/* GTK - The GIMP Toolkit
*
* Copyright (C) 2003 Ricardo Fernandez Pascual
* Copyright (C) 2004 Paolo Borelli
* Copyright (C) 2012 Bastien Nocera
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see .
*/
/**
* GtkMenuButton:
*
* The `GtkMenuButton` widget is used to display a popup when clicked.
*
* 
*
* This popup can be provided either as a `GtkPopover` or as an abstract
* `GMenuModel`.
*
* The `GtkMenuButton` widget can show either an icon (set with the
* [property@Gtk.MenuButton:icon-name] property) or a label (set with the
* [property@Gtk.MenuButton:label] property). If neither is explicitly set,
* a [class@Gtk.Image] is automatically created, using an arrow image oriented
* according to [property@Gtk.MenuButton:direction] or the generic
* “open-menu-symbolic” icon if the direction is not set.
*
* The positioning of the popup is determined by the
* [property@Gtk.MenuButton:direction] property of the menu button.
*
* For menus, the [property@Gtk.Widget:halign] and [property@Gtk.Widget:valign]
* properties of the menu are also taken into account. For example, when the
* direction is %GTK_ARROW_DOWN and the horizontal alignment is %GTK_ALIGN_START,
* the menu will be positioned below the button, with the starting edge
* (depending on the text direction) of the menu aligned with the starting
* edge of the button. If there is not enough space below the button, the
* menu is popped up above the button instead. If the alignment would move
* part of the menu offscreen, it is “pushed in”.
*
* | | start | center | end |
* | - | --- | --- | --- |
* | **down** |  |  |  |
* | **up** |  |  |  |
* | **left** |  |  |  |
* | **right** |  |  |  |
*
* # CSS nodes
*
* ```
* menubutton
* ╰── button.toggle
* ╰──
* ╰── [arrow]
* ```
*
* `GtkMenuButton` has a single CSS node with name `menubutton`
* which contains a `button` node with a `.toggle` style class.
*
* If the button contains an icon, it will have the `.image-button` style class,
* if it contains text, it will have `.text-button` style class. If an arrow is
* visible in addition to an icon, text or a custom child, it will also have
* `.arrow-button` style class.
*
* Inside the toggle button content, there is an `arrow` node for
* the indicator, which will carry one of the `.none`, `.up`, `.down`,
* `.left` or `.right` style classes to indicate the direction that
* the menu will appear in. The CSS is expected to provide a suitable
* image for each of these cases using the `-gtk-icon-source` property.
*
* Optionally, the `menubutton` node can carry the `.circular` style class
* to request a round appearance.
*
* # Accessibility
*
* `GtkMenuButton` uses the %GTK_ACCESSIBLE_ROLE_BUTTON role.
*/
#include "config.h"
#include "gtkactionable.h"
#include "gtkbuildable.h"
#include "gtkbuiltiniconprivate.h"
#include "gtkimage.h"
#include "gtkmain.h"
#include "gtkmenubutton.h"
#include "gtkmenubuttonprivate.h"
#include "gtkpopover.h"
#include "gtkpopovermenu.h"
#include "gtkprivate.h"
#include "gtktypebuiltins.h"
#include "gtklabel.h"
#include "gtkbox.h"
#include "gtkwidgetprivate.h"
#include "gtkbuttonprivate.h"
#include "gtknative.h"
#include "gtkwindow.h"
typedef struct _GtkMenuButtonClass GtkMenuButtonClass;
typedef struct _GtkMenuButtonPrivate GtkMenuButtonPrivate;
struct _GtkMenuButton
{
GtkWidget parent_instance;
GtkWidget *button;
GtkWidget *popover; /* Only one at a time can be set */
GMenuModel *model;
GtkMenuButtonCreatePopupFunc create_popup_func;
gpointer create_popup_user_data;
GDestroyNotify create_popup_destroy_notify;
GtkWidget *label_widget;
GtkWidget *image_widget;
GtkWidget *arrow_widget;
GtkWidget *child;
GtkArrowType arrow_type;
gboolean always_show_arrow;
gboolean primary;
};
struct _GtkMenuButtonClass
{
GtkWidgetClass parent_class;
void (* activate) (GtkMenuButton *self);
};
enum
{
PROP_0,
PROP_MENU_MODEL,
PROP_DIRECTION,
PROP_POPOVER,
PROP_ICON_NAME,
PROP_ALWAYS_SHOW_ARROW,
PROP_LABEL,
PROP_USE_UNDERLINE,
PROP_HAS_FRAME,
PROP_PRIMARY,
PROP_CHILD,
LAST_PROP
};
enum {
ACTIVATE,
LAST_SIGNAL
};
static GParamSpec *menu_button_props[LAST_PROP];
static guint signals[LAST_SIGNAL] = { 0 };
static void gtk_menu_button_buildable_iface_init (GtkBuildableIface *iface);
G_DEFINE_TYPE_WITH_CODE (GtkMenuButton, gtk_menu_button, GTK_TYPE_WIDGET,
G_IMPLEMENT_INTERFACE (GTK_TYPE_BUILDABLE, gtk_menu_button_buildable_iface_init))
static void gtk_menu_button_dispose (GObject *object);
static void
gtk_menu_button_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec)
{
GtkMenuButton *self = GTK_MENU_BUTTON (object);
switch (property_id)
{
case PROP_MENU_MODEL:
gtk_menu_button_set_menu_model (self, g_value_get_object (value));
break;
case PROP_DIRECTION:
gtk_menu_button_set_direction (self, g_value_get_enum (value));
break;
case PROP_POPOVER:
gtk_menu_button_set_popover (self, g_value_get_object (value));
break;
case PROP_ICON_NAME:
gtk_menu_button_set_icon_name (self, g_value_get_string (value));
break;
case PROP_ALWAYS_SHOW_ARROW:
gtk_menu_button_set_always_show_arrow (self, g_value_get_boolean (value));
break;
case PROP_LABEL:
gtk_menu_button_set_label (self, g_value_get_string (value));
break;
case PROP_USE_UNDERLINE:
