GTK+ 3 Reference Manual: GtkBuildable

## GtkBuildable GtkBuildable — Interface for objects that can be built by GtkBuilder |

## Synopsis

    #include <gtk/gtk.h>

                        GtkBuildable;
    struct              GtkBuildableIface;
    void                gtk_buildable_set_name              (GtkBuildable *buildable,
                                                             const gchar *name);
    const gchar *       gtk_buildable_get_name              (GtkBuildable *buildable);
    void                gtk_buildable_add_child             (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             GObject *child,
                                                             const gchar *type);
    void                gtk_buildable_set_buildable_property
                                                            (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             const gchar *name,
                                                             const GValue *value);
    GObject *           gtk_buildable_construct_child       (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             const gchar *name);
    gboolean            gtk_buildable_custom_tag_start      (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             GObject *child,
                                                             const gchar *tagname,
                                                             GMarkupParser *parser,
                                                             gpointer *data);
    void                gtk_buildable_custom_tag_end        (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             GObject *child,
                                                             const gchar *tagname,
                                                             gpointer *data);
    void                gtk_buildable_custom_finished       (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             GObject *child,
                                                             const gchar *tagname,
                                                             gpointer data);
    void                gtk_buildable_parser_finished       (GtkBuildable *buildable,
                                                             GtkBuilder *builder);
    GObject *           gtk_buildable_get_internal_child    (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             const gchar *childname);

## Object Hierarchy

      GInterface
       +----GtkBuildable

## Prerequisites

GtkBuildable requires GObject.

## Known Implementations

GtkBuildable is implemented by GtkAboutDialog, GtkAccelLabel, GtkAction, GtkActionGroup, GtkAlignment, GtkAppChooserButton, GtkAppChooserDialog, GtkAppChooserWidget, GtkApplicationWindow, GtkArrow, GtkAspectFrame, GtkAssistant, GtkBin, GtkBox, GtkButton, GtkButtonBox, GtkCalendar, GtkCellArea, GtkCellAreaBox, GtkCellView, GtkCheckButton, GtkCheckMenuItem, GtkColorButton, GtkColorChooserDialog, GtkColorChooserWidget, GtkColorSelection, GtkColorSelectionDialog, GtkComboBox, GtkComboBoxText, GtkContainer, GtkDialog, GtkDrawingArea, GtkEntry, GtkEntryCompletion, GtkEventBox, GtkExpander, GtkFileChooserButton, GtkFileChooserDialog, GtkFileChooserWidget, GtkFileFilter, GtkFixed, GtkFontButton, GtkFontChooserDialog, GtkFontChooserWidget, GtkFontSelection, GtkFontSelectionDialog, GtkFrame, GtkGrid, GtkHBox, GtkHButtonBox, GtkHPaned, GtkHSV, GtkHScale, GtkHScrollbar, GtkHSeparator, GtkHandleBox, GtkHeaderBar, GtkIconFactory, GtkIconView, GtkImage, GtkImageMenuItem, GtkInfoBar, GtkInvisible, GtkLabel, GtkLayout, GtkLevelBar, GtkLinkButton, GtkListBox, GtkListBoxRow, GtkListStore, GtkLockButton, GtkMenu, GtkMenuBar, GtkMenuButton, GtkMenuItem, GtkMenuShell, GtkMenuToolButton, GtkMessageDialog, GtkMisc, GtkNotebook, GtkOffscreenWindow, GtkOverlay, GtkPageSetupUnixDialog, GtkPaned, GtkPlacesSidebar, GtkPrintUnixDialog, GtkProgressBar, GtkRadioAction, GtkRadioButton, GtkRadioMenuItem, GtkRadioToolButton, GtkRange, GtkRecentAction, GtkRecentChooserDialog, GtkRecentChooserMenu, GtkRecentChooserWidget, GtkRecentFilter, GtkRevealer, GtkScale, GtkScaleButton, GtkScrollbar, GtkScrolledWindow, GtkSearchBar, GtkSearchEntry, GtkSeparator, GtkSeparatorMenuItem, GtkSeparatorToolItem, GtkSizeGroup, GtkSpinButton, GtkSpinner, GtkStack, GtkStackSwitcher, GtkStatusbar, GtkSwitch, GtkTable, GtkTearoffMenuItem, GtkTextTagTable, GtkTextView, GtkToggleAction, GtkToggleButton, GtkToggleToolButton, GtkToolButton, GtkToolItem, GtkToolItemGroup, GtkToolPalette, GtkToolbar, GtkTreeStore, GtkTreeView, GtkTreeViewColumn, GtkUIManager, GtkVBox, GtkVButtonBox, GtkVPaned, GtkVScale, GtkVScrollbar, GtkVSeparator, GtkViewport, GtkVolumeButton, GtkWidget and GtkWindow.

