gtk4/auto/

im_context.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
#![allow(deprecated)]

use crate::{InputHints, InputPurpose, Widget, ffi};
use glib::{
    object::ObjectType as _,
    prelude::*,
    signal::{SignalHandlerId, connect_raw},
    translate::*,
};
use std::boxed::Box as Box_;

glib::wrapper! {
    ///  keys, preediting ends and the
    /// character is inserted as text. For example,
    ///
    ///     Ctrl+Shift+u 2 0 A C
    ///
    /// results in the € sign.
    ///
    /// Additional input methods can be made available for use by GTK widgets as
    /// loadable modules. An input method module is a small shared library which
    /// provides a `GIOExtension` for the extension point named "gtk-im-module".
    ///
    /// To connect a widget to the users preferred input method, you should use
    /// [`IMMulticontext`][crate::IMMulticontext].
    ///
    /// This is an Abstract Base Class, you cannot instantiate it.
    ///
    /// ## Properties
    ///
    ///
    /// #### `input-hints`
    ///  Additional hints that allow input methods to fine-tune
    /// their behaviour.
    ///
    /// Readable | Writable
    ///
    ///
    /// #### `input-purpose`
    ///  The purpose of the text field that the `GtkIMContext is connected to.
    ///
    /// This property can be used by on-screen keyboards and other input
    /// methods to adjust their behaviour.
    ///
    /// Readable | Writable
    ///
    /// ## Signals
    ///
    ///
    /// #### `commit`
    ///  The ::commit signal is emitted when a complete input sequence
    /// has been entered by the user.
    ///
    /// If the commit comes after a preediting sequence, the
    /// ::commit signal is emitted after ::preedit-end.
    ///
    /// This can be a single character immediately after a key press or
    /// the final result of preediting.
    ///
    ///
    ///
    ///
    /// #### `delete-surrounding`
    ///  The ::delete-surrounding signal is emitted when the input method
    /// needs to delete all or part of the context surrounding the cursor.
    ///
    ///
    ///
    ///
    /// #### `invalid-composition`
    ///  Emitted when the filtered keys do not compose to a single valid character.
    ///
    ///
    ///
    ///
    /// #### `preedit-changed`
    ///  The ::preedit-changed signal is emitted whenever the preedit sequence
    /// currently being entered has changed.
    ///
    /// It is also emitted at the end of a preedit sequence, in which case
    /// [`IMContextExt::preedit_string()`][crate::prelude::IMContextExt::preedit_string()] returns the empty string.
    ///
    ///
    ///
    ///
    /// #### `preedit-end`
    ///  The ::preedit-end signal is emitted when a preediting sequence
    /// has been completed or canceled.
    ///
    ///
    ///
    ///
    /// #### `preedit-start`
    ///  The ::preedit-start signal is emitted when a new preediting sequence
    /// starts.
    ///
    ///
    ///
    ///
    /// #### `retrieve-surrounding`
    ///  The ::retrieve-surrounding signal is emitted when the input method
    /// requires the context surrounding the cursor.
    ///
    /// The callback should set the input method surrounding context by
    /// calling the [`IMContextExt::set_surrounding()`][crate::prelude::IMContextExt::set_surrounding()] method.
    ///
    ///
    ///
    /// # Implements
    ///
    /// [`IMContextExt`][trait@crate::prelude::IMContextExt], [`trait@glib::ObjectExt`]
    #[doc(alias = "GtkIMContext")]
    pub struct IMContext(Object<ffi::GtkIMContext, ffi::GtkIMContextClass>);

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

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

/// Trait containing all [`struct@IMContext`] methods.
///
/// # Implementors
///
/// [`IMContextSimple`][struct@crate::IMContextSimple], [`IMContext`][struct@crate::IMContext], [`IMMulticontext`][struct@crate::IMMulticontext]
pub trait IMContextExt: IsA<IMContext> + 'static {
    /// Requests the platform to show an on-screen keyboard for user input.
    ///
    /// This method will return [`true`] if this request was actually performed
    /// to the platform, other environmental factors may result in an on-screen
    /// keyboard effectively not showing up.
    /// ## `event`
    /// a [`gdk::Event`][crate::gdk::Event]
    ///
    /// # Returns
    ///
    /// [`true`] if an on-screen keyboard could be requested to the platform.
    #[cfg(feature = "v4_14")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v4_14")))]
    #[doc(alias = "gtk_im_context_activate_osk")]
    fn activate_osk(&self, event: Option<impl AsRef<gdk::Event>>) -> bool {
        unsafe {
            from_glib(ffi::gtk_im_context_activate_osk(
                self.as_ref().to_glib_none().0,
                event.as_ref().map(|p| p.as_ref()).to_glib_none().0,
            ))
        }
    }

