gtk4/subclass/

widget.rs

// Take a look at the license at the top of the repository in the LICENSE file.

// rustdoc-stripper-ignore-next
//! Traits intended for subclassing [`Widget`].

use std::{boxed::Box as Box_, collections::HashMap, fmt, future::Future};

use glib::{
    GString, Variant,
    clone::Downgrade,
    property::{Property, PropertyGet},
    subclass::SignalId,
    translate::*,
};

use crate::{
    AccessibleRole, Buildable, BuilderRustScope, BuilderScope, ConstraintTarget, DirectionType,
    LayoutManager, Orientation, SizeRequestMode, Snapshot, StateFlags, SystemSetting,
    TextDirection, Tooltip, Widget, ffi, prelude::*, subclass::prelude::*,
};

#[derive(Debug, Default)]
struct Internal {
    pub(crate) actions: HashMap<String, glib::ffi::gpointer>,
    pub(crate) scope: Option<*mut <<BuilderRustScope as glib::object::ObjectSubclassIs>::Subclass as ObjectSubclass>::Instance>,
}
unsafe impl Sync for Internal {}
unsafe impl Send for Internal {}

pub struct WidgetActionIter(*mut ffi::GtkWidgetClass, u32);

impl WidgetActionIter {
    pub(crate) fn new(widget_class: *mut ffi::GtkWidgetClass) -> Self {
        Self(widget_class, 0)
    }
}

pub struct WidgetAction(
    glib::Type,
    GString,
    Option<glib::VariantType>,
    Option<GString>,
);

impl WidgetAction {
    // rustdoc-stripper-ignore-next
    /// The type where the action was defined
    pub fn owner(&self) -> glib::Type {
        self.0
    }

    // rustdoc-stripper-ignore-next
    /// The action name
    pub fn name(&self) -> &str {
        self.1.as_ref()
    }

    // rustdoc-stripper-ignore-next
    /// The action parameter type
    pub fn parameter_type(&self) -> Option<&glib::VariantType> {
        self.2.as_ref()
    }

    // rustdoc-stripper-ignore-next
    /// The action property name
    pub fn property_name(&self) -> Option<&str> {
        self.3.as_ref().map(|s| s.as_ref())
    }
}

impl fmt::Debug for WidgetAction {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("WidgetAction")
            .field("owner", &self.owner())
            .field("name", &self.name())
            .field("parameter_type", &self.parameter_type())
            .field("property_name", &self.property_name())
            .finish()
    }
}

impl Iterator for WidgetActionIter {
    type Item = WidgetAction;

    fn next(&mut self) -> Option<Self::Item> {
        unsafe {
            let mut owner = std::mem::MaybeUninit::uninit();
            let mut action_name_ptr = std::ptr::null();
            let mut parameter_type = std::ptr::null();
            let mut property_name_ptr = std::ptr::null();
            let found: bool = from_glib(ffi::gtk_widget_class_query_action(
                self.0,
                self.1,
                owner.as_mut_ptr(),
                &mut action_name_ptr,
                &mut parameter_type,
                &mut property_name_ptr,
            ));
            if found {
                self.1 += 1;
                let property_name: Option<GString> = from_glib_none(property_name_ptr);
                let action_name: GString = from_glib_none(action_name_ptr);

                Some(WidgetAction(
                    from_glib(owner.assume_init()),
                    action_name,
                    from_glib_none(parameter_type),
                    property_name,
                ))
            } else {
                None
            }
        }
    }
}

impl std::iter::FusedIterator for WidgetActionIter {}

#[cfg(feature = "v4_10")]
#[doc(hidden)]
pub trait WidgetImplBounds:
    IsA<Widget> + IsA<crate::Accessible> + IsA<Buildable> + IsA<ConstraintTarget>
{
}
#[cfg(feature = "v4_10")]
impl<T: IsA<Widget> + IsA<crate::Accessible> + IsA<Buildable> + IsA<ConstraintTarget>>
    WidgetImplBounds for T
{
}

#[cfg(not(feature = "v4_10"))]
#[doc(hidden)]
pub trait WidgetImplBounds: IsA<Widget> + IsA<Buildable> + IsA<ConstraintTarget> {}
#[cfg(not(feature = "v4_10"))]
impl<T: IsA<Widget> + IsA<Buildable> + IsA<ConstraintTarget>> WidgetImplBounds for T {}

pub trait WidgetImpl: ObjectImpl + ObjectSubclass<Type: WidgetImplBounds> {
    /// Computes whether a container should give this
    ///   widget extra space when possible.
    fn compute_expand(&self, hexpand: &mut bool, vexpand: &mut bool) {
        self.parent_compute_expand(hexpand, vexpand)
    }

    /// Tests if a given point is contained in the widget.
    ///
    /// The coordinates for (x, y) must be in widget coordinates, so
    /// (0, 0) is assumed to be the top left of @widget's content area.
    /// ## `x`
    /// X coordinate to test, relative to @widget's origin
    /// ## `y`
    /// Y coordinate to test, relative to @widget's origin
    ///
    /// # Returns
    ///
    /// true if @widget contains the point (x, y)
    fn contains(&self, x: f64, y: f64) -> bool {
        self.parent_contains(x, y)
    }

    /// Signal emitted when the text direction of a
    ///   widget changes.
    fn direction_changed(&self, previous_direction: TextDirection) {
        self.parent_direction_changed(previous_direction)
    }

    /// Vfunc for gtk_widget_child_focus()
    fn focus(&self, direction_type: DirectionType) -> bool {
        self.parent_focus(direction_type)
    }

    /// Gets whether the widget prefers a height-for-width layout
    /// or a width-for-height layout.
    ///
    /// Single-child widgets generally propagate the preference of
    /// their child, more complex widgets need to request something
    /// either in context of their children or in context of their
    /// allocation capabilities.
    ///
    /// # Returns
    ///
    /// The [`SizeRequestMode`][crate::SizeRequestMode] preferred by @widget.
    #[doc(alias = "get_request_mode")]
    fn request_mode(&self) -> SizeRequestMode {
        self.parent_request_mode()
    }