## Description

GtkBuildable allows objects to extend and customize their deserialization from GtkBuilder UI descriptions. The interface includes methods for setting names and properties of objects, parsing custom tags and constructing child objects.

The GtkBuildable interface is implemented by all widgets and many of the non-widget objects that are provided by GTK+. The main user of this interface is GtkBuilder. There should be very little need for applications to call any `gtk_buildable_...` functions.

### Note

An object only needs to implement this interface if it needs to extend the GtkBuilder format or run any extra routines at deserialization time

## Details

### GtkBuildable

    typedef struct _GtkBuildable GtkBuildable;

### struct GtkBuildableIface

    struct GtkBuildableIface {
      GTypeInterface g_iface;

      /* virtual table */
      void          (* set_name)               (GtkBuildable  *buildable,
                                                const gchar   *name);
      const gchar * (* get_name)               (GtkBuildable  *buildable);
      void          (* add_child)              (GtkBuildable  *buildable,
    					    GtkBuilder    *builder,
    					    GObject       *child,
    					    const gchar   *type);
      void          (* set_buildable_property) (GtkBuildable  *buildable,
    					    GtkBuilder    *builder,
    					    const gchar   *name,
    					    const GValue  *value);
      GObject *     (* construct_child)        (GtkBuildable  *buildable,
    					    GtkBuilder    *builder,
    					    const gchar   *name);
      gboolean      (* custom_tag_start)       (GtkBuildable  *buildable,
    					    GtkBuilder    *builder,
    					    GObject       *child,
    					    const gchar   *tagname,
    					    GMarkupParser *parser,
    					    gpointer      *data);
      void          (* custom_tag_end)         (GtkBuildable  *buildable,
    					    GtkBuilder    *builder,
    					    GObject       *child,
    					    const gchar   *tagname,
    					    gpointer      *data);
      void          (* custom_finished)        (GtkBuildable  *buildable,
    					    GtkBuilder    *builder,
    					    GObject       *child,
    					    const gchar   *tagname,
    					    gpointer       data);
      void          (* parser_finished)        (GtkBuildable  *buildable,
    					    GtkBuilder    *builder);

      GObject *     (* get_internal_child)     (GtkBuildable  *buildable,
    					    GtkBuilder    *builder,
    					    const gchar   *childname);
    };

The GtkBuildableIface interface contains method that are necessary to allow GtkBuilder to construct an object from a GtkBuilder UI definition.

GTypeInterface `g_iface`; | the parent class
`set_name` () | Stores the name attribute given in the GtkBuilder UI definition. GtkWidget stores the name as object data. Implement this method if your object has some notion of "name" and it makes sense to map the XML name attribute to it.
`get_name` () | The getter corresponding to `set_name`. Implement this if you implement `set_name`.
`add_child` () | Adds a child. The `type` parameter can be used to differentiate the kind of child. GtkContainer implements this to add add a child widget to the container, GtkNotebook uses the `type` to distinguish between page labels (of type "page-label") and normal children.
`set_buildable_property` () | Sets a property of a buildable object. It is normally not necessary to implement this, `g_object_set_property()` is used by default. GtkWindow implements this to delay showing itself (i.e. setting the "visible" property) until the whole interface is created.
`construct_child` () | Constructs a child of a buildable that has been specified as "constructor" in the UI definition. GtkUIManager implements this to reference to a widget created in a <ui> tag which is outside of the normal GtkBuilder UI definition hierarchy. A reference to the constructed object is returned and becomes owned by the caller.
`custom_tag_start` () | Implement this if the buildable needs to parse content below <child>. To handle an element, the implementation must fill in the `parser` structure and `user_data` and return `TRUE`. GtkWidget implements this to parse keyboard accelerators specified in <accelerator> elements. GtkContainer implements it to map properties defined via <packing> elements to child properties. Note that `user_data` must be freed in `custom_tag_end` or `custom_finished`.
`custom_tag_end` () | Called for the end tag of each custom element that is handled by the buildable (see `custom_tag_start`).
`custom_finished` () | Called for each custom tag handled by the buildable when the builder finishes parsing (see `custom_tag_start`)
`parser_finished` () | Called when a builder finishes the parsing of a UI definition. It is normally not necessary to implement this, unless you need to perform special cleanup actions. GtkWindow sets the "visible" property here.
`get_internal_child` () | Returns an internal child of a buildable. GtkDialog implements this to give access to its `vbox`, making it possible to add children to the vbox in a UI definition. Implement this if the buildable has internal children that may need to be accessed from a UI definition.

