The GtkAboutDialog offers a simple way to display information about a program like its logo, name, copyright, website and license. It is also possible to give credits to the authors, documenters, translators and artists who have worked on the program. An about dialog is typically opened when the user selects the About option from the Help menu. All parts of the dialog are optional.

About dialogs often contain links and email addresses. GtkAboutDialog displays these as clickable links. By default, it calls gtk_show_uri_on_window() when a user clicks one. The behaviour can be overridden with the GtkAboutDialog::activate-link signal.

To specify a person with an email address, use a string like “Edgar Allan Poe <edgar`poe.com`>”. To specify a website with a title, use a string like “GTK+ team http://www.gtk.org”.

To make constructing a GtkAboutDialog as convenient as possible, you can use the function gtk_show_about_dialog() which constructs and shows a dialog and keeps it around so that it can be shown again.

Note that GTK+ sets a default title of _("About %s") on the dialog window (where `s` is replaced by the name of the application, but in order to ensure proper translation of the title, applications should set the title property explicitly when constructing a GtkAboutDialog, as shown in the following example: (C Language Example):

GdkPixbuf *example_logo = gdk_pixbuf_new_from_file ("./logo.png", NULL);
gtk_show_about_dialog (NULL,
                       "program-name", "ExampleCode",
                       "logo", example_logo,
                       "title", _("About ExampleCode"),
                       NULL);

It is also possible to show a GtkAboutDialog like any other GtkDialog, e.g. using gtk_dialog_run(). In this case, you might need to know that the “Close” button returns the GTK_RESPONSE_CANCEL response id.

The AboutDialogRef type acts as a lightweight Swift reference to an underlying GtkAboutDialog instance. It exposes methods that can operate on this data type through AboutDialogProtocol conformance. Use AboutDialogRef only as an unowned reference to an existing GtkAboutDialog instance.

A GtkAccelGroup represents a group of keyboard accelerators, typically attached to a toplevel GtkWindow (with gtk_window_add_accel_group()). Usually you won’t need to create a GtkAccelGroup directly; instead, when using GtkUIManager, GTK+ automatically sets up the accelerators for your menus in the ui manager’s GtkAccelGroup.

Note that “accelerators” are different from “mnemonics”. Accelerators are shortcuts for activating a menu item; they appear alongside the menu item they’re a shortcut for. For example “Ctrl+Q” might appear alongside the “Quit” menu item. Mnemonics are shortcuts for GUI elements such as text entries or buttons; they appear as underlined characters. See gtk_label_new_with_mnemonic(). Menu items can have both accelerators and mnemonics, of course.

The AccelGroupRef type acts as a lightweight Swift reference to an underlying GtkAccelGroup instance. It exposes methods that can operate on this data type through AccelGroupProtocol conformance. Use AccelGroupRef only as an unowned reference to an existing GtkAccelGroup instance.

The GtkAccelLabel widget is a subclass of GtkLabel that also displays an accelerator key on the right of the label text, e.g. “Ctrl+S”. It is commonly used in menus to show the keyboard short-cuts for commands.

The accelerator key to display is typically not set explicitly (although it can be, with gtk_accel_label_set_accel()). Instead, the GtkAccelLabel displays the accelerators which have been added to a particular widget. This widget is set by calling gtk_accel_label_set_accel_widget().

For example, a GtkMenuItem widget may have an accelerator added to emit the “activate” signal when the “Ctrl+S” key combination is pressed. A GtkAccelLabel is created and added to the GtkMenuItem, and gtk_accel_label_set_accel_widget() is called with the GtkMenuItem as the second argument. The GtkAccelLabel will now display “Ctrl+S” after its label.

Note that creating a GtkMenuItem with gtk_menu_item_new_with_label() (or one of the similar functions for GtkCheckMenuItem and GtkRadioMenuItem) automatically adds a GtkAccelLabel to the GtkMenuItem and calls gtk_accel_label_set_accel_widget() to set it up for you.

A GtkAccelLabel will only display accelerators which have GTK_ACCEL_VISIBLE set (see GtkAccelFlags). A GtkAccelLabel can display multiple accelerators and even signal names, though it is almost always used to display just one accelerator key.

Creating a simple menu item with an accelerator key.

(C Language Example):

  GtkWidget *window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  GtkWidget *menu = gtk_menu_new ();
  GtkWidget *save_item;
  GtkAccelGroup *accel_group;

  // Create a GtkAccelGroup and add it to the window.
  accel_group = gtk_accel_group_new ();
  gtk_window_add_accel_group (GTK_WINDOW (window), accel_group);

  // Create the menu item using the convenience function.
  save_item = gtk_menu_item_new_with_label ("Save");
  gtk_widget_show (save_item);
  gtk_container_add (GTK_CONTAINER (menu), save_item);

  // Now add the accelerator to the GtkMenuItem. Note that since we
  // called gtk_menu_item_new_with_label() to create the GtkMenuItem
  // the GtkAccelLabel is automatically set up to display the
  // GtkMenuItem accelerators. We just need to make sure we use
  // GTK_ACCEL_VISIBLE here.
  gtk_widget_add_accelerator (save_item, "activate", accel_group,
                              GDK_KEY_s, GDK_CONTROL_MASK, GTK_ACCEL_VISIBLE);

CSS nodes

(plain Language Example):

label
╰── accelerator

Like GtkLabel, GtkAccelLabel has a main CSS node with the name label. It adds a subnode with name accelerator.

The AccelLabelRef type acts as a lightweight Swift reference to an underlying GtkAccelLabel instance. It exposes methods that can operate on this data type through AccelLabelProtocol conformance. Use AccelLabelRef only as an unowned reference to an existing GtkAccelLabel instance.

Accelerator maps are used to define runtime configurable accelerators. Functions for manipulating them are are usually used by higher level convenience mechanisms like GtkUIManager and are thus considered “low-level”. You’ll want to use them if you’re manually creating menus that should have user-configurable accelerators.

An accelerator is uniquely defined by:

• accelerator path
• accelerator key
• accelerator modifiers

The accelerator path must consist of “<WINDOWTYPE>/Category1/Category2/…/Action”, where WINDOWTYPE should be a unique application-specific identifier that corresponds to the kind of window the accelerator is being used in, e.g. “Gimp-Image”, “Abiword-Document” or “Gnumeric-Settings”. The “Category1/…/Action” portion is most appropriately chosen by the action the accelerator triggers, i.e. for accelerators on menu items, choose the item’s menu path, e.g. “File/Save As”, “Image/View/Zoom” or “Edit/Select All”. So a full valid accelerator path may look like: “<Gimp-Toolbox>/File/Dialogs/Tool Options…”.

All accelerators are stored inside one global GtkAccelMap that can be obtained using gtk_accel_map_get(). See Monitoring changes for additional details.

Manipulating accelerators

New accelerators can be added using gtk_accel_map_add_entry(). To search for specific accelerator, use gtk_accel_map_lookup_entry(). Modifications of existing accelerators should be done using gtk_accel_map_change_entry().

In order to avoid having some accelerators changed, they can be locked using gtk_accel_map_lock_path(). Unlocking is done using gtk_accel_map_unlock_path().

Saving and loading accelerator maps

Accelerator maps can be saved to and loaded from some external resource. For simple saving and loading from file, gtk_accel_map_save() and gtk_accel_map_load() are provided. Saving and loading can also be done by providing file descriptor to gtk_accel_map_save_fd() and gtk_accel_map_load_fd().

Monitoring changes

GtkAccelMap object is only useful for monitoring changes of accelerators. By connecting to GtkAccelMap::changed signal, one can monitor changes of all accelerators. It is also possible to monitor only single accelerator path by using it as a detail of the GtkAccelMap::changed signal.

The AccelMapRef type acts as a lightweight Swift reference to an underlying GtkAccelMap instance. It exposes methods that can operate on this data type through AccelMapProtocol conformance. Use AccelMapRef only as an unowned reference to an existing GtkAccelMap instance.

The GtkAccessible class is the base class for accessible implementations for GtkWidget subclasses. It is a thin wrapper around AtkObject, which adds facilities for associating a widget with its accessible object.

An accessible implementation for a third-party widget should derive from GtkAccessible and implement the suitable interfaces from ATK, such as AtkText or AtkSelection. To establish the connection between the widget class and its corresponding acccessible implementation, override the get_accessible vfunc in GtkWidgetClass.

The AccessibleRef type acts as a lightweight Swift reference to an underlying GtkAccessible instance. It exposes methods that can operate on this data type through AccessibleProtocol conformance. Use AccessibleRef only as an unowned reference to an existing GtkAccessible instance.

> In GTK+ 3.10, GtkAction has been deprecated. Use GAction > instead, and associate actions with GtkActionable widgets. Use > GMenuModel for creating menus with gtk_menu_new_from_model().

Actions represent operations that the user can be perform, along with some information how it should be presented in the interface. Each action provides methods to create icons, menu items and toolbar items representing itself.

As well as the callback that is called when the action gets activated, the following also gets associated with the action:

• a name (not translated, for path lookup)

• a label (translated, for display)

• an accelerator

• whether label indicates a stock id

• a tooltip (optional, translated)

• a toolbar label (optional, shorter than label)

The action will also have some state information:

• visible (shown/hidden)

• sensitive (enabled/disabled)

Apart from regular actions, there are toggle actions, which can be toggled between two states and radio actions, of which only one in a group can be in the “active” state. Other actions can be implemented as GtkAction subclasses.

Each action can have one or more proxy widgets. To act as an action proxy, widget needs to implement GtkActivatable interface. Proxies mirror the state of the action and should change when the action’s state changes. Properties that are always mirrored by proxies are GtkAction:sensitive and GtkAction:visible. GtkAction:gicon, GtkAction:icon-name, GtkAction:label, GtkAction:short-label and GtkAction:stock-id properties are only mirorred if proxy widget has GtkActivatable:use-action-appearance property set to true.

When the proxy is activated, it should activate its action.

The ActionRef type acts as a lightweight Swift reference to an underlying GtkAction instance. It exposes methods that can operate on this data type through ActionProtocol conformance. Use ActionRef only as an unowned reference to an existing GtkAction instance.

GtkActionBar is designed to present contextual actions. It is expected to be displayed below the content and expand horizontally to fill the area.

It allows placing children at the start or the end. In addition, it contains an internal centered box which is centered with respect to the full width of the box, even if the children at either side take up different amounts of space.

CSS nodes

GtkActionBar has a single CSS node with name actionbar.

The ActionBarRef type acts as a lightweight Swift reference to an underlying GtkActionBar instance. It exposes methods that can operate on this data type through ActionBarProtocol conformance. Use ActionBarRef only as an unowned reference to an existing GtkActionBar instance.

Actions are organised into groups. An action group is essentially a map from names to GtkAction objects.

All actions that would make sense to use in a particular context should be in a single group. Multiple action groups may be used for a particular user interface. In fact, it is expected that most nontrivial applications will make use of multiple groups. For example, in an application that can edit multiple documents, one group holding global actions (e.g. quit, about, new), and one group per document holding actions that act on that document (eg. save, cut/copy/paste, etc). Each window’s menus would be constructed from a combination of two action groups.

Accelerators ##

Accelerators are handled by the GTK+ accelerator map. All actions are assigned an accelerator path (which normally has the form <Actions>/group-name/action-name) and a shortcut is associated with this accelerator path. All menuitems and toolitems take on this accelerator path. The GTK+ accelerator map code makes sure that the correct shortcut is displayed next to the menu item.

GtkActionGroup as GtkBuildable #

The GtkActionGroup implementation of the GtkBuildable interface accepts GtkAction objects as <child> elements in UI definitions.

Note that it is probably more common to define actions and action groups in the code, since they are directly related to what the code can do.

The GtkActionGroup implementation of the GtkBuildable interface supports a custom <accelerator> element, which has attributes named “key“ and “modifiers“ and allows to specify accelerators. This is similar to the <accelerator> element of GtkWidget, the main difference is that it doesn’t allow you to specify a signal.

A GtkDialog UI definition fragment.

<object class="GtkActionGroup" id="actiongroup">
  <child>
      <object class="GtkAction" id="About">
          <property name="name">About</property>
          <property name="stock_id">gtk-about</property>
          <signal handler="about_activate" name="activate"/>
      </object>
      <accelerator key="F1" modifiers="GDK_CONTROL_MASK | GDK_SHIFT_MASK"/>
  </child>
</object>

The ActionGroupRef type acts as a lightweight Swift reference to an underlying GtkActionGroup instance. It exposes methods that can operate on this data type through ActionGroupProtocol conformance. Use ActionGroupRef only as an unowned reference to an existing GtkActionGroup instance.

The GtkAdjustment object represents a value which has an associated lower and upper bound, together with step and page increments, and a page size. It is used within several GTK+ widgets, including GtkSpinButton, GtkViewport, and GtkRange (which is a base class for GtkScrollbar and GtkScale).

The GtkAdjustment object does not update the value itself. Instead it is left up to the owner of the GtkAdjustment to control the value.

The AdjustmentRef type acts as a lightweight Swift reference to an underlying GtkAdjustment instance. It exposes methods that can operate on this data type through AdjustmentProtocol conformance. Use AdjustmentRef only as an unowned reference to an existing GtkAdjustment instance.

The GtkAlignment widget controls the alignment and size of its child widget. It has four settings: xscale, yscale, xalign, and yalign.

The scale settings are used to specify how much the child widget should expand to fill the space allocated to the GtkAlignment. The values can range from 0 (meaning the child doesn’t expand at all) to 1 (meaning the child expands to fill all of the available space).

The align settings are used to place the child widget within the available area. The values range from 0 (top or left) to 1 (bottom or right). Of course, if the scale settings are both set to 1, the alignment settings have no effect.

GtkAlignment has been deprecated in 3.14 and should not be used in newly-written code. The desired effect can be achieved by using the GtkWidget:halign, GtkWidget:valign and GtkWidget:margin properties on the child widget.

The AlignmentRef type acts as a lightweight Swift reference to an underlying GtkAlignment instance. It exposes methods that can operate on this data type through AlignmentProtocol conformance. Use AlignmentRef only as an unowned reference to an existing GtkAlignment instance.

The GtkAppChooserButton is a widget that lets the user select an application. It implements the GtkAppChooser interface.

Initially, a GtkAppChooserButton selects the first application in its list, which will either be the most-recently used application or, if GtkAppChooserButton:show-default-item is true, the default application.

The list of applications shown in a GtkAppChooserButton includes the recommended applications for the given content type. When GtkAppChooserButton:show-default-item is set, the default application is also included. To let the user chooser other applications, you can set the GtkAppChooserButton:show-dialog-item property, which allows to open a full GtkAppChooserDialog.

It is possible to add custom items to the list, using gtk_app_chooser_button_append_custom_item(). These items cause the GtkAppChooserButton::custom-item-activated signal to be emitted when they are selected.

To track changes in the selected application, use the GtkComboBox::changed signal.