    /// Causes @widget to have the keyboard focus for the window
    /// that it belongs to.
    ///
    /// If @widget is not focusable, or its [`WidgetImpl::grab_focus()`][crate::subclass::prelude::WidgetImpl::grab_focus()]
    /// implementation cannot transfer the focus to a descendant of @widget
    /// that is focusable, it will not take focus and false will be returned.
    ///
    /// Calling [`WidgetExt::grab_focus()`][crate::prelude::WidgetExt::grab_focus()] on an already focused widget
    /// is allowed, should not have an effect, and return true.
    ///
    /// # Returns
    ///
    /// true if focus is now inside @widget
    fn grab_focus(&self) -> bool {
        self.parent_grab_focus()
    }

    /// Reverses the effects of [method.Gtk.Widget.show].
    ///
    /// This is causing the widget to be hidden (invisible to the user).
    ///
    /// # Deprecated since 4.10
    ///
    /// Use [`WidgetExt::set_visible()`][crate::prelude::WidgetExt::set_visible()] instead
    #[cfg_attr(feature = "v4_10", deprecated = "Since 4.10")]
    #[allow(deprecated)]
    fn hide(&self) {
        self.parent_hide()
    }

    /// s toplevel.
    ///
    /// The default [`keynav-failed`][struct@crate::Widget#keynav-failed] handler returns
    /// false for [enum@Gtk.DirectionType.tab-forward] and
    /// [enum@Gtk.DirectionType.tab-backward]. For the other values
    /// of [`DirectionType`][crate::DirectionType] it returns true.
    ///
    /// Whenever the default handler returns true, it also calls
    /// [`WidgetExt::error_bell()`][crate::prelude::WidgetExt::error_bell()] to notify the user of the
    /// failed keyboard navigation.
    ///
    /// A use case for providing an own implementation of `::keynav-failed`
    /// (either by connecting to it or by overriding it) would be a row of
    /// [`Entry`][crate::Entry] widgets where the user should be able to navigate
    /// the entire row with the cursor keys, as e.g. known from user
    /// interfaces that require entering license keys.
    /// ## `direction`
    /// direction of focus movement
    ///
    /// # Returns
    ///
    /// true if stopping keyboard navigation is fine, false
    ///   if the emitting widget should try to handle the keyboard
    ///   navigation attempt in its parent widget
    fn keynav_failed(&self, direction_type: DirectionType) -> bool {
        self.parent_keynav_failed(direction_type)
    }

    /// t already.
    ///
    /// This function is only for use in widget implementations.
    fn map(&self) {
        self.parent_map()
    }

    /// s geometry management section](class.Widget.html#height-for-width-geometry-management) for
    /// a more details on implementing `GtkWidgetClass.measure()`.
    /// ## `orientation`
    /// the orientation to measure
    /// ## `for_size`
    /// Size for the opposite of @orientation, i.e.
    ///   if @orientation is [`Orientation::Horizontal`][crate::Orientation::Horizontal], this is
    ///   the height the widget should be measured with. The [`Orientation::Vertical`][crate::Orientation::Vertical]
    ///   case is analogous. This way, both height-for-width and width-for-height
    ///   requests can be implemented. If no size is known, -1 can be passed.
    ///
    /// # Returns
    ///
    ///
    /// ## `minimum`
    /// location to store the minimum size
    ///
    /// ## `natural`
    /// location to store the natural size
    ///
    /// ## `minimum_baseline`
    /// location to store the baseline
    ///   position for the minimum size, or -1 to report no baseline
    ///
    /// ## `natural_baseline`
    /// location to store the baseline
    ///   position for the natural size, or -1 to report no baseline
    fn measure(&self, orientation: Orientation, for_size: i32) -> (i32, i32, i32, i32) {
        self.parent_measure(orientation, for_size)
    }

    /// Emits the [`mnemonic-activate`][struct@crate::Widget#mnemonic-activate] signal.
    /// ## `group_cycling`
    /// true if there are other widgets with the same mnemonic
    ///
    /// # Returns
    ///
    /// true if the signal has been handled
    fn mnemonic_activate(&self, group_cycling: bool) -> bool {
        self.parent_mnemonic_activate(group_cycling)
    }

    /// Signal emitted when a change of focus is requested
    fn move_focus(&self, direction_type: DirectionType) {
        self.parent_move_focus(direction_type)
    }

    ///
    ///   widget; or emitted when widget got focus in keyboard mode.
    fn query_tooltip(&self, x: i32, y: i32, keyboard_tooltip: bool, tooltip: &Tooltip) -> bool {
        self.parent_query_tooltip(x, y, keyboard_tooltip, tooltip)
    }

    /// t very useful otherwise. Many times when you think you might
    /// need it, a better approach is to connect to a signal that will be
    /// called after the widget is realized automatically, such as
    /// [`realize`][struct@crate::Widget#realize].
    fn realize(&self) {
        self.parent_realize()
    }

    /// Called when the widget gets added to a [`Root`][crate::Root] widget. Must
    ///   chain up
    fn root(&self) {
        self.parent_root()
    }

    /// Set the focus child of the widget.
    ///
    /// This function is only suitable for widget implementations.
    /// If you want a certain widget to get the input focus, call
    /// [`WidgetExt::grab_focus()`][crate::prelude::WidgetExt::grab_focus()] on it.
    /// ## `child`
    /// a direct child widget of @widget
    ///   or `NULL` to unset the focus child
    fn set_focus_child(&self, child: Option<&Widget>) {
        self.parent_set_focus_child(child)
    }

    /// t shown will not appear on the screen.
    ///
    /// Remember that you have to show the containers containing a widget,
    /// in addition to the widget itself, before it will appear onscreen.
    ///
    /// When a toplevel widget is shown, it is immediately realized and
    /// mapped; other shown widgets are realized and mapped when their
    /// toplevel widget is realized and mapped.
    ///
    /// # Deprecated since 4.10
    ///
    /// Use [`WidgetExt::set_visible()`][crate::prelude::WidgetExt::set_visible()] instead
    #[cfg_attr(feature = "v4_10", deprecated = "Since 4.10")]
    #[allow(deprecated)]
    fn show(&self) {
        self.parent_show()
    }

    /// Called to set the allocation, if the widget does
    ///   not have a layout manager.
    fn size_allocate(&self, width: i32, height: i32, baseline: i32) {
        self.parent_size_allocate(width, height, baseline)
    }

