gtk4/subclass/

cell_renderer.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 [`CellRenderer`](crate::CellRenderer).

use std::mem;

use glib::{translate::*, GString};
use libc::{c_char, c_int};

use crate::{
    ffi, prelude::*, subclass::prelude::*, CellEditable, CellRenderer, CellRendererState,
    SizeRequestMode, Snapshot, Widget,
};

#[cfg_attr(feature = "v4_10", deprecated = "Since 4.10")]
#[allow(deprecated)]
pub trait CellRendererImpl: CellRendererImplExt + ObjectImpl {
    /// Passes an activate event to the cell renderer for possible processing.
    /// Some cell renderers may use events; for example, [`CellRendererToggle`][crate::CellRendererToggle]
    /// toggles when it gets a mouse click.
    ///
    /// # Deprecated since 4.10
    ///
    /// ## `event`
    /// a [`gdk::Event`][crate::gdk::Event]
    /// ## `widget`
    /// widget that received the event
    /// ## `path`
    /// widget-dependent string representation of the event location;
    ///    e.g. for [`TreeView`][crate::TreeView], a string representation of [`TreePath`][crate::TreePath]
    /// ## `background_area`
    /// background area as passed to gtk_cell_renderer_render()
    /// ## `cell_area`
    /// cell area as passed to gtk_cell_renderer_render()
    /// ## `flags`
    /// render flags
    ///
    /// # Returns
    ///
    /// [`true`] if the event was consumed/handled
    fn activate<P: IsA<Widget>>(
        &self,
        event: Option<&gdk::Event>,
        widget: &P,
        path: &str,
        background_area: &gdk::Rectangle,
        cell_area: &gdk::Rectangle,
        flags: CellRendererState,
    ) -> bool {
        self.parent_activate(event, widget, path, background_area, cell_area, flags)
    }

    /// Signal gets emitted when the user cancels the process of editing a cell.
    fn editing_canceled(&self) {
        self.parent_editing_canceled()
    }

    /// Signal gets emitted when a cell starts to be edited.
    fn editing_started(&self, editable: &CellEditable, path: &str) {
        self.parent_editing_started(editable, path)
    }

    /// Gets the aligned area used by @self inside @cell_area. Used for finding
    /// the appropriate edit and focus rectangle.
    ///
    /// # Deprecated since 4.10
    ///
    /// ## `widget`
    /// the [`Widget`][crate::Widget] this cell will be rendering to
    /// ## `flags`
    /// render flags
    /// ## `cell_area`
    /// cell area which would be passed to gtk_cell_renderer_render()
    ///
    /// # Returns
    ///
    ///
    /// ## `aligned_area`
    /// the return location for the space inside @cell_area
    ///                that would actually be used to render.
    #[doc(alias = "get_aligned_area")]
    fn aligned_area<P: IsA<Widget>>(
        &self,
        widget: &P,
        flags: CellRendererState,
        cell_area: &gdk::Rectangle,
    ) -> gdk::Rectangle {
        self.parent_aligned_area(widget, flags, cell_area)
    }

    /// Retrieves a cell renderers’s minimum and natural height if it were rendered to
    /// @widget with the specified @width.
    ///
    /// # Deprecated since 4.10
    ///
    /// ## `widget`
    /// the [`Widget`][crate::Widget] this cell will be rendering to
    /// ## `width`
    /// the size which is available for allocation
    ///
    /// # Returns
    ///
    ///
    /// ## `minimum_height`
    /// location for storing the minimum size
    ///
    /// ## `natural_height`
    /// location for storing the preferred size
    #[doc(alias = "get_preferred_height_for_width")]
    fn preferred_height_for_width<P: IsA<Widget>>(&self, widget: &P, width: i32) -> (i32, i32) {
        self.parent_preferred_height_for_width(widget, width)
    }