The AppChooserButtonRef type acts as a lightweight Swift reference to an underlying GtkAppChooserButton instance. It exposes methods that can operate on this data type through AppChooserButtonProtocol conformance. Use AppChooserButtonRef only as an unowned reference to an existing GtkAppChooserButton instance.

GtkAppChooserDialog shows a GtkAppChooserWidget inside a GtkDialog.

Note that GtkAppChooserDialog does not have any interesting methods of its own. Instead, you should get the embedded GtkAppChooserWidget using gtk_app_chooser_dialog_get_widget() and call its methods if the generic GtkAppChooser interface is not sufficient for your needs.

To set the heading that is shown above the GtkAppChooserWidget, use gtk_app_chooser_dialog_set_heading().

The AppChooserDialogRef type acts as a lightweight Swift reference to an underlying GtkAppChooserDialog instance. It exposes methods that can operate on this data type through AppChooserDialogProtocol conformance. Use AppChooserDialogRef only as an unowned reference to an existing GtkAppChooserDialog instance.

GtkAppChooserWidget is a widget for selecting applications. It is the main building block for GtkAppChooserDialog. Most applications only need to use the latter; but you can use this widget as part of a larger widget if you have special needs.

GtkAppChooserWidget offers detailed control over what applications are shown, using the GtkAppChooserWidget:show-default, GtkAppChooserWidget:show-recommended, GtkAppChooserWidget:show-fallback, GtkAppChooserWidget:show-other and GtkAppChooserWidget:show-all properties. See the GtkAppChooser documentation for more information about these groups of applications.

To keep track of the selected application, use the GtkAppChooserWidget::application-selected and GtkAppChooserWidget::application-activated signals.

CSS nodes

GtkAppChooserWidget has a single CSS node with name appchooser.

The AppChooserWidgetRef type acts as a lightweight Swift reference to an underlying GtkAppChooserWidget instance. It exposes methods that can operate on this data type through AppChooserWidgetProtocol conformance. Use AppChooserWidgetRef only as an unowned reference to an existing GtkAppChooserWidget instance.

GtkApplication is a class that handles many important aspects of a GTK+ application in a convenient fashion, without enforcing a one-size-fits-all application model.

Currently, GtkApplication handles GTK+ initialization, application uniqueness, session management, provides some basic scriptability and desktop shell integration by exporting actions and menus and manages a list of toplevel windows whose life-cycle is automatically tied to the life-cycle of your application.

While GtkApplication works fine with plain GtkWindows, it is recommended to use it together with GtkApplicationWindow.

When GDK threads are enabled, GtkApplication will acquire the GDK lock when invoking actions that arrive from other processes. The GDK lock is not touched for local action invocations. In order to have actions invoked in a predictable context it is therefore recommended that the GDK lock be held while invoking actions locally with g_action_group_activate_action(). The same applies to actions associated with GtkApplicationWindow and to the “activate” and “open” GApplication methods.

Automatic resources ##

GtkApplication will automatically load menus from the GtkBuilder resource located at “gtk/menus.ui”, relative to the application’s resource base path (see g_application_set_resource_base_path()). The menu with the ID “app-menu” is taken as the application’s app menu and the menu with the ID “menubar” is taken as the application’s menubar. Additional menus (most interesting submenus) can be named and accessed via gtk_application_get_menu_by_id() which allows for dynamic population of a part of the menu structure.

If the resources “gtk/menus-appmenu.ui” or “gtk/menus-traditional.ui” are present then these files will be used in preference, depending on the value of gtk_application_prefers_app_menu(). If the resource “gtk/menus-common.ui” is present it will be loaded as well. This is useful for storing items that are referenced from both “gtk/menus-appmenu.ui” and “gtk/menus-traditional.ui”.

It is also possible to provide the menus manually using gtk_application_set_app_menu() and gtk_application_set_menubar().

GtkApplication will also automatically setup an icon search path for the default icon theme by appending “icons” to the resource base path. This allows your application to easily store its icons as resources. See gtk_icon_theme_add_resource_path() for more information.

If there is a resource located at “gtk/help-overlay.ui” which defines a GtkShortcutsWindow with ID “help_overlay” then GtkApplication associates an instance of this shortcuts window with each GtkApplicationWindow and sets up keyboard accelerators (Control-F1 and Control-?) to open it. To create a menu item that displays the shortcuts window, associate the item with the action win.show-help-overlay.

A simple application ##

A simple example

GtkApplication optionally registers with a session manager of the users session (if you set the GtkApplication:register-session property) and offers various functionality related to the session life-cycle.

An application can block various ways to end the session with the gtk_application_inhibit() function. Typical use cases for this kind of inhibiting are long-running, uninterruptible operations, such as burning a CD or performing a disk backup. The session manager may not honor the inhibitor, but it can be expected to inform the user about the negative consequences of ending the session while inhibitors are present.

See Also ##

HowDoI: Using GtkApplication, Getting Started with GTK+: Basics

The ApplicationRef type acts as a lightweight Swift reference to an underlying GtkApplication instance. It exposes methods that can operate on this data type through ApplicationProtocol conformance. Use ApplicationRef only as an unowned reference to an existing GtkApplication instance.

GtkApplicationWindow is a GtkWindow subclass that offers some extra functionality for better integration with GtkApplication features. Notably, it can handle both the application menu as well as the menubar. See gtk_application_set_app_menu() and gtk_application_set_menubar().

This class implements the GActionGroup and GActionMap interfaces, to let you add window-specific actions that will be exported by the associated GtkApplication, together with its application-wide actions. Window-specific actions are prefixed with the “win.” prefix and application-wide actions are prefixed with the “app.” prefix. Actions must be addressed with the prefixed name when referring to them from a GMenuModel.

Note that widgets that are placed inside a GtkApplicationWindow can also activate these actions, if they implement the GtkActionable interface.

As with GtkApplication, the GDK lock will be acquired when processing actions arriving from other processes and should therefore be held when activating actions locally (if GDK threads are enabled).

The settings GtkSettings:gtk-shell-shows-app-menu and GtkSettings:gtk-shell-shows-menubar tell GTK+ whether the desktop environment is showing the application menu and menubar models outside the application as part of the desktop shell. For instance, on OS X, both menus will be displayed remotely; on Windows neither will be. gnome-shell (starting with version 3.4) will display the application menu, but not the menubar.

If the desktop environment does not display the menubar, then GtkApplicationWindow will automatically show a GtkMenuBar for it. This behaviour can be overridden with the GtkApplicationWindow:show-menubar property. If the desktop environment does not display the application menu, then it will automatically be included in the menubar or in the windows client-side decorations.

A GtkApplicationWindow with a menubar

(C Language Example):

GtkApplication *app = gtk_application_new ("org.gtk.test", 0);

GtkBuilder *builder = gtk_builder_new_from_string (
    "<interface>"
    "  <menu id='menubar'>"
    "    <submenu label='_Edit'>"
    "      <item label='_Copy' action='win.copy'/>"
    "      <item label='_Paste' action='win.paste'/>"
    "    </submenu>"
    "  </menu>"
    "</interface>",
    -1);

GMenuModel *menubar = G_MENU_MODEL (gtk_builder_get_object (builder,
                                                            "menubar"));
gtk_application_set_menubar (GTK_APPLICATION (app), menubar);
g_object_unref (builder);

// ...

GtkWidget *window = gtk_application_window_new (app);

Handling fallback yourself

A simple example

The XML format understood by GtkBuilder for GMenuModel consists of a toplevel <menu> element, which contains one or more <item> elements. Each <item> element contains <attribute> and <link> elements with a mandatory name attribute. <link> elements have the same content model as <menu>. Instead of <link name="submenu> or <link name="section">, you can use <submenu> or <section> elements.

Attribute values can be translated using gettext, like other GtkBuilder content. <attribute> elements can be marked for translation with a translatable="yes" attribute. It is also possible to specify message context and translator comments, using the context and comments attributes. To make use of this, the GtkBuilder must have been given the gettext domain to use.

The following attributes are used when constructing menu items:

• “label”: a user-visible string to display
• “action”: the prefixed name of the action to trigger
• “target”: the parameter to use when activating the action
• “icon” and “verb-icon”: names of icons that may be displayed
• “submenu-action”: name of an action that may be used to determine if a submenu can be opened
• “hidden-when”: a string used to determine when the item will be hidden. Possible values include “action-disabled”, “action-missing”, “macos-menubar”.

The following attributes are used when constructing sections:

• “label”: a user-visible string to use as section heading
• “display-hint”: a string used to determine special formatting for the section. Possible values include “horizontal-buttons”.
• “text-direction”: a string used to determine the GtkTextDirection to use when “display-hint” is set to “horizontal-buttons”. Possible values include “rtl”, “ltr”, and “none”.

The following attributes are used when constructing submenus:

• “label”: a user-visible string to display
• “icon”: icon name to display

The ApplicationWindowRef type acts as a lightweight Swift reference to an underlying GtkApplicationWindow instance. It exposes methods that can operate on this data type through ApplicationWindowProtocol conformance. Use ApplicationWindowRef only as an unowned reference to an existing GtkApplicationWindow instance.

GtkArrow should be used to draw simple arrows that need to point in one of the four cardinal directions (up, down, left, or right). The style of the arrow can be one of shadow in, shadow out, etched in, or etched out. Note that these directions and style types may be amended in versions of GTK+ to come.

GtkArrow will fill any space alloted to it, but since it is inherited from GtkMisc, it can be padded and/or aligned, to fill exactly the space the programmer desires.

Arrows are created with a call to gtk_arrow_new(). The direction or style of an arrow can be changed after creation by using gtk_arrow_set().

GtkArrow has been deprecated; you can simply use a GtkImage with a suitable icon name, such as “pan-down-symbolic“. When replacing GtkArrow by an image, pay attention to the fact that GtkArrow is doing automatic flipping between GTK_ARROW_LEFT and GTK_ARROW_RIGHT, depending on the text direction. To get the same effect with an image, use the icon names “pan-start-symbolic“ and “pan-end-symbolic“, which react to the text direction.

The ArrowRef type acts as a lightweight Swift reference to an underlying GtkArrow instance. It exposes methods that can operate on this data type through ArrowProtocol conformance. Use ArrowRef only as an unowned reference to an existing GtkArrow instance.

The ArrowAccessibleRef type acts as a lightweight Swift reference to an underlying GtkArrowAccessible instance. It exposes methods that can operate on this data type through ArrowAccessibleProtocol conformance. Use ArrowAccessibleRef only as an unowned reference to an existing GtkArrowAccessible instance.

The GtkAspectFrame is useful when you want pack a widget so that it can resize but always retains the same aspect ratio. For instance, one might be drawing a small preview of a larger image. GtkAspectFrame derives from GtkFrame, so it can draw a label and a frame around the child. The frame will be “shrink-wrapped” to the size of the child.

CSS nodes

GtkAspectFrame uses a CSS node with name frame.

The AspectFrameRef type acts as a lightweight Swift reference to an underlying GtkAspectFrame instance. It exposes methods that can operate on this data type through AspectFrameProtocol conformance. Use AspectFrameRef only as an unowned reference to an existing GtkAspectFrame instance.

A GtkAssistant is a widget used to represent a generally complex operation splitted in several steps, guiding the user through its pages and controlling the page flow to collect the necessary data.

The design of GtkAssistant is that it controls what buttons to show and to make sensitive, based on what it knows about the page sequence and the type of each page, in addition to state information like the page completion and committed status.

If you have a case that doesn’t quite fit in GtkAssistants way of handling buttons, you can use the GTK_ASSISTANT_PAGE_CUSTOM page type and handle buttons yourself.

GtkAssistant as GtkBuildable

The GtkAssistant implementation of the GtkBuildable interface exposes the action_area as internal children with the name “action_area”.

To add pages to an assistant in GtkBuilder, simply add it as a child to the GtkAssistant object, and set its child properties as necessary.

CSS nodes

GtkAssistant has a single CSS node with the name assistant.

The AssistantRef type acts as a lightweight Swift reference to an underlying GtkAssistant instance. It exposes methods that can operate on this data type through AssistantProtocol conformance. Use AssistantRef only as an unowned reference to an existing GtkAssistant instance.

The GtkBin widget is a container with just one child. It is not very useful itself, but it is useful for deriving subclasses, since it provides common code needed for handling a single child widget.

Many GTK+ widgets are subclasses of GtkBin, including GtkWindow, GtkButton, GtkFrame, GtkHandleBox or GtkScrolledWindow.

The BinRef type acts as a lightweight Swift reference to an underlying GtkBin instance. It exposes methods that can operate on this data type through BinProtocol conformance. Use BinRef only as an unowned reference to an existing GtkBin instance.

The AboutDialogClassRef type acts as a lightweight Swift reference to an underlying GtkAboutDialogClass instance. It exposes methods that can operate on this data type through AboutDialogClassProtocol conformance. Use AboutDialogClassRef only as an unowned reference to an existing GtkAboutDialogClass instance.

The AccelGroupClassRef type acts as a lightweight Swift reference to an underlying GtkAccelGroupClass instance. It exposes methods that can operate on this data type through AccelGroupClassProtocol conformance. Use AccelGroupClassRef only as an unowned reference to an existing GtkAccelGroupClass instance.

The AccelGroupEntryRef type acts as a lightweight Swift reference to an underlying GtkAccelGroupEntry instance. It exposes methods that can operate on this data type through AccelGroupEntryProtocol conformance. Use AccelGroupEntryRef only as an unowned reference to an existing GtkAccelGroupEntry instance.

The AccelKeyRef type acts as a lightweight Swift reference to an underlying GtkAccelKey instance. It exposes methods that can operate on this data type through AccelKeyProtocol conformance. Use AccelKeyRef only as an unowned reference to an existing GtkAccelKey instance.

The AccelLabelClassRef type acts as a lightweight Swift reference to an underlying GtkAccelLabelClass instance. It exposes methods that can operate on this data type through AccelLabelClassProtocol conformance. Use AccelLabelClassRef only as an unowned reference to an existing GtkAccelLabelClass instance.

The AccelMapClassRef type acts as a lightweight Swift reference to an underlying GtkAccelMapClass instance. It exposes methods that can operate on this data type through AccelMapClassProtocol conformance. Use AccelMapClassRef only as an unowned reference to an existing GtkAccelMapClass instance.

The AccessibleClassRef type acts as a lightweight Swift reference to an underlying GtkAccessibleClass instance. It exposes methods that can operate on this data type through AccessibleClassProtocol conformance. Use AccessibleClassRef only as an unowned reference to an existing GtkAccessibleClass instance.

The ActionBarClassRef type acts as a lightweight Swift reference to an underlying GtkActionBarClass instance. It exposes methods that can operate on this data type through ActionBarClassProtocol conformance. Use ActionBarClassRef only as an unowned reference to an existing GtkActionBarClass instance.

The ActionClassRef type acts as a lightweight Swift reference to an underlying GtkActionClass instance. It exposes methods that can operate on this data type through ActionClassProtocol conformance. Use ActionClassRef only as an unowned reference to an existing GtkActionClass instance.