    /// Vfunc called when a new snapshot of the widget has to be taken.
    fn snapshot(&self, snapshot: &Snapshot) {
        self.parent_snapshot(snapshot)
    }

    /// Signal emitted when the widget state changes,
    ///   see gtk_widget_get_state_flags().
    fn state_flags_changed(&self, state_flags: &StateFlags) {
        self.parent_state_flags_changed(state_flags)
    }

    /// Emitted when a system setting was changed. Must chain up.
    fn system_setting_changed(&self, settings: &SystemSetting) {
        self.parent_system_setting_changed(settings)
    }

    /// s currently mapped.
    ///
    /// This function is only for use in widget implementations.
    fn unmap(&self) {
        self.parent_unmap()
    }

    /// Causes a widget to be unrealized.
    ///
    /// This frees all GDK resources associated with the widget.
    ///
    /// This function is only useful in widget implementations.
    fn unrealize(&self) {
        self.parent_unrealize()
    }

    /// Called when the widget is about to be removed from its
    ///   [`Root`][crate::Root] widget. Must chain up
    fn unroot(&self) {
        self.parent_unroot()
    }
}

pub trait WidgetImplExt: WidgetImpl {
    fn parent_compute_expand(&self, hexpand: &mut bool, vexpand: &mut bool) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).compute_expand {
                let mut hexpand_glib = hexpand.into_glib();
                let mut vexpand_glib = vexpand.into_glib();
                f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    &mut hexpand_glib,
                    &mut vexpand_glib,
                );
                *hexpand = from_glib(hexpand_glib);
                *vexpand = from_glib(vexpand_glib);
            }
        }
    }

    // true if the widget contains (x, y)
    fn parent_contains(&self, x: f64, y: f64) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).contains {
                from_glib(f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    x,
                    y,
                ))
            } else {
                false
            }
        }
    }

    fn parent_direction_changed(&self, previous_direction: TextDirection) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).direction_changed {
                f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    previous_direction.into_glib(),
                )
            }
        }
    }

    // Returns true if focus ended up inside widget
    fn parent_focus(&self, direction_type: DirectionType) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).focus {
                from_glib(f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    direction_type.into_glib(),
                ))
            } else {
                false
            }
        }
    }

    fn parent_request_mode(&self) -> SizeRequestMode {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            let f = (*parent_class)
                .get_request_mode
                .expect("No parent class impl for \"get_request_mode\"");
            from_glib(f(self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0))
        }
    }

    // Returns true if focus ended up inside widget
    fn parent_grab_focus(&self) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).grab_focus {
                from_glib(f(self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0))
            } else {
                false
            }
        }
    }

    #[cfg_attr(feature = "v4_10", deprecated = "Since 4.10")]
    #[allow(deprecated)]
    fn parent_hide(&self) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).hide {
                f(self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0)
            }
        }
    }

    // TRUE if stopping keyboard navigation is fine,
    // FALSE if the emitting widget should try to handle the keyboard navigation
    // attempt in its parent container(s).
    fn parent_keynav_failed(&self, direction_type: DirectionType) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).keynav_failed {
                from_glib(f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    direction_type.into_glib(),
                ))
            } else {
                false
            }
        }
    }

    fn parent_map(&self) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).map {
                f(self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0)
            }
        }
    }

    fn parent_measure(&self, orientation: Orientation, for_size: i32) -> (i32, i32, i32, i32) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;

            let f = (*parent_class)
                .measure
                .expect("No parent class impl for \"measure\"");

            let mut min = 0;
            let mut nat = 0;
            let mut min_base = -1;
            let mut nat_base = -1;
            f(
                self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                orientation.into_glib(),
                for_size,
                &mut min,
                &mut nat,
                &mut min_base,
                &mut nat_base,
            );
            (min, nat, min_base, nat_base)
        }
    }

    // True if the signal has been handled
    fn parent_mnemonic_activate(&self, group_cycling: bool) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).mnemonic_activate {
                from_glib(f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    group_cycling.into_glib(),
                ))
            } else {
                false
            }
        }
    }

    fn parent_move_focus(&self, direction_type: DirectionType) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).move_focus {
                f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    direction_type.into_glib(),
                )
            }
        }
    }

    fn parent_query_tooltip(
        &self,
        x: i32,
        y: i32,
        keyboard_tooltip: bool,
        tooltip: &Tooltip,
    ) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).query_tooltip {
                from_glib(f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    x,
                    y,
                    keyboard_tooltip.into_glib(),
                    tooltip.to_glib_none().0,
                ))
            } else {
                false
            }
        }
    }

    fn parent_realize(&self) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).realize {
                f(self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0)
            }
        }
    }

    fn parent_root(&self) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).root {
                f(self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0)
            }
        }
    }

    fn parent_set_focus_child(&self, child: Option<&Widget>) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).set_focus_child {
                f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    child.to_glib_none().0,
                )
            }
        }
    }

    #[cfg_attr(feature = "v4_10", deprecated = "Since 4.10")]
    #[allow(deprecated)]
    fn parent_show(&self) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).show {
                f(self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0)
            }
        }
    }

    fn parent_size_allocate(&self, width: i32, height: i32, baseline: i32) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).size_allocate {
                f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    width,
                    height,
                    baseline,
                )
            }
        }
    }

    fn parent_snapshot(&self, snapshot: &Snapshot) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).snapshot {
                f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    snapshot.to_glib_none().0,
                )
            }
        }
    }

    fn parent_state_flags_changed(&self, state_flags: &StateFlags) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).state_flags_changed {
                f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    state_flags.into_glib(),
                )
            }
        }
    }

    fn parent_system_setting_changed(&self, settings: &SystemSetting) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).system_setting_changed {
                f(
                    self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0,
                    settings.into_glib(),
                )
            }
        }
    }

    fn parent_unmap(&self) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).unmap {
                f(self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0)
            }
        }
    }

    fn parent_unrealize(&self) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).unrealize {
                f(self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0)
            }
        }
    }

    fn parent_unroot(&self) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkWidgetClass;
            if let Some(f) = (*parent_class).unroot {
                f(self.obj().unsafe_cast_ref::<Widget>().to_glib_none().0)
            }
        }
    }
}

impl<T: WidgetImpl> WidgetImplExt for T {}

unsafe impl<T: WidgetImpl> IsSubclassable<T> for Widget {
    fn class_init(class: &mut ::glib::Class<Self>) {
        Self::parent_class_init::<T>(class);

