[207:7] extends: object
Reads XML descriptions of a user interface and instantiates the described
objects. To create a GtkBuilder from a user interface description, call
[ctor@Gtk.Builder.new_from_file], [ctor@Gtk.Builder.new_from_resource] or
[ctor@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 [ctor@Gtk.Builder.new] to get an empty builder and
populate it by (multiple) calls to [method@Gtk.Builder.add_from_file],
[method@Gtk.Builder.add_from_resource] or
[method@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
[method@Gtk.Window.destroy] to get rid of them and all the widgets they
contain. The functions [method@Gtk.Builder.get_object] and
[method@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 [method@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 GtkBuilder
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. ### Structure of UI definitions UI
definition files are always encoded in UTF-8. 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
[method@Gtk.Builder.set_translation_domain] on the builder. For example:
... </interface> ``` ### Requirements 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>`”. `GtkBuilder` will error out if the version
requirements are not met. For example: ```xml <?xml version="1.0"
encoding="UTF-8"?> <interface domain="your-app"> <requires lib="gtk"
version="4.0" /> </interface> ``` ### Objects Objects are defined as children
of the `<interface>` element. 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. 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. If your UI definition is
referencing internal types, you should make sure to call `g_type_ensure()`
for each object type before parsing the UI definition. Objects may be given a
name with the “id” attribute, which allows the application to retrieve them
from the builder with [method@Gtk.Builder.get_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. ### Properties 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: ```xml <object class="GtkButton">
<property name="label">Hello, world</property> </object> ``` 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: ```xml <object
class="GtkButton"> <property name="label" translatable="yes" context="button"
comments="A classic">Hello, world</property> </object> ``` The xgettext tool
that is part of gettext can extract these strings, but note that it only
looks for translatable="yes". `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 values, strings like “FALSE”, “f”, “no”, “n”, “0” are
interpreted as false values) - string lists (separated by newlines) -
enumeration types (can be specified by their full C identifier their short
name used when registering the enumeration type, or their integer value) -
flag types (can be specified by their C identifier or short name, optionally
combined with “|” for bitwise OR, or a single integer value e.g.,
“GTK_INPUT_HINT_EMOJI|GTK_INPUT_HINT_LOWERCASE”, or “emoji|lowercase” or
520). - colors (in the format understood by [method@Gdk.RGBA.parse]) -
transforms (in the format understood by [func@Gsk.Transform.parse]) - Pango
attribute lists (in the format understood by
[method@Pango.AttrList.to_string]) - Pango tab arrays (in the format
understood by [method@Pango.TabArray.to_string]) - Pango font descriptions
(in the format understood by [func@Pango.FontDescription.from_string]) -
`GVariant` (in the format understood by [func@GLib.Variant.parse]) - textures
(can be specified as an object id, a resource path or a filename of an image
file to load relative to the Builder file or the CWD if
[method@Gtk.Builder.add_from_string] was used) - GFile (like textures, can be
specified as an object id, a URI or a filename of a file to load relative to
the Builder file or the CWD if [method@Gtk.Builder.add_from_string] was used)
Objects can be referred to by their name and by default refer to objects
declared in the local XML fragment and objects exposed via
[method@Gtk.Builder.expose_object]. 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. ### Child objects Many widgets have properties for
child widgets, such as [property@Gtk.Expander:child]. In this case, the
preferred way to specify the child widget in a ui file is to simply set the
property: ```xml <object class="GtkExpander"> <property name="child"> <object
class="GtkLabel"> ... </object> </property> </object> ``` Generic containers
that can contain an arbitrary number of children, such as [class@Gtk.Box]
instead use the `<child>` element. A `<child>` element contains an `<object>`
element which describes the child object. Most often, child objects are
widgets inside a container, but they can also be, e.g., actions in an action
group, or columns in a tree model. Any object type that implements the
[iface@Gtk.Buildable] interface can specify how children may be added to it.
