gtk/auto/

expander.rs

// This file was generated by gir (https://github.com/gtk-rs/gir)
// from gir-files (https://github.com/gtk-rs/gir-files)
// DO NOT EDIT

use crate::{Align, Bin, Buildable, Container, ResizeMode, Widget, ffi};
use glib::{
    object::ObjectType as _,
    prelude::*,
    signal::{SignalHandlerId, connect_raw},
    translate::*,
};
use std::boxed::Box as Box_;

glib::wrapper! {
    /// A [`Expander`][crate::Expander] allows the user to hide or show its child by clicking
    /// on an expander triangle similar to the triangles used in a [`TreeView`][crate::TreeView].
    ///
    /// Normally you use an expander as you would use any other descendant
    /// of [`Bin`][crate::Bin]; you create the child widget and use [`ContainerExt::add()`][crate::prelude::ContainerExt::add()]
    /// to add it to the expander. When the expander is toggled, it will take
    /// care of showing and hiding the child automatically.
    ///
    /// # Special Usage
    ///
    /// There are situations in which you may prefer to show and hide the
    /// expanded widget yourself, such as when you want to actually create
    /// the widget at expansion time. In this case, create a [`Expander`][crate::Expander]
    /// but do not add a child to it. The expander widget has an
    /// [`expanded`][struct@crate::Expander#expanded] property which can be used to monitor
    /// its expansion state. You should watch this property with a signal
    /// connection as follows:
    ///
    ///
    ///
    /// **⚠️ The following code is in C ⚠️**
    ///
    /// ```C
    /// static void
    /// expander_callback (GObject    *object,
    ///                    GParamSpec *param_spec,
    ///                    gpointer    user_data)
    /// {
    ///   GtkExpander *expander;
    ///
    ///   expander = GTK_EXPANDER (object);
    ///
    ///   if (gtk_expander_get_expanded (expander))
    ///     {
    ///       // Show or create widgets
    ///     }
    ///   else
    ///     {
    ///       // Hide or destroy widgets
    ///     }
    /// }
    ///
    /// static void
    /// create_expander (void)
    /// {
    ///   GtkWidget *expander = gtk_expander_new_with_mnemonic ("_More Options");
    ///   g_signal_connect (expander, "notify::expanded",
    ///                     G_CALLBACK (expander_callback), NULL);
    ///
    ///   // ...
    /// }
    /// ```
    ///
    /// # GtkExpander as GtkBuildable
    ///
    /// The GtkExpander implementation of the GtkBuildable interface supports
    /// placing a child in the label position by specifying “label” as the
    /// “type” attribute of a ``<child>`` element. A normal content child can be
    /// specified without specifying a ``<child>`` type attribute.
    ///
    /// An example of a UI definition fragment with GtkExpander:
    ///
    ///
    ///
    /// **⚠️ The following code is in xml ⚠️**
    ///
    /// ```xml
    /// <object class="GtkExpander">
    ///   <child type="label">
    ///     <object class="GtkLabel" id="expander-label"/>
    ///   </child>
    ///   <child>
    ///     <object class="GtkEntry" id="expander-content"/>
    ///   </child>
    /// </object>
    /// ```
    ///
    /// # CSS nodes
    ///
    ///
    ///
    /// **⚠️ The following code is in plain ⚠️**
    ///
    /// ```plain
    /// expander
    /// ├── title
    /// │   ├── arrow
    /// │   ╰── <label widget>
    /// ╰── <child>
    /// ```
    ///
    /// GtkExpander has three CSS nodes, the main node with the name expander,
    /// a subnode with name title and node below it with name arrow. The arrow of an
    /// expander that is showing its child gets the :checked pseudoclass added to it.
    ///
    /// ## Properties
    ///
    ///
    /// #### `expanded`
    ///  Readable | Writable | Construct
    ///
    ///
    /// #### `label`
    ///  Readable | Writable | Construct
    ///
    ///
    /// #### `label-fill`
    ///  Whether the label widget should fill all available horizontal space.
    ///
    /// Note that this property is ignored since 3.20.
    ///
    /// Readable | Writable | Construct
    ///
    ///
    /// #### `label-widget`
    ///  Readable | Writable
    ///
    ///
    /// #### `resize-toplevel`
    ///  When this property is [`true`], the expander will resize the toplevel
    /// widget containing the expander upon expanding and collapsing.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `spacing`
    ///  Space to put between the label and the child when the
    /// expander is expanded.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `use-markup`
    ///  Readable | Writable | Construct
    ///
    ///
    /// #### `use-underline`
    ///  Readable | Writable | Construct
    /// <details><summary><h4>Container</h4></summary>
    ///
    ///
    /// #### `border-width`
    ///  Readable | Writable
    ///
    ///
    /// #### `child`
    ///  Writable
    ///
    ///
    /// #### `resize-mode`
    ///  Readable | Writable
    /// </details>
    /// <details><summary><h4>Widget</h4></summary>
    ///
    ///
    /// #### `app-paintable`
    ///  Readable | Writable
    ///
    ///
    /// #### `can-default`
    ///  Readable | Writable
    ///
    ///
    /// #### `can-focus`
    ///  Readable | Writable
    ///
    ///
    /// #### `composite-child`
    ///  Readable
    ///
    ///
    /// #### `double-buffered`
    ///  Whether the widget is double buffered.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `events`
    ///  Readable | Writable
    ///
    ///
    /// #### `expand`
    ///  Whether to expand in both directions. Setting this sets both [`hexpand`][struct@crate::Widget#hexpand] and [`vexpand`][struct@crate::Widget#vexpand]
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `focus-on-click`
    ///  Whether the widget should grab focus when it is clicked with the mouse.
    ///
    /// This property is only relevant for widgets that can take focus.
    ///
    /// Before 3.20, several widgets (GtkButton, GtkFileChooserButton,
    /// GtkComboBox) implemented this property individually.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `halign`
    ///  How to distribute horizontal space if widget gets extra space, see [`Align`][crate::Align]
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `has-default`
    ///  Readable | Writable
    ///
    ///
    /// #### `has-focus`
    ///  Readable | Writable
    ///
    ///
    /// #### `has-tooltip`
    ///  Enables or disables the emission of [`query-tooltip`][struct@crate::Widget#query-tooltip] on `widget`.
    /// A value of [`true`] indicates that `widget` can have a tooltip, in this case
    /// the widget will be queried using [`query-tooltip`][struct@crate::Widget#query-tooltip] to determine
    /// whether it will provide a tooltip or not.
    ///
    /// Note that setting this property to [`true`] for the first time will change
    /// the event masks of the GdkWindows of this widget to include leave-notify
    /// and motion-notify events. This cannot and will not be undone when the
    /// property is set to [`false`] again.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `height-request`
    ///  Readable | Writable
    ///
    ///
    /// #### `hexpand`
    ///  Whether to expand horizontally. See [`WidgetExt::set_hexpand()`][crate::prelude::WidgetExt::set_hexpand()].
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `hexpand-set`
    ///  Whether to use the [`hexpand`][struct@crate::Widget#hexpand] property. See [`WidgetExt::is_hexpand_set()`][crate::prelude::WidgetExt::is_hexpand_set()].
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `is-focus`
    ///  Readable | Writable
    ///
    ///
    /// #### `margin`
    ///  Sets all four sides' margin at once. If read, returns max
    /// margin on any side.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `margin-bottom`
    ///  Margin on bottom side of widget.
    ///
    /// This property adds margin outside of the widget's normal size
    /// request, the margin will be added in addition to the size from
    /// [`WidgetExt::set_size_request()`][crate::prelude::WidgetExt::set_size_request()] for example.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `margin-end`
    ///  Margin on end of widget, horizontally. This property supports
    /// left-to-right and right-to-left text directions.
    ///
    /// This property adds margin outside of the widget's normal size
    /// request, the margin will be added in addition to the size from
    /// [`WidgetExt::set_size_request()`][crate::prelude::WidgetExt::set_size_request()] for example.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `margin-left`
    ///  Margin on left side of widget.
    ///
    /// This property adds margin outside of the widget's normal size
    /// request, the margin will be added in addition to the size from
    /// [`WidgetExt::set_size_request()`][crate::prelude::WidgetExt::set_size_request()] for example.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `margin-right`