    /// Retrieves a renderer’s natural size when rendered to @widget.
    ///
    /// # Deprecated since 4.10
    ///
    /// ## `widget`
    /// the [`Widget`][crate::Widget] this cell will be rendering to
    ///
    /// # Returns
    ///
    ///
    /// ## `minimum_size`
    /// location to store the minimum size
    ///
    /// ## `natural_size`
    /// location to store the natural size
    #[doc(alias = "get_preferred_height")]
    fn preferred_height<P: IsA<Widget>>(&self, widget: &P) -> (i32, i32) {
        self.parent_preferred_height(widget)
    }

    /// Retrieves a cell renderers’s minimum and natural width if it were rendered to
    /// @widget with the specified @height.
    ///
    /// # Deprecated since 4.10
    ///
    /// ## `widget`
    /// the [`Widget`][crate::Widget] this cell will be rendering to
    /// ## `height`
    /// the size which is available for allocation
    ///
    /// # Returns
    ///
    ///
    /// ## `minimum_width`
    /// location for storing the minimum size
    ///
    /// ## `natural_width`
    /// location for storing the preferred size
    #[doc(alias = "get_preferred_width_for_height")]
    fn preferred_width_for_height<P: IsA<Widget>>(&self, widget: &P, height: i32) -> (i32, i32) {
        self.parent_preferred_width_for_height(widget, height)
    }

    /// Retrieves a renderer’s natural size when rendered to @widget.
    ///
    /// # Deprecated since 4.10
    ///
    /// ## `widget`
    /// the [`Widget`][crate::Widget] this cell will be rendering to
    ///
    /// # Returns
    ///
    ///
    /// ## `minimum_size`
    /// location to store the minimum size
    ///
    /// ## `natural_size`
    /// location to store the natural size
    #[doc(alias = "get_preferred_width")]
    fn preferred_width<P: IsA<Widget>>(&self, widget: &P) -> (i32, i32) {
        self.parent_preferred_width(widget)
    }

    /// Gets whether the cell renderer prefers a height-for-width layout
    /// or a width-for-height layout.
    ///
    /// # Deprecated since 4.10
    ///
    ///
    /// # Returns
    ///
    /// The [`SizeRequestMode`][crate::SizeRequestMode] preferred by this renderer.
    #[doc(alias = "get_request_mode")]
    fn request_mode(&self) -> SizeRequestMode {
        self.parent_request_mode()
    }

    /// Invokes the virtual render function of the [`CellRenderer`][crate::CellRenderer]. The three
    /// passed-in rectangles are areas in @cr. Most renderers will draw within
    /// @cell_area; the xalign, yalign, xpad, and ypad fields of the [`CellRenderer`][crate::CellRenderer]
    /// should be honored with respect to @cell_area. @background_area includes the
    /// blank space around the cell, and also the area containing the tree expander;
    /// so the @background_area rectangles for all cells tile to cover the entire
    /// @window.
    ///
    /// # Deprecated since 4.10
    ///
    /// ## `snapshot`
    /// a [`Snapshot`][crate::Snapshot] to draw to
    /// ## `widget`
    /// the widget owning @window
    /// ## `background_area`
    /// entire cell area (including tree expanders and maybe
    ///    padding on the sides)
    /// ## `cell_area`
    /// area normally rendered by a cell renderer
    /// ## `flags`
    /// flags that affect rendering
    fn snapshot<P: IsA<Widget>>(
        &self,
        snapshot: &Snapshot,
        widget: &P,
        background_area: &gdk::Rectangle,
        cell_area: &gdk::Rectangle,
        flags: CellRendererState,
    ) {
        self.parent_snapshot(snapshot, widget, background_area, cell_area, flags);
    }