Since many objects and widgets that are included with GTK already implement
the `GtkBuildable` interface, typically child objects can be added using the
`<child>` element without having to be concerned about the underlying
implementation. See the [`GtkWidget`
documentation](class.Widget.html#gtkwidget-as-gtkbuildable) for many examples
of using `GtkBuilder` with widgets, including setting child objects using the
`<child>` element. A noteworthy special case to the general rule that only
objects implementing `GtkBuildable` may specify how to handle the `<child>`
element is that `GtkBuilder` provides special support for adding objects to a
[class@Gio.ListStore] by using the `<child>` element. For instance: ```xml
<object class="GListStore"> <property name="item-type">MyObject</property>
<child> <object class="MyObject" /> </child> ... </object> ``` ### Property
bindings 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, `GtkBuilder` implements this using [class@GObject.Binding]
objects. For instance, in the example below the “label” property of the
`bottom_label` widget is bound to the “label” property of the `top_button`
widget: ```xml <object class="GtkBox"> <property
name="orientation">vertical</property> <child> <object class="GtkButton"
id="top_button"> <property name="label">Hello, world</property> </object>
</child> <child> <object class="GtkLabel" id="bottom_label"> <property
name="label" bind-source="top_button" bind-property="label"
bind-flags="sync-create" /> </object> </child> </object> ``` For more
information, see the documentation of the
[method@GObject.Object.bind_property] method. Please note that another way to
set up bindings between objects in .ui files is to use the `GtkExpression`
methodology. See the [`GtkExpression`
documentation](class.Expression.html#gtkexpression-in-ui-files) for more
information. ### Internal children 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 `GtkDialog`). This can be achieved by setting the
“internal-child” property 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. ### Specialized children 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. ```xml <object class="GtkButton"
id="hello_button"> <signal name="clicked" handler="hello_button__clicked" />
</object> ``` The remaining attributes, “after”, “swapped” and “object”, have
the same meaning as the corresponding parameters of the
[func@GObject.signal_connect_object] or [func@GObject.signal_connect_data]
functions: - “after” matches the `G_CONNECT_AFTER` flag, and will ensure that
the handler is called after the default class closure for the signal -
“swapped” matches the `G_CONNECT_SWAPPED` flag, and will swap the instance
and closure arguments when invoking the signal handler - “object” will bind
the signal handler to the lifetime of the object referenced by the attribute
By default "swapped" will be set to "yes" if not specified otherwise, in the
case where "object" is set, for convenience. A “last_modification_time”
attribute is also allowed, but it does not have a meaning to the builder.
When compiling applications for Windows, you must declare signal callbacks
with the `G_MODULE_EXPORT` decorator, or they will not be put in the symbol
table: ```c G_MODULE_EXPORT void hello_button__clicked (GtkButton *button,
gpointer data) { // ... } ``` On Linux and Unix, this is not necessary;
applications should instead be compiled with the `-Wl,--export-dynamic`
argument inside their compiler flags, and linked against
`gmodule-export-2.0`. ## Example UI Definition ```xml <interface> <object
class="GtkDialog" id="dialog1"> <child internal-child="content_area"> <object
class="GtkBox"> <child internal-child="action_area"> <object class="GtkBox">
<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> ``` ## Using GtkBuildable for extending UI
definitions Objects can implement the [iface@Gtk.Buildable] interface to add
custom elements and attributes to the XML. Typically, any extension will be
documented in each type that implements the interface. ## Menus In addition
to objects with properties that are created with `<object>` and `<property>`
elements, `GtkBuilder` also allows to parse XML menu definitions as used by
[class@Gio.Menu] when exporting menu models over D-Bus, and as described in
the [class@Gtk.PopoverMenu] documentation. Menus can be defined as toplevel
elements, or as property values for properties of type `GMenuModel`. ##
Templates When describing a [class@Gtk.Widget], you can use the `<template>`
tag to describe a UI bound to a specific widget type. GTK will automatically
load the UI definition when instantiating the type, and bind children and
signal handlers to instance fields and function symbols. For more
information, see the [`GtkWidget`
documentation](class.Widget.html#building-composite-widgets-from-template-xml)
for details.
#### Members
- **handleObj**
- **lib**
- **retainedCallbacks**
- **signalHandlerNames**
- **signalSetterHandlers**
#### Methods
- **Builder** ()
> Creates a new empty builder object. This function is only useful if you intend to make multiple calls to [method@Gtk.Builder.add_from_file], [method@Gtk.Builder.add_from_resource] or [method@Gtk.Builder.add_from_string] in order to merge multiple UI descriptions into a single builder.
- **toNativeHandle** (`Source`)
> Normalizes a constructor argument into a raw pointer carrier. Accepts a raw NativeHandle, a raw NativeBuffer returned from `fn.call(...)`, another generated wrapper exposing `handle()`, or null. Returns null when the argument carries no pointer.
- **@p** `Source` is the raw handle, raw buffer, wrapper, or null.
- **@r** `A` raw pointer carrier or null when no pointer is present.
- **getLib** ()
> Returns the opened native library for this generated wrapper.
- **@r** `The` opened native library.
- **handle** ()
> Returns the wrapped NativeHandle.
- **@r** `The` wrapped NativeHandle.
- **isNull** ()
> Returns true when the wrapped handle is null.
- **@r** `A` bool.
- **describe** ()
> Returns a small string for debugging generated wrappers.
- **@r** `A` string.
- **asObject** ()
> Wraps this handle as `Object`.
- **@r** `A` `Object` object.
- **getProperty** (`string Name`)
> Reads one generated property by name.
- **setProperty** (`string Name, Value`)
> Writes one generated property by name.
- **setCurrentobject** (`object Value`)
> The object the builder is evaluating for.
- **@p** `Value` is the new property value.
- **@r** `None.`
- **setScope** (`object Value`)
> The scope the builder is operating in
- **@p** `Value` is the new property value.
- **@r** `None.`
- **setTranslationdomain** (`string Value`)
> The translation domain used when translating property values that have been marked as translatable. If the translation domain is %NULL, `GtkBuilder` uses gettext(), otherwise g_dgettext().
- **@p** `Value` is the new property value.
- **@r** `None.`
- **add\_from\_file** (`string filename`)
> Parses a file containing a UI definition and merges it with the current contents of @builder. This function is useful if you need to call [method@Gtk.Builder.set_current_object]) to add user data to callbacks before loading GtkBuilder UI. Otherwise, you probably want [ctor@Gtk.Builder.new_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 `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()`.