    ///  Margin on right side of widget.
    ///
    /// This property adds margin outside of the widget's normal size
    /// request, the margin will be added in addition to the size from
    /// [`WidgetExt::set_size_request()`][crate::prelude::WidgetExt::set_size_request()] for example.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `margin-start`
    ///  Margin on start of widget, horizontally. This property supports
    /// left-to-right and right-to-left text directions.
    ///
    /// This property adds margin outside of the widget's normal size
    /// request, the margin will be added in addition to the size from
    /// [`WidgetExt::set_size_request()`][crate::prelude::WidgetExt::set_size_request()] for example.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `margin-top`
    ///  Margin on top side of widget.
    ///
    /// This property adds margin outside of the widget's normal size
    /// request, the margin will be added in addition to the size from
    /// [`WidgetExt::set_size_request()`][crate::prelude::WidgetExt::set_size_request()] for example.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `name`
    ///  Readable | Writable
    ///
    ///
    /// #### `no-show-all`
    ///  Readable | Writable
    ///
    ///
    /// #### `opacity`
    ///  The requested opacity of the widget. See [`WidgetExt::set_opacity()`][crate::prelude::WidgetExt::set_opacity()] for
    /// more details about window opacity.
    ///
    /// Before 3.8 this was only available in GtkWindow
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `parent`
    ///  Readable | Writable
    ///
    ///
    /// #### `receives-default`
    ///  Readable | Writable
    ///
    ///
    /// #### `scale-factor`
    ///  The scale factor of the widget. See [`WidgetExt::scale_factor()`][crate::prelude::WidgetExt::scale_factor()] for
    /// more details about widget scaling.
    ///
    /// Readable
    ///
    ///
    /// #### `sensitive`
    ///  Readable | Writable
    ///
    ///
    /// #### `style`
    ///  The style of the widget, which contains information about how it will look (colors, etc).
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `tooltip-markup`
    ///  Sets the text of tooltip to be the given string, which is marked up
    /// with the [Pango text markup language][PangoMarkupFormat].
    /// Also see [`Tooltip::set_markup()`][crate::Tooltip::set_markup()].
    ///
    /// This is a convenience property which will take care of getting the
    /// tooltip shown if the given string is not [`None`]: [`has-tooltip`][struct@crate::Widget#has-tooltip]
    /// will automatically be set to [`true`] and there will be taken care of
    /// [`query-tooltip`][struct@crate::Widget#query-tooltip] in the default signal handler.
    ///
    /// Note that if both [`tooltip-text`][struct@crate::Widget#tooltip-text] and [`tooltip-markup`][struct@crate::Widget#tooltip-markup]
    /// are set, the last one wins.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `tooltip-text`
    ///  Sets the text of tooltip to be the given string.
    ///
    /// Also see [`Tooltip::set_text()`][crate::Tooltip::set_text()].
    ///
    /// This is a convenience property which will take care of getting the
    /// tooltip shown if the given string is not [`None`]: [`has-tooltip`][struct@crate::Widget#has-tooltip]
    /// will automatically be set to [`true`] and there will be taken care of
    /// [`query-tooltip`][struct@crate::Widget#query-tooltip] in the default signal handler.
    ///
    /// Note that if both [`tooltip-text`][struct@crate::Widget#tooltip-text] and [`tooltip-markup`][struct@crate::Widget#tooltip-markup]
    /// are set, the last one wins.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `valign`
    ///  How to distribute vertical space if widget gets extra space, see [`Align`][crate::Align]
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `vexpand`
    ///  Whether to expand vertically. See [`WidgetExt::set_vexpand()`][crate::prelude::WidgetExt::set_vexpand()].
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `vexpand-set`
    ///  Whether to use the [`vexpand`][struct@crate::Widget#vexpand] property. See [`WidgetExt::is_vexpand_set()`][crate::prelude::WidgetExt::is_vexpand_set()].
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `visible`
    ///  Readable | Writable
    ///
    ///
    /// #### `width-request`
    ///  Readable | Writable
    ///
    ///
    /// #### `window`
    ///  The widget's window if it is realized, [`None`] otherwise.
    ///
    /// Readable
    /// </details>
    ///
    /// ## Signals
    ///
    ///
    /// #### `activate`
    ///  Action
    /// <details><summary><h4>Container</h4></summary>
    ///
    ///
    /// #### `add`
    ///
    ///
    ///
    /// #### `check-resize`
    ///
    ///
    ///
    /// #### `remove`
    ///
    ///
    ///
    /// #### `set-focus-child`
    ///
    /// </details>
    /// <details><summary><h4>Widget</h4></summary>
    ///
    ///
    /// #### `accel-closures-changed`
    ///
    ///
    ///
    /// #### `button-press-event`
    ///  The ::button-press-event signal will be emitted when a button
    /// (typically from a mouse) is pressed.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the
    /// widget needs to enable the [`gdk::EventMask::BUTTON_PRESS_MASK`][crate::gdk::EventMask::BUTTON_PRESS_MASK] mask.
    ///
    /// This signal will be sent to the grab widget if there is one.
    ///
    ///
    ///
    ///
    /// #### `button-release-event`
    ///  The ::button-release-event signal will be emitted when a button
    /// (typically from a mouse) is released.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the
    /// widget needs to enable the [`gdk::EventMask::BUTTON_RELEASE_MASK`][crate::gdk::EventMask::BUTTON_RELEASE_MASK] mask.
    ///
    /// This signal will be sent to the grab widget if there is one.
    ///
    ///
    ///
    ///
    /// #### `can-activate-accel`
    ///  Determines whether an accelerator that activates the signal
    /// identified by `signal_id` can currently be activated.
    /// This signal is present to allow applications and derived
    /// widgets to override the default [`Widget`][crate::Widget] handling
    /// for determining whether an accelerator can be activated.
    ///
    ///
    ///
    ///
    /// #### `child-notify`
    ///  The ::child-notify signal is emitted for each
    /// [child property][child-properties] that has
    /// changed on an object. The signal's detail holds the property name.
    ///
    /// Detailed
    ///
    ///
    /// #### `composited-changed`
    ///  The ::composited-changed signal is emitted when the composited
    /// status of `widgets` screen changes.
    /// See [`Screen::is_composited()`][crate::gdk::Screen::is_composited()].
    ///
    /// Action
    ///
    ///
    /// #### `configure-event`
    ///  The ::configure-event signal will be emitted when the size, position or
    /// stacking of the `widget`'s window has changed.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::STRUCTURE_MASK`][crate::gdk::EventMask::STRUCTURE_MASK] mask. GDK will enable this mask
    /// automatically for all new windows.
    ///
    ///
    ///
    ///
    /// #### `damage-event`
    ///  Emitted when a redirected window belonging to `widget` gets drawn into.
    /// The region/area members of the event shows what area of the redirected
    /// drawable was drawn into.
    ///
    ///
    ///
    ///
    /// #### `delete-event`
    ///  The ::delete-event signal is emitted if a user requests that
    /// a toplevel window is closed. The default handler for this signal
    /// destroys the window. Connecting [`WidgetExtManual::hide_on_delete()`][crate::prelude::WidgetExtManual::hide_on_delete()] to
    /// this signal will cause the window to be hidden instead, so that
    /// it can later be shown again without reconstructing it.
    ///
    ///
    ///
    ///
    /// #### `destroy`
    ///  Signals that all holders of a reference to the widget should release
    /// the reference that they hold. May result in finalization of the widget
    /// if all references are released.
    ///
    /// This signal is not suitable for saving widget state.
    ///
    ///
    ///
    ///
    /// #### `destroy-event`
    ///  The ::destroy-event signal is emitted when a [`gdk::Window`][crate::gdk::Window] is destroyed.
    /// You rarely get this signal, because most widgets disconnect themselves
    /// from their window before they destroy it, so no widget owns the
    /// window at destroy time.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::STRUCTURE_MASK`][crate::gdk::EventMask::STRUCTURE_MASK] mask. GDK will enable this mask
    /// automatically for all new windows.
    ///
    ///
    ///
    ///
    /// #### `direction-changed`
    ///  The ::direction-changed signal is emitted when the text direction
    /// of a widget changes.
    ///