    /// Starts editing the contents of this @self, through a new [`CellEditable`][crate::CellEditable]
    /// widget created by the [`CellRenderer`][crate::CellRenderer]Class.start_editing virtual function.
    ///
    /// # Deprecated since 4.10
    ///
    /// ## `event`
    /// a [`gdk::Event`][crate::gdk::Event]
    /// ## `widget`
    /// widget that received the event
    /// ## `path`
    /// widget-dependent string representation of the event location;
    ///    e.g. for [`TreeView`][crate::TreeView], a string representation of [`TreePath`][crate::TreePath]
    /// ## `background_area`
    /// background area as passed to gtk_cell_renderer_render()
    /// ## `cell_area`
    /// cell area as passed to gtk_cell_renderer_render()
    /// ## `flags`
    /// render flags
    ///
    /// # Returns
    ///
    /// A new [`CellEditable`][crate::CellEditable] for editing this
    ///   @self, or [`None`] if editing is not possible
    fn start_editing<P: IsA<Widget>>(
        &self,
        event: Option<&gdk::Event>,
        widget: &P,
        path: &str,
        background_area: &gdk::Rectangle,
        cell_area: &gdk::Rectangle,
        flags: CellRendererState,
    ) -> Option<CellEditable> {
        self.parent_start_editing(event, widget, path, background_area, cell_area, flags)
    }
}

mod sealed {
    pub trait Sealed {}
    impl<T: super::CellRendererImplExt> Sealed for T {}
}

#[cfg_attr(feature = "v4_10", deprecated = "Since 4.10")]
#[allow(deprecated)]
pub trait CellRendererImplExt: sealed::Sealed + ObjectSubclass {
    fn parent_request_mode(&self) -> SizeRequestMode {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkCellRendererClass;
            let f = (*parent_class).get_request_mode.unwrap();
            from_glib(f(self
                .obj()
                .unsafe_cast_ref::<CellRenderer>()
                .to_glib_none()
                .0))
        }
    }

    fn parent_preferred_width<P: IsA<Widget>>(&self, widget: &P) -> (i32, i32) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkCellRendererClass;
            let f = (*parent_class).get_preferred_width.unwrap();

            let mut minimum_size = mem::MaybeUninit::uninit();
            let mut natural_size = mem::MaybeUninit::uninit();
            f(
                self.obj()
                    .unsafe_cast_ref::<CellRenderer>()
                    .to_glib_none()
                    .0,
                widget.as_ref().to_glib_none().0,
                minimum_size.as_mut_ptr(),
                natural_size.as_mut_ptr(),
            );
            (minimum_size.assume_init(), natural_size.assume_init())
        }
    }

    fn parent_preferred_width_for_height<P: IsA<Widget>>(
        &self,
        widget: &P,
        height: i32,
    ) -> (i32, i32) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkCellRendererClass;
            let f = (*parent_class).get_preferred_width_for_height.unwrap();

            let mut minimum_size = mem::MaybeUninit::uninit();
            let mut natural_size = mem::MaybeUninit::uninit();
            f(
                self.obj()
                    .unsafe_cast_ref::<CellRenderer>()
                    .to_glib_none()
                    .0,
                widget.as_ref().to_glib_none().0,
                height,
                minimum_size.as_mut_ptr(),
                natural_size.as_mut_ptr(),
            );
            (minimum_size.assume_init(), natural_size.assume_init())
        }
    }
    fn parent_preferred_height<P: IsA<Widget>>(&self, widget: &P) -> (i32, i32) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkCellRendererClass;
            let f = (*parent_class).get_preferred_height.unwrap();
            let mut minimum_size = mem::MaybeUninit::uninit();
            let mut natural_size = mem::MaybeUninit::uninit();
            f(
                self.obj()
                    .unsafe_cast_ref::<CellRenderer>()
                    .to_glib_none()
                    .0,
                widget.as_ref().to_glib_none().0,
                minimum_size.as_mut_ptr(),
                natural_size.as_mut_ptr(),
            );
            (minimum_size.assume_init(), natural_size.assume_init())
        }
    }
    fn parent_preferred_height_for_width<P: IsA<Widget>>(
        &self,
        widget: &P,
        width: i32,
    ) -> (i32, i32) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkCellRendererClass;
            let f = (*parent_class).get_preferred_height_for_width.unwrap();
            let mut minimum_size = mem::MaybeUninit::uninit();
            let mut natural_size = mem::MaybeUninit::uninit();
            f(
                self.obj()
                    .unsafe_cast_ref::<CellRenderer>()
                    .to_glib_none()
                    .0,
                widget.as_ref().to_glib_none().0,
                width,
                minimum_size.as_mut_ptr(),
                natural_size.as_mut_ptr(),
            );
            (minimum_size.assume_init(), natural_size.assume_init())
        }
    }