gtk_menu_button_set_use_underline (self, g_value_get_boolean (value));
break;
case PROP_HAS_FRAME:
gtk_menu_button_set_has_frame (self, g_value_get_boolean (value));
break;
case PROP_PRIMARY:
gtk_menu_button_set_primary (self, g_value_get_boolean (value));
break;
case PROP_CHILD:
gtk_menu_button_set_child (self, g_value_get_object (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}
}
static void
gtk_menu_button_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec)
{
GtkMenuButton *self = GTK_MENU_BUTTON (object);
switch (property_id)
{
case PROP_MENU_MODEL:
g_value_set_object (value, self->model);
break;
case PROP_DIRECTION:
g_value_set_enum (value, self->arrow_type);
break;
case PROP_POPOVER:
g_value_set_object (value, self->popover);
break;
case PROP_ICON_NAME:
g_value_set_string (value, gtk_menu_button_get_icon_name (GTK_MENU_BUTTON (object)));
break;
case PROP_ALWAYS_SHOW_ARROW:
g_value_set_boolean (value, gtk_menu_button_get_always_show_arrow (self));
break;
case PROP_LABEL:
g_value_set_string (value, gtk_menu_button_get_label (GTK_MENU_BUTTON (object)));
break;
case PROP_USE_UNDERLINE:
g_value_set_boolean (value, gtk_menu_button_get_use_underline (GTK_MENU_BUTTON (object)));
break;
case PROP_HAS_FRAME:
g_value_set_boolean (value, gtk_menu_button_get_has_frame (GTK_MENU_BUTTON (object)));
break;
case PROP_PRIMARY:
g_value_set_boolean (value, gtk_menu_button_get_primary (GTK_MENU_BUTTON (object)));
break;
case PROP_CHILD:
g_value_set_object (value, gtk_menu_button_get_child (self));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}
}
static void
gtk_menu_button_notify (GObject *object,
GParamSpec *pspec)
{
if (strcmp (pspec->name, "focus-on-click") == 0)
{
GtkMenuButton *self = GTK_MENU_BUTTON (object);
gtk_widget_set_focus_on_click (self->button,
gtk_widget_get_focus_on_click (GTK_WIDGET (self)));
}
if (G_OBJECT_CLASS (gtk_menu_button_parent_class)->notify)
G_OBJECT_CLASS (gtk_menu_button_parent_class)->notify (object, pspec);
}
static void
gtk_menu_button_state_flags_changed (GtkWidget *widget,
GtkStateFlags previous_state_flags)
{
GtkMenuButton *self = GTK_MENU_BUTTON (widget);
if (!gtk_widget_is_sensitive (widget))
{
if (self->popover)
gtk_widget_hide (self->popover);
}
}
static void
gtk_menu_button_toggled (GtkMenuButton *self)
{
const gboolean active = gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (self->button));
/* Might set a new menu/popover */
if (active && self->create_popup_func)
{
self->create_popup_func (self, self->create_popup_user_data);
}
if (self->popover)
{
if (active)
{
gtk_popover_popup (GTK_POPOVER (self->popover));
gtk_accessible_update_state (GTK_ACCESSIBLE (self),
GTK_ACCESSIBLE_STATE_EXPANDED, TRUE,
-1);
}
else
{
gtk_popover_popdown (GTK_POPOVER (self->popover));
gtk_accessible_reset_state (GTK_ACCESSIBLE (self),
GTK_ACCESSIBLE_STATE_EXPANDED);
}
}
}
static void
gtk_menu_button_measure (GtkWidget *widget,
GtkOrientation orientation,
int for_size,
int *minimum,
int *natural,
int *minimum_baseline,
int *natural_baseline)
{
GtkMenuButton *self = GTK_MENU_BUTTON (widget);
gtk_widget_measure (self->button,
orientation,
for_size,
minimum, natural,
minimum_baseline, natural_baseline);
}
static void
gtk_menu_button_size_allocate (GtkWidget *widget,
int width,
int height,
int baseline)
{
GtkMenuButton *self= GTK_MENU_BUTTON (widget);
gtk_widget_size_allocate (self->button,
&(GtkAllocation) { 0, 0, width, height },
baseline);
if (self->popover)
gtk_popover_present (GTK_POPOVER (self->popover));
}
static gboolean
gtk_menu_button_focus (GtkWidget *widget,
GtkDirectionType direction)
{
GtkMenuButton *self = GTK_MENU_BUTTON (widget);
if (self->popover && gtk_widget_get_visible (self->popover))
return gtk_widget_child_focus (self->popover, direction);
else
return gtk_widget_child_focus (self->button, direction);
}
static gboolean
gtk_menu_button_grab_focus (GtkWidget *widget)
{
GtkMenuButton *self = GTK_MENU_BUTTON (widget);
return gtk_widget_grab_focus (self->button);
}
static void
gtk_menu_button_activate (GtkMenuButton *self)
{
gtk_widget_activate (self->button);
}
static void gtk_menu_button_root (GtkWidget *widget);
static void gtk_menu_button_unroot (GtkWidget *widget);
static void
gtk_menu_button_class_init (GtkMenuButtonClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
gobject_class->set_property = gtk_menu_button_set_property;
gobject_class->get_property = gtk_menu_button_get_property;
gobject_class->notify = gtk_menu_button_notify;
gobject_class->dispose = gtk_menu_button_dispose;
widget_class->root = gtk_menu_button_root;
widget_class->unroot = gtk_menu_button_unroot;
widget_class->measure = gtk_menu_button_measure;
widget_class->size_allocate = gtk_menu_button_size_allocate;
widget_class->state_flags_changed = gtk_menu_button_state_flags_changed;
widget_class->focus = gtk_menu_button_focus;
widget_class->grab_focus = gtk_menu_button_grab_focus;
klass->activate = gtk_menu_button_activate;
/**
* GtkMenuButton:menu-model: (attributes org.gtk.Property.get=gtk_menu_button_get_menu_model org.gtk.Property.set=gtk_menu_button_set_menu_model)
*
* The `GMenuModel` from which the popup will be created.