    ///
    ///
    ///
    /// #### `drag-begin`
    ///  The ::drag-begin signal is emitted on the drag source when a drag is
    /// started. A typical reason to connect to this signal is to set up a
    /// custom drag icon with e.g. [`WidgetExt::drag_source_set_icon_pixbuf()`][crate::prelude::WidgetExt::drag_source_set_icon_pixbuf()].
    ///
    /// Note that some widgets set up a drag icon in the default handler of
    /// this signal, so you may have to use `g_signal_connect_after()` to
    /// override what the default handler did.
    ///
    ///
    ///
    ///
    /// #### `drag-data-delete`
    ///  The ::drag-data-delete signal is emitted on the drag source when a drag
    /// with the action [`gdk::DragAction::MOVE`][crate::gdk::DragAction::MOVE] is successfully completed. The signal
    /// handler is responsible for deleting the data that has been dropped. What
    /// "delete" means depends on the context of the drag operation.
    ///
    ///
    ///
    ///
    /// #### `drag-data-get`
    ///  The ::drag-data-get signal is emitted on the drag source when the drop
    /// site requests the data which is dragged. It is the responsibility of
    /// the signal handler to fill `data` with the data in the format which
    /// is indicated by `info`. See [`SelectionData::set()`][crate::SelectionData::set()] and
    /// [`SelectionData::set_text()`][crate::SelectionData::set_text()].
    ///
    ///
    ///
    ///
    /// #### `drag-data-received`
    ///  The ::drag-data-received signal is emitted on the drop site when the
    /// dragged data has been received. If the data was received in order to
    /// determine whether the drop will be accepted, the handler is expected
    /// to call `gdk_drag_status()` and not finish the drag.
    /// If the data was received in response to a [`drag-drop`][struct@crate::Widget#drag-drop] signal
    /// (and this is the last target to be received), the handler for this
    /// signal is expected to process the received data and then call
    /// `gtk_drag_finish()`, setting the `success` parameter depending on
    /// whether the data was processed successfully.
    ///
    /// Applications must create some means to determine why the signal was emitted
    /// and therefore whether to call `gdk_drag_status()` or `gtk_drag_finish()`.
    ///
    /// The handler may inspect the selected action with
    /// [`DragContext::selected_action()`][crate::gdk::DragContext::selected_action()] before calling
    /// `gtk_drag_finish()`, e.g. to implement [`gdk::DragAction::ASK`][crate::gdk::DragAction::ASK] as
    /// shown in the following example:
    ///
    ///
    /// **⚠️ The following code is in C ⚠️**
    ///
    /// ```C
    /// void
    /// drag_data_received (GtkWidget          *widget,
    ///                     GdkDragContext     *context,
    ///                     gint                x,
    ///                     gint                y,
    ///                     GtkSelectionData   *data,
    ///                     guint               info,
    ///                     guint               time)
    /// {
    ///   if ((data->length >= 0) && (data->format == 8))
    ///     {
    ///       GdkDragAction action;
    ///
    ///       // handle data here
    ///
    ///       action = gdk_drag_context_get_selected_action (context);
    ///       if (action == GDK_ACTION_ASK)
    ///         {
    ///           GtkWidget *dialog;
    ///           gint response;
    ///
    ///           dialog = gtk_message_dialog_new (NULL,
    ///                                            GTK_DIALOG_MODAL |
    ///                                            GTK_DIALOG_DESTROY_WITH_PARENT,
    ///                                            GTK_MESSAGE_INFO,
    ///                                            GTK_BUTTONS_YES_NO,
    ///                                            "Move the data ?\n");
    ///           response = gtk_dialog_run (GTK_DIALOG (dialog));
    ///           gtk_widget_destroy (dialog);
    ///
    ///           if (response == GTK_RESPONSE_YES)
    ///             action = GDK_ACTION_MOVE;
    ///           else
    ///             action = GDK_ACTION_COPY;
    ///          }
    ///
    ///       gtk_drag_finish (context, TRUE, action == GDK_ACTION_MOVE, time);
    ///     }
    ///   else
    ///     gtk_drag_finish (context, FALSE, FALSE, time);
    ///  }
    /// ```
    ///
    ///
    ///
    ///
    /// #### `drag-drop`
    ///  The ::drag-drop signal is emitted on the drop site when the user drops
    /// the data onto the widget. The signal handler must determine whether
    /// the cursor position is in a drop zone or not. If it is not in a drop
    /// zone, it returns [`false`] and no further processing is necessary.
    /// Otherwise, the handler returns [`true`]. In this case, the handler must
    /// ensure that `gtk_drag_finish()` is called to let the source know that
    /// the drop is done. The call to `gtk_drag_finish()` can be done either
    /// directly or in a [`drag-data-received`][struct@crate::Widget#drag-data-received] handler which gets
    /// triggered by calling [`WidgetExt::drag_get_data()`][crate::prelude::WidgetExt::drag_get_data()] to receive the data for one
    /// or more of the supported targets.
    ///
    ///
    ///
    ///
    /// #### `drag-end`
    ///  The ::drag-end signal is emitted on the drag source when a drag is
    /// finished. A typical reason to connect to this signal is to undo
    /// things done in [`drag-begin`][struct@crate::Widget#drag-begin].
    ///
    ///
    ///
    ///
    /// #### `drag-failed`
    ///  The ::drag-failed signal is emitted on the drag source when a drag has
    /// failed. The signal handler may hook custom code to handle a failed DnD
    /// operation based on the type of error, it returns [`true`] is the failure has
    /// been already handled (not showing the default "drag operation failed"
    /// animation), otherwise it returns [`false`].
    ///
    ///
    ///
    ///
    /// #### `drag-leave`
    ///  The ::drag-leave signal is emitted on the drop site when the cursor
    /// leaves the widget. A typical reason to connect to this signal is to
    /// undo things done in [`drag-motion`][struct@crate::Widget#drag-motion], e.g. undo highlighting
    /// with [`WidgetExt::drag_unhighlight()`][crate::prelude::WidgetExt::drag_unhighlight()].
    ///
    ///
    /// Likewise, the [`drag-leave`][struct@crate::Widget#drag-leave] signal is also emitted before the
    /// ::drag-drop signal, for instance to allow cleaning up of a preview item
    /// created in the [`drag-motion`][struct@crate::Widget#drag-motion] signal handler.
    ///
    ///
    ///
    ///
    /// #### `drag-motion`
    ///  The ::drag-motion signal is emitted on the drop site when the user
    /// moves the cursor over the widget during a drag. The signal handler
    /// must determine whether the cursor position is in a drop zone or not.
    /// If it is not in a drop zone, it returns [`false`] and no further processing
    /// is necessary. Otherwise, the handler returns [`true`]. In this case, the
    /// handler is responsible for providing the necessary information for
    /// displaying feedback to the user, by calling `gdk_drag_status()`.
    ///
    /// If the decision whether the drop will be accepted or rejected can't be
    /// made based solely on the cursor position and the type of the data, the
    /// handler may inspect the dragged data by calling [`WidgetExt::drag_get_data()`][crate::prelude::WidgetExt::drag_get_data()] and
    /// defer the `gdk_drag_status()` call to the [`drag-data-received`][struct@crate::Widget#drag-data-received]
    /// handler. Note that you must pass [`DestDefaults::DROP`][crate::DestDefaults::DROP],
    /// [`DestDefaults::MOTION`][crate::DestDefaults::MOTION] or [`DestDefaults::ALL`][crate::DestDefaults::ALL] to [`WidgetExtManual::drag_dest_set()`][crate::prelude::WidgetExtManual::drag_dest_set()]
    /// when using the drag-motion signal that way.
    ///
    /// Also note that there is no drag-enter signal. The drag receiver has to
    /// keep track of whether he has received any drag-motion signals since the
    /// last [`drag-leave`][struct@crate::Widget#drag-leave] and if not, treat the drag-motion signal as
    /// an "enter" signal. Upon an "enter", the handler will typically highlight
    /// the drop site with [`WidgetExt::drag_highlight()`][crate::prelude::WidgetExt::drag_highlight()].
    ///
    ///
    /// **⚠️ The following code is in C ⚠️**
    ///
    /// ```C
    /// static void
    /// drag_motion (GtkWidget      *widget,
    ///              GdkDragContext *context,
    ///              gint            x,
    ///              gint            y,
    ///              guint           time)
    /// {
    ///   GdkAtom target;
    ///
    ///   PrivateData *private_data = GET_PRIVATE_DATA (widget);
    ///
    ///   if (!private_data->drag_highlight)