    fn parent_aligned_area<P: IsA<Widget>>(
        &self,
        widget: &P,
        flags: CellRendererState,
        cell_area: &gdk::Rectangle,
    ) -> gdk::Rectangle {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkCellRendererClass;
            let mut aligned_area = gdk::Rectangle::uninitialized();
            let f = (*parent_class).get_aligned_area.unwrap();
            f(
                self.obj()
                    .unsafe_cast_ref::<CellRenderer>()
                    .to_glib_none()
                    .0,
                widget.as_ref().to_glib_none().0,
                flags.into_glib(),
                cell_area.to_glib_none().0,
                aligned_area.to_glib_none_mut().0,
            );
            aligned_area
        }
    }

    fn parent_snapshot<P: IsA<Widget>>(
        &self,
        snapshot: &Snapshot,
        widget: &P,
        background_area: &gdk::Rectangle,
        cell_area: &gdk::Rectangle,
        flags: CellRendererState,
    ) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkCellRendererClass;
            if let Some(f) = (*parent_class).snapshot {
                f(
                    self.obj()
                        .unsafe_cast_ref::<CellRenderer>()
                        .to_glib_none()
                        .0,
                    snapshot.to_glib_none().0,
                    widget.as_ref().to_glib_none().0,
                    background_area.to_glib_none().0,
                    cell_area.to_glib_none().0,
                    flags.into_glib(),
                )
            }
        }
    }

    // Returns true if the event was consumed/handled
    fn parent_activate<P: IsA<Widget>>(
        &self,
        event: Option<&gdk::Event>,
        widget: &P,
        path: &str,
        background_area: &gdk::Rectangle,
        cell_area: &gdk::Rectangle,
        flags: CellRendererState,
    ) -> bool {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkCellRendererClass;
            if let Some(f) = (*parent_class).activate {
                from_glib(f(
                    self.obj()
                        .unsafe_cast_ref::<CellRenderer>()
                        .to_glib_none()
                        .0,
                    mut_override(event.to_glib_none().0),
                    widget.as_ref().to_glib_none().0,
                    path.to_glib_none().0,
                    background_area.to_glib_none().0,
                    cell_area.to_glib_none().0,
                    flags.into_glib(),
                ))
            } else {
                false
            }
        }
    }

    fn parent_start_editing<P: IsA<Widget>>(
        &self,
        event: Option<&gdk::Event>,
        widget: &P,
        path: &str,
        background_area: &gdk::Rectangle,
        cell_area: &gdk::Rectangle,
        flags: CellRendererState,
    ) -> Option<CellEditable> {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkCellRendererClass;
            if let Some(f) = (*parent_class).start_editing {
                from_glib_none(f(
                    self.obj()
                        .unsafe_cast_ref::<CellRenderer>()
                        .to_glib_none()
                        .0,
                    mut_override(event.to_glib_none().0),
                    widget.as_ref().to_glib_none().0,
                    path.to_glib_none().0,
                    background_area.to_glib_none().0,
                    cell_area.to_glib_none().0,
                    flags.into_glib(),
                ))
            } else {
                None
            }
        }
    }

    fn parent_editing_canceled(&self) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkCellRendererClass;
            if let Some(f) = (*parent_class).editing_canceled {
                f(self
                    .obj()
                    .unsafe_cast_ref::<CellRenderer>()
                    .to_glib_none()
                    .0)
            }
        }
    }