*
* See [method@Gtk.MenuButton.set_menu_model] for the interaction
* with the [property@Gtk.MenuButton:popover] property.
*/
menu_button_props[PROP_MENU_MODEL] =
g_param_spec_object ("menu-model", NULL, NULL,
G_TYPE_MENU_MODEL,
GTK_PARAM_READWRITE);
/**
* GtkMenuButton:direction: (attributes org.gtk.Property.get=gtk_menu_button_get_direction org.gtk.Property.set=gtk_menu_button_set_direction)
*
* The `GtkArrowType` representing the direction in which the
* menu or popover will be popped out.
*/
menu_button_props[PROP_DIRECTION] =
g_param_spec_enum ("direction", NULL, NULL,
GTK_TYPE_ARROW_TYPE,
GTK_ARROW_DOWN,
GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkMenuButton:popover: (attributes org.gtk.Property.get=gtk_menu_button_get_popover org.gtk.Property.set=gtk_menu_button_set_popover)
*
* The `GtkPopover` that will be popped up when the button is clicked.
*/
menu_button_props[PROP_POPOVER] =
g_param_spec_object ("popover", NULL, NULL,
GTK_TYPE_POPOVER,
G_PARAM_READWRITE);
/**
* GtkMenuButton:icon-name: (attributes org.gtk.Property.get=gtk_menu_button_get_icon_name org.gtk.Property.set=gtk_menu_button_set_icon_name)
*
* The name of the icon used to automatically populate the button.
*/
menu_button_props[PROP_ICON_NAME] =
g_param_spec_string ("icon-name", NULL, NULL,
NULL,
GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkMenuButton:always-show-arrow: (attributes org.gtk.Property.get=gtk_menu_button_get_always_show_arrow org.gtk.Property.set=gtk_menu_button_set_always_show_arrow)
*
* Whether to show a dropdown arrow even when using an icon or a custom child.
*
* Since: 4.4
*/
menu_button_props[PROP_ALWAYS_SHOW_ARROW] =
g_param_spec_boolean ("always-show-arrow", NULL, NULL,
FALSE,
GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkMenuButton:label: (attributes org.gtk.Property.get=gtk_menu_button_get_label org.gtk.Property.set=gtk_menu_button_set_label)
*
* The label for the button.
*/
menu_button_props[PROP_LABEL] =
g_param_spec_string ("label", NULL, NULL,
NULL,
GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkMenuButton:use-underline: (attributes org.gtk.Property.get=gtk_menu_button_get_use_underline org.gtk.Property.set=gtk_menu_button_set_use_underline)
*
* If set an underscore in the text indicates a mnemonic.
*/
menu_button_props[PROP_USE_UNDERLINE] =
g_param_spec_boolean ("use-underline", NULL, NULL,
FALSE,
GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkMenuButton:has-frame: (attributes org.gtk.Property.get=gtk_menu_button_get_has_frame org.gtk.Property.set=gtk_menu_button_set_has_frame)
*
* Whether the button has a frame.
*/
menu_button_props[PROP_HAS_FRAME] =
g_param_spec_boolean ("has-frame", NULL, NULL,
TRUE,
GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkMenuButton:primary: (attributes org.gtk.Property.get=gtk_menu_button_get_primary org.gtk.Property.set=gtk_menu_button_set_primary)
*
* Whether the menu button acts as a primary menu.
*
* Primary menus can be opened using the F10 key
*
* Since: 4.4
*/
menu_button_props[PROP_PRIMARY] =
g_param_spec_boolean ("primary", NULL, NULL,
FALSE,
GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkMenuButton:child: (attributes org.gtk.Property.get=gtk_menu_button_get_child org.gtk.Property.set=gtk_menu_button_set_child)
*
* The child widget.
*
* Since: 4.6
*/
menu_button_props[PROP_CHILD] =
g_param_spec_object ("child", NULL, NULL,
GTK_TYPE_WIDGET,
GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
g_object_class_install_properties (gobject_class, LAST_PROP, menu_button_props);
/**
* GtkMenuButton::activate:
* @widget: the object which received the signal.
*
* Emitted to when the menu button is activated.
*
* The `::activate` signal on `GtkMenuButton` is an action signal and
* emitting it causes the button to pop up its menu.