- **@p** `filename` is the name of the file to parse.
- **add\_from\_resource** (`string resource_path`)
> Parses a resource file containing a UI definition and merges it with the current contents of @builder. This function is useful if you need to call [method@Gtk.Builder.set_current_object] to add user data to callbacks before loading GtkBuilder UI. Otherwise, you probably want [ctor@Gtk.Builder.new_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().
- **@p** `resource_path` is the path of the resource file to parse.
- **add\_from\_string** (`string buffer, int length`)
> Parses a string containing a UI definition and merges it with the current contents of @builder. This function is useful if you need to call [method@Gtk.Builder.set_current_object] to add user data to callbacks before loading `GtkBuilder` UI. Otherwise, you probably want [ctor@Gtk.Builder.new_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().
- **@p** `buffer` is the string to parse.
- **@p** `length` is the length of @buffer (may be -1 if @buffer is nul-terminated).
- **add\_objects\_from\_file** (`string filename, list object_ids`)
> Parses a file containing a 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 explicitly list all of them in @object_ids.
- **@p** `filename` is the name of the file to parse.
- **@p** `object_ids` is nul-terminated array of objects to build.
- **add\_objects\_from\_resource** (`string resource_path, list object_ids`)
> Parses a resource file containing a 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 explicitly list all of them in @object_ids.
- **@p** `resource_path` is the path of the resource file to parse.
- **@p** `object_ids` is nul-terminated array of objects to build.
- **add\_objects\_from\_string** (`string buffer, int length, list object_ids`)
> Parses a string containing a UI definition, building only the requested objects and merges them with the current contents of @builder. 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 `GtkTreeView` that depends on its `GtkTreeModel`), you have to explicitly list all of them in @object_ids.
- **@p** `buffer` is the string to parse.
- **@p** `length` is the length of @buffer (may be -1 if @buffer is nul-terminated).
- **@p** `object_ids` is nul-terminated array of objects to build.
- **create\_closure** (`string function_name, string flags, object object`)
> Creates a closure to invoke the function called @function_name. This is using the create_closure() implementation of @builder's [iface@Gtk.BuilderScope]. If no closure could be created, %NULL will be returned and @error will be set.
- **@p** `function_name` is name of the function to look up.
- **@p** `flags` is closure creation flags.
- **@p** `object` is Object to create the closure with.
- **expose\_object** (`string name, object object`)
> Add @object to the @builder 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.
- **@p** `name` is the name of the object exposed to the builder.
- **@p** `object` is the object to expose.
- **@r** `None.`
- **get\_current\_object** ()
> Gets the current object set via gtk_builder_set_current_object().
- **get\_object** (`string name`)
> Gets the object named @name. Note that this function does not increment the reference count of the returned object.
- **@p** `name` is name of object to get.
- **get\_objects** ()
> Gets all objects that have been constructed by @builder. Note that this function does not increment the reference counts of the returned objects.
- **get\_scope** ()
> Gets the scope in use that was set via gtk_builder_set_scope().
- **get\_translation\_domain** ()
> Gets the translation domain of @builder.
- **set\_current\_object** (`object current_object`)
> Sets the current object for the @builder. 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. [method@Gtk.Widget.init_template] for example will set the current object to the widget the template is inited for. For functions like [ctor@Gtk.Builder.new_from_resource], the current object will be %NULL.
- **@p** `current_object` is the new current object.
- **@r** `None.`
- **set\_scope** (`object scope`)
> Sets the scope the builder should operate in. If @scope is %NULL, a new [class@Gtk.BuilderCScope] will be created.
- **@p** `scope` is the scope to use.
- **@r** `None.`
- **set\_translation\_domain** (`string domain`)
> Sets the translation domain of @builder.
- **@p** `domain` is the translation domain.
- **@r** `None.`
- **objects** ()
> Returns `get_objects` as an Aussom list of wrapper objects. This companion method materializes the full collection up front; use `get_objects()` when lazy or change-notify access is required.
- **@r** `An` Aussom list of elements.
## class: BuilderCtors
[632:14] `static` **extends: object**
Alternate constructors for `Builder`. Usage:
`BuilderCtors.<name>(...)`. The primary constructor lives
directly on `Builder`.
#### Methods
- **newFromFile** (`string filename`)
> 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.
- **@p** `filename` is filename of user interface description file.
- **@r** `A` new `Builder`.
- **newFromResource** (`string resource_path`)
> 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.
- **@p** `resource_path` is a `GResource` resource path.
- **@r** `A` new `Builder`.
- **newFromString** (`string arg0String, int length`)
> Parses the UI definition in @string. 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.
- **@p** `string` is a user interface (XML) description.
- **@p** `length` is the length of @string, or -1.
- **@r** `A` new `Builder`.
## class: BuilderMeta
[687:14] `static` **extends: object**
Generated metadata helpers for `Builder` class surfaces.
#### Methods
- **properties** ()
> Returns property metadata for `Builder`.
- **@r** `A` list.