    ///    {
    ///      private_data->drag_highlight = 1;
    ///      gtk_drag_highlight (widget);
    ///    }
    ///
    ///   target = gtk_drag_dest_find_target (widget, context, NULL);
    ///   if (target == GDK_NONE)
    ///     gdk_drag_status (context, 0, time);
    ///   else
    ///    {
    ///      private_data->pending_status
    ///         = gdk_drag_context_get_suggested_action (context);
    ///      gtk_drag_get_data (widget, context, target, time);
    ///    }
    ///
    ///   return TRUE;
    /// }
    ///
    /// static void
    /// drag_data_received (GtkWidget        *widget,
    ///                     GdkDragContext   *context,
    ///                     gint              x,
    ///                     gint              y,
    ///                     GtkSelectionData *selection_data,
    ///                     guint             info,
    ///                     guint             time)
    /// {
    ///   PrivateData *private_data = GET_PRIVATE_DATA (widget);
    ///
    ///   if (private_data->suggested_action)
    ///    {
    ///      private_data->suggested_action = 0;
    ///
    ///      // We are getting this data due to a request in drag_motion,
    ///      // rather than due to a request in drag_drop, so we are just
    ///      // supposed to call gdk_drag_status(), not actually paste in
    ///      // the data.
    ///
    ///      str = gtk_selection_data_get_text (selection_data);
    ///      if (!data_is_acceptable (str))
    ///        gdk_drag_status (context, 0, time);
    ///      else
    ///        gdk_drag_status (context,
    ///                         private_data->suggested_action,
    ///                         time);
    ///    }
    ///   else
    ///    {
    ///      // accept the drop
    ///    }
    /// }
    /// ```
    ///
    ///
    ///
    ///
    /// #### `draw`
    ///  This signal is emitted when a widget is supposed to render itself.
    /// The `widget`'s top left corner must be painted at the origin of
    /// the passed in context and be sized to the values returned by
    /// [`WidgetExt::allocated_width()`][crate::prelude::WidgetExt::allocated_width()] and
    /// [`WidgetExt::allocated_height()`][crate::prelude::WidgetExt::allocated_height()].
    ///
    /// Signal handlers connected to this signal can modify the cairo
    /// context passed as `cr` in any way they like and don't need to
    /// restore it. The signal emission takes care of calling `cairo_save()`
    /// before and `cairo_restore()` after invoking the handler.
    ///
    /// The signal handler will get a `cr` with a clip region already set to the
    /// widget's dirty region, i.e. to the area that needs repainting. Complicated
    /// widgets that want to avoid redrawing themselves completely can get the full
    /// extents of the clip region with `gdk_cairo_get_clip_rectangle()`, or they can
    /// get a finer-grained representation of the dirty region with
    /// `cairo_copy_clip_rectangle_list()`.
    ///
    ///
    ///
    ///
    /// #### `enter-notify-event`
    ///  The ::enter-notify-event will be emitted when the pointer enters
    /// the `widget`'s window.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::ENTER_NOTIFY_MASK`][crate::gdk::EventMask::ENTER_NOTIFY_MASK] mask.
    ///
    /// This signal will be sent to the grab widget if there is one.
    ///
    ///
    ///
    ///
    /// #### `event`
    ///  The GTK+ main loop will emit three signals for each GDK event delivered
    /// to a widget: one generic ::event signal, another, more specific,
    /// signal that matches the type of event delivered (e.g.
    /// [`key-press-event`][struct@crate::Widget#key-press-event]) and finally a generic
    /// [`event-after`][struct@crate::Widget#event-after] signal.
    ///
    ///
    ///
    ///
    /// #### `event-after`
    ///  After the emission of the [`event`][struct@crate::Widget#event] signal and (optionally)
    /// the second more specific signal, ::event-after will be emitted
    /// regardless of the previous two signals handlers return values.
    ///
    ///
    ///
    ///
    /// #### `focus`
    ///
    ///
    ///
    /// #### `focus-in-event`
    ///  The ::focus-in-event signal will be emitted when the keyboard focus
    /// enters the `widget`'s window.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::FOCUS_CHANGE_MASK`][crate::gdk::EventMask::FOCUS_CHANGE_MASK] mask.
    ///
    ///
    ///
    ///
    /// #### `focus-out-event`
    ///  The ::focus-out-event signal will be emitted when the keyboard focus
    /// leaves the `widget`'s window.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::FOCUS_CHANGE_MASK`][crate::gdk::EventMask::FOCUS_CHANGE_MASK] mask.
    ///
    ///
    ///
    ///
    /// #### `grab-broken-event`
    ///  Emitted when a pointer or keyboard grab on a window belonging
    /// to `widget` gets broken.
    ///
    /// On X11, this happens when the grab window becomes unviewable
    /// (i.e. it or one of its ancestors is unmapped), or if the same
    /// application grabs the pointer or keyboard again.
    ///
    ///
    ///
    ///
    /// #### `grab-focus`
    ///  Action
    ///
    ///
    /// #### `grab-notify`
    ///  The ::grab-notify signal is emitted when a widget becomes
    /// shadowed by a GTK+ grab (not a pointer or keyboard grab) on
    /// another widget, or when it becomes unshadowed due to a grab
    /// being removed.
    ///
    /// A widget is shadowed by a [`WidgetExt::grab_add()`][crate::prelude::WidgetExt::grab_add()] when the topmost
    /// grab widget in the grab stack of its window group is not
    /// its ancestor.
    ///
    ///
    ///
    ///
    /// #### `hide`
    ///  The ::hide signal is emitted when `widget` is hidden, for example with
    /// [`WidgetExt::hide()`][crate::prelude::WidgetExt::hide()].
    ///
    ///
    ///
    ///
    /// #### `hierarchy-changed`
    ///  The ::hierarchy-changed signal is emitted when the
    /// anchored state of a widget changes. A widget is
    /// “anchored” when its toplevel
    /// ancestor is a [`Window`][crate::Window]. This signal is emitted when
    /// a widget changes from un-anchored to anchored or vice-versa.
    ///
    ///
    ///
    ///
    /// #### `key-press-event`
    ///  The ::key-press-event signal is emitted when a key is pressed. The signal
    /// emission will reoccur at the key-repeat rate when the key is kept pressed.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::KEY_PRESS_MASK`][crate::gdk::EventMask::KEY_PRESS_MASK] mask.
    ///
    /// This signal will be sent to the grab widget if there is one.
    ///
    ///
    ///
    ///
    /// #### `key-release-event`
    ///  The ::key-release-event signal is emitted when a key is released.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::KEY_RELEASE_MASK`][crate::gdk::EventMask::KEY_RELEASE_MASK] mask.
    ///
    /// This signal will be sent to the grab widget if there is one.
    ///
    ///
    ///
    ///
    /// #### `keynav-failed`
    ///  Gets emitted if keyboard navigation fails.
    /// See [`WidgetExt::keynav_failed()`][crate::prelude::WidgetExt::keynav_failed()] for details.
    ///
    ///
    ///
    ///
    /// #### `leave-notify-event`
    ///  The ::leave-notify-event will be emitted when the pointer leaves
    /// the `widget`'s window.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::LEAVE_NOTIFY_MASK`][crate::gdk::EventMask::LEAVE_NOTIFY_MASK] mask.
    ///
    /// This signal will be sent to the grab widget if there is one.
    ///
    ///
    ///
    ///
    /// #### `map`
    ///  The ::map signal is emitted when `widget` is going to be mapped, that is
    /// when the widget is visible (which is controlled with
    /// [`WidgetExt::set_visible()`][crate::prelude::WidgetExt::set_visible()]) and all its parents up to the toplevel widget
    /// are also visible. Once the map has occurred, [`map-event`][struct@crate::Widget#map-event] will
    /// be emitted.
    ///
    /// The ::map signal can be used to determine whether a widget will be drawn,
    /// for instance it can resume an animation that was stopped during the
    /// emission of [`unmap`][struct@crate::Widget#unmap].
    ///
    ///
    ///
    ///
    /// #### `map-event`
    ///  The ::map-event signal will be emitted when the `widget`'s window is
    /// mapped. A window is mapped when it becomes visible on the screen.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::STRUCTURE_MASK`][crate::gdk::EventMask::STRUCTURE_MASK] mask. GDK will enable this mask
    /// automatically for all new windows.
    ///
    ///
    ///
    ///
    /// #### `mnemonic-activate`
    ///  The default handler for this signal activates `widget` if `group_cycling`
    /// is [`false`], or just makes `widget` grab focus if `group_cycling` is [`true`].
    ///
    ///
    ///
    ///
    /// #### `motion-notify-event`
    ///  The ::motion-notify-event signal is emitted when the pointer moves