*
* Since: 4.4
*/
signals[ACTIVATE] =
g_signal_new (I_ ("activate"),
G_OBJECT_CLASS_TYPE (gobject_class),
G_SIGNAL_RUN_FIRST | G_SIGNAL_ACTION,
G_STRUCT_OFFSET (GtkMenuButtonClass, activate),
NULL, NULL,
NULL,
G_TYPE_NONE, 0);
gtk_widget_class_set_activate_signal (widget_class, signals[ACTIVATE]);
gtk_widget_class_set_css_name (widget_class, I_("menubutton"));
gtk_widget_class_set_accessible_role (widget_class, GTK_ACCESSIBLE_ROLE_BUTTON);
}
static void
set_arrow_type (GtkWidget *arrow,
GtkArrowType arrow_type,
gboolean visible)
{
gtk_widget_remove_css_class (arrow, "none");
gtk_widget_remove_css_class (arrow, "down");
gtk_widget_remove_css_class (arrow, "up");
gtk_widget_remove_css_class (arrow, "left");
gtk_widget_remove_css_class (arrow, "right");
switch (arrow_type)
{
case GTK_ARROW_NONE:
gtk_widget_add_css_class (arrow, "none");
break;
case GTK_ARROW_DOWN:
gtk_widget_add_css_class (arrow, "down");
break;
case GTK_ARROW_UP:
gtk_widget_add_css_class (arrow, "up");
break;
case GTK_ARROW_LEFT:
gtk_widget_add_css_class (arrow, "left");
break;
case GTK_ARROW_RIGHT:
gtk_widget_add_css_class (arrow, "right");
break;
default:
break;
}
if (visible)
gtk_widget_show (arrow);
else
gtk_widget_hide (arrow);
}
static void
update_style_classes (GtkMenuButton *menu_button)
{
gboolean has_icon = menu_button->image_widget != NULL;
gboolean has_label = menu_button->label_widget != NULL;
gboolean has_only_arrow = menu_button->arrow_widget == gtk_button_get_child (GTK_BUTTON (menu_button->button));
gboolean has_arrow = gtk_widget_get_visible (menu_button->arrow_widget);
if (has_only_arrow || has_icon)
gtk_widget_add_css_class (menu_button->button, "image-button");
else
gtk_widget_remove_css_class (menu_button->button, "image-button");
if (has_label)
gtk_widget_add_css_class (menu_button->button, "text-button");
else
gtk_widget_remove_css_class (menu_button->button, "text-button");
if (has_arrow && !has_only_arrow)
gtk_widget_add_css_class (menu_button->button, "arrow-button");
else
gtk_widget_remove_css_class (menu_button->button, "arrow-button");
}
static void
update_arrow (GtkMenuButton *menu_button)
{
gboolean has_only_arrow, is_text_button;
if (menu_button->arrow_widget == NULL)
return;
has_only_arrow = menu_button->arrow_widget == gtk_button_get_child (GTK_BUTTON (menu_button->button));
is_text_button = menu_button->label_widget != NULL;
set_arrow_type (menu_button->arrow_widget,
menu_button->arrow_type,
has_only_arrow ||
((is_text_button || menu_button->always_show_arrow) &&
(menu_button->arrow_type != GTK_ARROW_NONE)));
update_style_classes (menu_button);
}
static void
add_arrow (GtkMenuButton *self)
{
GtkWidget *arrow;
arrow = gtk_builtin_icon_new ("arrow");
gtk_widget_set_halign (arrow, GTK_ALIGN_CENTER);
set_arrow_type (arrow, self->arrow_type, TRUE);
gtk_button_set_child (GTK_BUTTON (self->button), arrow);
self->arrow_widget = arrow;
}
static void
gtk_menu_button_init (GtkMenuButton *self)
{
self->arrow_type = GTK_ARROW_DOWN;
self->button = gtk_toggle_button_new ();
gtk_widget_set_parent (self->button, GTK_WIDGET (self));
g_signal_connect_swapped (self->button, "toggled", G_CALLBACK (gtk_menu_button_toggled), self);
add_arrow (self);
update_style_classes (self);
gtk_widget_set_sensitive (self->button, FALSE);
gtk_widget_add_css_class (GTK_WIDGET (self), "popup");
gtk_accessible_update_relation (GTK_ACCESSIBLE (self->button),
GTK_ACCESSIBLE_RELATION_LABELLED_BY, self, NULL,
GTK_ACCESSIBLE_RELATION_DESCRIBED_BY, self, NULL,
-1);
}
static GtkBuildableIface *parent_buildable_iface;
static void
gtk_menu_button_buildable_add_child (GtkBuildable *buildable,
GtkBuilder *builder,
GObject *child,
const char *type)
{
if (GTK_IS_WIDGET (child))
gtk_menu_button_set_child (GTK_MENU_BUTTON (buildable), GTK_WIDGET (child));
else
parent_buildable_iface->add_child (buildable, builder, child, type);
}
static void
gtk_menu_button_buildable_iface_init (GtkBuildableIface *iface)
{
parent_buildable_iface = g_type_interface_peek_parent (iface);
iface->add_child = gtk_menu_button_buildable_add_child;
}
/**
* gtk_menu_button_new:
*
* Creates a new `GtkMenuButton` widget with downwards-pointing
* arrow as the only child.
*
* You can replace the child widget with another `GtkWidget`
* should you wish to.
*
* Returns: The newly created `GtkMenuButton`
*/
GtkWidget *
gtk_menu_button_new (void)
{
return g_object_new (GTK_TYPE_MENU_BUTTON, NULL);
}
static void
update_sensitivity (GtkMenuButton *self)
{
gboolean has_popup;
has_popup = self->popover != NULL || self->create_popup_func != NULL;
gtk_widget_set_sensitive (self->button, has_popup);
gtk_accessible_update_property (GTK_ACCESSIBLE (self),
GTK_ACCESSIBLE_PROPERTY_HAS_POPUP, has_popup,
-1);
if (self->popover != NULL)
gtk_accessible_update_relation (GTK_ACCESSIBLE (self),
GTK_ACCESSIBLE_RELATION_CONTROLS, self->popover, NULL,
-1);
else
gtk_accessible_reset_relation (GTK_ACCESSIBLE (self),
GTK_ACCESSIBLE_RELATION_CONTROLS);
}
static gboolean
menu_deactivate_cb (GtkMenuButton *self)
{
gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (self->button), FALSE);
return TRUE;
}
/**
* gtk_menu_button_set_menu_model: (attributes org.gtk.Method.set_property=menu-model)
* @menu_button: a `GtkMenuButton`
* @menu_model: (nullable): a `GMenuModel`, or %NULL to unset and disable the
* button
*
* Sets the `GMenuModel` from which the popup will be constructed.
*
* If @menu_model is %NULL, the button is disabled.