        assert_initialized_main_thread!();

        let klass = class.as_mut();
        unsafe {
            let mut data = T::type_data();
            let data = data.as_mut();
            // Used to store actions for `install_action` and `rust_builder_scope`
            data.set_class_data(<T as ObjectSubclassType>::type_(), Internal::default());
        }

        klass.compute_expand = Some(widget_compute_expand::<T>);
        klass.contains = Some(widget_contains::<T>);
        klass.direction_changed = Some(widget_direction_changed::<T>);
        klass.focus = Some(widget_focus::<T>);
        klass.get_request_mode = Some(widget_get_request_mode::<T>);
        klass.grab_focus = Some(widget_grab_focus::<T>);
        klass.hide = Some(widget_hide::<T>);
        klass.keynav_failed = Some(widget_keynav_failed::<T>);
        klass.map = Some(widget_map::<T>);
        klass.measure = Some(widget_measure::<T>);
        klass.mnemonic_activate = Some(widget_mnemonic_activate::<T>);
        klass.move_focus = Some(widget_move_focus::<T>);
        klass.query_tooltip = Some(widget_query_tooltip::<T>);
        klass.realize = Some(widget_realize::<T>);
        klass.root = Some(widget_root::<T>);
        klass.set_focus_child = Some(widget_set_focus_child::<T>);
        klass.show = Some(widget_show::<T>);
        klass.size_allocate = Some(widget_size_allocate::<T>);
        klass.snapshot = Some(widget_snapshot::<T>);
        klass.state_flags_changed = Some(widget_state_flags_changed::<T>);
        klass.system_setting_changed = Some(widget_system_setting_changed::<T>);
        klass.unmap = Some(widget_unmap::<T>);
        klass.unrealize = Some(widget_unrealize::<T>);
        klass.unroot = Some(widget_unroot::<T>);
    }
}

unsafe extern "C" fn widget_compute_expand<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    hexpand_ptr: *mut glib::ffi::gboolean,
    vexpand_ptr: *mut glib::ffi::gboolean,
) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        let widget = imp.obj();
        let widget = widget.unsafe_cast_ref::<Widget>();
        let mut hexpand: bool = if widget.is_hexpand_set() {
            widget.hexpands()
        } else {
            from_glib(*hexpand_ptr)
        };
        let mut vexpand: bool = if widget.is_vexpand_set() {
            widget.vexpands()
        } else {
            from_glib(*vexpand_ptr)
        };

        imp.compute_expand(&mut hexpand, &mut vexpand);

        *hexpand_ptr = hexpand.into_glib();
        *vexpand_ptr = vexpand.into_glib();
    }
}

unsafe extern "C" fn widget_contains<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    x: f64,
    y: f64,
) -> glib::ffi::gboolean {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.contains(x, y).into_glib()
    }
}

unsafe extern "C" fn widget_direction_changed<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    direction_ptr: ffi::GtkTextDirection,
) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();
        let direction_wrap = from_glib(direction_ptr);

        imp.direction_changed(direction_wrap)
    }
}

unsafe extern "C" fn widget_focus<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    direction_type_ptr: ffi::GtkDirectionType,
) -> glib::ffi::gboolean {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();
        let direction_type = from_glib(direction_type_ptr);

        imp.focus(direction_type).into_glib()
    }
}

unsafe extern "C" fn widget_get_request_mode<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
) -> ffi::GtkSizeRequestMode {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.request_mode().into_glib()
    }
}

unsafe extern "C" fn widget_grab_focus<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
) -> glib::ffi::gboolean {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.grab_focus().into_glib()
    }
}

unsafe extern "C" fn widget_hide<T: WidgetImpl>(ptr: *mut ffi::GtkWidget) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.hide()
    }
}

unsafe extern "C" fn widget_keynav_failed<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    direction_type_ptr: ffi::GtkDirectionType,
) -> glib::ffi::gboolean {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();
        let direction_type = from_glib(direction_type_ptr);

        imp.keynav_failed(direction_type).into_glib()
    }
}

unsafe extern "C" fn widget_map<T: WidgetImpl>(ptr: *mut ffi::GtkWidget) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.map()
    }
}

unsafe extern "C" fn widget_measure<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    orientation_ptr: ffi::GtkOrientation,
    for_size: i32,
    min_ptr: *mut libc::c_int,
    nat_ptr: *mut libc::c_int,
    min_base_ptr: *mut libc::c_int,
    nat_base_ptr: *mut libc::c_int,
) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();
        let orientation = from_glib(orientation_ptr);
        let (min, nat, min_base, nat_base) = imp.measure(orientation, for_size);
        if !min_ptr.is_null() {
            *min_ptr = min;
        }
        if !nat_ptr.is_null() {
            *nat_ptr = nat;
        }
        if !min_base_ptr.is_null() {
            *min_base_ptr = min_base;
        }
        if !nat_base_ptr.is_null() {
            *nat_base_ptr = nat_base;
        }
    }
}

unsafe extern "C" fn widget_mnemonic_activate<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    group_cycling_ptr: glib::ffi::gboolean,
) -> glib::ffi::gboolean {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();
        let group_cycling: bool = from_glib(group_cycling_ptr);

        imp.mnemonic_activate(group_cycling).into_glib()
    }
}

unsafe extern "C" fn widget_move_focus<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    direction_type_ptr: ffi::GtkDirectionType,
) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();
        let direction_type = from_glib(direction_type_ptr);

        imp.move_focus(direction_type)
    }
}

unsafe extern "C" fn widget_query_tooltip<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    x: i32,
    y: i32,
    keyboard_tooltip_ptr: glib::ffi::gboolean,
    tooltip_ptr: *mut ffi::GtkTooltip,
) -> glib::ffi::gboolean {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        let keyboard_tooltip: bool = from_glib(keyboard_tooltip_ptr);
        let tooltip = from_glib_borrow(tooltip_ptr);

        imp.query_tooltip(x, y, keyboard_tooltip, &tooltip)
            .into_glib()
    }
}

unsafe extern "C" fn widget_realize<T: WidgetImpl>(ptr: *mut ffi::GtkWidget) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.realize()
    }
}