    /// Asks the widget that the input context is attached to delete
    /// characters around the cursor position by emitting the
    /// `::delete_surrounding` signal.
    ///
    /// Note that @offset and @n_chars are in characters not in bytes
    /// which differs from the usage other places in [`IMContext`][crate::IMContext].
    ///
    /// In order to use this function, you should first call
    /// [`surrounding()`][Self::surrounding()] to get the current context,
    /// and call this function immediately afterwards to make sure that you
    /// know what you are deleting. You should also account for the fact
    /// that even if the signal was handled, the input context might not
    /// have deleted all the characters that were requested to be deleted.
    ///
    /// This function is used by an input method that wants to make
    /// substitutions in the existing text in response to new input.
    /// It is not useful for applications.
    /// ## `offset`
    /// offset from cursor position in chars;
    ///    a negative value means start before the cursor.
    /// ## `n_chars`
    /// number of characters to delete.
    ///
    /// # Returns
    ///
    /// [`true`] if the signal was handled.
    #[doc(alias = "gtk_im_context_delete_surrounding")]
    fn delete_surrounding(&self, offset: i32, n_chars: i32) -> bool {
        unsafe {
            from_glib(ffi::gtk_im_context_delete_surrounding(
                self.as_ref().to_glib_none().0,
                offset,
                n_chars,
            ))
        }
    }

    /// Allow an input method to forward key press and release events
    /// to another input method without necessarily having a [`gdk::Event`][crate::gdk::Event]
    /// available.
    /// ## `press`
    /// whether to forward a key press or release event
    /// ## `surface`
    /// the surface the event is for
    /// ## `device`
    /// the device that the event is for
    /// ## `time`
    /// the timestamp for the event
    /// ## `keycode`
    /// the keycode for the event
    /// ## `state`
    /// modifier state for the event
    /// ## `group`
    /// the active keyboard group for the event
    ///
    /// # Returns
    ///
    /// [`true`] if the input method handled the key event.
    #[doc(alias = "gtk_im_context_filter_key")]
    fn filter_key(
        &self,
        press: bool,
        surface: &impl IsA<gdk::Surface>,
        device: &gdk::Device,
        time: u32,
        keycode: u32,
        state: gdk::ModifierType,
        group: i32,
    ) -> bool {
        unsafe {
            from_glib(ffi::gtk_im_context_filter_key(
                self.as_ref().to_glib_none().0,
                press.into_glib(),
                surface.as_ref().to_glib_none().0,
                device.to_glib_none().0,
                time,
                keycode,
                state.into_glib(),
                group,
            ))
        }
    }

    /// Allow an input method to internally handle key press and release
    /// events.
    ///
    /// If this function returns [`true`], then no further processing
    /// should be done for this key event.
    /// ## `event`
    /// the key event
    ///
    /// # Returns
    ///
    /// [`true`] if the input method handled the key event.
    #[doc(alias = "gtk_im_context_filter_keypress")]
    fn filter_keypress(&self, event: impl AsRef<gdk::Event>) -> bool {
        unsafe {
            from_glib(ffi::gtk_im_context_filter_keypress(
                self.as_ref().to_glib_none().0,
                event.as_ref().to_glib_none().0,
            ))
        }
    }

    /// Notify the input method that the widget to which this
    /// input context corresponds has gained focus.
    ///
    /// The input method may, for example, change the displayed
    /// feedback to reflect this change.
    #[doc(alias = "gtk_im_context_focus_in")]
    fn focus_in(&self) {
        unsafe {
            ffi::gtk_im_context_focus_in(self.as_ref().to_glib_none().0);
        }
    }

    /// Notify the input method that the widget to which this
    /// input context corresponds has lost focus.
    ///
    /// The input method may, for example, change the displayed
    /// feedback or reset the contexts state to reflect this change.
    #[doc(alias = "gtk_im_context_focus_out")]
    fn focus_out(&self) {
        unsafe {
            ffi::gtk_im_context_focus_out(self.as_ref().to_glib_none().0);
        }
    }

