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

## Functions

const char * | gtk_buildable_get_buildable_id ()

## Types and Values

| GtkBuildable
struct | GtkBuildableIface
struct | GtkBuildableParser

## Object Hierarchy

        GInterface
        ╰── GtkBuildable

## Prerequisites

GtkBuildable requires GObject.

## Known Implementations

GtkBuildable is implemented by GtkAboutDialog, GtkActionBar, GtkAnyFilter, GtkAppChooserButton, GtkAppChooserDialog, GtkAppChooserWidget, GtkApplicationWindow, GtkAspectFrame, GtkAssistant, GtkBox, GtkButton, GtkCalendar, GtkCellArea, GtkCellAreaBox, GtkCellView, GtkCheckButton, GtkColorButton, GtkColorChooserDialog, GtkColorChooserWidget, GtkColumnView, GtkComboBox, GtkComboBoxText, GtkConstraintLayout, GtkDialog, GtkDragIcon, GtkDrawingArea, GtkDropDown, GtkEditableLabel, GtkEmojiChooser, GtkEntry, GtkEntryCompletion, GtkEveryFilter, GtkExpander, GtkFileChooserButton, GtkFileChooserDialog, GtkFileChooserWidget, GtkFileFilter, GtkFixed, GtkFlowBox, GtkFlowBoxChild, GtkFontButton, GtkFontChooserDialog, GtkFontChooserWidget, GtkFrame, GtkGLArea, GtkGrid, GtkGridView, GtkHeaderBar, GtkIconView, GtkImage, GtkInfoBar, GtkLabel, GtkLevelBar, GtkLinkButton, GtkListBox, GtkListBoxRow, GtkListStore, GtkListView, GtkLockButton, GtkMediaControls, GtkMenuButton, GtkMessageDialog, GtkMultiFilter, GtkMultiSorter, GtkNotebook, GtkOverlay, GtkPageSetupUnixDialog, GtkPaned, GtkPasswordEntry, GtkPicture, GtkPopover, GtkPopoverMenu, GtkPopoverMenuBar, GtkPrintUnixDialog, GtkProgressBar, GtkRange, GtkRevealer, GtkScale, GtkScaleButton, GtkScrollbar, GtkScrolledWindow, GtkSearchBar, GtkSearchEntry, GtkSeparator, GtkShortcutController, GtkShortcutLabel, GtkShortcutsGroup, GtkShortcutsSection, GtkShortcutsShortcut, GtkShortcutsWindow, GtkSizeGroup, GtkSpinButton, GtkSpinner, GtkStack, GtkStackSidebar, GtkStackSwitcher, GtkStatusbar, GtkStringList, GtkSwitch, GtkText, GtkTextTagTable, GtkTextView, GtkToggleButton, GtkTreeExpander, GtkTreeStore, GtkTreeView, GtkTreeViewColumn, GtkVideo, GtkViewport, GtkVolumeButton, GtkWidget, GtkWindow, GtkWindowControls and GtkWindowHandle.

## Includes

    #include <gtk/gtk.h>

## 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 of these functions directly.

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

## Functions

### gtk_buildable_get_buildable_id ()

    const char *
    gtk_buildable_get_buildable_id (GtkBuildable *buildable);

Gets the ID of the `buildable` object.

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

#### Parameters

buildable | a GtkBuildable |

#### Returns

the ID set with `gtk_buildable_set_buildable_id()`

## Types and Values

### GtkBuildable

    typedef struct _GtkBuildable GtkBuildable;

### struct GtkBuildableIface

    struct GtkBuildableIface {
      GTypeInterface g_iface;

      /* virtual table */
      void          (* set_id)                 (GtkBuildable       *buildable,
                                                const char         *id);
      const char * (* get_id)                  (GtkBuildable       *buildable);
      void          (* add_child)              (GtkBuildable       *buildable,
                                                GtkBuilder         *builder,
                                                GObject            *child,
                                                const char         *type);
      void          (* set_buildable_property) (GtkBuildable       *buildable,
                                                GtkBuilder         *builder,
                                                const char         *name,
                                                const GValue       *value);
      GObject *     (* construct_child)        (GtkBuildable       *buildable,
                                                GtkBuilder         *builder,
                                                const char         *name);
      gboolean      (* custom_tag_start)       (GtkBuildable       *buildable,
                                                GtkBuilder         *builder,
                                                GObject            *child,
                                                const char         *tagname,
                                                GtkBuildableParser *parser,
                                                gpointer           *data);
      void          (* custom_tag_end)         (GtkBuildable       *buildable,
                                                GtkBuilder         *builder,
                                                GObject            *child,
                                                const char         *tagname,
                                                gpointer            data);
      void          (* custom_finished)        (GtkBuildable       *buildable,
                                                GtkBuilder         *builder,
                                                GObject            *child,
                                                const char         *tagname,
                                                gpointer            data);
      void          (* parser_finished)        (GtkBuildable       *buildable,
                                                GtkBuilder         *builder);

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

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

#### Members

`set_id` () | Stores the id attribute given in the GtkBuilder UI definition. GtkWidget stores the name as object data. Implement this method if your object has some notion of “ID” and it makes sense to map the XML id attribute to it. |
`get_id` () | The getter corresponding to `set_id` . Implement this if you implement `set_id` . |
`add_child` () | Adds a child. The `type` parameter can be used to differentiate the kind of child. GtkWidget implements this to add event controllers to the widget, 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. This can be used to reference 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` and `user_data` and return `TRUE`. GtkWidget implements this to parse keyboard accelerators specified in <accelerator> elements. 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. |

### struct GtkBuildableParser

    struct GtkBuildableParser {
      /* Called for open tags <foo bar="baz"> */
      void (*start_element)  (GtkBuildableParseContext *context,
                              const char               *element_name,
                              const char              **attribute_names,
                              const char              **attribute_values,
                              gpointer                  user_data,
                              GError                  **error);

      /* Called for close tags </foo> */
      void (*end_element)    (GtkBuildableParseContext *context,
                              const char               *element_name,
                              gpointer                  user_data,
                              GError                  **error);

      /* Called for character data */
      /* text is not nul-terminated */
      void (*text)           (GtkBuildableParseContext *context,
                              const char               *text,
                              gsize                     text_len,
                              gpointer                  user_data,
                              GError                  **error);

      /* Called on error, including one set by other
       * methods in the vtable. The GError should not be freed.
       */
      void (*error)          (GtkBuildableParseContext *context,
                              GError                   *error,
                              gpointer                 user_data);

      gpointer padding[4];
    };