GtkActionEntry structs are used with gtk_action_group_add_actions() to construct actions.

The ActionEntryRef type acts as a lightweight Swift reference to an underlying GtkActionEntry instance. It exposes methods that can operate on this data type through ActionEntryProtocol conformance. Use ActionEntryRef only as an unowned reference to an existing GtkActionEntry instance.

The ActionGroupClassRef type acts as a lightweight Swift reference to an underlying GtkActionGroupClass instance. It exposes methods that can operate on this data type through ActionGroupClassProtocol conformance. Use ActionGroupClassRef only as an unowned reference to an existing GtkActionGroupClass instance.

The interface vtable for GtkActionable.

The ActionableInterfaceRef type acts as a lightweight Swift reference to an underlying GtkActionableInterface instance. It exposes methods that can operate on this data type through ActionableInterfaceProtocol conformance. Use ActionableInterfaceRef only as an unowned reference to an existing GtkActionableInterface instance.

> This method can be called with a nil action at times.

The ActivatableIfaceRef type acts as a lightweight Swift reference to an underlying GtkActivatableIface instance. It exposes methods that can operate on this data type through ActivatableIfaceProtocol conformance. Use ActivatableIfaceRef only as an unowned reference to an existing GtkActivatableIface instance.

The AdjustmentClassRef type acts as a lightweight Swift reference to an underlying GtkAdjustmentClass instance. It exposes methods that can operate on this data type through AdjustmentClassProtocol conformance. Use AdjustmentClassRef only as an unowned reference to an existing GtkAdjustmentClass instance.

The AlignmentClassRef type acts as a lightweight Swift reference to an underlying GtkAlignmentClass instance. It exposes methods that can operate on this data type through AlignmentClassProtocol conformance. Use AlignmentClassRef only as an unowned reference to an existing GtkAlignmentClass instance.

The AppChooserButtonClassRef type acts as a lightweight Swift reference to an underlying GtkAppChooserButtonClass instance. It exposes methods that can operate on this data type through AppChooserButtonClassProtocol conformance. Use AppChooserButtonClassRef only as an unowned reference to an existing GtkAppChooserButtonClass instance.

The AppChooserDialogClassRef type acts as a lightweight Swift reference to an underlying GtkAppChooserDialogClass instance. It exposes methods that can operate on this data type through AppChooserDialogClassProtocol conformance. Use AppChooserDialogClassRef only as an unowned reference to an existing GtkAppChooserDialogClass instance.

The AppChooserWidgetClassRef type acts as a lightweight Swift reference to an underlying GtkAppChooserWidgetClass instance. It exposes methods that can operate on this data type through AppChooserWidgetClassProtocol conformance. Use AppChooserWidgetClassRef only as an unowned reference to an existing GtkAppChooserWidgetClass instance.

The ApplicationClassRef type acts as a lightweight Swift reference to an underlying GtkApplicationClass instance. It exposes methods that can operate on this data type through ApplicationClassProtocol conformance. Use ApplicationClassRef only as an unowned reference to an existing GtkApplicationClass instance.

The ApplicationWindowClassRef type acts as a lightweight Swift reference to an underlying GtkApplicationWindowClass instance. It exposes methods that can operate on this data type through ApplicationWindowClassProtocol conformance. Use ApplicationWindowClassRef only as an unowned reference to an existing GtkApplicationWindowClass instance.

The ArrowAccessibleClassRef type acts as a lightweight Swift reference to an underlying GtkArrowAccessibleClass instance. It exposes methods that can operate on this data type through ArrowAccessibleClassProtocol conformance. Use ArrowAccessibleClassRef only as an unowned reference to an existing GtkArrowAccessibleClass instance.

The ArrowClassRef type acts as a lightweight Swift reference to an underlying GtkArrowClass instance. It exposes methods that can operate on this data type through ArrowClassProtocol conformance. Use ArrowClassRef only as an unowned reference to an existing GtkArrowClass instance.

The AspectFrameClassRef type acts as a lightweight Swift reference to an underlying GtkAspectFrameClass instance. It exposes methods that can operate on this data type through AspectFrameClassProtocol conformance. Use AspectFrameClassRef only as an unowned reference to an existing GtkAspectFrameClass instance.

The AssistantClassRef type acts as a lightweight Swift reference to an underlying GtkAssistantClass instance. It exposes methods that can operate on this data type through AssistantClassProtocol conformance. Use AssistantClassRef only as an unowned reference to an existing GtkAssistantClass instance.

The BinClassRef type acts as a lightweight Swift reference to an underlying GtkBinClass instance. It exposes methods that can operate on this data type through BinClassProtocol conformance. Use BinClassRef only as an unowned reference to an existing GtkBinClass instance.

This interface provides a convenient way of associating widgets with actions on a GtkApplicationWindow or GtkApplication.

It primarily consists of two properties: GtkActionable:action-name and GtkActionable:action-target. There are also some convenience APIs for setting these properties.

The action will be looked up in action groups that are found among the widgets ancestors. Most commonly, these will be the actions with the “win.” or “app.” prefix that are associated with the GtkApplicationWindow or GtkApplication, but other action groups that are added with gtk_widget_insert_action_group() will be consulted as well.

The ActionableRef type acts as a lightweight Swift reference to an underlying GtkActionable instance. It exposes methods that can operate on this data type through ActionableProtocol conformance. Use ActionableRef only as an unowned reference to an existing GtkActionable instance.

Activatable widgets can be connected to a GtkAction and reflects the state of its action. A GtkActivatable can also provide feedback through its action, as they are responsible for activating their related actions.

Implementing GtkActivatable

When extending a class that is already GtkActivatable; it is only necessary to implement the GtkActivatable->sync_action_properties() and GtkActivatable->update() methods and chain up to the parent implementation, however when introducing a new GtkActivatable class; the GtkActivatable:related-action and GtkActivatable:use-action-appearance properties need to be handled by the implementor. Handling these properties is mostly a matter of installing the action pointer and boolean flag on your instance, and calling gtk_activatable_do_set_related_action() and gtk_activatable_sync_action_properties() at the appropriate times.

A class fragment implementing GtkActivatable

(C Language Example):

enum {
...

PROP_ACTIVATABLE_RELATED_ACTION,
PROP_ACTIVATABLE_USE_ACTION_APPEARANCE
}

struct _FooBarPrivate
{

  ...

  GtkAction      *action;
  gboolean        use_action_appearance;
};

...

static void foo_bar_activatable_interface_init         (GtkActivatableIface  *iface);
static void foo_bar_activatable_update                 (GtkActivatable       *activatable,
                                   GtkAction            *action,
                                   const gchar          *property_name);
static void foo_bar_activatable_sync_action_properties (GtkActivatable       *activatable,
                                   GtkAction            *action);
...


static void
foo_bar_class_init (FooBarClass *klass)
{

  ...

  g_object_class_override_property (gobject_class, PROP_ACTIVATABLE_RELATED_ACTION, "related-action");
  g_object_class_override_property (gobject_class, PROP_ACTIVATABLE_USE_ACTION_APPEARANCE, "use-action-appearance");

  ...
}


static void
foo_bar_activatable_interface_init (GtkActivatableIface  *iface)
{
  iface->update = foo_bar_activatable_update;
  iface->sync_action_properties = foo_bar_activatable_sync_action_properties;
}

... Break the reference using gtk_activatable_do_set_related_action()...

static void
foo_bar_dispose (GObject *object)
{
  FooBar *bar = FOO_BAR (object);
  FooBarPrivate *priv = FOO_BAR_GET_PRIVATE (bar);

  ...

  if (priv->action)
    {
      gtk_activatable_do_set_related_action (GTK_ACTIVATABLE (bar), NULL);
      priv->action = NULL;
    }
  G_OBJECT_CLASS (foo_bar_parent_class)->dispose (object);
}

... Handle the “related-action” and “use-action-appearance” properties ...

static void
foo_bar_set_property (GObject         *object,
                      guint            prop_id,
                      const GValue    *value,
                      GParamSpec      *pspec)
{
  FooBar *bar = FOO_BAR (object);
  FooBarPrivate *priv = FOO_BAR_GET_PRIVATE (bar);

  switch (prop_id)
    {

      ...

    case PROP_ACTIVATABLE_RELATED_ACTION:
      foo_bar_set_related_action (bar, g_value_get_object (value));
      break;
    case PROP_ACTIVATABLE_USE_ACTION_APPEARANCE:
      foo_bar_set_use_action_appearance (bar, g_value_get_boolean (value));
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }
}

static void
foo_bar_get_property (GObject         *object,
                         guint            prop_id,
                         GValue          *value,
                         GParamSpec      *pspec)
{
  FooBar *bar = FOO_BAR (object);
  FooBarPrivate *priv = FOO_BAR_GET_PRIVATE (bar);

  switch (prop_id)
    {

      ...

    case PROP_ACTIVATABLE_RELATED_ACTION:
      g_value_set_object (value, priv->action);
      break;
    case PROP_ACTIVATABLE_USE_ACTION_APPEARANCE:
      g_value_set_boolean (value, priv->use_action_appearance);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }
}


static void
foo_bar_set_use_action_appearance (FooBar   *bar,
                   gboolean  use_appearance)
{
  FooBarPrivate *priv = FOO_BAR_GET_PRIVATE (bar);

  if (priv->use_action_appearance != use_appearance)
    {
      priv->use_action_appearance = use_appearance;

      gtk_activatable_sync_action_properties (GTK_ACTIVATABLE (bar), priv->action);
    }
}

... call gtk_activatable_do_set_related_action() and then assign the action pointer,
no need to reference the action here since gtk_activatable_do_set_related_action() already
holds a reference here for you...
static void
foo_bar_set_related_action (FooBar    *bar,
                GtkAction *action)
{
  FooBarPrivate *priv = FOO_BAR_GET_PRIVATE (bar);

  if (priv->action == action)
    return;

  gtk_activatable_do_set_related_action (GTK_ACTIVATABLE (bar), action);

  priv->action = action;
}

... Selectively reset and update activatable depending on the use-action-appearance property ...
static void
gtk_button_activatable_sync_action_properties (GtkActivatable       *activatable,
                                          GtkAction            *action)
{
  GtkButtonPrivate *priv = GTK_BUTTON_GET_PRIVATE (activatable);

  if (!action)
    return;

  if (gtk_action_is_visible (action))
    gtk_widget_show (GTK_WIDGET (activatable));
  else
    gtk_widget_hide (GTK_WIDGET (activatable));

  gtk_widget_set_sensitive (GTK_WIDGET (activatable), gtk_action_is_sensitive (action));

  ...

  if (priv->use_action_appearance)
    {
      if (gtk_action_get_stock_id (action))
    foo_bar_set_stock (button, gtk_action_get_stock_id (action));
      else if (gtk_action_get_label (action))
    foo_bar_set_label (button, gtk_action_get_label (action));

      ...

    }
}

static void
foo_bar_activatable_update (GtkActivatable       *activatable,
                   GtkAction            *action,
                   const gchar          *property_name)
{
  FooBarPrivate *priv = FOO_BAR_GET_PRIVATE (activatable);

  if (strcmp (property_name, "visible") == 0)
    {
      if (gtk_action_is_visible (action))
    gtk_widget_show (GTK_WIDGET (activatable));
      else
    gtk_widget_hide (GTK_WIDGET (activatable));
    }
  else if (strcmp (property_name, "sensitive") == 0)
    gtk_widget_set_sensitive (GTK_WIDGET (activatable), gtk_action_is_sensitive (action));

  ...

  if (!priv->use_action_appearance)
    return;

  if (strcmp (property_name, "stock-id") == 0)
    foo_bar_set_stock (button, gtk_action_get_stock_id (action));
  else if (strcmp (property_name, "label") == 0)
    foo_bar_set_label (button, gtk_action_get_label (action));

  ...
}

The ActivatableRef type acts as a lightweight Swift reference to an underlying GtkActivatable instance. It exposes methods that can operate on this data type through ActivatableProtocol conformance. Use ActivatableRef only as an unowned reference to an existing GtkActivatable instance.

GtkAppChooser is an interface that can be implemented by widgets which allow the user to choose an application (typically for the purpose of opening a file). The main objects that implement this interface are GtkAppChooserWidget, GtkAppChooserDialog and GtkAppChooserButton.

Applications are represented by GIO GAppInfo objects here. GIO has a concept of recommended and fallback applications for a given content type. Recommended applications are those that claim to handle the content type itself, while fallback also includes applications that handle a more generic content type. GIO also knows the default and last-used application for a given content type. The GtkAppChooserWidget provides detailed control over whether the shown list of applications should include default, recommended or fallback applications.

To obtain the application that has been selected in a GtkAppChooser, use gtk_app_chooser_get_app_info().

The AppChooserRef type acts as a lightweight Swift reference to an underlying GtkAppChooser instance. It exposes methods that can operate on this data type through AppChooserProtocol conformance. Use AppChooserRef only as an unowned reference to an existing GtkAppChooser instance.

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.

The BuildableRef type acts as a lightweight Swift reference to an underlying GtkBuildable instance. It exposes methods that can operate on this data type through BuildableProtocol conformance. Use BuildableRef only as an unowned reference to an existing GtkBuildable instance.

A GtkBindingArg holds the data associated with an argument for a key binding signal emission as stored in GtkBindingSignal.

The BindingArgRef type acts as a lightweight Swift reference to an underlying GtkBindingArg instance. It exposes methods that can operate on this data type through BindingArgProtocol conformance. Use BindingArgRef only as an unowned reference to an existing GtkBindingArg instance.

Each key binding element of a binding sets binding list is represented by a GtkBindingEntry.

The BindingEntryRef type acts as a lightweight Swift reference to an underlying GtkBindingEntry instance. It exposes methods that can operate on this data type through BindingEntryProtocol conformance. Use BindingEntryRef only as an unowned reference to an existing GtkBindingEntry instance.

A binding set maintains a list of activatable key bindings. A single binding set can match multiple types of widgets. Similar to style contexts, can be matched by any information contained in a widgets GtkWidgetPath. When a binding within a set is matched upon activation, an action signal is emitted on the target widget to carry out the actual activation.

The BindingSetRef type acts as a lightweight Swift reference to an underlying GtkBindingSet instance. It exposes methods that can operate on this data type through BindingSetProtocol conformance. Use BindingSetRef only as an unowned reference to an existing GtkBindingSet instance.

A GtkBindingSignal stores the necessary information to activate a widget in response to a key press via a signal emission.

The BindingSignalRef type acts as a lightweight Swift reference to an underlying GtkBindingSignal instance. It exposes methods that can operate on this data type through BindingSignalProtocol conformance. Use BindingSignalRef only as an unowned reference to an existing GtkBindingSignal instance.