*
* A [class@Gtk.Popover] will be created from the menu model with
* [ctor@Gtk.PopoverMenu.new_from_model]. Actions will be connected
* as documented for this function.
*
* If [property@Gtk.MenuButton:popover] is already set, it will be
* dissociated from the @menu_button, and the property is set to %NULL.
*/
void
gtk_menu_button_set_menu_model (GtkMenuButton *menu_button,
GMenuModel *menu_model)
{
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
g_return_if_fail (G_IS_MENU_MODEL (menu_model) || menu_model == NULL);
g_object_freeze_notify (G_OBJECT (menu_button));
if (menu_model)
g_object_ref (menu_model);
if (menu_model)
{
GtkWidget *popover;
popover = gtk_popover_menu_new_from_model (menu_model);
gtk_menu_button_set_popover (menu_button, popover);
}
else
{
gtk_menu_button_set_popover (menu_button, NULL);
}
menu_button->model = menu_model;
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_MENU_MODEL]);
g_object_thaw_notify (G_OBJECT (menu_button));
}
/**
* gtk_menu_button_get_menu_model: (attributes org.gtk.Method.get_property=menu-model)
* @menu_button: a `GtkMenuButton`
*
* Returns the `GMenuModel` used to generate the popup.
*
* Returns: (nullable) (transfer none): a `GMenuModel`
*/
GMenuModel *
gtk_menu_button_get_menu_model (GtkMenuButton *menu_button)
{
g_return_val_if_fail (GTK_IS_MENU_BUTTON (menu_button), NULL);
return menu_button->model;
}
static void
update_popover_direction (GtkMenuButton *self)
{
if (!self->popover)
return;
switch (self->arrow_type)
{
case GTK_ARROW_UP:
gtk_popover_set_position (GTK_POPOVER (self->popover), GTK_POS_TOP);
break;
case GTK_ARROW_DOWN:
case GTK_ARROW_NONE:
gtk_popover_set_position (GTK_POPOVER (self->popover), GTK_POS_BOTTOM);
break;
case GTK_ARROW_LEFT:
gtk_popover_set_position (GTK_POPOVER (self->popover), GTK_POS_LEFT);
break;
case GTK_ARROW_RIGHT:
gtk_popover_set_position (GTK_POPOVER (self->popover), GTK_POS_RIGHT);
break;
default:
break;
}
}
static void
popover_destroy_cb (GtkMenuButton *menu_button)
{
gtk_menu_button_set_popover (menu_button, NULL);
}
/**
* gtk_menu_button_set_direction: (attributes org.gtk.Method.set_property=direction)
* @menu_button: a `GtkMenuButton`
* @direction: a `GtkArrowType`
*
* Sets the direction in which the popup will be popped up.
*
* If the button is automatically populated with an arrow icon,
* its direction will be changed to match.
*
* If the does not fit in the available space in the given direction,
* GTK will its best to keep it inside the screen and fully visible.
*
* If you pass %GTK_ARROW_NONE for a @direction, the popup will behave
* as if you passed %GTK_ARROW_DOWN (although you won’t see any arrows).
*/
void
gtk_menu_button_set_direction (GtkMenuButton *menu_button,
GtkArrowType direction)
{
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
if (menu_button->arrow_type == direction)
return;
menu_button->arrow_type = direction;
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_DIRECTION]);
update_arrow (menu_button);
update_popover_direction (menu_button);
}
/**
* gtk_menu_button_get_direction: (attributes org.gtk.Method.get_property=direction)
* @menu_button: a `GtkMenuButton`
*
* Returns the direction the popup will be pointing at when popped up.
*
* Returns: a `GtkArrowType` value
*/
GtkArrowType
gtk_menu_button_get_direction (GtkMenuButton *menu_button)
{
g_return_val_if_fail (GTK_IS_MENU_BUTTON (menu_button), GTK_ARROW_DOWN);
return menu_button->arrow_type;
}
static void
gtk_menu_button_dispose (GObject *object)
{
GtkMenuButton *self = GTK_MENU_BUTTON (object);
if (self->popover)
{
g_signal_handlers_disconnect_by_func (self->popover,
menu_deactivate_cb,
object);
g_signal_handlers_disconnect_by_func (self->popover,
popover_destroy_cb,
object);
gtk_widget_unparent (self->popover);
self->popover = NULL;
}
g_clear_object (&self->model);
g_clear_pointer (&self->button, gtk_widget_unparent);
if (self->create_popup_destroy_notify)
self->create_popup_destroy_notify (self->create_popup_user_data);
G_OBJECT_CLASS (gtk_menu_button_parent_class)->dispose (object);
}
/**
* gtk_menu_button_set_popover: (attributes org.gtk.Method.set_property=popover)
* @menu_button: a `GtkMenuButton`
* @popover: (nullable): a `GtkPopover`, or %NULL to unset and disable the button
*
* Sets the `GtkPopover` that will be popped up when the @menu_button is clicked.
*
* If @popover is %NULL, the button is disabled.
*
* If [property@Gtk.MenuButton:menu-model] is set, the menu model is dissociated
* from the @menu_button, and the property is set to %NULL.
*/
void
gtk_menu_button_set_popover (GtkMenuButton *menu_button,
GtkWidget *popover)
{
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
g_return_if_fail (GTK_IS_POPOVER (popover) || popover == NULL);
g_object_freeze_notify (G_OBJECT (menu_button));
g_clear_object (&menu_button->model);
if (menu_button->popover)
{
if (gtk_widget_get_visible (menu_button->popover))
gtk_widget_hide (menu_button->popover);
g_signal_handlers_disconnect_by_func (menu_button->popover,
menu_deactivate_cb,
menu_button);
g_signal_handlers_disconnect_by_func (menu_button->popover,
popover_destroy_cb,
menu_button);
gtk_widget_unparent (menu_button->popover);
}
menu_button->popover = popover;
if (popover)
{
gtk_widget_set_parent (menu_button->popover, GTK_WIDGET (menu_button));
g_signal_connect_swapped (menu_button->popover, "closed",
G_CALLBACK (menu_deactivate_cb), menu_button);
g_signal_connect_swapped (menu_button->popover, "destroy",
G_CALLBACK (popover_destroy_cb), menu_button);
update_popover_direction (menu_button);
}
update_sensitivity (menu_button);
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_POPOVER]);
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_MENU_MODEL]);
g_object_thaw_notify (G_OBJECT (menu_button));
}
/**
* gtk_menu_button_get_popover: (attributes org.gtk.Method.get_property=popover)
* @menu_button: a `GtkMenuButton`
*
* Returns the `GtkPopover` that pops out of the button.