    /// over the widget's [`gdk::Window`][crate::gdk::Window].
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget
    /// needs to enable the [`gdk::EventMask::POINTER_MOTION_MASK`][crate::gdk::EventMask::POINTER_MOTION_MASK] mask.
    ///
    /// This signal will be sent to the grab widget if there is one.
    ///
    ///
    ///
    ///
    /// #### `move-focus`
    ///  Action
    ///
    ///
    /// #### `parent-set`
    ///  The ::parent-set signal is emitted when a new parent
    /// has been set on a widget.
    ///
    ///
    ///
    ///
    /// #### `popup-menu`
    ///  This signal gets emitted whenever a widget should pop up a context
    /// menu. This usually happens through the standard key binding mechanism;
    /// by pressing a certain key while a widget is focused, the user can cause
    /// the widget to pop up a menu. For example, the [`Entry`][crate::Entry] widget creates
    /// a menu with clipboard commands. See the
    /// [Popup Menu Migration Checklist][checklist-popup-menu]
    /// for an example of how to use this signal.
    ///
    /// Action
    ///
    ///
    /// #### `property-notify-event`
    ///  The ::property-notify-event signal will be emitted when a property on
    /// the `widget`'s window has been changed or deleted.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::PROPERTY_CHANGE_MASK`][crate::gdk::EventMask::PROPERTY_CHANGE_MASK] mask.
    ///
    ///
    ///
    ///
    /// #### `proximity-in-event`
    ///  To receive this signal the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::PROXIMITY_IN_MASK`][crate::gdk::EventMask::PROXIMITY_IN_MASK] mask.
    ///
    /// This signal will be sent to the grab widget if there is one.
    ///
    ///
    ///
    ///
    /// #### `proximity-out-event`
    ///  To receive this signal the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::PROXIMITY_OUT_MASK`][crate::gdk::EventMask::PROXIMITY_OUT_MASK] mask.
    ///
    /// This signal will be sent to the grab widget if there is one.
    ///
    ///
    ///
    ///
    /// #### `query-tooltip`
    ///  Emitted when [`has-tooltip`][struct@crate::Widget#has-tooltip] is [`true`] and the hover timeout
    /// has expired with the cursor hovering "above" `widget`; or emitted when `widget` got
    /// focus in keyboard mode.
    ///
    /// Using the given coordinates, the signal handler should determine
    /// whether a tooltip should be shown for `widget`. If this is the case
    /// [`true`] should be returned, [`false`] otherwise. Note that if
    /// `keyboard_mode` is [`true`], the values of `x` and `y` are undefined and
    /// should not be used.
    ///
    /// The signal handler is free to manipulate `tooltip` with the therefore
    /// destined function calls.
    ///
    ///
    ///
    ///
    /// #### `realize`
    ///  The ::realize signal is emitted when `widget` is associated with a
    /// [`gdk::Window`][crate::gdk::Window], which means that [`WidgetExt::realize()`][crate::prelude::WidgetExt::realize()] has been called or the
    /// widget has been mapped (that is, it is going to be drawn).
    ///
    ///
    ///
    ///
    /// #### `screen-changed`
    ///  The ::screen-changed signal gets emitted when the
    /// screen of a widget has changed.
    ///
    ///
    ///
    ///
    /// #### `scroll-event`
    ///  The ::scroll-event signal is emitted when a button in the 4 to 7
    /// range is pressed. Wheel mice are usually configured to generate
    /// button press events for buttons 4 and 5 when the wheel is turned.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::SCROLL_MASK`][crate::gdk::EventMask::SCROLL_MASK] mask.
    ///
    /// This signal will be sent to the grab widget if there is one.
    ///
    ///
    ///
    ///
    /// #### `selection-clear-event`
    ///  The ::selection-clear-event signal will be emitted when the
    /// the `widget`'s window has lost ownership of a selection.
    ///
    ///
    ///
    ///
    /// #### `selection-get`
    ///
    ///
    ///
    /// #### `selection-notify-event`
    ///
    ///
    ///
    /// #### `selection-received`
    ///
    ///
    ///
    /// #### `selection-request-event`
    ///  The ::selection-request-event signal will be emitted when
    /// another client requests ownership of the selection owned by
    /// the `widget`'s window.
    ///
    ///
    ///
    ///
    /// #### `show`
    ///  The ::show signal is emitted when `widget` is shown, for example with
    /// [`WidgetExt::show()`][crate::prelude::WidgetExt::show()].
    ///
    ///
    ///
    ///
    /// #### `show-help`
    ///  Action
    ///
    ///
    /// #### `size-allocate`
    ///
    ///
    ///
    /// #### `state-changed`
    ///  The ::state-changed signal is emitted when the widget state changes.
    /// See `gtk_widget_get_state()`.
    ///
    ///
    ///
    ///
    /// #### `state-flags-changed`
    ///  The ::state-flags-changed signal is emitted when the widget state
    /// changes, see [`WidgetExt::state_flags()`][crate::prelude::WidgetExt::state_flags()].
    ///
    ///
    ///
    ///
    /// #### `style-set`
    ///  The ::style-set signal is emitted when a new style has been set
    /// on a widget. Note that style-modifying functions like
    /// `gtk_widget_modify_base()` also cause this signal to be emitted.
    ///
    /// Note that this signal is emitted for changes to the deprecated
    /// `GtkStyle`. To track changes to the [`StyleContext`][crate::StyleContext] associated
    /// with a widget, use the [`style-updated`][struct@crate::Widget#style-updated] signal.
    ///
    ///
    ///
    ///
    /// #### `style-updated`
    ///  The ::style-updated signal is a convenience signal that is emitted when the
    /// [`changed`][struct@crate::StyleContext#changed] signal is emitted on the `widget`'s associated
    /// [`StyleContext`][crate::StyleContext] as returned by [`WidgetExt::style_context()`][crate::prelude::WidgetExt::style_context()].
    ///
    /// Note that style-modifying functions like `gtk_widget_override_color()` also
    /// cause this signal to be emitted.
    ///
    ///
    ///
    ///
    /// #### `touch-event`
    ///
    ///
    ///
    /// #### `unmap`
    ///  The ::unmap signal is emitted when `widget` is going to be unmapped, which
    /// means that either it or any of its parents up to the toplevel widget have
    /// been set as hidden.
    ///
    /// As ::unmap indicates that a widget will not be shown any longer, it can be
    /// used to, for example, stop an animation on the widget.
    ///
    ///
    ///
    ///
    /// #### `unmap-event`
    ///  The ::unmap-event signal will be emitted when the `widget`'s window is
    /// unmapped. A window is unmapped when it becomes invisible on the screen.
    ///
    /// To receive this signal, the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::STRUCTURE_MASK`][crate::gdk::EventMask::STRUCTURE_MASK] mask. GDK will enable this mask
    /// automatically for all new windows.
    ///
    ///
    ///
    ///
    /// #### `unrealize`
    ///  The ::unrealize signal is emitted when the [`gdk::Window`][crate::gdk::Window] associated with
    /// `widget` is destroyed, which means that [`WidgetExt::unrealize()`][crate::prelude::WidgetExt::unrealize()] has been
    /// called or the widget has been unmapped (that is, it is going to be
    /// hidden).
    ///
    ///
    ///
    ///
    /// #### `visibility-notify-event`
    ///  The ::visibility-notify-event will be emitted when the `widget`'s
    /// window is obscured or unobscured.
    ///
    /// To receive this signal the [`gdk::Window`][crate::gdk::Window] associated to the widget needs
    /// to enable the [`gdk::EventMask::VISIBILITY_NOTIFY_MASK`][crate::gdk::EventMask::VISIBILITY_NOTIFY_MASK] mask.
    ///
    ///
    ///
    ///
    /// #### `window-state-event`
    ///  The ::window-state-event will be emitted when the state of the
    /// toplevel window associated to the `widget` changes.
    ///
    /// To receive this signal the [`gdk::Window`][crate::gdk::Window] associated to the widget
    /// needs to enable the [`gdk::EventMask::STRUCTURE_MASK`][crate::gdk::EventMask::STRUCTURE_MASK] mask. GDK will enable
    /// this mask automatically for all new windows.
    ///
    ///
    /// </details>
    ///
    /// # Implements
    ///
    /// [`ExpanderExt`][trait@crate::prelude::ExpanderExt], [`BinExt`][trait@crate::prelude::BinExt], [`ContainerExt`][trait@crate::prelude::ContainerExt], [`WidgetExt`][trait@crate::prelude::WidgetExt], [`trait@glib::ObjectExt`], [`BuildableExt`][trait@crate::prelude::BuildableExt], [`ContainerExtManual`][trait@crate::prelude::ContainerExtManual], [`WidgetExtManual`][trait@crate::prelude::WidgetExtManual], [`BuildableExtManual`][trait@crate::prelude::BuildableExtManual]
    #[doc(alias = "GtkExpander")]
    pub struct Expander(Object<ffi::GtkExpander, ffi::GtkExpanderClass>) @extends Bin, Container, Widget, @implements Buildable;