    /// Retrieves the client widget for the input context.
    ///
    /// # Returns
    ///
    /// The client widget
    #[cfg(feature = "v4_24")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v4_24")))]
    #[doc(alias = "gtk_im_context_get_client_widget")]
    #[doc(alias = "get_client_widget")]
    fn client_widget(&self) -> Option<Widget> {
        unsafe {
            from_glib_none(ffi::gtk_im_context_get_client_widget(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    /// Retrieve the current preedit string for the input context,
    /// and a list of attributes to apply to the string.
    ///
    /// This string should be displayed inserted at the insertion point.
    ///
    /// # Returns
    ///
    ///
    /// ## `str`
    /// location to store the retrieved
    ///   string. The string retrieved must be freed with g_free().
    ///
    /// ## `attrs`
    /// location to store the retrieved
    ///   attribute list. When you are done with this list, you
    ///   must unreference it with `Pango::AttrList::unref()`.
    ///
    /// ## `cursor_pos`
    /// location to store position of cursor
    ///   (in characters) within the preedit string.
    #[doc(alias = "gtk_im_context_get_preedit_string")]
    #[doc(alias = "get_preedit_string")]
    fn preedit_string(&self) -> (glib::GString, pango::AttrList, i32) {
        unsafe {
            let mut str = std::ptr::null_mut();
            let mut attrs = std::ptr::null_mut();
            let mut cursor_pos = std::mem::MaybeUninit::uninit();
            ffi::gtk_im_context_get_preedit_string(
                self.as_ref().to_glib_none().0,
                &mut str,
                &mut attrs,
                cursor_pos.as_mut_ptr(),
            );
            (
                from_glib_full(str),
                from_glib_full(attrs),
                cursor_pos.assume_init(),
            )
        }
    }

    /// Retrieves context around the insertion point.
    ///
    /// Input methods typically want context in order to constrain input text
    /// based on existing text; this is important for languages such as Thai
    /// where only some sequences of characters are allowed.
    ///
    /// This function is implemented by emitting the
    /// [`retrieve-surrounding`][struct@crate::IMContext#retrieve-surrounding] signal on the input method;
    /// in response to this signal, a widget should provide as much context as
    /// is available, up to an entire paragraph, by calling
    /// [`set_surrounding()`][Self::set_surrounding()].
    ///
    /// Note that there is no obligation for a widget to respond to the
    /// `::retrieve-surrounding` signal, so input methods must be prepared to
    /// function without context.
    ///
    /// # Deprecated since 4.2
    ///
    /// Use [`surrounding_with_selection()`][Self::surrounding_with_selection()] instead.
    ///
    /// # Returns
    ///
    /// `TRUE` if surrounding text was provided; in this case
    ///    you must free the result stored in `text`.
    ///
    /// ## `text`
    /// location to store a UTF-8 encoded
    ///   string of text holding context around the insertion point.
    ///   If the function returns [`true`], then you must free the result
    ///   stored in this location with g_free().
    ///
    /// ## `cursor_index`
    /// location to store byte index of the insertion
    ///   cursor within @text.
    #[cfg_attr(feature = "v4_2", deprecated = "Since 4.2")]
    #[allow(deprecated)]
    #[doc(alias = "gtk_im_context_get_surrounding")]
    #[doc(alias = "get_surrounding")]
    fn surrounding(&self) -> Option<(glib::GString, i32)> {
        unsafe {
            let mut text = std::ptr::null_mut();
            let mut cursor_index = std::mem::MaybeUninit::uninit();
            let ret = from_glib(ffi::gtk_im_context_get_surrounding(
                self.as_ref().to_glib_none().0,
                &mut text,
                cursor_index.as_mut_ptr(),
            ));
            if ret {
                Some((from_glib_full(text), cursor_index.assume_init()))
            } else {
                None
            }
        }
    }