*
* If the button is not using a `GtkPopover`, this function
* returns %NULL.
*
* Returns: (nullable) (transfer none): a `GtkPopover` or %NULL
*/
GtkPopover *
gtk_menu_button_get_popover (GtkMenuButton *menu_button)
{
g_return_val_if_fail (GTK_IS_MENU_BUTTON (menu_button), NULL);
return GTK_POPOVER (menu_button->popover);
}
/**
* gtk_menu_button_set_icon_name: (attributes org.gtk.Method.set_property=icon-name)
* @menu_button: a `GtkMenuButton`
* @icon_name: the icon name
*
* Sets the name of an icon to show inside the menu button.
*
* Setting icon name resets [property@Gtk.MenuButton:label] and
* [property@Gtk.MenuButton:child].
*
* If [property@Gtk.MenuButton:always-show-arrow] is set to `TRUE` and
* [property@Gtk.MenuButton:direction] is not `GTK_ARROW_NONE`, a dropdown arrow
* will be shown next to the icon.
*/
void
gtk_menu_button_set_icon_name (GtkMenuButton *menu_button,
const char *icon_name)
{
GtkWidget *box, *image_widget, *arrow;
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
g_object_freeze_notify (G_OBJECT (menu_button));
if (gtk_menu_button_get_label (menu_button))
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_LABEL]);
if (gtk_menu_button_get_child (menu_button))
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_CHILD]);
box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
gtk_widget_set_halign (box, GTK_ALIGN_CENTER);
/* Because we are setting only an icon, let the inner button be labelled by us
* so the accessible label can be overridden from, for example, an UI file
* using GtkMenuButton as a child of something.
*/
gtk_accessible_update_relation (GTK_ACCESSIBLE (menu_button->button),
GTK_ACCESSIBLE_RELATION_LABELLED_BY, menu_button, NULL,
GTK_ACCESSIBLE_RELATION_DESCRIBED_BY, menu_button, NULL,
-1);
image_widget = g_object_new (GTK_TYPE_IMAGE,
"accessible-role", GTK_ACCESSIBLE_ROLE_PRESENTATION,
"icon-name", icon_name,
NULL);
menu_button->image_widget = image_widget;
arrow = gtk_builtin_icon_new ("arrow");
menu_button->arrow_widget = arrow;
gtk_box_append (GTK_BOX (box), image_widget);
gtk_box_append (GTK_BOX (box), arrow);
gtk_button_set_child (GTK_BUTTON (menu_button->button), box);
menu_button->label_widget = NULL;
menu_button->child = NULL;
update_arrow (menu_button);
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_ICON_NAME]);
g_object_thaw_notify (G_OBJECT (menu_button));
}
/**
* gtk_menu_button_get_icon_name: (attributes org.gtk.Method.get_property=icon-name)
* @menu_button: a `GtkMenuButton`
*
* Gets the name of the icon shown in the button.
*
* Returns: (nullable): the name of the icon shown in the button
*/
const char *
gtk_menu_button_get_icon_name (GtkMenuButton *menu_button)
{
g_return_val_if_fail (GTK_IS_MENU_BUTTON (menu_button), NULL);
if (menu_button->image_widget)
return gtk_image_get_icon_name (GTK_IMAGE (menu_button->image_widget));
return NULL;
}
/**
* gtk_menu_button_set_always_show_arrow: (attributes org.gtk.Method.set_property=always-show-arrow)
* @menu_button: a `GtkMenuButton`
* @always_show_arrow: hether to show a dropdown arrow even when using an icon
*
* Sets whether to show a dropdown arrow even when using an icon or a custom
* child.
*
* Since: 4.4
*/
void
gtk_menu_button_set_always_show_arrow (GtkMenuButton *menu_button,
gboolean always_show_arrow)
{
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
always_show_arrow = !!always_show_arrow;
if (always_show_arrow == menu_button->always_show_arrow)
return;
menu_button->always_show_arrow = always_show_arrow;
update_arrow (menu_button);
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_ALWAYS_SHOW_ARROW]);
}
/**
* gtk_menu_button_get_always_show_arrow: (attributes org.gtk.Method.get_property=always-show-arrow)
* @menu_button: a `GtkMenuButton`
*
* Gets whether to show a dropdown arrow even when using an icon.
*
* Returns: whether to show a dropdown arrow even when using an icon
*
* Since: 4.4
*/
gboolean
gtk_menu_button_get_always_show_arrow (GtkMenuButton *menu_button)
{
g_return_val_if_fail (GTK_IS_MENU_BUTTON (menu_button), FALSE);
return menu_button->always_show_arrow;
}
/**
* gtk_menu_button_set_label: (attributes org.gtk.Method.set_property=label)
* @menu_button: a `GtkMenuButton`
* @label: the label
*
* Sets the label to show inside the menu button.
*
* Setting a label resets [property@Gtk.MenuButton:icon-name] and
* [property@Gtk.MenuButton:child].
*
* If [property@Gtk.MenuButton:direction] is not `GTK_ARROW_NONE`, a dropdown
* arrow will be shown next to the label.