unsafe extern "C" fn widget_root<T: WidgetImpl>(ptr: *mut ffi::GtkWidget) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.root()
    }
}

unsafe extern "C" fn widget_set_focus_child<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    child_ptr: *mut ffi::GtkWidget,
) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();
        let child: Borrowed<Option<Widget>> = from_glib_borrow(child_ptr);

        imp.set_focus_child(child.as_ref().as_ref())
    }
}

unsafe extern "C" fn widget_show<T: WidgetImpl>(ptr: *mut ffi::GtkWidget) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.show()
    }
}

unsafe extern "C" fn widget_size_allocate<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    width: i32,
    height: i32,
    baseline: i32,
) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.size_allocate(width, height, baseline)
    }
}

unsafe extern "C" fn widget_snapshot<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    snapshot_ptr: *mut ffi::GtkSnapshot,
) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();
        let snapshot = from_glib_borrow(snapshot_ptr);

        imp.snapshot(&snapshot)
    }
}

unsafe extern "C" fn widget_state_flags_changed<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    state_flags_ptr: ffi::GtkStateFlags,
) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();
        let state_flags = from_glib(state_flags_ptr);

        imp.state_flags_changed(&state_flags)
    }
}

unsafe extern "C" fn widget_system_setting_changed<T: WidgetImpl>(
    ptr: *mut ffi::GtkWidget,
    settings_ptr: ffi::GtkSystemSetting,
) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();
        let settings = from_glib(settings_ptr);

        imp.system_setting_changed(&settings)
    }
}

unsafe extern "C" fn widget_unmap<T: WidgetImpl>(ptr: *mut ffi::GtkWidget) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.unmap()
    }
}

unsafe extern "C" fn widget_unrealize<T: WidgetImpl>(ptr: *mut ffi::GtkWidget) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.unrealize()
    }
}

unsafe extern "C" fn widget_unroot<T: WidgetImpl>(ptr: *mut ffi::GtkWidget) {
    unsafe {
        let instance = &*(ptr as *mut T::Instance);
        let imp = instance.imp();

        imp.unroot()
    }
}

#[allow(clippy::missing_safety_doc)]
pub unsafe trait WidgetClassExt: ClassStruct {
    #[doc(alias = "gtk_widget_class_set_template")]
    fn set_template_bytes(&mut self, template: &glib::Bytes) {
        unsafe {
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            ffi::gtk_widget_class_set_template(widget_class, template.to_glib_none().0);
        }
    }

    /// s instance initializer.
    /// ## `template_bytes`
    /// `GBytes` holding the [`Builder`][crate::Builder] XML
    fn set_template(&mut self, template: &[u8]) {
        let template_bytes = glib::Bytes::from(template);
        self.set_template_bytes(&template_bytes);
    }

    fn set_template_static(&mut self, template: &'static [u8]) {
        let template_bytes = glib::Bytes::from_static(template);
        self.set_template_bytes(&template_bytes);
    }

    /// s instance
    /// initializer.
    /// ## `resource_name`
    /// resource path to load the template from
    #[doc(alias = "gtk_widget_class_set_template_from_resource")]
    fn set_template_from_resource(&mut self, resource_name: &str) {
        unsafe {
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            ffi::gtk_widget_class_set_template_from_resource(
                widget_class,
                resource_name.to_glib_none().0,
            );
        }
    }

    fn install_action_async<Fut, F>(
        &mut self,
        action_name: &str,
        parameter_type: Option<&glib::VariantTy>,
        activate: F,
    ) where
        F: Fn(
                <<Self as ClassStruct>::Type as ObjectSubclass>::Type,
                String,
                Option<Variant>,
            ) -> Fut
            + 'static
            + Clone,
        Fut: Future<Output = ()>,
    {
        self.install_action(
            action_name,
            parameter_type,
            move |this, action_name, parameter_type| {
                let ctx = glib::MainContext::default();
                let action_name = action_name.to_owned();
                let parameter_type = parameter_type.map(ToOwned::to_owned);
                ctx.spawn_local(glib::clone!(
                    #[strong]
                    this,
                    #[strong]
                    action_name,
                    #[strong]
                    parameter_type,
                    #[strong]
                    activate,
                    async move {
                        activate(this, action_name, parameter_type).await;
                    }
                ));
            },
        );
    }

    /// Adds an action for all instances of a widget class.
    ///
    /// This function should be called at class initialization time.
    ///
    /// Actions installed by this function are stateless. The only state
    /// they have is whether they are enabled or not (which can be changed
    /// with [`WidgetExt::action_set_enabled()`][crate::prelude::WidgetExt::action_set_enabled()]).
    /// ## `action_name`
    /// a prefixed action name, such as "clipboard.paste"
    /// ## `parameter_type`
    /// the parameter type
    /// ## `activate`
    /// callback to use when the action is activated
    #[doc(alias = "gtk_widget_class_install_action")]
    fn install_action<F>(
        &mut self,
        action_name: &str,
        parameter_type: Option<&glib::VariantTy>,
        activate: F,
    ) where
        F: Fn(&<<Self as ClassStruct>::Type as ObjectSubclass>::Type, &str, Option<&Variant>)
            + 'static,
    {
        unsafe {
            // We store the activate callbacks in a HashMap<action_name, activate>
            // so that we can retrieve f later on the activate_trampoline call
            let mut data = <Self::Type as ObjectSubclassType>::type_data();
            let data = data.as_mut();

            let f: Box_<F> = Box_::new(activate);

            let internal = data
                .class_data_mut::<Internal>(<Self::Type as ObjectSubclassType>::type_())
                .expect("Something bad happened at class_init, the internal class_data is missing");
            let callback_ptr = Box_::into_raw(f) as glib::ffi::gpointer;
            internal
                .actions
                .insert(action_name.to_string(), callback_ptr);

            unsafe extern "C" fn activate_trampoline<F, S>(
                this: *mut ffi::GtkWidget,
                action_name: *const libc::c_char,
                parameter: *mut glib::ffi::GVariant,
            ) where
                S: ClassStruct,
                <S as ClassStruct>::Type: ObjectSubclass,
                F: Fn(&<<S as ClassStruct>::Type as ObjectSubclass>::Type, &str, Option<&Variant>)
                    + 'static,
            {
                unsafe {
                    let action_name = GString::from_glib_borrow(action_name);