    match fn {
        type_ => || ffi::gtk_expander_get_type(),
    }
}

impl Expander {
    pub const NONE: Option<&'static Expander> = None;

    /// Creates a new expander using `label` as the text of the label.
    /// ## `label`
    /// the text of the label
    ///
    /// # Returns
    ///
    /// a new [`Expander`][crate::Expander] widget.
    #[doc(alias = "gtk_expander_new")]
    pub fn new(label: Option<&str>) -> Expander {
        assert_initialized_main_thread!();
        unsafe {
            Widget::from_glib_none(ffi::gtk_expander_new(label.to_glib_none().0)).unsafe_cast()
        }
    }

    /// Creates a new expander using `label` as the text of the label.
    /// If characters in `label` are preceded by an underscore, they are underlined.
    /// If you need a literal underscore character in a label, use “__” (two
    /// underscores). The first underlined character represents a keyboard
    /// accelerator called a mnemonic.
    /// Pressing Alt and that key activates the button.
    /// ## `label`
    /// the text of the label with an underscore
    ///  in front of the mnemonic character
    ///
    /// # Returns
    ///
    /// a new [`Expander`][crate::Expander] widget.
    #[doc(alias = "gtk_expander_new_with_mnemonic")]
    #[doc(alias = "new_with_mnemonic")]
    pub fn with_mnemonic(label: &str) -> Expander {
        assert_initialized_main_thread!();
        unsafe {
            Widget::from_glib_none(ffi::gtk_expander_new_with_mnemonic(label.to_glib_none().0))
                .unsafe_cast()
        }
    }

    // rustdoc-stripper-ignore-next
    /// Creates a new builder-pattern struct instance to construct [`Expander`] objects.
    ///
    /// This method returns an instance of [`ExpanderBuilder`](crate::builders::ExpanderBuilder) which can be used to create [`Expander`] objects.
    pub fn builder() -> ExpanderBuilder {
        ExpanderBuilder::new()
    }
}

impl Default for Expander {
    fn default() -> Self {
        glib::object::Object::new::<Self>()
    }
}

// rustdoc-stripper-ignore-next
/// A [builder-pattern] type to construct [`Expander`] objects.
///
/// [builder-pattern]: https://doc.rust-lang.org/1.0.0/style/ownership/builders.html
#[must_use = "The builder must be built to be used"]
pub struct ExpanderBuilder {
    builder: glib::object::ObjectBuilder<'static, Expander>,
}

impl ExpanderBuilder {
    fn new() -> Self {
        Self {
            builder: glib::object::Object::builder(),
        }
    }

    pub fn expanded(self, expanded: bool) -> Self {
        Self {
            builder: self.builder.property("expanded", expanded),
        }
    }

    pub fn label(self, label: impl Into<glib::GString>) -> Self {
        Self {
            builder: self.builder.property("label", label.into()),
        }
    }

    /// Whether the label widget should fill all available horizontal space.
    ///
    /// Note that this property is ignored since 3.20.
    pub fn label_fill(self, label_fill: bool) -> Self {
        Self {
            builder: self.builder.property("label-fill", label_fill),
        }
    }

    pub fn label_widget(self, label_widget: &impl IsA<Widget>) -> Self {
        Self {
            builder: self
                .builder
                .property("label-widget", label_widget.clone().upcast()),
        }
    }

    /// When this property is [`true`], the expander will resize the toplevel
    /// widget containing the expander upon expanding and collapsing.
    pub fn resize_toplevel(self, resize_toplevel: bool) -> Self {
        Self {
            builder: self.builder.property("resize-toplevel", resize_toplevel),
        }
    }

    pub fn use_markup(self, use_markup: bool) -> Self {
        Self {
            builder: self.builder.property("use-markup", use_markup),
        }
    }

    pub fn use_underline(self, use_underline: bool) -> Self {
        Self {
            builder: self.builder.property("use-underline", use_underline),
        }
    }

    pub fn border_width(self, border_width: u32) -> Self {
        Self {
            builder: self.builder.property("border-width", border_width),
        }
    }

    pub fn child(self, child: &impl IsA<Widget>) -> Self {
        Self {
            builder: self.builder.property("child", child.clone().upcast()),
        }
    }

    pub fn resize_mode(self, resize_mode: ResizeMode) -> Self {
        Self {
            builder: self.builder.property("resize-mode", resize_mode),
        }
    }

    pub fn app_paintable(self, app_paintable: bool) -> Self {
        Self {
            builder: self.builder.property("app-paintable", app_paintable),
        }
    }

    pub fn can_default(self, can_default: bool) -> Self {
        Self {
            builder: self.builder.property("can-default", can_default),
        }
    }

    pub fn can_focus(self, can_focus: bool) -> Self {
        Self {
            builder: self.builder.property("can-focus", can_focus),
        }
    }

    pub fn events(self, events: gdk::EventMask) -> Self {
        Self {
            builder: self.builder.property("events", events),
        }
    }

    /// Whether to expand in both directions. Setting this sets both [`hexpand`][struct@crate::Widget#hexpand] and [`vexpand`][struct@crate::Widget#vexpand]
    pub fn expand(self, expand: bool) -> Self {
        Self {
            builder: self.builder.property("expand", expand),
        }
    }

    /// Whether the widget should grab focus when it is clicked with the mouse.
    ///
    /// This property is only relevant for widgets that can take focus.
    ///
    /// Before 3.20, several widgets (GtkButton, GtkFileChooserButton,
    /// GtkComboBox) implemented this property individually.
    pub fn focus_on_click(self, focus_on_click: bool) -> Self {
        Self {
            builder: self.builder.property("focus-on-click", focus_on_click),
        }
    }

    /// How to distribute horizontal space if widget gets extra space, see [`Align`][crate::Align]
    pub fn halign(self, halign: Align) -> Self {
        Self {
            builder: self.builder.property("halign", halign),
        }
    }

    pub fn has_default(self, has_default: bool) -> Self {
        Self {
            builder: self.builder.property("has-default", has_default),
        }
    }

    pub fn has_focus(self, has_focus: bool) -> Self {
        Self {
            builder: self.builder.property("has-focus", has_focus),
        }
    }

    /// Enables or disables the emission of [`query-tooltip`][struct@crate::Widget#query-tooltip] on `widget`.
    /// A value of [`true`] indicates that `widget` can have a tooltip, in this case
    /// the widget will be queried using [`query-tooltip`][struct@crate::Widget#query-tooltip] to determine
    /// whether it will provide a tooltip or not.
    ///
    /// Note that setting this property to [`true`] for the first time will change
    /// the event masks of the GdkWindows of this widget to include leave-notify
    /// and motion-notify events. This cannot and will not be undone when the
    /// property is set to [`false`] again.
    pub fn has_tooltip(self, has_tooltip: bool) -> Self {
        Self {
            builder: self.builder.property("has-tooltip", has_tooltip),
        }
    }

    pub fn height_request(self, height_request: i32) -> Self {
        Self {
            builder: self.builder.property("height-request", height_request),
        }
    }

    /// Whether to expand horizontally. See [`WidgetExt::set_hexpand()`][crate::prelude::WidgetExt::set_hexpand()].
    pub fn hexpand(self, hexpand: bool) -> Self {
        Self {
            builder: self.builder.property("hexpand", hexpand),
        }
    }

    /// Whether to use the [`hexpand`][struct@crate::Widget#hexpand] property. See [`WidgetExt::is_hexpand_set()`][crate::prelude::WidgetExt::is_hexpand_set()].
    pub fn hexpand_set(self, hexpand_set: bool) -> Self {
        Self {
            builder: self.builder.property("hexpand-set", hexpand_set),
        }
    }

    pub fn is_focus(self, is_focus: bool) -> Self {
        Self {
            builder: self.builder.property("is-focus", is_focus),
        }
    }

    /// Sets all four sides' margin at once. If read, returns max
    /// margin on any side.
    pub fn margin(self, margin: i32) -> Self {
        Self {
            builder: self.builder.property("margin", margin),
        }
    }