*/
void
gtk_menu_button_set_label (GtkMenuButton *menu_button,
const char *label)
{
GtkWidget *box;
GtkWidget *label_widget;
GtkWidget *arrow;
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
g_object_freeze_notify (G_OBJECT (menu_button));
if (gtk_menu_button_get_icon_name (menu_button))
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_ICON_NAME]);
if (gtk_menu_button_get_child (menu_button))
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_CHILD]);
box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
label_widget = gtk_label_new (label);
gtk_label_set_xalign (GTK_LABEL (label_widget), 0);
gtk_label_set_use_underline (GTK_LABEL (label_widget),
gtk_button_get_use_underline (GTK_BUTTON (menu_button->button)));
gtk_widget_set_hexpand (label_widget, TRUE);
gtk_widget_set_halign (label_widget, GTK_ALIGN_CENTER);
arrow = gtk_builtin_icon_new ("arrow");
menu_button->arrow_widget = arrow;
gtk_box_append (GTK_BOX (box), label_widget);
gtk_box_append (GTK_BOX (box), arrow);
gtk_button_set_child (GTK_BUTTON (menu_button->button), box);
menu_button->label_widget = label_widget;
gtk_accessible_update_relation (GTK_ACCESSIBLE (menu_button->button),
GTK_ACCESSIBLE_RELATION_LABELLED_BY, menu_button->label_widget, NULL,
GTK_ACCESSIBLE_RELATION_DESCRIBED_BY, menu_button->label_widget, NULL,
-1);
menu_button->image_widget = NULL;
menu_button->child = NULL;
update_arrow (menu_button);
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_LABEL]);
g_object_thaw_notify (G_OBJECT (menu_button));
}
/**
* gtk_menu_button_get_label: (attributes org.gtk.Method.get_property=label)
* @menu_button: a `GtkMenuButton`
*
* Gets the label shown in the button
*
* Returns: (nullable): the label shown in the button
*/
const char *
gtk_menu_button_get_label (GtkMenuButton *menu_button)
{
g_return_val_if_fail (GTK_IS_MENU_BUTTON (menu_button), NULL);
if (menu_button->label_widget)
return gtk_label_get_label (GTK_LABEL (menu_button->label_widget));
return NULL;
}
/**
* gtk_menu_button_set_has_frame: (attributes org.gtk.Method.set_property=has-frame)
* @menu_button: a `GtkMenuButton`
* @has_frame: whether the button should have a visible frame
*
* Sets the style of the button.
*/
void
gtk_menu_button_set_has_frame (GtkMenuButton *menu_button,
gboolean has_frame)
{
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
if (gtk_button_get_has_frame (GTK_BUTTON (menu_button->button)) == has_frame)
return;
gtk_button_set_has_frame (GTK_BUTTON (menu_button->button), has_frame);
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_HAS_FRAME]);
}
/**
* gtk_menu_button_get_has_frame: (attributes org.gtk.Method.get_property=has-frame)
* @menu_button: a `GtkMenuButton`
*
* Returns whether the button has a frame.
*
* Returns: %TRUE if the button has a frame
*/
gboolean
gtk_menu_button_get_has_frame (GtkMenuButton *menu_button)
{
g_return_val_if_fail (GTK_IS_MENU_BUTTON (menu_button), TRUE);
return gtk_button_get_has_frame (GTK_BUTTON (menu_button->button));
}
/**
* gtk_menu_button_popup:
* @menu_button: a `GtkMenuButton`
*
* Pop up the menu.
*/
void
gtk_menu_button_popup (GtkMenuButton *menu_button)
{
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (menu_button->button), TRUE);
}
/**
* gtk_menu_button_popdown:
* @menu_button: a `GtkMenuButton`
*
* Dismiss the menu.
*/
void
gtk_menu_button_popdown (GtkMenuButton *menu_button)
{
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (menu_button->button), FALSE);
}
/**
* gtk_menu_button_set_create_popup_func:
* @menu_button: a `GtkMenuButton`
* @func: (nullable): function to call when a popup is about to
* be shown, but none has been provided via other means, or %NULL
* to reset to default behavior.
* @user_data: (closure): user data to pass to @func.
* @destroy_notify: (nullable): destroy notify for @user_data
*
* Sets @func to be called when a popup is about to be shown.
*
* @func should use one of
*
* - [method@Gtk.MenuButton.set_popover]
* - [method@Gtk.MenuButton.set_menu_model]
*
* to set a popup for @menu_button.
* If @func is non-%NULL, @menu_button will always be sensitive.
*
* Using this function will not reset the menu widget attached to
* @menu_button. Instead, this can be done manually in @func.
*/
void
gtk_menu_button_set_create_popup_func (GtkMenuButton *menu_button,
GtkMenuButtonCreatePopupFunc func,
gpointer user_data,
GDestroyNotify destroy_notify)
{
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
if (menu_button->create_popup_destroy_notify)
menu_button->create_popup_destroy_notify (menu_button->create_popup_user_data);
menu_button->create_popup_func = func;
menu_button->create_popup_user_data = user_data;
menu_button->create_popup_destroy_notify = destroy_notify;
update_sensitivity (menu_button);
}
/**
* gtk_menu_button_set_use_underline: (attributes org.gtk.Method.set_property=use-underline)
* @menu_button: a `GtkMenuButton`
* @use_underline: %TRUE if underlines in the text indicate mnemonics
*
* If true, an underline in the text indicates a mnemonic.
*/
void
gtk_menu_button_set_use_underline (GtkMenuButton *menu_button,
gboolean use_underline)
{
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
if (gtk_button_get_use_underline (GTK_BUTTON (menu_button->button)) == use_underline)
return;
gtk_button_set_use_underline (GTK_BUTTON (menu_button->button), use_underline);
if (menu_button->label_widget)
gtk_label_set_use_underline (GTK_LABEL (menu_button->label_widget), use_underline);
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_USE_UNDERLINE]);
}
/**
* gtk_menu_button_get_use_underline: (attributes org.gtk.Method.get_property=use-underline)
* @menu_button: a `GtkMenuButton`
*
* Returns whether an embedded underline in the text indicates a
* mnemonic.
