gtk2/gtk/gtkmenubutton.c

/* 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 <http://www.gnu.org/licenses/>.
 */

/**
 * SECTION:gtkmenubutton
 * @short_description: A widget that shows a popup when clicked on
 * @title: GtkMenuButton
 *
 * The #GtkMenuButton widget is used to display a popup when clicked on.
 * 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
 * #GtkMenuButton:icon-name property) or a label (set with the
 * #GtkMenuButton:label property). If neither is explicitly set,
 * a #GtkImage is automatically created, using an arrow image oriented
 * according to #GtkMenuButton:direction or the generic “open-menu-symbolic”
 * icon if the direction is not set.
 *
 * The positioning of the popup is determined by the #GtkMenuButton:direction
 * property of the menu button.
 *
 * For menus, the #GtkWidget:halign and #GtkWidget: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”.
 *
 * ## Direction = Down
 *
 * - halign = start
 *
 *     ![](down-start.png)
 *
 * - halign = center
 *
 *     ![](down-center.png)
 *
 * - halign = end
 *
 *     ![](down-end.png)
 *
 * ## Direction = Up
 *
 * - halign = start
 *
 *     ![](up-start.png)
 *
 * - halign = center
 *
 *     ![](up-center.png)
 *
 * - halign = end
 *
 *     ![](up-end.png)
 *
 * ## Direction = Left
 *
 * - valign = start
 *
 *     ![](left-start.png)
 *
 * - valign = center
 *
 *     ![](left-center.png)
 *
 * - valign = end
 *
 *     ![](left-end.png)
 *
 * ## Direction = Right
 *
 * - valign = start
 *
 *     ![](right-start.png)
 *
 * - valign = center
 *
 *     ![](right-center.png)
 *
 * - valign = end
 *
 *     ![](right-end.png)
 *
 * # CSS nodes
 *
 * GtkMenuButton has a single CSS node with name button. To differentiate
 * it from a plain #GtkButton, it gets the .popup style class.
 */

#include "config.h"

#include "gtkactionable.h"
#include "gtkimage.h"
#include "gtkintl.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"

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 *arrow_widget;
  GtkArrowType arrow_type;
};

struct _GtkMenuButtonClass
{
  GtkWidgetClass parent_class;
};

enum
{
  PROP_0,
  PROP_MENU_MODEL,
  PROP_DIRECTION,
  PROP_POPOVER,
  PROP_ICON_NAME,
  PROP_LABEL,
  PROP_USE_UNDERLINE,
  PROP_HAS_FRAME,
  LAST_PROP
};

static GParamSpec *menu_button_props[LAST_PROP];

G_DEFINE_TYPE (GtkMenuButton, gtk_menu_button, GTK_TYPE_WIDGET)

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_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;
      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_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;
      default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, 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));
      else
        gtk_popover_popdown (GTK_POPOVER (self->popover));
    }
}

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_native_check_resize (GTK_NATIVE (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_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->dispose = gtk_menu_button_dispose;

  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;

  /**
   * GtkMenuButton:menu-model:
   *
   * The #GMenuModel from which the popup will be created.
   *
   * See gtk_menu_button_set_menu_model() for the interaction with the
   * #GtkMenuButton:popup property.
   */
  menu_button_props[PROP_MENU_MODEL] =
      g_param_spec_object ("menu-model",
                           P_("Menu model"),
                           P_("The model from which the popup is made."),
                           G_TYPE_MENU_MODEL,
                           GTK_PARAM_READWRITE);

  /**
   * GtkMenuButton: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",
                         P_("Direction"),
                         P_("The direction the arrow should point."),
                         GTK_TYPE_ARROW_TYPE,
                         GTK_ARROW_DOWN,
                         GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);

  /**
   * GtkMenuButton:popover:
   *
   * The #GtkPopover that will be popped up when the button is clicked.
   */
  menu_button_props[PROP_POPOVER] =
      g_param_spec_object ("popover",
                           P_("Popover"),
                           P_("The popover"),
                           GTK_TYPE_POPOVER,
                           G_PARAM_READWRITE);

  menu_button_props[PROP_ICON_NAME] =
      g_param_spec_string ("icon-name",
                           P_("Icon Name"),
                           P_("The name of the icon used to automatically populate the button"),
                           NULL,
                           GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);

  menu_button_props[PROP_LABEL] =
      g_param_spec_string ("label",
                           P_("Label"),
                           P_("The label for the button"),
                           NULL,
                           GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);

  menu_button_props[PROP_USE_UNDERLINE] =
      g_param_spec_boolean ("use-underline",
                            P_("Use underline"),
                            P_("If set, an underline in the text indicates the next character should be used for the mnemonic accelerator key"),
                           FALSE,
                           GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);

  menu_button_props[PROP_HAS_FRAME] =
    g_param_spec_boolean ("has-frame",
                          P_("Has frame"),
                          P_("Whether the button has a frame"),
                          TRUE,
                          GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);

  g_object_class_install_properties (gobject_class, LAST_PROP, menu_button_props);