    /// Margin on bottom side of widget.
    ///
    /// This property adds margin outside of the widget's normal size
    /// request, the margin will be added in addition to the size from
    /// [`WidgetExt::set_size_request()`][crate::prelude::WidgetExt::set_size_request()] for example.
    pub fn margin_bottom(self, margin_bottom: i32) -> Self {
        Self {
            builder: self.builder.property("margin-bottom", margin_bottom),
        }
    }

    /// Margin on end of widget, horizontally. This property supports
    /// left-to-right and right-to-left text directions.
    ///
    /// This property adds margin outside of the widget's normal size
    /// request, the margin will be added in addition to the size from
    /// [`WidgetExt::set_size_request()`][crate::prelude::WidgetExt::set_size_request()] for example.
    pub fn margin_end(self, margin_end: i32) -> Self {
        Self {
            builder: self.builder.property("margin-end", margin_end),
        }
    }

    /// Margin on start of widget, horizontally. This property supports
    /// left-to-right and right-to-left text directions.
    ///
    /// This property adds margin outside of the widget's normal size
    /// request, the margin will be added in addition to the size from
    /// [`WidgetExt::set_size_request()`][crate::prelude::WidgetExt::set_size_request()] for example.
    pub fn margin_start(self, margin_start: i32) -> Self {
        Self {
            builder: self.builder.property("margin-start", margin_start),
        }
    }

    /// Margin on top side of widget.
    ///
    /// This property adds margin outside of the widget's normal size
    /// request, the margin will be added in addition to the size from
    /// [`WidgetExt::set_size_request()`][crate::prelude::WidgetExt::set_size_request()] for example.
    pub fn margin_top(self, margin_top: i32) -> Self {
        Self {
            builder: self.builder.property("margin-top", margin_top),
        }
    }

    pub fn name(self, name: impl Into<glib::GString>) -> Self {
        Self {
            builder: self.builder.property("name", name.into()),
        }
    }

    pub fn no_show_all(self, no_show_all: bool) -> Self {
        Self {
            builder: self.builder.property("no-show-all", no_show_all),
        }
    }

    /// The requested opacity of the widget. See [`WidgetExt::set_opacity()`][crate::prelude::WidgetExt::set_opacity()] for
    /// more details about window opacity.
    ///
    /// Before 3.8 this was only available in GtkWindow
    pub fn opacity(self, opacity: f64) -> Self {
        Self {
            builder: self.builder.property("opacity", opacity),
        }
    }

    pub fn parent(self, parent: &impl IsA<Container>) -> Self {
        Self {
            builder: self.builder.property("parent", parent.clone().upcast()),
        }
    }

    pub fn receives_default(self, receives_default: bool) -> Self {
        Self {
            builder: self.builder.property("receives-default", receives_default),
        }
    }

    pub fn sensitive(self, sensitive: bool) -> Self {
        Self {
            builder: self.builder.property("sensitive", sensitive),
        }
    }

    /// Sets the text of tooltip to be the given string, which is marked up
    /// with the [Pango text markup language][PangoMarkupFormat].
    /// Also see [`Tooltip::set_markup()`][crate::Tooltip::set_markup()].
    ///
    /// This is a convenience property which will take care of getting the
    /// tooltip shown if the given string is not [`None`]: [`has-tooltip`][struct@crate::Widget#has-tooltip]
    /// will automatically be set to [`true`] and there will be taken care of
    /// [`query-tooltip`][struct@crate::Widget#query-tooltip] in the default signal handler.
    ///
    /// Note that if both [`tooltip-text`][struct@crate::Widget#tooltip-text] and [`tooltip-markup`][struct@crate::Widget#tooltip-markup]
    /// are set, the last one wins.
    pub fn tooltip_markup(self, tooltip_markup: impl Into<glib::GString>) -> Self {
        Self {
            builder: self
                .builder
                .property("tooltip-markup", tooltip_markup.into()),
        }
    }

    /// Sets the text of tooltip to be the given string.
    ///
    /// Also see [`Tooltip::set_text()`][crate::Tooltip::set_text()].
    ///
    /// This is a convenience property which will take care of getting the
    /// tooltip shown if the given string is not [`None`]: [`has-tooltip`][struct@crate::Widget#has-tooltip]
    /// will automatically be set to [`true`] and there will be taken care of
    /// [`query-tooltip`][struct@crate::Widget#query-tooltip] in the default signal handler.
    ///
    /// Note that if both [`tooltip-text`][struct@crate::Widget#tooltip-text] and [`tooltip-markup`][struct@crate::Widget#tooltip-markup]
    /// are set, the last one wins.
    pub fn tooltip_text(self, tooltip_text: impl Into<glib::GString>) -> Self {
        Self {
            builder: self.builder.property("tooltip-text", tooltip_text.into()),
        }
    }

    /// How to distribute vertical space if widget gets extra space, see [`Align`][crate::Align]
    pub fn valign(self, valign: Align) -> Self {
        Self {
            builder: self.builder.property("valign", valign),
        }
    }

    /// Whether to expand vertically. See [`WidgetExt::set_vexpand()`][crate::prelude::WidgetExt::set_vexpand()].
    pub fn vexpand(self, vexpand: bool) -> Self {
        Self {
            builder: self.builder.property("vexpand", vexpand),
        }
    }

    /// Whether to use the [`vexpand`][struct@crate::Widget#vexpand] property. See [`WidgetExt::is_vexpand_set()`][crate::prelude::WidgetExt::is_vexpand_set()].
    pub fn vexpand_set(self, vexpand_set: bool) -> Self {
        Self {
            builder: self.builder.property("vexpand-set", vexpand_set),
        }
    }

    pub fn visible(self, visible: bool) -> Self {
        Self {
            builder: self.builder.property("visible", visible),
        }
    }

    pub fn width_request(self, width_request: i32) -> Self {
        Self {
            builder: self.builder.property("width-request", width_request),
        }
    }

    // rustdoc-stripper-ignore-next
    /// Build the [`Expander`].
    #[must_use = "Building the object from the builder is usually expensive and is not expected to have side effects"]
    pub fn build(self) -> Expander {
        assert_initialized_main_thread!();
        self.builder.build()
    }
}

/// Trait containing all [`struct@Expander`] methods.
///
/// # Implementors
///
/// [`Expander`][struct@crate::Expander]
pub trait ExpanderExt: IsA<Expander> + 'static {
    /// Queries a [`Expander`][crate::Expander] and returns its current state. Returns [`true`]
    /// if the child widget is revealed.
    ///
    /// See [`set_expanded()`][Self::set_expanded()].
    ///
    /// # Returns
    ///
    /// the current state of the expander
    #[doc(alias = "gtk_expander_get_expanded")]
    #[doc(alias = "get_expanded")]
    #[doc(alias = "expanded")]
    fn is_expanded(&self) -> bool {
        unsafe {
            from_glib(ffi::gtk_expander_get_expanded(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    /// Fetches the text from a label widget including any embedded
    /// underlines indicating mnemonics and Pango markup, as set by
    /// [`set_label()`][Self::set_label()]. If the label text has not been set the
    /// return value will be [`None`]. This will be the case if you create an
    /// empty button with [`Button::new()`][crate::Button::new()] to use as a container.
    ///
    /// Note that this function behaved differently in versions prior to
    /// 2.14 and used to return the label text stripped of embedded
    /// underlines indicating mnemonics and Pango markup. This problem can
    /// be avoided by fetching the label text directly from the label
    /// widget.
    ///
    /// # Returns
    ///
    /// The text of the label widget. This string is owned
    ///  by the widget and must not be modified or freed.
    #[doc(alias = "gtk_expander_get_label")]
    #[doc(alias = "get_label")]
    fn label(&self) -> Option<glib::GString> {
        unsafe { from_glib_none(ffi::gtk_expander_get_label(self.as_ref().to_glib_none().0)) }
    }