    fn parent_editing_started(&self, editable: &CellEditable, path: &str) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkCellRendererClass;
            if let Some(f) = (*parent_class).editing_started {
                f(
                    self.obj()
                        .unsafe_cast_ref::<CellRenderer>()
                        .to_glib_none()
                        .0,
                    editable.to_glib_none().0,
                    path.to_glib_none().0,
                )
            }
        }
    }
}

impl<T: CellRendererImpl> CellRendererImplExt for T {}

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

        assert_initialized_main_thread!();

        let klass = class.as_mut();

        klass.activate = Some(cell_renderer_activate::<T>);
        klass.editing_canceled = Some(cell_renderer_editing_canceled::<T>);
        klass.editing_started = Some(cell_renderer_editing_started::<T>);
        klass.get_aligned_area = Some(cell_renderer_get_aligned_area::<T>);
        klass.get_preferred_height_for_width =
            Some(cell_renderer_get_preferred_height_for_width::<T>);
        klass.get_preferred_height = Some(cell_renderer_get_preferred_height::<T>);
        klass.get_preferred_width_for_height =
            Some(cell_renderer_get_preferred_width_for_height::<T>);
        klass.get_preferred_width = Some(cell_renderer_get_preferred_width::<T>);
        klass.get_request_mode = Some(cell_renderer_get_request_mode::<T>);
        klass.snapshot = Some(cell_renderer_snapshot::<T>);
        klass.start_editing = Some(cell_renderer_start_editing::<T>);
    }
}

unsafe extern "C" fn cell_renderer_activate<T: CellRendererImpl>(
    ptr: *mut ffi::GtkCellRenderer,
    evtptr: *mut gdk::ffi::GdkEvent,
    wdgtptr: *mut ffi::GtkWidget,
    pathptr: *const c_char,
    bgptr: *const gdk::ffi::GdkRectangle,
    cellptr: *const gdk::ffi::GdkRectangle,
    flags: ffi::GtkCellRendererState,
) -> glib::ffi::gboolean {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let widget: Borrowed<Widget> = from_glib_borrow(wdgtptr);
    let evt: Borrowed<Option<gdk::Event>> = from_glib_borrow(evtptr);

    imp.activate(
        evt.as_ref().as_ref(),
        &*widget,
        &GString::from_glib_borrow(pathptr),
        &from_glib_borrow(bgptr),
        &from_glib_borrow(cellptr),
        from_glib(flags),
    )
    .into_glib()
}

unsafe extern "C" fn cell_renderer_editing_canceled<T: CellRendererImpl>(
    ptr: *mut ffi::GtkCellRenderer,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    imp.editing_canceled();
}

unsafe extern "C" fn cell_renderer_editing_started<T: CellRendererImpl>(
    ptr: *mut ffi::GtkCellRenderer,
    editableptr: *mut ffi::GtkCellEditable,
    pathptr: *const c_char,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let editable = from_glib_borrow(editableptr);

    imp.editing_started(&editable, &GString::from_glib_borrow(pathptr));
}

unsafe extern "C" fn cell_renderer_get_aligned_area<T: CellRendererImpl>(
    ptr: *mut ffi::GtkCellRenderer,
    wdgtptr: *mut ffi::GtkWidget,
    flags: ffi::GtkCellRendererState,
    cellarea: *const gdk::ffi::GdkRectangle,
    alignedptr: *mut gdk::ffi::GdkRectangle,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let widget: Borrowed<Widget> = from_glib_borrow(wdgtptr);

    let rectangle = imp.aligned_area(&*widget, from_glib(flags), &from_glib_borrow(cellarea));
    *alignedptr = *rectangle.to_glib_none().0;
}

unsafe extern "C" fn cell_renderer_get_preferred_height_for_width<T: CellRendererImpl>(
    ptr: *mut ffi::GtkCellRenderer,
    wdgtptr: *mut ffi::GtkWidget,
    width: c_int,
    min_height_ptr: *mut c_int,
    nat_height_ptr: *mut c_int,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let widget: Borrowed<Widget> = from_glib_borrow(wdgtptr);