  gtk_widget_class_set_css_name (widget_class, I_("menubutton"));
}

static void
set_arrow_type (GtkImage     *image,
                GtkArrowType  arrow_type,
                gboolean      visible)
{
  switch (arrow_type)
    {
    case GTK_ARROW_NONE:
      gtk_image_set_from_icon_name (image, "open-menu-symbolic");
      break;
    case GTK_ARROW_DOWN:
      gtk_image_set_from_icon_name (image, "pan-down-symbolic");
      break;
    case GTK_ARROW_UP:
      gtk_image_set_from_icon_name (image, "pan-up-symbolic");
      break;
    case GTK_ARROW_LEFT:
      gtk_image_set_from_icon_name (image, "pan-start-symbolic");
      break;
    case GTK_ARROW_RIGHT:
      gtk_image_set_from_icon_name (image, "pan-end-symbolic");
      break;
    default:
      break;
    }

  if (visible)
    gtk_widget_show (GTK_WIDGET (image));
  else
    gtk_widget_hide (GTK_WIDGET (image));
}

static void
add_arrow (GtkMenuButton *self)
{
  GtkWidget *arrow;

  arrow = gtk_image_new ();
  set_arrow_type (GTK_IMAGE (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);

  gtk_widget_set_sensitive (self->button, FALSE);

  gtk_widget_add_css_class (GTK_WIDGET (self), "popup");
}

/**
 * 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 widget
 */
GtkWidget *
gtk_menu_button_new (void)
{
  return g_object_new (GTK_TYPE_MENU_BUTTON, NULL);
}

static void
update_sensitivity (GtkMenuButton *self)
{
  gtk_widget_set_sensitive (self->button,
                            self->popover != NULL ||
                            self->create_popup_func != NULL);
}

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:
 * @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,
 * or %NULL to dissociate any existing menu model and disable the button.
 *
 * A #GtkPopover will be created from the menu model with gtk_popover_menu_new_from_model().
 * Actions will be connected as documented for this function.
 *
 * If #GtkMenuButton: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:
 * @menu_button: a #GtkMenuButton
 *
 * Returns the #GMenuModel used to generate the popup.
 *
 * Returns: (nullable) (transfer none): a #GMenuModel or %NULL
 */
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:
 * @menu_button: a #GtkMenuButton
 * @direction: a #GtkArrowType
 *
 * Sets the direction in which the popup will be popped up, as
 * well as changing the arrow’s direction. The child will not
 * be changed to an arrow if it was customized.
 *
 * 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)
{
  gboolean is_image_button;

  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]);

  /* Is it custom content? We don't change that */
  is_image_button = menu_button->label_widget == NULL;
  if (is_image_button && (menu_button->arrow_widget != gtk_button_get_child (GTK_BUTTON (menu_button->button))))
    return;

  set_arrow_type (GTK_IMAGE (menu_button->arrow_widget),
                  menu_button->arrow_type,
                  is_image_button || (menu_button->arrow_type != GTK_ARROW_NONE));
  update_popover_direction (menu_button);
}

/**
 * gtk_menu_button_get_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:
 * @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,
 * or %NULL to dissociate any existing popover and disable the button.
 *
 * If #GtkMenuButton: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:
 * @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:
 * @menu_button: a #GtkMenuButton
 * @icon_name: the icon name
 *
 * Sets the name of an icon to show inside the menu button.
 */
void
gtk_menu_button_set_icon_name (GtkMenuButton *menu_button,
                               const char    *icon_name)
{
  g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));

  gtk_button_set_icon_name (GTK_BUTTON (menu_button->button), icon_name);
  g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_ICON_NAME]);
}

/**
 * gtk_menu_button_get_icon_name:
 * @menu_button: a #GtkMenuButton
 *
 * Gets the name of the icon shown in the button.
 *
 * Returns: 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);

  return gtk_button_get_icon_name (GTK_BUTTON (menu_button->button));
}

/**
 * gtk_menu_button_set_label:
 * @menu_button: a #GtkMenuButton
 * @label: the label
 *
 * Sets the label to show inside the menu button.
 */
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));

  box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
  label_widget = gtk_label_new (label);
  g_return_if_fail (GTK_IS_MENU_BUTTON (menu_button));
  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_image_new ();
  menu_button->arrow_widget = arrow;
  set_arrow_type (GTK_IMAGE (arrow), menu_button->arrow_type, menu_button->arrow_type != GTK_ARROW_NONE);
  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;

  g_object_notify_by_pspec (G_OBJECT (menu_button), menu_button_props[PROP_LABEL]);
}

/**
 * gtk_menu_button_get_label:
 * @menu_button: a #GtkMenuButton
 *
 * Gets the label shown in the button
 *
 * Returns: the label shown in the button
 */
const char *
gtk_menu_button_get_label (GtkMenuButton *menu_button)
{
  GtkWidget *child;

  g_return_val_if_fail (GTK_IS_MENU_BUTTON (menu_button), NULL);

  child = gtk_button_get_child (GTK_BUTTON (menu_button->button));
  if (GTK_IS_BOX (child))
    {
      child = gtk_widget_get_first_child (child);
      return gtk_label_get_label (GTK_LABEL (child));
    }

  return NULL;
}

/**
 * gtk_menu_button_set_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:
 * @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 popuop 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
 *
 *  - gtk_menu_button_set_popover()
 *  - gtk_menu_button_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:
 * @menu_button: a #GtkMenuButton
 * @use_underline: %TRUE if underlines in the text indicate mnemonics
 *
 * If true, an underline in the text indicates the next character should be
 * used for the mnemonic accelerator key.
 */
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:
 * @menu_button: a #GtkMenuButton
 *
 * Returns whether an embedded underline in the text indicates a
 * mnemonic. See gtk_menu_button_set_use_underline().
 *
 * 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));
}