*
* Returns: %TRUE whether an embedded underline in the text indicates
* the mnemonic accelerator keys.
*/
gboolean
gtk_menu_button_get_use_underline (GtkMenuButton *menu_button)
{
g_return_val_if_fail (GTK_IS_MENU_BUTTON (menu_button), FALSE);
return gtk_button_get_use_underline (GTK_BUTTON (menu_button->button));
}
static GList *
get_menu_bars (GtkWindow *window)
{
return g_object_get_data (G_OBJECT (window), "gtk-menu-bar-list");
}
static void
set_menu_bars (GtkWindow *window,
GList *menubars)
{
g_object_set_data (G_OBJECT (window), I_("gtk-menu-bar-list"), menubars);
}
static void
add_to_window (GtkWindow *window,
GtkMenuButton *button)
{
GList *menubars = get_menu_bars (window);
set_menu_bars (window, g_list_prepend (menubars, button));
}
static void
remove_from_window (GtkWindow *window,
GtkMenuButton *button)
{
GList *menubars = get_menu_bars (window);
menubars = g_list_remove (menubars, button);
set_menu_bars (window, menubars);
}
static void
gtk_menu_button_root (GtkWidget *widget)
{
GtkMenuButton *button = GTK_MENU_BUTTON (widget);
GTK_WIDGET_CLASS (gtk_menu_button_parent_class)->root (widget);
if (button->primary)
{
GtkWidget *toplevel = GTK_WIDGET (gtk_widget_get_root (widget));
add_to_window (GTK_WINDOW (toplevel), button);
}
}
static void
gtk_menu_button_unroot (GtkWidget *widget)
{
GtkWidget *toplevel;
toplevel = GTK_WIDGET (gtk_widget_get_root (widget));
remove_from_window (GTK_WINDOW (toplevel), GTK_MENU_BUTTON (widget));
GTK_WIDGET_CLASS (gtk_menu_button_parent_class)->unroot (widget);
}
/**
* gtk_menu_button_set_primary: (attributes org.gtk.Method.set_property=primary)
* @menu_button: a `GtkMenuButton`
* @primary: whether the menubutton should act as a primary menu
*
* Sets whether menu button acts as a primary menu.
*
* Primary menus can be opened with the F10 key.
*
* Since: 4.4
*/
void
gtk_menu_button_set_primary (GtkMenuButton *menu_button,
gboolean primary)
{
GtkRoot *toplevel;
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
if (menu_button->primary == primary)
return;
menu_button->primary = primary;
toplevel = gtk_widget_get_root (GTK_WIDGET (menu_button));
if (toplevel)
{
if (menu_button->primary)
add_to_window (GTK_WINDOW (toplevel), menu_button);
else
remove_from_window (GTK_WINDOW (toplevel), menu_button);
}
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_PRIMARY]);
}
/**
* gtk_menu_button_get_primary: (attributes org.gtk.Method.get_property=primary)
* @menu_button: a `GtkMenuButton`
*
* Returns whether the menu button acts as a primary menu.
*
* Returns: %TRUE if the button is a primary menu
*
* Since: 4.4
*/
gboolean
gtk_menu_button_get_primary (GtkMenuButton *menu_button)
{
g_return_val_if_fail (GTK_IS_MENU_BUTTON (menu_button), FALSE);
return menu_button->primary;
}
/**
* gtk_menu_button_set_child: (attributes org.gtk.Method.set_property=child)
* @menu_button: a `GtkMenuButton`
* @child: (nullable): the child widget
*
* Sets the child widget of @menu_button.
*
* Setting a child resets [property@Gtk.MenuButton:label] and
* [property@Gtk.MenuButton:icon-name].
*
* If [property@Gtk.MenuButton:always-show-arrow] is set to `TRUE` and
* [property@Gtk.MenuButton:direction] is not `GTK_ARROW_NONE`, a dropdown arrow
* will be shown next to the child.
*
* Since: 4.6
*/
void
gtk_menu_button_set_child (GtkMenuButton *menu_button,
GtkWidget *child)
{
GtkWidget *box, *arrow;
g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
g_return_if_fail (child == NULL || GTK_IS_WIDGET (child));
g_object_freeze_notify (G_OBJECT (menu_button));
if (gtk_menu_button_get_label (menu_button))
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_LABEL]);
if (gtk_menu_button_get_icon_name (menu_button))
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_ICON_NAME]);
box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
gtk_widget_set_halign (box, GTK_ALIGN_CENTER);
arrow = gtk_builtin_icon_new ("arrow");
menu_button->arrow_widget = arrow;
gtk_box_append (GTK_BOX (box), child);
gtk_box_append (GTK_BOX (box), arrow);
gtk_button_set_child (GTK_BUTTON (menu_button->button), box);
menu_button->child = child;
menu_button->image_widget = NULL;
menu_button->label_widget = NULL;
update_arrow (menu_button);
g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_CHILD]);
g_object_thaw_notify (G_OBJECT (menu_button));
}
/**
* gtk_menu_button_get_child: (attributes org.gtk.Method.get_property=child)
* @menu_button: a `GtkMenuButton`
*
* Gets the child widget of @menu_button.
*
* Returns: (nullable) (transfer none): the child widget of @menu_button
*
* Since: 4.6
*/
GtkWidget *
gtk_menu_button_get_child (GtkMenuButton *menu_button)
{
g_return_val_if_fail (GTK_IS_MENU_BUTTON (menu_button), NULL);
return menu_button->child;
}