The BooleanCellAccessibleClassRef type acts as a lightweight Swift reference to an underlying GtkBooleanCellAccessibleClass instance. It exposes methods that can operate on this data type through BooleanCellAccessibleClassProtocol conformance. Use BooleanCellAccessibleClassRef only as an unowned reference to an existing GtkBooleanCellAccessibleClass instance.

A struct that specifies a border around a rectangular area that can be of different width on each side.

The BorderRef type acts as a lightweight Swift reference to an underlying GtkBorder instance. It exposes methods that can operate on this data type through BorderProtocol conformance. Use BorderRef only as an unowned reference to an existing GtkBorder instance.

The BoxClassRef type acts as a lightweight Swift reference to an underlying GtkBoxClass instance. It exposes methods that can operate on this data type through BoxClassProtocol conformance. Use BoxClassRef only as an unowned reference to an existing GtkBoxClass instance.

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

The BuildableIfaceRef type acts as a lightweight Swift reference to an underlying GtkBuildableIface instance. It exposes methods that can operate on this data type through BuildableIfaceProtocol conformance. Use BuildableIfaceRef only as an unowned reference to an existing GtkBuildableIface instance.

The BuilderClassRef type acts as a lightweight Swift reference to an underlying GtkBuilderClass instance. It exposes methods that can operate on this data type through BuilderClassProtocol conformance. Use BuilderClassRef only as an unowned reference to an existing GtkBuilderClass instance.

The ButtonAccessibleClassRef type acts as a lightweight Swift reference to an underlying GtkButtonAccessibleClass instance. It exposes methods that can operate on this data type through ButtonAccessibleClassProtocol conformance. Use ButtonAccessibleClassRef only as an unowned reference to an existing GtkButtonAccessibleClass instance.

The ButtonBoxClassRef type acts as a lightweight Swift reference to an underlying GtkButtonBoxClass instance. It exposes methods that can operate on this data type through ButtonBoxClassProtocol conformance. Use ButtonBoxClassRef only as an unowned reference to an existing GtkButtonBoxClass instance.

The ButtonClassRef type acts as a lightweight Swift reference to an underlying GtkButtonClass instance. It exposes methods that can operate on this data type through ButtonClassProtocol conformance. Use ButtonClassRef only as an unowned reference to an existing GtkButtonClass instance.

The CalendarClassRef type acts as a lightweight Swift reference to an underlying GtkCalendarClass instance. It exposes methods that can operate on this data type through CalendarClassProtocol conformance. Use CalendarClassRef only as an unowned reference to an existing GtkCalendarClass instance.

The BooleanCellAccessibleRef type acts as a lightweight Swift reference to an underlying GtkBooleanCellAccessible instance. It exposes methods that can operate on this data type through BooleanCellAccessibleProtocol conformance. Use BooleanCellAccessibleRef only as an unowned reference to an existing GtkBooleanCellAccessible instance.

The GtkBox widget arranges child widgets into a single row or column, depending upon the value of its GtkOrientable:orientation property. Within the other dimension, all children are allocated the same size. Of course, the GtkWidget:halign and GtkWidget:valign properties can be used on the children to influence their allocation.

GtkBox uses a notion of packing. Packing refers to adding widgets with reference to a particular position in a GtkContainer. For a GtkBox, there are two reference positions: the start and the end of the box. For a vertical GtkBox, the start is defined as the top of the box and the end is defined as the bottom. For a horizontal GtkBox the start is defined as the left side and the end is defined as the right side.

Use repeated calls to gtk_box_pack_start() to pack widgets into a GtkBox from start to end. Use gtk_box_pack_end() to add widgets from end to start. You may intersperse these calls and add widgets from both ends of the same GtkBox.

Because GtkBox is a GtkContainer, you may also use gtk_container_add() to insert widgets into the box, and they will be packed with the default values for expand and fill child properties. Use gtk_container_remove() to remove widgets from the GtkBox.

Use gtk_box_set_homogeneous() to specify whether or not all children of the GtkBox are forced to get the same amount of space.

Use gtk_box_set_spacing() to determine how much space will be minimally placed between all children in the GtkBox. Note that spacing is added between the children, while padding added by gtk_box_pack_start() or gtk_box_pack_end() is added on either side of the widget it belongs to.

Use gtk_box_reorder_child() to move a GtkBox child to a different place in the box.

Use gtk_box_set_child_packing() to reset the expand, fill and padding child properties. Use gtk_box_query_child_packing() to query these fields.

CSS nodes

GtkBox uses a single CSS node with name box.

In horizontal orientation, the nodes of the children are always arranged from left to right. So :first-child will always select the leftmost child, regardless of text direction.

The BoxRef type acts as a lightweight Swift reference to an underlying GtkBox instance. It exposes methods that can operate on this data type through BoxProtocol conformance. Use BoxRef only as an unowned reference to an existing GtkBox instance.

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 gtk_builder_new_from_file(), gtk_builder_new_from_resource() or 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 gtk_builder_new() to get an empty builder and populate it by (multiple) calls to gtk_builder_add_from_file(), gtk_builder_add_from_resource() or 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 gtk_widget_destroy() to get rid of them and all the widgets they contain.

The functions gtk_builder_get_object() and 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 gtk_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 gtk_builder_connect_signals() and variants thereof can be used to connect handlers to the named signals in the description.

GtkBuilder UI Definitions #

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, which are more limited in scope. It is common to use .ui as the filename extension for files containing GtkBuilder UI definitions.

RELAX NG Compact Syntax

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 gtk_builder_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>”. 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 GtkUIManager in another part of the UI definition by specifying the id of the GtkUIManager 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 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 ___ (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 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 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.

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 implements 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 g_module_symbol(), but this can be changed by passing a custom GtkBuilderConnectFunc to gtk_builder_connect_signals_full(). 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 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.

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.

A GtkBuilder UI Definition

<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 for details.

The BuilderRef type acts as a lightweight Swift reference to an underlying GtkBuilder instance. It exposes methods that can operate on this data type through BuilderProtocol conformance. Use BuilderRef only as an unowned reference to an existing GtkBuilder instance.

The GtkButton widget is generally used to trigger a callback function that is called when the button is pressed. The various signals and how to use them are outlined below.

The GtkButton widget can hold any valid child widget. That is, it can hold almost any other standard GtkWidget. The most commonly used child is the GtkLabel.

CSS nodes

GtkButton has a single CSS node with name button. The node will get the style classes .image-button or .text-button, if the content is just an image or label, respectively. It may also receive the .flat style class.

Other style classes that are commonly used with GtkButton include .suggested-action and .destructive-action. In special cases, buttons can be made round by adding the .circular style class.

Button-like widgets like GtkToggleButton, GtkMenuButton, GtkVolumeButton, GtkLockButton, GtkColorButton, GtkFontButton or GtkFileChooserButton use style classes such as .toggle, .popup, .scale, .lock, .color, .font, .file to differentiate themselves from a plain GtkButton.

The ButtonRef type acts as a lightweight Swift reference to an underlying GtkButton instance. It exposes methods that can operate on this data type through ButtonProtocol conformance. Use ButtonRef only as an unowned reference to an existing GtkButton instance.

The ButtonAccessibleRef type acts as a lightweight Swift reference to an underlying GtkButtonAccessible instance. It exposes methods that can operate on this data type through ButtonAccessibleProtocol conformance. Use ButtonAccessibleRef only as an unowned reference to an existing GtkButtonAccessible instance.

The ButtonBoxRef type acts as a lightweight Swift reference to an underlying GtkButtonBox instance. It exposes methods that can operate on this data type through ButtonBoxProtocol conformance. Use ButtonBoxRef only as an unowned reference to an existing GtkButtonBox instance.

GtkCalendar is a widget that displays a Gregorian calendar, one month at a time. It can be created with gtk_calendar_new().

The month and year currently displayed can be altered with gtk_calendar_select_month(). The exact day can be selected from the displayed month using gtk_calendar_select_day().

To place a visual marker on a particular day, use gtk_calendar_mark_day() and to remove the marker, gtk_calendar_unmark_day(). Alternative, all marks can be cleared with gtk_calendar_clear_marks().

The way in which the calendar itself is displayed can be altered using gtk_calendar_set_display_options().

The selected date can be retrieved from a GtkCalendar using gtk_calendar_get_date().

Users should be aware that, although the Gregorian calendar is the legal calendar in most countries, it was adopted progressively between 1582 and 1929. Display before these dates is likely to be historically incorrect.

The CalendarRef type acts as a lightweight Swift reference to an underlying GtkCalendar instance. It exposes methods that can operate on this data type through CalendarProtocol conformance. Use CalendarRef only as an unowned reference to an existing GtkCalendar instance.

The CellAccessibleRef type acts as a lightweight Swift reference to an underlying GtkCellAccessible instance. It exposes methods that can operate on this data type through CellAccessibleProtocol conformance. Use CellAccessibleRef only as an unowned reference to an existing GtkCellAccessible instance.

The GtkCellArea is an abstract class for GtkCellLayout widgets (also referred to as “layouting widgets”) to interface with an arbitrary number of GtkCellRenderers and interact with the user for a given GtkTreeModel row.

The cell area handles events, focus navigation, drawing and size requests and allocations for a given row of data.

Usually users dont have to interact with the GtkCellArea directly unless they are implementing a cell-layouting widget themselves.

Requesting area sizes

As outlined in GtkWidget’s geometry management section, GTK+ uses a height-for-width geometry management system to compute the sizes of widgets and user interfaces. GtkCellArea uses the same semantics to calculate the size of an area for an arbitrary number of GtkTreeModel rows.

When requesting the size of a cell area one needs to calculate the size for a handful of rows, and this will be done differently by different layouting widgets. For instance a GtkTreeViewColumn always lines up the areas from top to bottom while a GtkIconView on the other hand might enforce that all areas received the same width and wrap the areas around, requesting height for more cell areas when allocated less width.

It’s also important for areas to maintain some cell alignments with areas rendered for adjacent rows (cells can appear “columnized” inside an area even when the size of cells are different in each row). For this reason the GtkCellArea uses a GtkCellAreaContext object to store the alignments and sizes along the way (as well as the overall largest minimum and natural size for all the rows which have been calculated with the said context).

The GtkCellAreaContext is an opaque object specific to the GtkCellArea which created it (see gtk_cell_area_create_context()). The owning cell-layouting widget can create as many contexts as it wishes to calculate sizes of rows which should receive the same size in at least one orientation (horizontally or vertically), However, it’s important that the same GtkCellAreaContext which was used to request the sizes for a given GtkTreeModel row be used when rendering or processing events for that row.

In order to request the width of all the rows at the root level of a GtkTreeModel one would do the following:

(C Language Example):

GtkTreeIter iter;
gint        minimum_width;
gint        natural_width;

valid = gtk_tree_model_get_iter_first (model, &iter);
while (valid)
  {
    gtk_cell_area_apply_attributes (area, model, &iter, FALSE, FALSE);
    gtk_cell_area_get_preferred_width (area, context, widget, NULL, NULL);

    valid = gtk_tree_model_iter_next (model, &iter);
  }
gtk_cell_area_context_get_preferred_width (context, &minimum_width, &natural_width);

Note that in this example it’s not important to observe the returned minimum and natural width of the area for each row unless the cell-layouting object is actually interested in the widths of individual rows. The overall width is however stored in the accompanying GtkCellAreaContext object and can be consulted at any time.

This can be useful since GtkCellLayout widgets usually have to support requesting and rendering rows in treemodels with an exceedingly large amount of rows. The GtkCellLayout widget in that case would calculate the required width of the rows in an idle or timeout source (see g_timeout_add()) and when the widget is requested its actual width in GtkWidgetClass.get_preferred_width() it can simply consult the width accumulated so far in the GtkCellAreaContext object.

A simple example where rows are rendered from top to bottom and take up the full width of the layouting widget would look like:

(C Language Example):

static void
foo_get_preferred_width (GtkWidget       *widget,
                         gint            *minimum_size,
                         gint            *natural_size)
{
  Foo        *foo  = FOO (widget);
  FooPrivate *priv = foo->priv;

  foo_ensure_at_least_one_handfull_of_rows_have_been_requested (foo);

  gtk_cell_area_context_get_preferred_width (priv->context, minimum_size, natural_size);
}

In the above example the Foo widget has to make sure that some row sizes have been calculated (the amount of rows that Foo judged was appropriate to request space for in a single timeout iteration) before simply returning the amount of space required by the area via the GtkCellAreaContext.

Requesting the height for width (or width for height) of an area is a similar task except in this case the GtkCellAreaContext does not store the data (actually, it does not know how much space the layouting widget plans to allocate it for every row. It’s up to the layouting widget to render each row of data with the appropriate height and width which was requested by the GtkCellArea).

In order to request the height for width of all the rows at the root level of a GtkTreeModel one would do the following:

(C Language Example):

GtkTreeIter iter;
gint        minimum_height;
gint        natural_height;
gint        full_minimum_height = 0;
gint        full_natural_height = 0;

valid = gtk_tree_model_get_iter_first (model, &iter);
while (valid)
  {
    gtk_cell_area_apply_attributes (area, model, &iter, FALSE, FALSE);
    gtk_cell_area_get_preferred_height_for_width (area, context, widget,
                                                  width, &minimum_height, &natural_height);

    if (width_is_for_allocation)
       cache_row_height (&iter, minimum_height, natural_height);

    full_minimum_height += minimum_height;
    full_natural_height += natural_height;

    valid = gtk_tree_model_iter_next (model, &iter);
  }

Note that in the above example we would need to cache the heights returned for each row so that we would know what sizes to render the areas for each row. However we would only want to really cache the heights if the request is intended for the layouting widgets real allocation.

In some cases the layouting widget is requested the height for an arbitrary for_width, this is a special case for layouting widgets who need to request size for tens of thousands of rows. For this case it’s only important that the layouting widget calculate one reasonably sized chunk of rows and return that height synchronously. The reasoning here is that any layouting widget is at least capable of synchronously calculating enough height to fill the screen height (or scrolled window height) in response to a single call to GtkWidgetClass.get_preferred_height_for_width(). Returning a perfect height for width that is larger than the screen area is inconsequential since after the layouting receives an allocation from a scrolled window it simply continues to drive the scrollbar values while more and more height is required for the row heights that are calculated in the background.

Rendering Areas

Once area sizes have been aquired at least for the rows in the visible area of the layouting widget they can be rendered at GtkWidgetClass.draw() time.

A crude example of how to render all the rows at the root level runs as follows:

(C Language Example):

GtkAllocation allocation;
GdkRectangle  cell_area = { 0, };
GtkTreeIter   iter;
gint          minimum_width;
gint          natural_width;

gtk_widget_get_allocation (widget, &allocation);
cell_area.width = allocation.width;

valid = gtk_tree_model_get_iter_first (model, &iter);
while (valid)
  {
    cell_area.height = get_cached_height_for_row (&iter);

    gtk_cell_area_apply_attributes (area, model, &iter, FALSE, FALSE);
    gtk_cell_area_render (area, context, widget, cr,
                          &cell_area, &cell_area, state_flags, FALSE);

    cell_area.y += cell_area.height;

    valid = gtk_tree_model_iter_next (model, &iter);
  }

Note that the cached height in this example really depends on how the layouting widget works. The layouting widget might decide to give every row its minimum or natural height or, if the model content is expected to fit inside the layouting widget without scrolling, it would make sense to calculate the allocation for each row at GtkWidget::size-allocate time using gtk_distribute_natural_allocation().