    /// Retrieves context around the insertion point.
    ///
    /// Input methods typically want context in order to constrain input
    /// text based on existing text; this is important for languages such
    /// as Thai where only some sequences of characters are allowed.
    ///
    /// This function is implemented by emitting the
    /// [`retrieve-surrounding`][struct@crate::IMContext#retrieve-surrounding] signal on the input method;
    /// in response to this signal, a widget should provide as much context as
    /// is available, up to an entire paragraph, by calling
    /// [`set_surrounding_with_selection()`][Self::set_surrounding_with_selection()].
    ///
    /// Note that there is no obligation for a widget to respond to the
    /// `::retrieve-surrounding` signal, so input methods must be prepared to
    /// function without context.
    ///
    /// # Returns
    ///
    /// `TRUE` if surrounding text was provided; in this case
    ///   you must free the result stored in `text`.
    ///
    /// ## `text`
    /// location to store a UTF-8 encoded
    ///   string of text holding context around the insertion point.
    ///   If the function returns [`true`], then you must free the result
    ///   stored in this location with g_free().
    ///
    /// ## `cursor_index`
    /// location to store byte index of the insertion
    ///   cursor within @text.
    ///
    /// ## `anchor_index`
    /// location to store byte index of the selection
    ///   bound within @text
    #[cfg(feature = "v4_2")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v4_2")))]
    #[doc(alias = "gtk_im_context_get_surrounding_with_selection")]
    #[doc(alias = "get_surrounding_with_selection")]
    fn surrounding_with_selection(&self) -> Option<(glib::GString, i32, i32)> {
        unsafe {
            let mut text = std::ptr::null_mut();
            let mut cursor_index = std::mem::MaybeUninit::uninit();
            let mut anchor_index = std::mem::MaybeUninit::uninit();
            let ret = from_glib(ffi::gtk_im_context_get_surrounding_with_selection(
                self.as_ref().to_glib_none().0,
                &mut text,
                cursor_index.as_mut_ptr(),
                anchor_index.as_mut_ptr(),
            ));
            if ret {
                Some((
                    from_glib_full(text),
                    cursor_index.assume_init(),
                    anchor_index.assume_init(),
                ))
            } else {
                None
            }
        }
    }

    /// Notify the input method that a change such as a change in cursor
    /// position has been made.
    ///
    /// This will typically cause the input method to clear the preedit state.
    #[doc(alias = "gtk_im_context_reset")]
    fn reset(&self) {
        unsafe {
            ffi::gtk_im_context_reset(self.as_ref().to_glib_none().0);
        }
    }

    /// Set the client widget for the input context.
    ///
    /// This is the [`Widget`][crate::Widget] holding the input focus. This widget is
    /// used in order to correctly position status windows, and may
    /// also be used for purposes internal to the input method.
    /// ## `widget`
    /// the client widget. This may be [`None`] to indicate
    ///   that the previous client widget no longer exists.
    #[doc(alias = "gtk_im_context_set_client_widget")]
    fn set_client_widget(&self, widget: Option<&impl IsA<Widget>>) {
        unsafe {
            ffi::gtk_im_context_set_client_widget(
                self.as_ref().to_glib_none().0,
                widget.map(|p| p.as_ref()).to_glib_none().0,
            );
        }
    }

    /// Notify the input method that a change in cursor
    /// position has been made.
    ///
    /// The location is relative to the client widget.
    /// ## `area`
    /// new location
    #[doc(alias = "gtk_im_context_set_cursor_location")]
    fn set_cursor_location(&self, area: &gdk::Rectangle) {
        unsafe {
            ffi::gtk_im_context_set_cursor_location(
                self.as_ref().to_glib_none().0,
                area.to_glib_none().0,
            );
        }
    }

    /// Sets surrounding context around the insertion point and preedit
    /// string.
    ///
    /// This function is expected to be called in response to the
    /// [`retrieve-surrounding`][struct@crate::IMContext#retrieve-surrounding] signal, and will
    /// likely have no effect if called at other times.
    ///
    /// # Deprecated since 4.2
    ///
    /// Use [`set_surrounding_with_selection()`][Self::set_surrounding_with_selection()] instead
    /// ## `text`
    /// text surrounding the insertion point, as UTF-8.
    ///   the preedit string should not be included within @text
    /// ## `len`
    /// the length of @text, or -1 if @text is nul-terminated
    /// ## `cursor_index`
    /// the byte index of the insertion cursor within @text.
    #[cfg_attr(feature = "v4_2", deprecated = "Since 4.2")]
    #[allow(deprecated)]
    #[doc(alias = "gtk_im_context_set_surrounding")]
    fn set_surrounding(&self, text: &str, cursor_index: i32) {
        let len = text.len() as _;
        unsafe {
            ffi::gtk_im_context_set_surrounding(
                self.as_ref().to_glib_none().0,
                text.to_glib_none().0,
                len,
                cursor_index,
            );
        }
    }