    let (min_height, nat_height) = imp.preferred_height_for_width(&*widget, width);
    if !min_height_ptr.is_null() {
        *min_height_ptr = min_height;
    }
    if !nat_height_ptr.is_null() {
        *nat_height_ptr = nat_height;
    }
}

unsafe extern "C" fn cell_renderer_get_preferred_height<T: CellRendererImpl>(
    ptr: *mut ffi::GtkCellRenderer,
    wdgtptr: *mut ffi::GtkWidget,
    minptr: *mut c_int,
    natptr: *mut c_int,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let widget: Borrowed<Widget> = from_glib_borrow(wdgtptr);

    let (min_size, nat_size) = imp.preferred_height(&*widget);
    if !minptr.is_null() {
        *minptr = min_size;
    }
    if !natptr.is_null() {
        *natptr = nat_size;
    }
}

unsafe extern "C" fn cell_renderer_get_preferred_width_for_height<T: CellRendererImpl>(
    ptr: *mut ffi::GtkCellRenderer,
    wdgtptr: *mut ffi::GtkWidget,
    height: c_int,
    min_width_ptr: *mut c_int,
    nat_width_ptr: *mut c_int,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let widget: Borrowed<Widget> = from_glib_borrow(wdgtptr);

    let (min_width, nat_width) = imp.preferred_width_for_height(&*widget, height);
    if !min_width_ptr.is_null() {
        *min_width_ptr = min_width;
    }
    if !nat_width_ptr.is_null() {
        *nat_width_ptr = nat_width;
    }
}

unsafe extern "C" fn cell_renderer_get_preferred_width<T: CellRendererImpl>(
    ptr: *mut ffi::GtkCellRenderer,
    wdgtptr: *mut ffi::GtkWidget,
    minptr: *mut c_int,
    natptr: *mut c_int,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let widget: Borrowed<Widget> = from_glib_borrow(wdgtptr);

    let (min_size, nat_size) = imp.preferred_width(&*widget);
    if !minptr.is_null() {
        *minptr = min_size;
    }
    if !natptr.is_null() {
        *natptr = nat_size;
    }
}

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

    imp.request_mode().into_glib()
}

unsafe extern "C" fn cell_renderer_snapshot<T: CellRendererImpl>(
    ptr: *mut ffi::GtkCellRenderer,
    snapshotptr: *mut ffi::GtkSnapshot,
    wdgtptr: *mut ffi::GtkWidget,
    bgptr: *const gdk::ffi::GdkRectangle,
    cellptr: *const gdk::ffi::GdkRectangle,
    flags: ffi::GtkCellRendererState,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let widget: Borrowed<Widget> = from_glib_borrow(wdgtptr);
    let snapshot: Borrowed<Snapshot> = from_glib_borrow(snapshotptr);

    imp.snapshot(
        &snapshot,
        &*widget,
        &from_glib_borrow(bgptr),
        &from_glib_borrow(cellptr),
        from_glib(flags),
    );
}

unsafe extern "C" fn cell_renderer_start_editing<T: CellRendererImpl>(
    ptr: *mut ffi::GtkCellRenderer,
    evtptr: *mut gdk::ffi::GdkEvent,
    wdgtptr: *mut ffi::GtkWidget,
    pathptr: *const c_char,
    bgptr: *const gdk::ffi::GdkRectangle,
    cellptr: *const gdk::ffi::GdkRectangle,
    flags: ffi::GtkCellRendererState,
) -> *mut ffi::GtkCellEditable {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();
    let widget: Borrowed<Widget> = from_glib_borrow(wdgtptr);
    let evt: Borrowed<Option<gdk::Event>> = from_glib_borrow(evtptr);

    imp.start_editing(
        evt.as_ref().as_ref(),
        &*widget,
        &GString::from_glib_borrow(pathptr),
        &from_glib_borrow(bgptr),
        &from_glib_borrow(cellptr),
        from_glib(flags),
    )
    .to_glib_none()
    .0
}