Handling Events and Driving Keyboard Focus

Passing events to the area is as simple as handling events on any normal widget and then passing them to the gtk_cell_area_event() API as they come in. Usually GtkCellArea is only interested in button events, however some customized derived areas can be implemented who are interested in handling other events. Handling an event can trigger the GtkCellArea::focus-changed signal to fire; as well as GtkCellArea::add-editable in the case that an editable cell was clicked and needs to start editing. You can call gtk_cell_area_stop_editing() at any time to cancel any cell editing that is currently in progress.

The GtkCellArea drives keyboard focus from cell to cell in a way similar to GtkWidget. For layouting widgets that support giving focus to cells it’s important to remember to pass GTK_CELL_RENDERER_FOCUSED to the area functions for the row that has focus and to tell the area to paint the focus at render time.

Layouting widgets that accept focus on cells should implement the GtkWidgetClass.focus() virtual method. The layouting widget is always responsible for knowing where GtkTreeModel rows are rendered inside the widget, so at GtkWidgetClass.focus() time the layouting widget should use the GtkCellArea methods to navigate focus inside the area and then observe the GtkDirectionType to pass the focus to adjacent rows and areas.

A basic example of how the GtkWidgetClass.focus() virtual method should be implemented:

(C Language Example):

static gboolean
foo_focus (GtkWidget       *widget,
           GtkDirectionType direction)
{
  Foo        *foo  = FOO (widget);
  FooPrivate *priv = foo->priv;
  gint        focus_row;
  gboolean    have_focus = FALSE;

  focus_row = priv->focus_row;

  if (!gtk_widget_has_focus (widget))
    gtk_widget_grab_focus (widget);

  valid = gtk_tree_model_iter_nth_child (priv->model, &iter, NULL, priv->focus_row);
  while (valid)
    {
      gtk_cell_area_apply_attributes (priv->area, priv->model, &iter, FALSE, FALSE);

      if (gtk_cell_area_focus (priv->area, direction))
        {
           priv->focus_row = focus_row;
           have_focus = TRUE;
           break;
        }
      else
        {
          if (direction == GTK_DIR_RIGHT ||
              direction == GTK_DIR_LEFT)
            break;
          else if (direction == GTK_DIR_UP ||
                   direction == GTK_DIR_TAB_BACKWARD)
           {
              if (focus_row == 0)
                break;
              else
               {
                  focus_row--;
                  valid = gtk_tree_model_iter_nth_child (priv->model, &iter, NULL, focus_row);
               }
            }
          else
            {
              if (focus_row == last_row)
                break;
              else
                {
                  focus_row++;
                  valid = gtk_tree_model_iter_next (priv->model, &iter);
                }
            }
        }
    }
    return have_focus;
}

Note that the layouting widget is responsible for matching the GtkDirectionType values to the way it lays out its cells.

Cell Properties

The GtkCellArea introduces cell properties for GtkCellRenderers in very much the same way that GtkContainer introduces child properties for GtkWidgets. This provides some general interfaces for defining the relationship cell areas have with their cells. For instance in a GtkCellAreaBox a cell might “expand” and receive extra space when the area is allocated more than its full natural request, or a cell might be configured to “align” with adjacent rows which were requested and rendered with the same GtkCellAreaContext.

Use gtk_cell_area_class_install_cell_property() to install cell properties for a cell area class and gtk_cell_area_class_find_cell_property() or gtk_cell_area_class_list_cell_properties() to get information about existing cell properties.

To set the value of a cell property, use gtk_cell_area_cell_set_property(), gtk_cell_area_cell_set() or gtk_cell_area_cell_set_valist(). To obtain the value of a cell property, use gtk_cell_area_cell_get_property(), gtk_cell_area_cell_get() or gtk_cell_area_cell_get_valist().

The CellAreaRef type acts as a lightweight Swift reference to an underlying GtkCellArea instance. It exposes methods that can operate on this data type through CellAreaProtocol conformance. Use CellAreaRef only as an unowned reference to an existing GtkCellArea instance.

The GtkCellAreaBox renders cell renderers into a row or a column depending on its GtkOrientation.

GtkCellAreaBox uses a notion of packing. Packing refers to adding cell renderers with reference to a particular position in a GtkCellAreaBox. There are two reference positions: the start and the end of the box. When the GtkCellAreaBox is oriented in the GTK_ORIENTATION_VERTICAL orientation, the start is defined as the top of the box and the end is defined as the bottom. In the GTK_ORIENTATION_HORIZONTAL orientation start is defined as the left side and the end is defined as the right side.

Alignments of GtkCellRenderers rendered in adjacent rows can be configured by configuring the GtkCellAreaBox align child cell property with gtk_cell_area_cell_set_property() or by specifying the “align” argument to gtk_cell_area_box_pack_start() and gtk_cell_area_box_pack_end().

The CellAreaBoxRef type acts as a lightweight Swift reference to an underlying GtkCellAreaBox instance. It exposes methods that can operate on this data type through CellAreaBoxProtocol conformance. Use CellAreaBoxRef only as an unowned reference to an existing GtkCellAreaBox instance.

The GtkCellAreaContext object is created by a given GtkCellArea implementation via its GtkCellAreaClass.create_context() virtual method and is used to store cell sizes and alignments for a series of GtkTreeModel rows that are requested and rendered in the same context.

GtkCellLayout widgets can create any number of contexts in which to request and render groups of data rows. However, it’s important that the same context which was used to request sizes for a given GtkTreeModel row also be used for the same row when calling other GtkCellArea APIs such as gtk_cell_area_render() and gtk_cell_area_event().

The CellAreaContextRef type acts as a lightweight Swift reference to an underlying GtkCellAreaContext instance. It exposes methods that can operate on this data type through CellAreaContextProtocol conformance. Use CellAreaContextRef only as an unowned reference to an existing GtkCellAreaContext instance.

The GtkCellRenderer is a base class of a set of objects used for rendering a cell to a cairo_t. These objects are used primarily by the GtkTreeView widget, though they aren’t tied to them in any specific way. It is worth noting that GtkCellRenderer is not a GtkWidget and cannot be treated as such.

The primary use of a GtkCellRenderer is for drawing a certain graphical elements on a cairo_t. Typically, one cell renderer is used to draw many cells on the screen. To this extent, it isn’t expected that a CellRenderer keep any permanent state around. Instead, any state is set just prior to use using GObjects property system. Then, the cell is measured using gtk_cell_renderer_get_size(). Finally, the cell is rendered in the correct location using gtk_cell_renderer_render().

There are a number of rules that must be followed when writing a new GtkCellRenderer. First and foremost, it’s important that a certain set of properties will always yield a cell renderer of the same size, barring a GtkStyle change. The GtkCellRenderer also has a number of generic properties that are expected to be honored by all children.

Beyond merely rendering a cell, cell renderers can optionally provide active user interface elements. A cell renderer can be “activatable” like GtkCellRendererToggle, which toggles when it gets activated by a mouse click, or it can be “editable” like GtkCellRendererText, which allows the user to edit the text using a widget implementing the GtkCellEditable interface, e.g. GtkEntry. To make a cell renderer activatable or editable, you have to implement the GtkCellRendererClass.activate or GtkCellRendererClass.start_editing virtual functions, respectively.

Many properties of GtkCellRenderer and its subclasses have a corresponding “set” property, e.g. “cell-background-set” corresponds to “cell-background”. These “set” properties reflect whether a property has been set or not. You should not set them independently.

The CellRendererRef type acts as a lightweight Swift reference to an underlying GtkCellRenderer instance. It exposes methods that can operate on this data type through CellRendererProtocol conformance. Use CellRendererRef only as an unowned reference to an existing GtkCellRenderer instance.

GtkCellRendererAccel displays a keyboard accelerator (i.e. a key combination like Control + a). If the cell renderer is editable, the accelerator can be changed by simply typing the new combination.

The GtkCellRendererAccel cell renderer was added in GTK+ 2.10.

The CellRendererAccelRef type acts as a lightweight Swift reference to an underlying GtkCellRendererAccel instance. It exposes methods that can operate on this data type through CellRendererAccelProtocol conformance. Use CellRendererAccelRef only as an unowned reference to an existing GtkCellRendererAccel instance.

GtkCellRendererCombo renders text in a cell like GtkCellRendererText from which it is derived. But while GtkCellRendererText offers a simple entry to edit the text, GtkCellRendererCombo offers a GtkComboBox widget to edit the text. The values to display in the combo box are taken from the tree model specified in the GtkCellRendererCombo:model property.

The combo cell renderer takes care of adding a text cell renderer to the combo box and sets it to display the column specified by its GtkCellRendererCombo:text-column property. Further properties of the combo box can be set in a handler for the GtkCellRenderer::editing-started signal.

The GtkCellRendererCombo cell renderer was added in GTK+ 2.6.

The CellRendererComboRef type acts as a lightweight Swift reference to an underlying GtkCellRendererCombo instance. It exposes methods that can operate on this data type through CellRendererComboProtocol conformance. Use CellRendererComboRef only as an unowned reference to an existing GtkCellRendererCombo instance.

A GtkCellRendererPixbuf can be used to render an image in a cell. It allows to render either a given GdkPixbuf (set via the GtkCellRendererPixbuf:pixbuf property) or a named icon (set via the GtkCellRendererPixbuf:icon-name property).

To support the tree view, GtkCellRendererPixbuf also supports rendering two alternative pixbufs, when the GtkCellRenderer:is-expander property is true. If the GtkCellRenderer:is-expanded property is true and the GtkCellRendererPixbuf:pixbuf-expander-open property is set to a pixbuf, it renders that pixbuf, if the GtkCellRenderer:is-expanded property is false and the GtkCellRendererPixbuf:pixbuf-expander-closed property is set to a pixbuf, it renders that one.

The CellRendererPixbufRef type acts as a lightweight Swift reference to an underlying GtkCellRendererPixbuf instance. It exposes methods that can operate on this data type through CellRendererPixbufProtocol conformance. Use CellRendererPixbufRef only as an unowned reference to an existing GtkCellRendererPixbuf instance.

GtkCellRendererProgress renders a numeric value as a progress par in a cell. Additionally, it can display a text on top of the progress bar.

The GtkCellRendererProgress cell renderer was added in GTK+ 2.6.

The CellRendererProgressRef type acts as a lightweight Swift reference to an underlying GtkCellRendererProgress instance. It exposes methods that can operate on this data type through CellRendererProgressProtocol conformance. Use CellRendererProgressRef only as an unowned reference to an existing GtkCellRendererProgress instance.

GtkCellRendererSpin renders text in a cell like GtkCellRendererText from which it is derived. But while GtkCellRendererText offers a simple entry to edit the text, GtkCellRendererSpin offers a GtkSpinButton widget. Of course, that means that the text has to be parseable as a floating point number.

The range of the spinbutton is taken from the adjustment property of the cell renderer, which can be set explicitly or mapped to a column in the tree model, like all properties of cell renders. GtkCellRendererSpin also has properties for the GtkCellRendererSpin:climb-rate and the number of GtkCellRendererSpin:digits to display. Other GtkSpinButton properties can be set in a handler for the GtkCellRenderer::editing-started signal.

The GtkCellRendererSpin cell renderer was added in GTK+ 2.10.

The CellRendererSpinRef type acts as a lightweight Swift reference to an underlying GtkCellRendererSpin instance. It exposes methods that can operate on this data type through CellRendererSpinProtocol conformance. Use CellRendererSpinRef only as an unowned reference to an existing GtkCellRendererSpin instance.

GtkCellRendererSpinner renders a spinning animation in a cell, very similar to GtkSpinner. It can often be used as an alternative to a GtkCellRendererProgress for displaying indefinite activity, instead of actual progress.

To start the animation in a cell, set the GtkCellRendererSpinner:active property to true and increment the GtkCellRendererSpinner:pulse property at regular intervals. The usual way to set the cell renderer properties for each cell is to bind them to columns in your tree model using e.g. gtk_tree_view_column_add_attribute().

The CellRendererSpinnerRef type acts as a lightweight Swift reference to an underlying GtkCellRendererSpinner instance. It exposes methods that can operate on this data type through CellRendererSpinnerProtocol conformance. Use CellRendererSpinnerRef only as an unowned reference to an existing GtkCellRendererSpinner instance.

A GtkCellRendererText renders a given text in its cell, using the font, color and style information provided by its properties. The text will be ellipsized if it is too long and the GtkCellRendererText:ellipsize property allows it.

If the GtkCellRenderer:mode is GTK_CELL_RENDERER_MODE_EDITABLE, the GtkCellRendererText allows to edit its text using an entry.

The CellRendererTextRef type acts as a lightweight Swift reference to an underlying GtkCellRendererText instance. It exposes methods that can operate on this data type through CellRendererTextProtocol conformance. Use CellRendererTextRef only as an unowned reference to an existing GtkCellRendererText instance.

GtkCellRendererToggle renders a toggle button in a cell. The button is drawn as a radio or a checkbutton, depending on the GtkCellRendererToggle:radio property. When activated, it emits the GtkCellRendererToggle::toggled signal.

The CellRendererToggleRef type acts as a lightweight Swift reference to an underlying GtkCellRendererToggle instance. It exposes methods that can operate on this data type through CellRendererToggleProtocol conformance. Use CellRendererToggleRef only as an unowned reference to an existing GtkCellRendererToggle instance.

A GtkCellView displays a single row of a GtkTreeModel using a GtkCellArea and GtkCellAreaContext. A GtkCellAreaContext can be provided to the GtkCellView at construction time in order to keep the cellview in context of a group of cell views, this ensures that the renderers displayed will be properly aligned with eachother (like the aligned cells in the menus of GtkComboBox).

GtkCellView is GtkOrientable in order to decide in which orientation the underlying GtkCellAreaContext should be allocated. Taking the GtkComboBox menu as an example, cellviews should be oriented horizontally if the menus are listed top-to-bottom and thus all share the same width but may have separate individual heights (left-to-right menus should be allocated vertically since they all share the same height but may have variable widths).

CSS nodes

GtkCellView has a single CSS node with name cellview.

The CellViewRef type acts as a lightweight Swift reference to an underlying GtkCellView instance. It exposes methods that can operate on this data type through CellViewProtocol conformance. Use CellViewRef only as an unowned reference to an existing GtkCellView instance.

A GtkCheckButton places a discrete GtkToggleButton next to a widget, (usually a GtkLabel). See the section on GtkToggleButton widgets for more information about toggle/check buttons.

The important signal ( GtkToggleButton::toggled ) is also inherited from GtkToggleButton.