    /// Sets surrounding context around the insertion point and preedit
    /// string. This function is expected to be called in response to the
    /// [`retrieve_surrounding`][struct@crate::IMContext#retrieve_surrounding] signal, and will likely
    /// have no effect if called at other times.
    /// ## `text`
    /// text surrounding the insertion point, as UTF-8.
    ///   the preedit string should not be included within @text
    /// ## `len`
    /// the length of @text, or -1 if @text is nul-terminated
    /// ## `cursor_index`
    /// the byte index of the insertion cursor within @text
    /// ## `anchor_index`
    /// the byte index of the selection bound within @text
    #[cfg(feature = "v4_2")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v4_2")))]
    #[doc(alias = "gtk_im_context_set_surrounding_with_selection")]
    fn set_surrounding_with_selection(&self, text: &str, cursor_index: i32, anchor_index: i32) {
        let len = text.len() as _;
        unsafe {
            ffi::gtk_im_context_set_surrounding_with_selection(
                self.as_ref().to_glib_none().0,
                text.to_glib_none().0,
                len,
                cursor_index,
                anchor_index,
            );
        }
    }

    /// Sets whether the IM context should use the preedit string
    /// to display feedback.
    ///
    /// If @use_preedit is [`false`] (default is [`true`]), then the IM context
    /// may use some other method to display feedback, such as displaying
    /// it in a child of the root window.
    /// ## `use_preedit`
    /// whether the IM context should use the preedit string.
    #[doc(alias = "gtk_im_context_set_use_preedit")]
    fn set_use_preedit(&self, use_preedit: bool) {
        unsafe {
            ffi::gtk_im_context_set_use_preedit(
                self.as_ref().to_glib_none().0,
                use_preedit.into_glib(),
            );
        }
    }

    /// Additional hints that allow input methods to fine-tune
    /// their behaviour.
    #[doc(alias = "input-hints")]
    fn input_hints(&self) -> InputHints {
        ObjectExt::property(self.as_ref(), "input-hints")
    }

    /// Additional hints that allow input methods to fine-tune
    /// their behaviour.
    #[doc(alias = "input-hints")]
    fn set_input_hints(&self, input_hints: InputHints) {
        ObjectExt::set_property(self.as_ref(), "input-hints", input_hints)
    }

    /// The purpose of the text field that the `GtkIMContext is connected to.
    ///
    /// This property can be used by on-screen keyboards and other input
    /// methods to adjust their behaviour.
    #[doc(alias = "input-purpose")]
    fn input_purpose(&self) -> InputPurpose {
        ObjectExt::property(self.as_ref(), "input-purpose")
    }

    /// The purpose of the text field that the `GtkIMContext is connected to.
    ///
    /// This property can be used by on-screen keyboards and other input
    /// methods to adjust their behaviour.
    #[doc(alias = "input-purpose")]
    fn set_input_purpose(&self, input_purpose: InputPurpose) {
        ObjectExt::set_property(self.as_ref(), "input-purpose", input_purpose)
    }