    /// Returns whether the label widget will fill all available
    /// horizontal space allocated to `self`.
    ///
    /// # Returns
    ///
    /// [`true`] if the label widget will fill all
    ///  available horizontal space
    #[doc(alias = "gtk_expander_get_label_fill")]
    #[doc(alias = "get_label_fill")]
    #[doc(alias = "label-fill")]
    fn is_label_fill(&self) -> bool {
        unsafe {
            from_glib(ffi::gtk_expander_get_label_fill(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    /// Retrieves the label widget for the frame. See
    /// [`set_label_widget()`][Self::set_label_widget()].
    ///
    /// # Returns
    ///
    /// the label widget,
    ///  or [`None`] if there is none
    #[doc(alias = "gtk_expander_get_label_widget")]
    #[doc(alias = "get_label_widget")]
    #[doc(alias = "label-widget")]
    fn label_widget(&self) -> Option<Widget> {
        unsafe {
            from_glib_none(ffi::gtk_expander_get_label_widget(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    /// Returns whether the expander will resize the toplevel widget
    /// containing the expander upon resizing and collpasing.
    ///
    /// # Returns
    ///
    /// the “resize toplevel” setting.
    #[doc(alias = "gtk_expander_get_resize_toplevel")]
    #[doc(alias = "get_resize_toplevel")]
    #[doc(alias = "resize-toplevel")]
    fn resizes_toplevel(&self) -> bool {
        unsafe {
            from_glib(ffi::gtk_expander_get_resize_toplevel(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    /// Returns whether the label’s text is interpreted as marked up with
    /// the [Pango text markup language][PangoMarkupFormat].
    /// See [`set_use_markup()`][Self::set_use_markup()].
    ///
    /// # Returns
    ///
    /// [`true`] if the label’s text will be parsed for markup
    #[doc(alias = "gtk_expander_get_use_markup")]
    #[doc(alias = "get_use_markup")]
    #[doc(alias = "use-markup")]
    fn uses_markup(&self) -> bool {
        unsafe {
            from_glib(ffi::gtk_expander_get_use_markup(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    /// Returns whether an embedded underline in the expander label
    /// indicates a mnemonic. See [`set_use_underline()`][Self::set_use_underline()].
    ///
    /// # Returns
    ///
    /// [`true`] if an embedded underline in the expander
    ///  label indicates the mnemonic accelerator keys
    #[doc(alias = "gtk_expander_get_use_underline")]
    #[doc(alias = "get_use_underline")]
    #[doc(alias = "use-underline")]
    fn uses_underline(&self) -> bool {
        unsafe {
            from_glib(ffi::gtk_expander_get_use_underline(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    /// Sets the state of the expander. Set to [`true`], if you want
    /// the child widget to be revealed, and [`false`] if you want the
    /// child widget to be hidden.
    /// ## `expanded`
    /// whether the child widget is revealed
    #[doc(alias = "gtk_expander_set_expanded")]
    #[doc(alias = "expanded")]
    fn set_expanded(&self, expanded: bool) {
        unsafe {
            ffi::gtk_expander_set_expanded(self.as_ref().to_glib_none().0, expanded.into_glib());
        }
    }

    /// Sets the text of the label of the expander to `label`.
    ///
    /// This will also clear any previously set labels.
    /// ## `label`
    /// a string
    #[doc(alias = "gtk_expander_set_label")]
    #[doc(alias = "label")]
    fn set_label(&self, label: Option<&str>) {
        unsafe {
            ffi::gtk_expander_set_label(self.as_ref().to_glib_none().0, label.to_glib_none().0);
        }
    }

    /// Sets whether the label widget should fill all available
    /// horizontal space allocated to `self`.
    ///
    /// Note that this function has no effect since 3.20.
    /// ## `label_fill`
    /// [`true`] if the label should should fill
    ///  all available horizontal space
    #[doc(alias = "gtk_expander_set_label_fill")]
    #[doc(alias = "label-fill")]
    fn set_label_fill(&self, label_fill: bool) {
        unsafe {
            ffi::gtk_expander_set_label_fill(
                self.as_ref().to_glib_none().0,
                label_fill.into_glib(),
            );
        }
    }

    /// Set the label widget for the expander. This is the widget
    /// that will appear embedded alongside the expander arrow.
    /// ## `label_widget`
    /// the new label widget
    #[doc(alias = "gtk_expander_set_label_widget")]
    #[doc(alias = "label-widget")]
    fn set_label_widget(&self, label_widget: Option<&impl IsA<Widget>>) {
        unsafe {
            ffi::gtk_expander_set_label_widget(
                self.as_ref().to_glib_none().0,
                label_widget.map(|p| p.as_ref()).to_glib_none().0,
            );
        }
    }

    /// Sets whether the expander will resize the toplevel widget
    /// containing the expander upon resizing and collpasing.
    /// ## `resize_toplevel`
    /// whether to resize the toplevel
    #[doc(alias = "gtk_expander_set_resize_toplevel")]
    #[doc(alias = "resize-toplevel")]
    fn set_resize_toplevel(&self, resize_toplevel: bool) {
        unsafe {
            ffi::gtk_expander_set_resize_toplevel(
                self.as_ref().to_glib_none().0,
                resize_toplevel.into_glib(),
            );
        }
    }

    /// Sets whether the text of the label contains markup in
    /// [Pango’s text markup language][PangoMarkupFormat].
    /// See [`LabelExt::set_markup()`][crate::prelude::LabelExt::set_markup()].
    /// ## `use_markup`
    /// [`true`] if the label’s text should be parsed for markup
    #[doc(alias = "gtk_expander_set_use_markup")]
    #[doc(alias = "use-markup")]
    fn set_use_markup(&self, use_markup: bool) {
        unsafe {
            ffi::gtk_expander_set_use_markup(
                self.as_ref().to_glib_none().0,
                use_markup.into_glib(),
            );
        }
    }

    /// If true, an underline in the text of the expander label indicates
    /// the next character should be used for the mnemonic accelerator key.
    /// ## `use_underline`
    /// [`true`] if underlines in the text indicate mnemonics
    #[doc(alias = "gtk_expander_set_use_underline")]
    #[doc(alias = "use-underline")]
    fn set_use_underline(&self, use_underline: bool) {
        unsafe {
            ffi::gtk_expander_set_use_underline(
                self.as_ref().to_glib_none().0,
                use_underline.into_glib(),
            );
        }
    }

    #[doc(alias = "activate")]
    fn connect_activate<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn activate_trampoline<P: IsA<Expander>, F: Fn(&P) + 'static>(
            this: *mut ffi::GtkExpander,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(Expander::from_glib_borrow(this).unsafe_cast_ref())
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"activate".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    activate_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    fn emit_activate(&self) {
        self.emit_by_name::<()>("activate", &[]);
    }

    #[doc(alias = "expanded")]
    fn connect_expanded_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_expanded_trampoline<P: IsA<Expander>, F: Fn(&P) + 'static>(
            this: *mut ffi::GtkExpander,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(Expander::from_glib_borrow(this).unsafe_cast_ref())
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"notify::expanded".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    notify_expanded_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[doc(alias = "label")]
    fn connect_label_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_label_trampoline<P: IsA<Expander>, F: Fn(&P) + 'static>(
            this: *mut ffi::GtkExpander,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(Expander::from_glib_borrow(this).unsafe_cast_ref())
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"notify::label".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    notify_label_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[doc(alias = "label-fill")]
    fn connect_label_fill_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_label_fill_trampoline<P: IsA<Expander>, F: Fn(&P) + 'static>(
            this: *mut ffi::GtkExpander,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(Expander::from_glib_borrow(this).unsafe_cast_ref())
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"notify::label-fill".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    notify_label_fill_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[doc(alias = "label-widget")]
    fn connect_label_widget_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_label_widget_trampoline<
            P: IsA<Expander>,
            F: Fn(&P) + 'static,
        >(
            this: *mut ffi::GtkExpander,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(Expander::from_glib_borrow(this).unsafe_cast_ref())
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"notify::label-widget".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    notify_label_widget_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[doc(alias = "resize-toplevel")]
    fn connect_resize_toplevel_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_resize_toplevel_trampoline<
            P: IsA<Expander>,
            F: Fn(&P) + 'static,
        >(
            this: *mut ffi::GtkExpander,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(Expander::from_glib_borrow(this).unsafe_cast_ref())
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"notify::resize-toplevel".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    notify_resize_toplevel_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[doc(alias = "use-markup")]
    fn connect_use_markup_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_use_markup_trampoline<P: IsA<Expander>, F: Fn(&P) + 'static>(
            this: *mut ffi::GtkExpander,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(Expander::from_glib_borrow(this).unsafe_cast_ref())
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"notify::use-markup".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    notify_use_markup_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[doc(alias = "use-underline")]
    fn connect_use_underline_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_use_underline_trampoline<
            P: IsA<Expander>,
            F: Fn(&P) + 'static,
        >(
            this: *mut ffi::GtkExpander,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(Expander::from_glib_borrow(this).unsafe_cast_ref())
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"notify::use-underline".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    notify_use_underline_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }
}

impl<O: IsA<Expander>> ExpanderExt for O {}