CSS nodes

(plain Language Example):

checkbutton
├── check
╰── <child>

A GtkCheckButton with indicator (see gtk_toggle_button_set_mode()) has a main CSS node with name checkbutton and a subnode with name check.

(plain Language Example):

button.check
├── check
╰── <child>

A GtkCheckButton without indicator changes the name of its main node to button and adds a .check style class to it. The subnode is invisible in this case.

The CheckButtonRef type acts as a lightweight Swift reference to an underlying GtkCheckButton instance. It exposes methods that can operate on this data type through CheckButtonProtocol conformance. Use CheckButtonRef only as an unowned reference to an existing GtkCheckButton instance.

A GtkCheckMenuItem is a menu item that maintains the state of a boolean value in addition to a GtkMenuItem usual role in activating application code.

A check box indicating the state of the boolean value is displayed at the left side of the GtkMenuItem. Activating the GtkMenuItem toggles the value.

CSS nodes

(plain Language Example):

menuitem
├── check.left
╰── <child>

GtkCheckMenuItem has a main CSS node with name menuitem, and a subnode with name check, which gets the .left or .right style class.

The CheckMenuItemRef type acts as a lightweight Swift reference to an underlying GtkCheckMenuItem instance. It exposes methods that can operate on this data type through CheckMenuItemProtocol conformance. Use CheckMenuItemRef only as an unowned reference to an existing GtkCheckMenuItem instance.

The CheckMenuItemAccessibleRef type acts as a lightweight Swift reference to an underlying GtkCheckMenuItemAccessible instance. It exposes methods that can operate on this data type through CheckMenuItemAccessibleProtocol conformance. Use CheckMenuItemAccessibleRef only as an unowned reference to an existing GtkCheckMenuItemAccessible instance.

The ClipboardRef type acts as a lightweight Swift reference to an underlying GtkClipboard instance. It exposes methods that can operate on this data type through ClipboardProtocol conformance. Use ClipboardRef only as an unowned reference to an existing GtkClipboard instance.

The GtkColorButton is a button which displays the currently selected color and allows to open a color selection dialog to change the color. It is suitable widget for selecting a color in a preference dialog.

CSS nodes

GtkColorButton has a single CSS node with name button. To differentiate it from a plain GtkButton, it gets the .color style class.

The ColorButtonRef type acts as a lightweight Swift reference to an underlying GtkColorButton instance. It exposes methods that can operate on this data type through ColorButtonProtocol conformance. Use ColorButtonRef only as an unowned reference to an existing GtkColorButton instance.

The GtkColorChooserDialog widget is a dialog for choosing a color. It implements the GtkColorChooser interface.

The ColorChooserDialogRef type acts as a lightweight Swift reference to an underlying GtkColorChooserDialog instance. It exposes methods that can operate on this data type through ColorChooserDialogProtocol conformance. Use ColorChooserDialogRef only as an unowned reference to an existing GtkColorChooserDialog instance.

The GtkColorChooserWidget widget lets the user select a color. By default, the chooser presents a predefined palette of colors, plus a small number of settable custom colors. It is also possible to select a different color with the single-color editor. To enter the single-color editing mode, use the context menu of any color of the palette, or use the ‘+’ button to add a new custom color.

The chooser automatically remembers the last selection, as well as custom colors.

To change the initially selected color, use gtk_color_chooser_set_rgba(). To get the selected color use gtk_color_chooser_get_rgba().

The GtkColorChooserWidget is used in the GtkColorChooserDialog to provide a dialog for selecting colors.

CSS names

GtkColorChooserWidget has a single CSS node with name colorchooser.

The ColorChooserWidgetRef type acts as a lightweight Swift reference to an underlying GtkColorChooserWidget instance. It exposes methods that can operate on this data type through ColorChooserWidgetProtocol conformance. Use ColorChooserWidgetRef only as an unowned reference to an existing GtkColorChooserWidget instance.

The ColorSelectionRef type acts as a lightweight Swift reference to an underlying GtkColorSelection instance. It exposes methods that can operate on this data type through ColorSelectionProtocol conformance. Use ColorSelectionRef only as an unowned reference to an existing GtkColorSelection instance.

The ColorSelectionDialogRef type acts as a lightweight Swift reference to an underlying GtkColorSelectionDialog instance. It exposes methods that can operate on this data type through ColorSelectionDialogProtocol conformance. Use ColorSelectionDialogRef only as an unowned reference to an existing GtkColorSelectionDialog instance.

A GtkComboBox is a widget that allows the user to choose from a list of valid choices. The GtkComboBox displays the selected choice. When activated, the GtkComboBox displays a popup which allows the user to make a new choice. The style in which the selected value is displayed, and the style of the popup is determined by the current theme. It may be similar to a Windows-style combo box.

The GtkComboBox uses the model-view pattern; the list of valid choices is specified in the form of a tree model, and the display of the choices can be adapted to the data in the model by using cell renderers, as you would in a tree view. This is possible since GtkComboBox implements the GtkCellLayout interface. The tree model holding the valid choices is not restricted to a flat list, it can be a real tree, and the popup will reflect the tree structure.

To allow the user to enter values not in the model, the “has-entry” property allows the GtkComboBox to contain a GtkEntry. This entry can be accessed by calling gtk_bin_get_child() on the combo box.

For a simple list of textual choices, the model-view API of GtkComboBox can be a bit overwhelming. In this case, GtkComboBoxText offers a simple alternative. Both GtkComboBox and GtkComboBoxText can contain an entry.

CSS nodes

(plain Language Example):

combobox
├── box.linked
│   ╰── button.combo
│       ╰── box
│           ├── cellview
│           ╰── arrow
╰── window.popup

A normal combobox contains a box with the .linked class, a button with the .combo class and inside those buttons, there are a cellview and an arrow.

(plain Language Example):

combobox
├── box.linked
│   ├── entry.combo
│   ╰── button.combo
│       ╰── box
│           ╰── arrow
╰── window.popup

A GtkComboBox with an entry has a single CSS node with name combobox. It contains a box with the .linked class. That box contains an entry and a button, both with the .combo class added. The button also contains another node with name arrow.

The ComboBoxRef type acts as a lightweight Swift reference to an underlying GtkComboBox instance. It exposes methods that can operate on this data type through ComboBoxProtocol conformance. Use ComboBoxRef only as an unowned reference to an existing GtkComboBox instance.

The ComboBoxAccessibleRef type acts as a lightweight Swift reference to an underlying GtkComboBoxAccessible instance. It exposes methods that can operate on this data type through ComboBoxAccessibleProtocol conformance. Use ComboBoxAccessibleRef only as an unowned reference to an existing GtkComboBoxAccessible instance.

A GtkComboBoxText is a simple variant of GtkComboBox that hides the model-view complexity for simple text-only use cases.

To create a GtkComboBoxText, use gtk_combo_box_text_new() or gtk_combo_box_text_new_with_entry().

You can add items to a GtkComboBoxText with gtk_combo_box_text_append_text(), gtk_combo_box_text_insert_text() or gtk_combo_box_text_prepend_text() and remove options with gtk_combo_box_text_remove().

If the GtkComboBoxText contains an entry (via the “has-entry” property), its contents can be retrieved using gtk_combo_box_text_get_active_text(). The entry itself can be accessed by calling gtk_bin_get_child() on the combo box.

You should not call gtk_combo_box_set_model() or attempt to pack more cells into this combo box via its GtkCellLayout interface.

GtkComboBoxText as GtkBuildable

The GtkComboBoxText implementation of the GtkBuildable interface supports adding items directly using the <items> element and specifying <item> elements for each item. Each <item> element can specify the “id” corresponding to the appended text and also supports the regular translation attributes “translatable”, “context” and “comments”.

Here is a UI definition fragment specifying GtkComboBoxText items:

<object class="GtkComboBoxText">
  <items>
    <item translatable="yes" id="factory">Factory</item>
    <item translatable="yes" id="home">Home</item>
    <item translatable="yes" id="subway">Subway</item>
  </items>
</object>

CSS nodes

(plain Language Example):

combobox
╰── box.linked
    ├── entry.combo
    ├── button.combo
    ╰── window.popup

GtkComboBoxText has a single CSS node with name combobox. It adds the style class .combo to the main CSS nodes of its entry and button children, and the .linked class to the node of its internal box.

The ComboBoxTextRef type acts as a lightweight Swift reference to an underlying GtkComboBoxText instance. It exposes methods that can operate on this data type through ComboBoxTextProtocol conformance. Use ComboBoxTextRef only as an unowned reference to an existing GtkComboBoxText instance.

A GTK+ user interface is constructed by nesting widgets inside widgets. Container widgets are the inner nodes in the resulting tree of widgets: they contain other widgets. So, for example, you might have a GtkWindow containing a GtkFrame containing a GtkLabel. If you wanted an image instead of a textual label inside the frame, you might replace the GtkLabel widget with a GtkImage widget.

There are two major kinds of container widgets in GTK+. Both are subclasses of the abstract GtkContainer base class.

The first type of container widget has a single child widget and derives from GtkBin. These containers are decorators, which add some kind of functionality to the child. For example, a GtkButton makes its child into a clickable button; a GtkFrame draws a frame around its child and a GtkWindow places its child widget inside a top-level window.

The second type of container can have more than one child; its purpose is to manage layout. This means that these containers assign sizes and positions to their children. For example, a GtkHBox arranges its children in a horizontal row, and a GtkGrid arranges the widgets it contains in a two-dimensional grid.

For implementations of GtkContainer the virtual method GtkContainerClass.forall() is always required, since it’s used for drawing and other internal operations on the children. If the GtkContainer implementation expect to have non internal children it’s needed to implement both GtkContainerClass.add() and GtkContainerClass.remove(). If the GtkContainer implementation has internal children, they should be added with gtk_widget_set_parent() on init() and removed with gtk_widget_unparent() in the GtkWidgetClass.destroy() implementation. See more about implementing custom widgets at https://wiki.gnome.org/HowDoI/CustomWidgets

Height for width geometry management

GTK+ uses a height-for-width (and width-for-height) geometry management system. Height-for-width means that a widget can change how much vertical space it needs, depending on the amount of horizontal space that it is given (and similar for width-for-height).

There are some things to keep in mind when implementing container widgets that make use of GTK+’s height for width geometry management system. First, it’s important to note that a container must prioritize one of its dimensions, that is to say that a widget or container can only have a GtkSizeRequestMode that is GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH or GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT. However, every widget and container must be able to respond to the APIs for both dimensions, i.e. even if a widget has a request mode that is height-for-width, it is possible that its parent will request its sizes using the width-for-height APIs.

To ensure that everything works properly, here are some guidelines to follow when implementing height-for-width (or width-for-height) containers.

Each request mode involves 2 virtual methods. Height-for-width apis run through gtk_widget_get_preferred_width() and then through gtk_widget_get_preferred_height_for_width(). When handling requests in the opposite GtkSizeRequestMode it is important that every widget request at least enough space to display all of its content at all times.

When gtk_widget_get_preferred_height() is called on a container that is height-for-width, the container must return the height for its minimum width. This is easily achieved by simply calling the reverse apis implemented for itself as follows:

(C Language Example):

static void
foo_container_get_preferred_height (GtkWidget *widget,
                                    gint *min_height,
                                    gint *nat_height)
{
   if (i_am_in_height_for_width_mode)
     {
       gint min_width;

       GTK_WIDGET_GET_CLASS (widget)->get_preferred_width (widget,
                                                           &min_width,
                                                           NULL);
       GTK_WIDGET_GET_CLASS (widget)->get_preferred_height_for_width
                                                          (widget,
                                                           min_width,
                                                           min_height,
                                                           nat_height);
     }
   else
     {
       ... many containers support both request modes, execute the
       real width-for-height request here by returning the
       collective heights of all widgets that are stacked
       vertically (or whatever is appropriate for this container)
       ...
     }
}

Similarly, when gtk_widget_get_preferred_width_for_height() is called for a container or widget that is height-for-width, it then only needs to return the base minimum width like so:

(C Language Example):

static void
foo_container_get_preferred_width_for_height (GtkWidget *widget,
                                              gint for_height,
                                              gint *min_width,
                                              gint *nat_width)
{
   if (i_am_in_height_for_width_mode)
     {
       GTK_WIDGET_GET_CLASS (widget)->get_preferred_width (widget,
                                                           min_width,
                                                           nat_width);
     }
   else
     {
       ... execute the real width-for-height request here based on
       the required width of the children collectively if the
       container were to be allocated the said height ...
     }
}

Height for width requests are generally implemented in terms of a virtual allocation of widgets in the input orientation. Assuming an height-for-width request mode, a container would implement the get_preferred_height_for_width() virtual function by first calling gtk_widget_get_preferred_width() for each of its children.

For each potential group of children that are lined up horizontally, the values returned by gtk_widget_get_preferred_width() should be collected in an array of GtkRequestedSize structures. Any child spacing should be removed from the input for_width and then the collective size should be allocated using the gtk_distribute_natural_allocation() convenience function.

The container will then move on to request the preferred height for each child by using gtk_widget_get_preferred_height_for_width() and using the sizes stored in the GtkRequestedSize array.

To allocate a height-for-width container, it’s again important to consider that a container must prioritize one dimension over the other. So if a container is a height-for-width container it must first allocate all widgets horizontally using a GtkRequestedSize array and gtk_distribute_natural_allocation() and then add any extra space (if and where appropriate) for the widget to expand.

After adding all the expand space, the container assumes it was allocated sufficient height to fit all of its content. At this time, the container must use the total horizontal sizes of each widget to request the height-for-width of each of its children and store the requests in a GtkRequestedSize array for any widgets that stack vertically (for tabular containers this can be generalized into the heights and widths of rows and columns). The vertical space must then again be distributed using gtk_distribute_natural_allocation() while this time considering the allocated height of the widget minus any vertical spacing that the container adds. Then vertical expand space should be added where appropriate and available and the container should go on to actually allocating the child widgets.

See GtkWidget’s geometry management section to learn more about implementing height-for-width geometry management for widgets.

Child properties

GtkContainer introduces child properties. These are object properties that are not specific to either the container or the contained widget, but rather to their relation. Typical examples of child properties are the position or pack-type of a widget which is contained in a GtkBox.

Use gtk_container_class_install_child_property() to install child properties for a container class and gtk_container_class_find_child_property() or gtk_container_class_list_child_properties() to get information about existing child properties.

To set the value of a child property, use gtk_container_child_set_property(), gtk_container_child_set() or gtk_container_child_set_valist(). To obtain the value of a child property, use gtk_container_child_get_property(), gtk_container_child_get() or gtk_container_child_get_valist(). To emit notification about child property changes, use gtk_widget_child_notify().

GtkContainer as GtkBuildable

The GtkContainer implementation of the GtkBuildable interface supports a <packing> element for children, which can contain multiple <property> elements that specify child properties for the child.

Since 2.16, child properties can also be marked as translatable using the same “translatable”, “comments” and “context” attributes that are used for regular properties.