                    let data = <S::Type as ObjectSubclassType>::type_data();
                    let internal = data
                        .as_ref()
                        .class_data::<Internal>(<S::Type as ObjectSubclassType>::type_())
                        .unwrap();
                    let activate_callback = *internal
                        .actions
                        .get(&action_name.to_string())
                        .unwrap_or_else(|| {
                            panic!("Action name '{}' was not found", action_name.as_str());
                        });

                    let widget = Widget::from_glib_borrow(this);

                    let f: &F = &*(activate_callback as *const F);
                    f(
                        widget.unsafe_cast_ref(),
                        &action_name,
                        Option::<Variant>::from_glib_borrow(parameter)
                            .as_ref()
                            .as_ref(),
                    )
                }
            }
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            let callback = activate_trampoline::<F, Self>;
            ffi::gtk_widget_class_install_action(
                widget_class,
                action_name.to_glib_none().0,
                parameter_type.map(|p| p.as_str()).to_glib_none().0,
                Some(callback),
            );
        }
    }

    /// Overrides the default scope to be used when parsing the class template.
    ///
    /// This function is intended for language bindings.
    ///
    /// Note that this must be called from a composite widget classes class
    /// initializer after calling [`set_template()`][Self::set_template()].
    /// ## `scope`
    /// [`BuilderScope`][crate::BuilderScope] to use when loading
    ///   the class template
    #[doc(alias = "gtk_widget_class_set_template_scope")]
    fn set_template_scope<S: IsA<BuilderScope>>(&mut self, scope: &S) {
        unsafe {
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            ffi::gtk_widget_class_set_template_scope(widget_class, scope.as_ref().to_glib_none().0);
        }
    }

    /// Creates a new shortcut for @self that calls the given @callback
    /// with arguments according to @format_string.
    ///
    /// The arguments and format string must be provided in the same way as
    /// with `GLib::Variant::new()`.
    ///
    /// This function is a convenience wrapper around
    /// [`add_shortcut()`][Self::add_shortcut()] and must be called during class
    /// initialization. It does not provide for user data, if you need that,
    /// you will have to use [`add_shortcut()`][Self::add_shortcut()] with a custom
    /// shortcut.
    ///
    /// Note: Since 4.24, this function takes key aliases into account.
    /// See `keyval_get_aliases()` for more information on key aliases.
    /// To make a shortcut for an individual key, use
    /// [`add_shortcut()`][Self::add_shortcut()].
    /// ## `keyval`
    /// key value of binding to install
    /// ## `mods`
    /// key modifier of binding to install
    /// ## `callback`
    /// the callback to call upon activation
    /// ## `format_string`
    /// `GVariant` format string for arguments
    #[doc(alias = "gtk_widget_class_add_binding")]
    fn add_binding<
        F: Fn(&<<Self as ClassStruct>::Type as ObjectSubclass>::Type) -> glib::Propagation + 'static,
    >(
        &mut self,
        keyval: gdk::Key,
        mods: gdk::ModifierType,
        callback: F,
    ) {
        let shortcut = crate::Shortcut::new(
            Some(crate::KeyvalTrigger::new(keyval, mods)),
            Some(crate::CallbackAction::new(
                move |widget, _| -> glib::Propagation {
                    unsafe { callback(widget.unsafe_cast_ref()) }
                },
            )),
        );
        unsafe {
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            ffi::gtk_widget_class_add_shortcut(widget_class, shortcut.to_glib_none().0);
        }
    }

    /// Creates a new shortcut for @self that emits the given action
    /// @signal with arguments read according to @format_string.
    ///
    /// The arguments and format string must be provided in the same way as
    /// with `GLib::Variant::new()`.
    ///
    /// This function is a convenience wrapper around
    /// [`add_shortcut()`][Self::add_shortcut()] and must be called during class
    /// initialization.
    ///
    /// Note: Since 4.24, this function takes key aliases into account.
    /// See `keyval_get_aliases()` for more information on key aliases.
    /// To make a shortcut for an individual key, use
    /// [`add_shortcut()`][Self::add_shortcut()].
    /// ## `keyval`
    /// key value of binding to install
    /// ## `mods`
    /// key modifier of binding to install
    /// ## `signal`
    /// the signal to execute
    /// ## `format_string`
    /// `GVariant` format string for arguments
    #[doc(alias = "gtk_widget_class_add_binding_signal")]
    fn add_binding_signal(&mut self, keyval: gdk::Key, mods: gdk::ModifierType, signal_name: &str) {
        let type_ = <Self::Type as ObjectSubclassType>::type_();
        assert!(
            SignalId::lookup(signal_name, type_).is_some(),
            "Signal '{signal_name}' doesn't exists for type '{type_}'",
        );

        let shortcut = crate::Shortcut::new(
            Some(crate::KeyvalTrigger::new(keyval, mods)),
            Some(crate::SignalAction::new(signal_name)),
        );
        unsafe {
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            ffi::gtk_widget_class_add_shortcut(widget_class, shortcut.to_glib_none().0);
        }
    }

    /// Sets the activation signal for a widget class.
    ///
    /// The signal will be emitted when calling [`WidgetExt::activate()`][crate::prelude::WidgetExt::activate()].
    ///
    /// The @signal_id must have been registered with [function.GObject.signal_new]
    /// or `signal_newv()` before calling this function.
    /// ## `signal_id`
    /// the id for the activate signal
    #[doc(alias = "gtk_widget_class_set_activate_signal")]
    fn set_activate_signal(&mut self, signal_id: SignalId) {
        unsafe {
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            ffi::gtk_widget_class_set_activate_signal(widget_class, signal_id.into_glib())
        }
    }

    /// Sets the activation signal for a widget class.
    ///
    /// The signal id will by looked up by @signal_name.
    ///
    /// The signal will be emitted when calling [`WidgetExt::activate()`][crate::prelude::WidgetExt::activate()].
    ///
    /// The @signal_name must have been registered with [function.GObject.signal_new]
    /// or `signal_newv()` before calling this function.
    /// ## `signal_name`
    /// the name of the activate signal of @widget_type
    #[doc(alias = "gtk_widget_class_set_activate_signal_from_name")]
    fn set_activate_signal_from_name(&mut self, signal_name: &str) {
        let type_ = <Self::Type as ObjectSubclassType>::type_();
        assert!(
            SignalId::lookup(signal_name, type_).is_some(),
            "Signal '{signal_name}' doesn't exists for type '{type_}'",
        );

        unsafe {
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            ffi::gtk_widget_class_set_activate_signal_from_name(
                widget_class,
                signal_name.to_glib_none().0,
            );
        }
    }