    /// The ::commit signal is emitted when a complete input sequence
    /// has been entered by the user.
    ///
    /// If the commit comes after a preediting sequence, the
    /// ::commit signal is emitted after ::preedit-end.
    ///
    /// This can be a single character immediately after a key press or
    /// the final result of preediting.
    /// ## `str`
    /// the completed character(s) entered by the user
    #[doc(alias = "commit")]
    fn connect_commit<F: Fn(&Self, &str) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn commit_trampoline<P: IsA<IMContext>, F: Fn(&P, &str) + 'static>(
            this: *mut ffi::GtkIMContext,
            str: *mut std::ffi::c_char,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(
                    IMContext::from_glib_borrow(this).unsafe_cast_ref(),
                    &glib::GString::from_glib_borrow(str),
                )
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"commit".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    commit_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    /// The ::delete-surrounding signal is emitted when the input method
    /// needs to delete all or part of the context surrounding the cursor.
    /// ## `offset`
    /// the character offset from the cursor position of the text
    ///   to be deleted. A negative value indicates a position before
    ///   the cursor.
    /// ## `n_chars`
    /// the number of characters to be deleted
    ///
    /// # Returns
    ///
    /// [`true`] if the signal was handled.
    #[doc(alias = "delete-surrounding")]
    fn connect_delete_surrounding<F: Fn(&Self, i32, i32) -> bool + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId {
        unsafe extern "C" fn delete_surrounding_trampoline<
            P: IsA<IMContext>,
            F: Fn(&P, i32, i32) -> bool + 'static,
        >(
            this: *mut ffi::GtkIMContext,
            offset: std::ffi::c_int,
            n_chars: std::ffi::c_int,
            f: glib::ffi::gpointer,
        ) -> glib::ffi::gboolean {
            unsafe {
                let f: &F = &*(f as *const F);
                f(
                    IMContext::from_glib_borrow(this).unsafe_cast_ref(),
                    offset,
                    n_chars,
                )
                .into_glib()
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"delete-surrounding".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    delete_surrounding_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    /// Emitted when the filtered keys do not compose to a single valid character.
    /// ## `str`
    /// the completed character(s) entered by the user
    ///
    /// # Returns
    ///
    /// true if the IM context avoid beeping on invalid composition
    #[cfg(feature = "v4_22")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v4_22")))]
    #[doc(alias = "invalid-composition")]
    fn connect_invalid_composition<F: Fn(&Self, &str) -> bool + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId {
        unsafe extern "C" fn invalid_composition_trampoline<
            P: IsA<IMContext>,
            F: Fn(&P, &str) -> bool + 'static,
        >(
            this: *mut ffi::GtkIMContext,
            str: *mut std::ffi::c_char,
            f: glib::ffi::gpointer,
        ) -> glib::ffi::gboolean {
            unsafe {
                let f: &F = &*(f as *const F);
                f(
                    IMContext::from_glib_borrow(this).unsafe_cast_ref(),
                    &glib::GString::from_glib_borrow(str),
                )
                .into_glib()
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"invalid-composition".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    invalid_composition_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    /// The ::preedit-changed signal is emitted whenever the preedit sequence
    /// currently being entered has changed.
    ///
    /// It is also emitted at the end of a preedit sequence, in which case
    /// [`preedit_string()`][Self::preedit_string()] returns the empty string.
    #[doc(alias = "preedit-changed")]
    fn connect_preedit_changed<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn preedit_changed_trampoline<P: IsA<IMContext>, F: Fn(&P) + 'static>(
            this: *mut ffi::GtkIMContext,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(IMContext::from_glib_borrow(this).unsafe_cast_ref())
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"preedit-changed".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    preedit_changed_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    /// The ::preedit-end signal is emitted when a preediting sequence
    /// has been completed or canceled.
    #[doc(alias = "preedit-end")]
    fn connect_preedit_end<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn preedit_end_trampoline<P: IsA<IMContext>, F: Fn(&P) + 'static>(
            this: *mut ffi::GtkIMContext,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(IMContext::from_glib_borrow(this).unsafe_cast_ref())
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"preedit-end".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    preedit_end_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    /// The ::preedit-start signal is emitted when a new preediting sequence
    /// starts.
    #[doc(alias = "preedit-start")]
    fn connect_preedit_start<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn preedit_start_trampoline<P: IsA<IMContext>, F: Fn(&P) + 'static>(
            this: *mut ffi::GtkIMContext,
            f: glib::ffi::gpointer,
        ) {
            unsafe {
                let f: &F = &*(f as *const F);
                f(IMContext::from_glib_borrow(this).unsafe_cast_ref())
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"preedit-start".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    preedit_start_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    /// The ::retrieve-surrounding signal is emitted when the input method
    /// requires the context surrounding the cursor.
    ///
    /// The callback should set the input method surrounding context by
    /// calling the [`set_surrounding()`][Self::set_surrounding()] method.
    ///
    /// # Returns
    ///
    /// [`true`] if the signal was handled.
    #[doc(alias = "retrieve-surrounding")]
    fn connect_retrieve_surrounding<F: Fn(&Self) -> bool + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId {
        unsafe extern "C" fn retrieve_surrounding_trampoline<
            P: IsA<IMContext>,
            F: Fn(&P) -> bool + 'static,
        >(
            this: *mut ffi::GtkIMContext,
            f: glib::ffi::gpointer,
        ) -> glib::ffi::gboolean {
            unsafe {
                let f: &F = &*(f as *const F);
                f(IMContext::from_glib_borrow(this).unsafe_cast_ref()).into_glib()
            }
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"retrieve-surrounding".as_ptr(),
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    retrieve_surrounding_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

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

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

impl<O: IsA<IMContext>> IMContextExt for O {}