Since 3.16, containers can have a <focus-chain> element containing multiple <widget> elements, one for each child that should be added to the focus chain. The ”name” attribute gives the id of the widget.

An example of these properties in UI definitions:

<object class="GtkBox">
  <child>
    <object class="GtkEntry" id="entry1"/>
    <packing>
      <property name="pack-type">start</property>
    </packing>
  </child>
  <child>
    <object class="GtkEntry" id="entry2"/>
  </child>
  <focus-chain>
    <widget name="entry1"/>
    <widget name="entry2"/>
  </focus-chain>
</object>

The ContainerRef type acts as a lightweight Swift reference to an underlying GtkContainer instance. It exposes methods that can operate on this data type through ContainerProtocol conformance. Use ContainerRef only as an unowned reference to an existing GtkContainer instance.

The ContainerAccessibleRef type acts as a lightweight Swift reference to an underlying GtkContainerAccessible instance. It exposes methods that can operate on this data type through ContainerAccessibleProtocol conformance. Use ContainerAccessibleRef only as an unowned reference to an existing GtkContainerAccessible instance.

The ContainerCellAccessibleRef type acts as a lightweight Swift reference to an underlying GtkContainerCellAccessible instance. It exposes methods that can operate on this data type through ContainerCellAccessibleProtocol conformance. Use ContainerCellAccessibleRef only as an unowned reference to an existing GtkContainerCellAccessible instance.

GtkCssProvider is an object implementing the GtkStyleProvider interface. It is able to parse CSS-like input in order to style widgets.

An application can make GTK+ parse a specific CSS style sheet by calling gtk_css_provider_load_from_file() or gtk_css_provider_load_from_resource() and adding the provider with gtk_style_context_add_provider() or gtk_style_context_add_provider_for_screen().

In addition, certain files will be read when GTK+ is initialized. First, the file $XDG_CONFIG_HOME/gtk-3.0/gtk.css is loaded if it exists. Then, GTK+ loads the first existing file among XDG_DATA_HOME/themes/THEME/gtk-VERSION/gtk.css, $HOME/.themes/THEME/gtk-VERSION/gtk.css, $XDG_DATA_DIRS/themes/THEME/gtk-VERSION/gtk.css and DATADIR/share/themes/THEME/gtk-VERSION/gtk.css, where THEME is the name of the current theme (see the GtkSettings:gtk-theme-name setting), DATADIR is the prefix configured when GTK+ was compiled (unless overridden by the GTK_DATA_PREFIX environment variable), and VERSION is the GTK+ version number. If no file is found for the current version, GTK+ tries older versions all the way back to 3.0.

In the same way, GTK+ tries to load a gtk-keys.css file for the current key theme, as defined by GtkSettings:gtk-key-theme-name.

The CssProviderRef type acts as a lightweight Swift reference to an underlying GtkCssProvider instance. It exposes methods that can operate on this data type through CssProviderProtocol conformance. Use CssProviderRef only as an unowned reference to an existing GtkCssProvider instance.

Dialog boxes are a convenient way to prompt the user for a small amount of input, e.g. to display a message, ask a question, or anything else that does not require extensive effort on the user’s part.

GTK+ treats a dialog as a window split vertically. The top section is a GtkVBox, and is where widgets such as a GtkLabel or a GtkEntry should be packed. The bottom area is known as the “action area”. This is generally used for packing buttons into the dialog which may perform functions such as cancel, ok, or apply.

GtkDialog boxes are created with a call to gtk_dialog_new() or gtk_dialog_new_with_buttons(). gtk_dialog_new_with_buttons() is recommended; it allows you to set the dialog title, some convenient flags, and add simple buttons.

If “dialog” is a newly created dialog, the two primary areas of the window can be accessed through gtk_dialog_get_content_area() and gtk_dialog_get_action_area(), as can be seen from the example below.

A “modal” dialog (that is, one which freezes the rest of the application from user input), can be created by calling gtk_window_set_modal() on the dialog. Use the GTK_WINDOW() macro to cast the widget returned from gtk_dialog_new() into a GtkWindow. When using gtk_dialog_new_with_buttons() you can also pass the GTK_DIALOG_MODAL flag to make a dialog modal.

If you add buttons to GtkDialog using gtk_dialog_new_with_buttons(), gtk_dialog_add_button(), gtk_dialog_add_buttons(), or gtk_dialog_add_action_widget(), clicking the button will emit a signal called GtkDialog::response with a response ID that you specified. GTK+ will never assign a meaning to positive response IDs; these are entirely user-defined. But for convenience, you can use the response IDs in the GtkResponseType enumeration (these all have values less than zero). If a dialog receives a delete event, the GtkDialog::response signal will be emitted with a response ID of GTK_RESPONSE_DELETE_EVENT.

If you want to block waiting for a dialog to return before returning control flow to your code, you can call gtk_dialog_run(). This function enters a recursive main loop and waits for the user to respond to the dialog, returning the response ID corresponding to the button the user clicked.

For the simple dialog in the following example, in reality you’d probably use GtkMessageDialog to save yourself some effort. But you’d need to create the dialog contents manually if you had more than a simple message in the dialog.

An example for simple GtkDialog usage: (C Language Example):

// Function to open a dialog box with a message
void
quick_message (GtkWindow *parent, gchar *message)
{
 GtkWidget *dialog, *label, *content_area;
 GtkDialogFlags flags;

 // Create the widgets
 flags = GTK_DIALOG_DESTROY_WITH_PARENT;
 dialog = gtk_dialog_new_with_buttons ("Message",
                                       parent,
                                       flags,
                                       _("_OK"),
                                       GTK_RESPONSE_NONE,
                                       NULL);
 content_area = gtk_dialog_get_content_area (GTK_DIALOG (dialog));
 label = gtk_label_new (message);

 // Ensure that the dialog box is destroyed when the user responds

 g_signal_connect_swapped (dialog,
                           "response",
                           G_CALLBACK (gtk_widget_destroy),
                           dialog);

 // Add the label, and show everything we’ve added

 gtk_container_add (GTK_CONTAINER (content_area), label);
 gtk_widget_show_all (dialog);
}

GtkDialog as GtkBuildable

The GtkDialog implementation of the GtkBuildable interface exposes the vbox and action_area as internal children with the names “vbox” and “action_area”.

GtkDialog supports a custom <action-widgets> element, which can contain multiple <action-widget> elements. The “response” attribute specifies a numeric response, and the content of the element is the id of widget (which should be a child of the dialogs action_area). To mark a response as default, set the “default“ attribute of the <action-widget> element to true.

GtkDialog supports adding action widgets by specifying “action“ as the “type“ attribute of a <child> element. The widget will be added either to the action area or the headerbar of the dialog, depending on the “use-header-bar“ property. The response id has to be associated with the action widget using the <action-widgets> element.

An example of a GtkDialog UI definition fragment:

<object class="GtkDialog" id="dialog1">
  <child type="action">
    <object class="GtkButton" id="button_cancel"/>
  </child>
  <child type="action">
    <object class="GtkButton" id="button_ok">
      <property name="can-default">True</property>
    </object>
  </child>
  <action-widgets>
    <action-widget response="cancel">button_cancel</action-widget>
    <action-widget response="ok" default="true">button_ok</action-widget>
  </action-widgets>
</object>

The DialogRef type acts as a lightweight Swift reference to an underlying GtkDialog instance. It exposes methods that can operate on this data type through DialogProtocol conformance. Use DialogRef only as an unowned reference to an existing GtkDialog instance.

The CellAccessibleClassRef type acts as a lightweight Swift reference to an underlying GtkCellAccessibleClass instance. It exposes methods that can operate on this data type through CellAccessibleClassProtocol conformance. Use CellAccessibleClassRef only as an unowned reference to an existing GtkCellAccessibleClass instance.

The CellAccessibleParentIfaceRef type acts as a lightweight Swift reference to an underlying GtkCellAccessibleParentIface instance. It exposes methods that can operate on this data type through CellAccessibleParentIfaceProtocol conformance. Use CellAccessibleParentIfaceRef only as an unowned reference to an existing GtkCellAccessibleParentIface instance.

The CellAreaBoxClassRef type acts as a lightweight Swift reference to an underlying GtkCellAreaBoxClass instance. It exposes methods that can operate on this data type through CellAreaBoxClassProtocol conformance. Use CellAreaBoxClassRef only as an unowned reference to an existing GtkCellAreaBoxClass instance.

The CellAreaClassRef type acts as a lightweight Swift reference to an underlying GtkCellAreaClass instance. It exposes methods that can operate on this data type through CellAreaClassProtocol conformance. Use CellAreaClassRef only as an unowned reference to an existing GtkCellAreaClass instance.

The CellAreaContextClassRef type acts as a lightweight Swift reference to an underlying GtkCellAreaContextClass instance. It exposes methods that can operate on this data type through CellAreaContextClassProtocol conformance. Use CellAreaContextClassRef only as an unowned reference to an existing GtkCellAreaContextClass instance.

The CellEditableIfaceRef type acts as a lightweight Swift reference to an underlying GtkCellEditableIface instance. It exposes methods that can operate on this data type through CellEditableIfaceProtocol conformance. Use CellEditableIfaceRef only as an unowned reference to an existing GtkCellEditableIface instance.

The CellLayoutIfaceRef type acts as a lightweight Swift reference to an underlying GtkCellLayoutIface instance. It exposes methods that can operate on this data type through CellLayoutIfaceProtocol conformance. Use CellLayoutIfaceRef only as an unowned reference to an existing GtkCellLayoutIface instance.

The CellRendererAccelClassRef type acts as a lightweight Swift reference to an underlying GtkCellRendererAccelClass instance. It exposes methods that can operate on this data type through CellRendererAccelClassProtocol conformance. Use CellRendererAccelClassRef only as an unowned reference to an existing GtkCellRendererAccelClass instance.

The CellRendererClassRef type acts as a lightweight Swift reference to an underlying GtkCellRendererClass instance. It exposes methods that can operate on this data type through CellRendererClassProtocol conformance. Use CellRendererClassRef only as an unowned reference to an existing GtkCellRendererClass instance.

The CellRendererClassPrivateRef type acts as a lightweight Swift reference to an underlying GtkCellRendererClassPrivate instance. It exposes methods that can operate on this data type through CellRendererClassPrivateProtocol conformance. Use CellRendererClassPrivateRef only as an unowned reference to an existing GtkCellRendererClassPrivate instance.

The CellRendererComboClassRef type acts as a lightweight Swift reference to an underlying GtkCellRendererComboClass instance. It exposes methods that can operate on this data type through CellRendererComboClassProtocol conformance. Use CellRendererComboClassRef only as an unowned reference to an existing GtkCellRendererComboClass instance.

The CellRendererPixbufClassRef type acts as a lightweight Swift reference to an underlying GtkCellRendererPixbufClass instance. It exposes methods that can operate on this data type through CellRendererPixbufClassProtocol conformance. Use CellRendererPixbufClassRef only as an unowned reference to an existing GtkCellRendererPixbufClass instance.

The CellRendererProgressClassRef type acts as a lightweight Swift reference to an underlying GtkCellRendererProgressClass instance. It exposes methods that can operate on this data type through CellRendererProgressClassProtocol conformance. Use CellRendererProgressClassRef only as an unowned reference to an existing GtkCellRendererProgressClass instance.

The CellRendererSpinClassRef type acts as a lightweight Swift reference to an underlying GtkCellRendererSpinClass instance. It exposes methods that can operate on this data type through CellRendererSpinClassProtocol conformance. Use CellRendererSpinClassRef only as an unowned reference to an existing GtkCellRendererSpinClass instance.

The CellRendererSpinnerClassRef type acts as a lightweight Swift reference to an underlying GtkCellRendererSpinnerClass instance. It exposes methods that can operate on this data type through CellRendererSpinnerClassProtocol conformance. Use CellRendererSpinnerClassRef only as an unowned reference to an existing GtkCellRendererSpinnerClass instance.

The CellRendererTextClassRef type acts as a lightweight Swift reference to an underlying GtkCellRendererTextClass instance. It exposes methods that can operate on this data type through CellRendererTextClassProtocol conformance. Use CellRendererTextClassRef only as an unowned reference to an existing GtkCellRendererTextClass instance.

The CellRendererToggleClassRef type acts as a lightweight Swift reference to an underlying GtkCellRendererToggleClass instance. It exposes methods that can operate on this data type through CellRendererToggleClassProtocol conformance. Use CellRendererToggleClassRef only as an unowned reference to an existing GtkCellRendererToggleClass instance.

The CellViewClassRef type acts as a lightweight Swift reference to an underlying GtkCellViewClass instance. It exposes methods that can operate on this data type through CellViewClassProtocol conformance. Use CellViewClassRef only as an unowned reference to an existing GtkCellViewClass instance.

The CheckButtonClassRef type acts as a lightweight Swift reference to an underlying GtkCheckButtonClass instance. It exposes methods that can operate on this data type through CheckButtonClassProtocol conformance. Use CheckButtonClassRef only as an unowned reference to an existing GtkCheckButtonClass instance.

The CheckMenuItemAccessibleClassRef type acts as a lightweight Swift reference to an underlying GtkCheckMenuItemAccessibleClass instance. It exposes methods that can operate on this data type through CheckMenuItemAccessibleClassProtocol conformance. Use CheckMenuItemAccessibleClassRef only as an unowned reference to an existing GtkCheckMenuItemAccessibleClass instance.

The CheckMenuItemClassRef type acts as a lightweight Swift reference to an underlying GtkCheckMenuItemClass instance. It exposes methods that can operate on this data type through CheckMenuItemClassProtocol conformance. Use CheckMenuItemClassRef only as an unowned reference to an existing GtkCheckMenuItemClass instance.

The ColorButtonClassRef type acts as a lightweight Swift reference to an underlying GtkColorButtonClass instance. It exposes methods that can operate on this data type through ColorButtonClassProtocol conformance. Use ColorButtonClassRef only as an unowned reference to an existing GtkColorButtonClass instance.

The ColorChooserDialogClassRef type acts as a lightweight Swift reference to an underlying GtkColorChooserDialogClass instance. It exposes methods that can operate on this data type through ColorChooserDialogClassProtocol conformance. Use ColorChooserDialogClassRef only as an unowned reference to an existing GtkColorChooserDialogClass instance.

The ColorChooserInterfaceRef type acts as a lightweight Swift reference to an underlying GtkColorChooserInterface instance. It exposes methods that can operate on this data type through ColorChooserInterfaceProtocol conformance. Use ColorChooserInterfaceRef only as an unowned reference to an existing GtkColorChooserInterface instance.

The ColorChooserWidgetClassRef type acts as a lightweight Swift reference to an underlying GtkColorChooserWidgetClass instance. It exposes methods that can operate on this data type through ColorChooserWidgetClassProtocol conformance. Use ColorChooserWidgetClassRef only as an unowned reference to an existing GtkColorChooserWidgetClass instance.