    /// Sets the type to be used for creating layout managers for
    /// widgets of @self.
    ///
    /// The given @type_ must be a subtype of [`LayoutManager`][crate::LayoutManager].
    ///
    /// This function should only be called from class init functions
    /// of widgets.
    /// ## `type_`
    /// the object type that implements the [`LayoutManager`][crate::LayoutManager]
    ///   for @self
    #[doc(alias = "gtk_widget_class_set_layout_manager_type")]
    fn set_layout_manager_type<T: IsA<LayoutManager>>(&mut self) {
        unsafe {
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            ffi::gtk_widget_class_set_layout_manager_type(
                widget_class,
                T::static_type().into_glib(),
            );
        }
    }

    /// Sets the name to be used for CSS matching of widgets.
    ///
    /// If this function is not called for a given class, the name
    /// set on the parent class is used. By default, [`Widget`][crate::Widget]
    /// uses the name "widget".
    /// ## `name`
    /// name to use
    #[doc(alias = "gtk_widget_class_set_css_name")]
    fn set_css_name(&mut self, name: &str) {
        unsafe {
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            ffi::gtk_widget_class_set_css_name(widget_class, name.to_glib_none().0);
        }
    }

    /// Sets the accessible role used by the given widget class.
    ///
    /// Different accessible roles have different states, and are
    /// rendered differently by assistive technologies.
    /// ## `accessible_role`
    /// the accessible role to use
    #[doc(alias = "gtk_widget_class_set_accessible_role")]
    fn set_accessible_role(&mut self, role: AccessibleRole) {
        unsafe {
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            ffi::gtk_widget_class_set_accessible_role(widget_class, role.into_glib());
        }
    }

    #[allow(clippy::missing_safety_doc)]
    #[doc(alias = "gtk_widget_class_bind_template_child_full")]
    unsafe fn bind_template_child_with_offset<T>(
        &mut self,
        name: &str,
        internal: bool,
        offset: field_offset::FieldOffset<Self::Type, TemplateChild<T>>,
    ) where
        T: ObjectType + FromGlibPtrNone<*mut <T as ObjectType>::GlibType>,
    {
        unsafe {
            let widget_class = self as *mut _ as *mut ffi::GtkWidgetClass;
            let private_offset = <Self::Type as ObjectSubclassType>::type_data()
                .as_ref()
                .impl_offset();
            ffi::gtk_widget_class_bind_template_child_full(
                widget_class,
                name.to_glib_none().0,
                internal.into_glib(),
                private_offset + (offset.get_byte_offset() as isize),
            )
        }
    }

    fn rust_template_scope(&mut self) -> BuilderRustScope {
        assert_initialized_main_thread!();
        unsafe {
            let mut data = <Self::Type as ObjectSubclassType>::type_data();
            let internal = data
                .as_mut()
                .class_data_mut::<Internal>(<Self::Type as ObjectSubclassType>::type_())
                .expect("Something bad happened at class_init, the internal class_data is missing");
            let scope = internal.scope.get_or_insert_with(|| {
                let scope = BuilderRustScope::new();
                self.set_template_scope(&scope);
                scope.into_glib_ptr()
            });
            from_glib_none(*scope)
        }
    }
}

unsafe impl<T: ClassStruct> WidgetClassExt for T where T::Type: WidgetImpl {}

#[derive(Debug, PartialEq, Eq)]
#[repr(transparent)]
pub struct TemplateChild<T>
where
    T: ObjectType + FromGlibPtrNone<*mut <T as ObjectType>::GlibType>,
{
    ptr: *mut <T as ObjectType>::GlibType,
}

impl<T: Property> Property for TemplateChild<T>
where
    T: ObjectType + FromGlibPtrNone<*mut <T as ObjectType>::GlibType>,
{
    type Value = T::Value;
}

impl<T> Default for TemplateChild<T>
where
    T: ObjectType + FromGlibPtrNone<*mut <T as ObjectType>::GlibType>,
{
    fn default() -> Self {
        T::static_type();

        Self {
            ptr: std::ptr::null_mut(),
        }
    }
}

impl<T> PropertyGet for TemplateChild<T>
where
    T: Property + ObjectType + FromGlibPtrNone<*mut <T as ObjectType>::GlibType>,
{
    type Value = T;

    fn get<R, F: Fn(&Self::Value) -> R>(&self, f: F) -> R {
        f(&self.get())
    }
}

impl<T> std::ops::Deref for TemplateChild<T>
where
    T: ObjectType + FromGlibPtrNone<*mut <T as ObjectType>::GlibType>,
{
    type Target = T;

    #[inline]
    fn deref(&self) -> &Self::Target {
        unsafe {
            if !self.is_bound() {
                let name = Self::name();
                panic!(
                    "Failed to retrieve template child. Please check that all fields of type `{name}` have been bound and have a #[template_child] attribute."
                );
            }
            &*(&self.ptr as *const _ as *const T)
        }
    }
}

impl<T> Downgrade for TemplateChild<T>
where
    T: ObjectType + FromGlibPtrNone<*mut <T as ObjectType>::GlibType> + Downgrade,
{
    type Weak = T::Weak;

    fn downgrade(&self) -> Self::Weak {
        T::downgrade(&self.get())
    }
}

impl<T> TemplateChild<T>
where
    T: ObjectType + FromGlibPtrNone<*mut <T as ObjectType>::GlibType>,
{
    pub(crate) fn name<'a>() -> &'a str {
        T::static_type().name()
    }

    #[track_caller]
    pub fn get(&self) -> T {
        self.try_get()
            .unwrap_or_else(|| {
                let name = Self::name();
                panic!("Failed to retrieve template child. Please check that all fields of type `{name}` have been bound and have a #[template_child] attribute.");
            })
    }

    // rustdoc-stripper-ignore-next
    /// Determines if the child has been bound. This is primarily
    /// useful for implementing the [`Buildable`][`crate::Buildable`] interface.
    pub fn is_bound(&self) -> bool {
        !self.ptr.is_null()
    }