### gtk_buildable_set_name ()

    void                gtk_buildable_set_name              (GtkBuildable *buildable,
                                                             const gchar *name);

Sets the name of the `buildable` object.

`buildable` : | a GtkBuildable
`name` : | name to set

Since 2.12

### gtk_buildable_get_name ()

    const gchar *       gtk_buildable_get_name              (GtkBuildable *buildable);

Gets the name of the `buildable` object.

GtkBuilder sets the name based on the GtkBuilder UI definition used to construct the `buildable`.

`buildable` : | a GtkBuildable
Returns : | the name set with `gtk_buildable_set_name()`

Since 2.12

### gtk_buildable_add_child ()

    void                gtk_buildable_add_child             (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             GObject *child,
                                                             const gchar *type);

Adds a child to `buildable`. `type` is an optional string describing how the child should be added.

`buildable` : | a GtkBuildable
`builder` : | a GtkBuilder
`child` : | child to add
`type` : | kind of child or `NULL`. [allow-none]

Since 2.12

### gtk_buildable_set_buildable_property ()

    void                gtk_buildable_set_buildable_property
                                                            (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             const gchar *name,
                                                             const GValue *value);

Sets the property name `name` to `value` on the `buildable` object.

`buildable` : | a GtkBuildable
`builder` : | a GtkBuilder
`name` : | name of property
`value` : | value of property

Since 2.12

### gtk_buildable_construct_child ()

    GObject *           gtk_buildable_construct_child       (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             const gchar *name);

Constructs a child of `buildable` with the name `name`.

GtkBuilder calls this function if a "constructor" has been specified in the UI definition.

`buildable` : | A GtkBuildable
`builder` : | GtkBuilder used to construct this object
`name` : | name of child to construct
Returns : | the constructed child. [transfer full]

Since 2.12

### gtk_buildable_custom_tag_start ()

    gboolean            gtk_buildable_custom_tag_start      (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             GObject *child,
                                                             const gchar *tagname,
                                                             GMarkupParser *parser,
                                                             gpointer *data);

This is called for each unknown element under <child>.

`buildable` : | a GtkBuildable
`builder` : | a GtkBuilder used to construct this object
`child` : | child object or `NULL` for non-child tags. [allow-none]
`tagname` : | name of tag
`parser` : | a GMarkupParser structure to fill in. [out]
`data` : | return location for user data that will be passed in to parser functions. [out]
Returns : | `TRUE` if a object has a custom implementation, `FALSE` if it doesn't.

Since 2.12

### gtk_buildable_custom_tag_end ()

    void                gtk_buildable_custom_tag_end        (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             GObject *child,
                                                             const gchar *tagname,
                                                             gpointer *data);

This is called at the end of each custom element handled by the buildable.

`buildable` : | A GtkBuildable
`builder` : | GtkBuilder used to construct this object
`child` : | child object or `NULL` for non-child tags. [allow-none]
`tagname` : | name of tag
`data` : | user data that will be passed in to parser functions. [type gpointer]

Since 2.12

### gtk_buildable_custom_finished ()

    void                gtk_buildable_custom_finished       (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             GObject *child,
                                                             const gchar *tagname,
                                                             gpointer data);

This is similar to `gtk_buildable_parser_finished()` but is called once for each custom tag handled by the `buildable`.

`buildable` : | a GtkBuildable
`builder` : | a GtkBuilder
`child` : | child object or `NULL` for non-child tags. [allow-none]
`tagname` : | the name of the tag
`data` : | user data created in custom_tag_start

Since 2.12

### gtk_buildable_parser_finished ()

    void                gtk_buildable_parser_finished       (GtkBuildable *buildable,
                                                             GtkBuilder *builder);

Called when the builder finishes the parsing of a GtkBuilder UI definition. Note that this will be called once for each time `gtk_builder_add_from_file()` or `gtk_builder_add_from_string()` is called on a builder.

`buildable` : | a GtkBuildable
`builder` : | a GtkBuilder

Since 2.12

### gtk_buildable_get_internal_child ()

    GObject *           gtk_buildable_get_internal_child    (GtkBuildable *buildable,
                                                             GtkBuilder *builder,
                                                             const gchar *childname);

Get the internal child called `childname` of the `buildable` object.

`buildable` : | a GtkBuildable
`builder` : | a GtkBuilder
`childname` : | name of child
Returns : | the internal child of the buildable object. [transfer none]

Since 2.12