The ColorSelectionClassRef type acts as a lightweight Swift reference to an underlying GtkColorSelectionClass instance. It exposes methods that can operate on this data type through ColorSelectionClassProtocol conformance. Use ColorSelectionClassRef only as an unowned reference to an existing GtkColorSelectionClass instance.

The ColorSelectionDialogClassRef type acts as a lightweight Swift reference to an underlying GtkColorSelectionDialogClass instance. It exposes methods that can operate on this data type through ColorSelectionDialogClassProtocol conformance. Use ColorSelectionDialogClassRef only as an unowned reference to an existing GtkColorSelectionDialogClass instance.

The ComboBoxAccessibleClassRef type acts as a lightweight Swift reference to an underlying GtkComboBoxAccessibleClass instance. It exposes methods that can operate on this data type through ComboBoxAccessibleClassProtocol conformance. Use ComboBoxAccessibleClassRef only as an unowned reference to an existing GtkComboBoxAccessibleClass instance.

The ComboBoxClassRef type acts as a lightweight Swift reference to an underlying GtkComboBoxClass instance. It exposes methods that can operate on this data type through ComboBoxClassProtocol conformance. Use ComboBoxClassRef only as an unowned reference to an existing GtkComboBoxClass instance.

The ComboBoxTextClassRef type acts as a lightweight Swift reference to an underlying GtkComboBoxTextClass instance. It exposes methods that can operate on this data type through ComboBoxTextClassProtocol conformance. Use ComboBoxTextClassRef only as an unowned reference to an existing GtkComboBoxTextClass instance.

The ContainerAccessibleClassRef type acts as a lightweight Swift reference to an underlying GtkContainerAccessibleClass instance. It exposes methods that can operate on this data type through ContainerAccessibleClassProtocol conformance. Use ContainerAccessibleClassRef only as an unowned reference to an existing GtkContainerAccessibleClass instance.

The ContainerCellAccessibleClassRef type acts as a lightweight Swift reference to an underlying GtkContainerCellAccessibleClass instance. It exposes methods that can operate on this data type through ContainerCellAccessibleClassProtocol conformance. Use ContainerCellAccessibleClassRef only as an unowned reference to an existing GtkContainerCellAccessibleClass instance.

Base class for containers.

The ContainerClassRef type acts as a lightweight Swift reference to an underlying GtkContainerClass instance. It exposes methods that can operate on this data type through ContainerClassProtocol conformance. Use ContainerClassRef only as an unowned reference to an existing GtkContainerClass instance.

The CssProviderClassRef type acts as a lightweight Swift reference to an underlying GtkCssProviderClass instance. It exposes methods that can operate on this data type through CssProviderClassProtocol conformance. Use CssProviderClassRef only as an unowned reference to an existing GtkCssProviderClass instance.

Defines a part of a CSS document. Because sections are nested into one another, you can use gtk_css_section_get_parent() to get the containing region.

The CssSectionRef type acts as a lightweight Swift reference to an underlying GtkCssSection instance. It exposes methods that can operate on this data type through CssSectionProtocol conformance. Use CssSectionRef only as an unowned reference to an existing GtkCssSection instance.

The DialogClassRef type acts as a lightweight Swift reference to an underlying GtkDialogClass instance. It exposes methods that can operate on this data type through DialogClassProtocol conformance. Use DialogClassRef only as an unowned reference to an existing GtkDialogClass instance.

The CellAccessibleParentRef type acts as a lightweight Swift reference to an underlying GtkCellAccessibleParent instance. It exposes methods that can operate on this data type through CellAccessibleParentProtocol conformance. Use CellAccessibleParentRef only as an unowned reference to an existing GtkCellAccessibleParent instance.

The GtkCellEditable interface must be implemented for widgets to be usable to edit the contents of a GtkTreeView cell. It provides a way to specify how temporary widgets should be configured for editing, get the new value, etc.

The CellEditableRef type acts as a lightweight Swift reference to an underlying GtkCellEditable instance. It exposes methods that can operate on this data type through CellEditableProtocol conformance. Use CellEditableRef only as an unowned reference to an existing GtkCellEditable instance.

GtkCellLayout is an interface to be implemented by all objects which want to provide a GtkTreeViewColumn like API for packing cells, setting attributes and data funcs.

One of the notable features provided by implementations of GtkCellLayout are attributes. Attributes let you set the properties in flexible ways. They can just be set to constant values like regular properties. But they can also be mapped to a column of the underlying tree model with gtk_cell_layout_set_attributes(), which means that the value of the attribute can change from cell to cell as they are rendered by the cell renderer. Finally, it is possible to specify a function with gtk_cell_layout_set_cell_data_func() that is called to determine the value of the attribute for each cell that is rendered.

GtkCellLayouts as GtkBuildable

Implementations of GtkCellLayout which also implement the GtkBuildable interface (GtkCellView, GtkIconView, GtkComboBox, GtkEntryCompletion, GtkTreeViewColumn) accept GtkCellRenderer objects as <child> elements in UI definitions. They support a custom <attributes> element for their children, which can contain multiple <attribute> elements. Each <attribute> element has a name attribute which specifies a property of the cell renderer; the content of the element is the attribute value.

This is an example of a UI definition fragment specifying attributes:

<object class="GtkCellView">
  <child>
    <object class="GtkCellRendererText"/>
    <attributes>
      <attribute name="text">0</attribute>
    </attributes>
  </child>"
</object>

Furthermore for implementations of GtkCellLayout that use a GtkCellArea to lay out cells (all GtkCellLayouts in GTK+ use a GtkCellArea) cell properties can also be defined in the format by specifying the custom <cell-packing> attribute which can contain multiple <property> elements defined in the normal way.

Here is a UI definition fragment specifying cell properties:

<object class="GtkTreeViewColumn">
  <child>
    <object class="GtkCellRendererText"/>
    <cell-packing>
      <property name="align">True</property>
      <property name="expand">False</property>
    </cell-packing>
  </child>"
</object>

Subclassing GtkCellLayout implementations

When subclassing a widget that implements GtkCellLayout like GtkIconView or GtkComboBox, there are some considerations related to the fact that these widgets internally use a GtkCellArea. The cell area is exposed as a construct-only property by these widgets. This means that it is possible to e.g. do

(C Language Example):

combo = g_object_new (GTK_TYPE_COMBO_BOX, "cell-area", my_cell_area, NULL);

to use a custom cell area with a combo box. But construct properties are only initialized after instance init() functions have run, which means that using functions which rely on the existence of the cell area in your subclass’ init() function will cause the default cell area to be instantiated. In this case, a provided construct property value will be ignored (with a warning, to alert you to the problem).

(C Language Example):

static void
my_combo_box_init (MyComboBox *b)
{
  GtkCellRenderer *cell;

  cell = gtk_cell_renderer_pixbuf_new ();
  // The following call causes the default cell area for combo boxes,
  // a GtkCellAreaBox, to be instantiated
  gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (b), cell, FALSE);
  ...
}

GtkWidget *
my_combo_box_new (GtkCellArea *area)
{
  // This call is going to cause a warning about area being ignored
  return g_object_new (MY_TYPE_COMBO_BOX, "cell-area", area, NULL);
}

If supporting alternative cell areas with your derived widget is not important, then this does not have to concern you. If you want to support alternative cell areas, you can do so by moving the problematic calls out of init() and into a constructor() for your class.

The CellLayoutRef type acts as a lightweight Swift reference to an underlying GtkCellLayout instance. It exposes methods that can operate on this data type through CellLayoutProtocol conformance. Use CellLayoutRef only as an unowned reference to an existing GtkCellLayout instance.

GtkColorChooser is an interface that is implemented by widgets for choosing colors. Depending on the situation, colors may be allowed to have alpha (translucency).

In GTK+, the main widgets that implement this interface are GtkColorChooserWidget, GtkColorChooserDialog and GtkColorButton.

The ColorChooserRef type acts as a lightweight Swift reference to an underlying GtkColorChooser instance. It exposes methods that can operate on this data type through ColorChooserProtocol conformance. Use ColorChooserRef only as an unowned reference to an existing GtkColorChooser instance.

The GtkEditable interface is an interface which should be implemented by text editing widgets, such as GtkEntry and GtkSpinButton. It contains functions for generically manipulating an editable widget, a large number of action signals used for key bindings, and several signals that an application can connect to to modify the behavior of a widget.

As an example of the latter usage, by connecting the following handler to GtkEditable::insert-text, an application can convert all entry into a widget into uppercase.

Forcing entry to uppercase.

(C Language Example):

#include <ctype.h>;

void
insert_text_handler (GtkEditable *editable,
                     const gchar *text,
                     gint         length,
                     gint        *position,
                     gpointer     data)
{
  gchar *result = g_utf8_strup (text, length);

  g_signal_handlers_block_by_func (editable,
                               (gpointer) insert_text_handler, data);
  gtk_editable_insert_text (editable, result, length, position);
  g_signal_handlers_unblock_by_func (editable,
                                     (gpointer) insert_text_handler, data);

  g_signal_stop_emission_by_name (editable, "insert_text");

  g_free (result);
}

The EditableRef type acts as a lightweight Swift reference to an underlying GtkEditable instance. It exposes methods that can operate on this data type through EditableProtocol conformance. Use EditableRef only as an unowned reference to an existing GtkEditable instance.

The GtkDrawingArea widget is used for creating custom user interface elements. It’s essentially a blank widget; you can draw on it. After creating a drawing area, the application may want to connect to:

• Mouse and button press signals to respond to input from the user. (Use gtk_widget_add_events() to enable events you wish to receive.)

• The GtkWidget::realize signal to take any necessary actions when the widget is instantiated on a particular display. (Create GDK resources in response to this signal.)

• The GtkWidget::size-allocate signal to take any necessary actions when the widget changes size.

• The GtkWidget::draw signal to handle redrawing the contents of the widget.

The following code portion demonstrates using a drawing area to display a circle in the normal widget foreground color.

Note that GDK automatically clears the exposed area before sending the expose event, and that drawing is implicitly clipped to the exposed area. If you want to have a theme-provided background, you need to call gtk_render_background() in your draw method.

Simple GtkDrawingArea usage

(C Language Example):

gboolean
draw_callback (GtkWidget *widget, cairo_t *cr, gpointer data)
{
  guint width, height;
  GdkRGBA color;
  GtkStyleContext *context;

  context = gtk_widget_get_style_context (widget);

  width = gtk_widget_get_allocated_width (widget);
  height = gtk_widget_get_allocated_height (widget);

  gtk_render_background (context, cr, 0, 0, width, height);

  cairo_arc (cr,
             width / 2.0, height / 2.0,
             MIN (width, height) / 2.0,
             0, 2 * G_PI);

  gtk_style_context_get_color (context,
                               gtk_style_context_get_state (context),
                               &color);
  gdk_cairo_set_source_rgba (cr, &color);

  cairo_fill (cr);

 return FALSE;
}
[...]
  GtkWidget *drawing_area = gtk_drawing_area_new ();
  gtk_widget_set_size_request (drawing_area, 100, 100);
  g_signal_connect (G_OBJECT (drawing_area), "draw",
                    G_CALLBACK (draw_callback), NULL);

Draw signals are normally delivered when a drawing area first comes onscreen, or when it’s covered by another window and then uncovered. You can also force an expose event by adding to the “damage region” of the drawing area’s window; gtk_widget_queue_draw_area() and gdk_window_invalidate_rect() are equally good ways to do this. You’ll then get a draw signal for the invalid region.

The available routines for drawing are documented on the GDK Drawing Primitives page and the cairo documentation.

To receive mouse events on a drawing area, you will need to enable them with gtk_widget_add_events(). To receive keyboard events, you will need to set the “can-focus” property on the drawing area, and you should probably draw some user-visible indication that the drawing area is focused. Use gtk_widget_has_focus() in your expose event handler to decide whether to draw the focus indicator. See gtk_render_focus() for one way to draw focus.

The DrawingAreaRef type acts as a lightweight Swift reference to an underlying GtkDrawingArea instance. It exposes methods that can operate on this data type through DrawingAreaProtocol conformance. Use DrawingAreaRef only as an unowned reference to an existing GtkDrawingArea instance.

The GtkEntry widget is a single line text entry widget. A fairly large set of key bindings are supported by default. If the entered text is longer than the allocation of the widget, the widget will scroll so that the cursor position is visible.

When using an entry for passwords and other sensitive information, it can be put into “password mode” using gtk_entry_set_visibility(). In this mode, entered text is displayed using a “invisible” character. By default, GTK+ picks the best invisible character that is available in the current font, but it can be changed with gtk_entry_set_invisible_char(). Since 2.16, GTK+ displays a warning when Caps Lock or input methods might interfere with entering text in a password entry. The warning can be turned off with the GtkEntry:caps-lock-warning property.

Since 2.16, GtkEntry has the ability to display progress or activity information behind the text. To make an entry display such information, use gtk_entry_set_progress_fraction() or gtk_entry_set_progress_pulse_step().

Additionally, GtkEntry can show icons at either side of the entry. These icons can be activatable by clicking, can be set up as drag source and can have tooltips. To add an icon, use gtk_entry_set_icon_from_gicon() or one of the various other functions that set an icon from a stock id, an icon name or a pixbuf. To trigger an action when the user clicks an icon, connect to the GtkEntry::icon-press signal. To allow DND operations from an icon, use gtk_entry_set_icon_drag_source(). To set a tooltip on an icon, use gtk_entry_set_icon_tooltip_text() or the corresponding function for markup.

Note that functionality or information that is only available by clicking on an icon in an entry may not be accessible at all to users which are not able to use a mouse or other pointing device. It is therefore recommended that any such functionality should also be available by other means, e.g. via the context menu of the entry.

CSS nodes

(plain Language Example):

entry[.read-only][.flat][.warning][.error]
├── image.left
├── image.right
├── undershoot.left
├── undershoot.right
├── [selection]
├── [progress[.pulse]]
╰── [window.popup]

GtkEntry has a main node with the name entry. Depending on the properties of the entry, the style classes .read-only and .flat may appear. The style classes .warning and .error may also be used with entries.

When the entry shows icons, it adds subnodes with the name image and the style class .left or .right, depending on where the icon appears.

When the entry has a selection, it adds a subnode with the name selection.

When the entry shows progress, it adds a subnode with the name progress. The node has the style class .pulse when the shown progress is pulsing.

The CSS node for a context menu is added as a subnode below entry as well.

The undershoot nodes are used to draw the underflow indication when content is scrolled out of view. These nodes get the .left and .right style classes added depending on where the indication is drawn.

When touch is used and touch selection handles are shown, they are using CSS nodes with name cursor-handle. They get the .top or .bottom style class depending on where they are shown in relation to the selection. If there is just a single handle for the text cursor, it gets the style class .insertion-cursor.

The EntryRef type acts as a lightweight Swift reference to an underlying GtkEntry instance. It exposes methods that can operate on this data type through EntryProtocol conformance. Use EntryRef only as an unowned reference to an existing GtkEntry instance.