuilder UI. Otherwise, you probably want from_file() instead.

If an error occurs, 0 will be returned and @error will be assigned a GError from the GTK_BUILDER_ERROR, G_MARKUP_ERROR or G_FILE_ERROR domains.

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 Builder 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().

filename

the name of the file to parse

Returns

true on success, false if an error occurred

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Returns the “default value” for a type. Read more

Formats the value using the given formatter. Read more

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

This method returns an Ordering between self and other. Read more

Compares and returns the maximum of two values. Read more

Compares and returns the minimum of two values. Read more

Restrict a value to a certain interval. Read more

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Returns the type identifier of Self.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Upcasts an object to a superclass or interface T. Read more

Upcasts an object to a reference of its superclass or interface T. Read more

Tries to downcast to a subclass or interface implementor T. Read more

Tries to downcast to a reference of its subclass or interface implementor T. Read more

Tries to cast to an object of type T. This handles upcasting, downcasting and casting between interface and interface implementors. All checks are performed at runtime, while downcast and upcast will do many checks at compile-time already. Read more

Tries to cast to reference to an object of type T. This handles upcasting, downcasting and casting between interface and interface implementors. All checks are performed at runtime, while downcast and upcast will do many checks at compile-time already. Read more

Casts to T unconditionally. Read more

Casts to &T unconditionally. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Returns true if the object is an instance of (can be cast to) T.

Returns the type of the object.

Returns the ObjectClass of the object. Read more

Returns the class of the object.

Returns the class of the object in the given type T. Read more

Returns the interface T of the object. Read more

Similar to Self::set_property but fails instead of panicking.

Sets the property property_name of the object to value value. Read more

Similar to Self::set_property but fails instead of panicking.

Sets the property property_name of the object to value value. Read more

Similar to Self::set_properties but fails instead of panicking.

Sets multiple properties of the object at once. Read more

Similar to Self::set_properties_from_value but fails instead of panicking.

Sets multiple properties of the object at once. Read more

Similar to Self::property but fails instead of panicking.

Gets the property property_name of the object and cast it to the type V. Read more

Similar to Self::property_value but fails instead of panicking.

Gets the property property_name of the object. Read more

Check if the object has a property property_name of the given type_. Read more

Get the type of the property property_name of this object. Read more

Get the ParamSpec of the property property_name of this object.

Return all ParamSpec of the properties of this object.

Freeze all property notifications until the return guard object is dropped. Read more

Set arbitrary data on this object with the given key. Read more

Return previously set arbitrary data of this object with the given key. Read more

Retrieve previously set arbitrary data of this object with the given key. Read more

Set arbitrary data on this object with the given key. Read more

Return previously set arbitrary data of this object with the given key. Read more

Retrieve previously set arbitrary data of this object with the given key. Read more

Block a given signal handler. Read more

Unblock a given signal handler.

Stop emission of the currently emitted signal.

Stop emission of the currently emitted signal by the (possibly detailed) signal name.

Similar to Self::connect but fails instead of panicking.

Connect to the signal signal_name on this object. Read more

Similar to Self::connect_id but fails instead of panicking.

Connect to the signal signal_id on this object. Read more

Similar to Self::connect_local but fails instead of panicking.

Connect to the signal signal_name on this object. Read more

Similar to Self::connect_local_id but fails instead of panicking.

Connect to the signal signal_id on this object. Read more

Similar to Self::connect_unsafe but fails instead of panicking.

Connect to the signal signal_name on this object. Read more

Similar to Self::connect_unsafe_id but fails instead of panicking.

Similar to Self::connect_closure but fails instead of panicking.

Connect a closure to the signal signal_name on this object. Read more

Similar to Self::connect_closure_id but fails instead of panicking.

Connect a closure to the signal signal_id on this object. Read more

Limits the lifetime of closure to the lifetime of the object. When the object’s reference count drops to zero, the closure will be invalidated. An invalidated closure will ignore any calls to invoke_with_values, or invoke when using Rust closures. Read more

Connect to the signal signal_id on this object. Read more

Similar to Self::emit but fails instead of panicking.

Emit signal by signal id. Read more

Similar to Self::emit_with_values but fails instead of panicking.

Same as Self::emit but takes Value for the arguments.

Similar to Self::emit_by_name but fails instead of panicking.

Emit signal by its name. Read more

Similar to Self::emit_by_name_with_values but fails instead of panicking.

Emit signal by its name. Read more

Similar to Self::emit_by_name_with_details but fails instead of panicking.

Emit signal by its name with details. Read more

Similar to Self::emit_by_name_with_details_and_values but fails instead of panicking.

Emit signal by its name with details. Read more

Similar to Self::emit_with_details but fails instead of panicking.

Emit signal by signal id with details. Read more

Similar to Self::emit_with_details_and_values but fails instead of panicking.

Emit signal by signal id with details. Read more

Disconnect a previously connected signal handler.

Connect to the notify signal of the object. Read more

Connect to the notify signal of the object. Read more

Connect to the notify signal of the object. Read more

Notify that the given property has changed its value. Read more

Notify that the given property has changed its value. Read more

Downgrade this object to a weak reference.

Add a callback to be notified when the Object is disposed.

Add a callback to be notified when the Object is disposed. Read more

Bind property source_property on this object to the target_property on the target object. Read more

Returns the strong reference count of this object.

Ensures that the type has been registered with the type system.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

Uses borrowed data to replace owned data, usually by cloning. Read more

Converts the given value to a String. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.