    // rustdoc-stripper-ignore-next
    /// Returns Some(child) if the widget has been bound.
    pub fn try_get(&self) -> Option<T> {
        unsafe { Option::<T>::from_glib_none(self.ptr) }
    }
}

// rustdoc-stripper-ignore-next
/// A trait for setting up template children inside
/// [`class_init`](glib::subclass::types::ObjectSubclass::class_init). This
/// trait is implemented automatically by the
/// [`CompositeTemplate`](crate::CompositeTemplate) macro.
pub trait CompositeTemplate: WidgetImpl {
    fn bind_template(klass: &mut Self::Class);
    fn check_template_children(widget: &<Self as ObjectSubclass>::Type);
}

// rustdoc-stripper-ignore-next
/// An extension trait for [`ClassStruct`](glib::subclass::types::ClassStruct)
/// types to allow binding a composite template directly on `self`. This is a
/// convenience wrapper around the [`CompositeTemplate`] trait.
pub trait CompositeTemplateClass {
    // rustdoc-stripper-ignore-next
    /// Binds the template callbacks from this type into the default template
    /// scope for `self`.
    fn bind_template(&mut self);
}

impl<T, U> CompositeTemplateClass for T
where
    T: ClassStruct<Type = U>,
    U: ObjectSubclass<Class = T> + CompositeTemplate,
{
    fn bind_template(&mut self) {
        <U as CompositeTemplate>::bind_template(self);
    }
}

pub type TemplateCallback = (&'static str, fn(&[glib::Value]) -> Option<glib::Value>);

// rustdoc-stripper-ignore-next
/// A trait for setting up template callbacks inside
/// [`class_init`](glib::subclass::types::ObjectSubclass::class_init). This
/// trait is implemented automatically by the
/// [`template_callbacks`](crate::template_callbacks) macro.
pub trait CompositeTemplateCallbacks {
    const CALLBACKS: &'static [TemplateCallback];

    // rustdoc-stripper-ignore-next
    /// Binds the template callbacks from this type into the default template
    /// scope for `klass`.
    fn bind_template_callbacks<T: WidgetClassExt>(klass: &mut T) {
        Self::add_callbacks_to_scope(&klass.rust_template_scope());
    }
    // rustdoc-stripper-ignore-next
    /// Binds the template callbacks from this type into the default template
    /// scope for `klass`, prepending `prefix` to each callback name.
    fn bind_template_callbacks_prefixed<T: WidgetClassExt>(klass: &mut T, prefix: &str) {
        Self::add_callbacks_to_scope_prefixed(&klass.rust_template_scope(), prefix);
    }
    // rustdoc-stripper-ignore-next
    /// Binds the template callbacks from this type into `scope`.
    fn add_callbacks_to_scope(scope: &BuilderRustScope) {
        for (name, func) in Self::CALLBACKS {
            scope.add_callback(*name, func);
        }
    }
    // rustdoc-stripper-ignore-next
    /// Binds the template callbacks from this type into `scope`, prepending
    /// `prefix` to each callback name.
    fn add_callbacks_to_scope_prefixed(scope: &BuilderRustScope, prefix: &str) {
        for (name, func) in Self::CALLBACKS {
            scope.add_callback(format!("{prefix}{name}"), func);
        }
    }
}

// rustdoc-stripper-ignore-next
/// An extension trait for [`ClassStruct`](glib::subclass::types::ClassStruct)
/// types to allow binding private template callbacks directly on `self`. This
/// is a convenience wrapper around the [`CompositeTemplateCallbacks`] trait.
pub trait CompositeTemplateCallbacksClass {
    // rustdoc-stripper-ignore-next
    /// Binds the template callbacks from the subclass type into the default
    /// template scope for `self`.
    fn bind_template_callbacks(&mut self);
}

impl<T, U> CompositeTemplateCallbacksClass for T
where
    T: ClassStruct<Type = U> + WidgetClassExt,
    U: ObjectSubclass<Class = T> + CompositeTemplateCallbacks,
{
    fn bind_template_callbacks(&mut self) {
        <U as CompositeTemplateCallbacks>::bind_template_callbacks(self);
    }
}

// rustdoc-stripper-ignore-next
/// An extension trait for [`ClassStruct`](glib::subclass::types::ClassStruct)
/// types to allow binding the instance template callbacks directly on `self`.
/// This is a convenience wrapper around the [`CompositeTemplateCallbacks`]
/// trait.
pub trait CompositeTemplateInstanceCallbacksClass {
    // rustdoc-stripper-ignore-next
    /// Binds the template callbacks from the instance type into the default
    /// template scope for `self`.
    fn bind_template_instance_callbacks(&mut self);
}

impl<T, U, V> CompositeTemplateInstanceCallbacksClass for T
where
    T: ClassStruct<Type = U> + WidgetClassExt,
    U: ObjectSubclass<Class = T, Type = V>,
    V: CompositeTemplateCallbacks,
{
    fn bind_template_instance_callbacks(&mut self) {
        <V as CompositeTemplateCallbacks>::bind_template_callbacks(self);
    }
}

pub trait CompositeTemplateInitializingExt {
    fn init_template(&self);
}

impl<T: WidgetImpl + CompositeTemplate> CompositeTemplateInitializingExt
    for glib::subclass::InitializingObject<T>
{
    fn init_template(&self) {
        unsafe {
            let widget = self
                .as_ref()
                .unsafe_cast_ref::<<T as ObjectSubclass>::Type>();
            ffi::gtk_widget_init_template(AsRef::<Widget>::as_ref(widget).to_glib_none().0);

            <T as CompositeTemplate>::check_template_children(widget);
        }
    }
}

pub trait CompositeTemplateDisposeExt {
    #[cfg(feature = "v4_8")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v4_8")))]
    fn dispose_template(&self);
}

impl<T: WidgetImpl + CompositeTemplate> CompositeTemplateDisposeExt for T {
    #[cfg(feature = "v4_8")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v4_8")))]
    fn dispose_template(&self) {
        unsafe {
            ffi::gtk_widget_dispose_template(
                self.obj().upcast_ref::<Widget>().to_glib_none().0,
                <T as ObjectSubclass>::Type::static_type().into_glib(),
            );
        }
    }
}