Struct gtk4::IMContext

#[repr(transparent)]
pub struct IMContext { /* private fields */ }

IMContext defines the interface for GTK input methods.

IMContext is used by GTK text input widgets like Text to map from key events to Unicode character strings.

An input method may consume multiple key events in sequence before finally outputting the composed result. This is called preediting, and an input method may provide feedback about this process by displaying the intermediate composition states as preedit text. To do so, the IMContext will emit preedit-start, preedit-changed and preedit-end signals.

For instance, the built-in GTK input method IMContextSimple implements the input of arbitrary Unicode code points by holding down the Control and Shift keys and then typing u followed by the hexadecimal digits of the code point. When releasing the Control and Shift 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.

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 | Writeable

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 | Writeable

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.

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() 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() method.

Implements

IMContextExt, glib::ObjectExt

Implementations

impl IMContext

pub const NONE: Option<&'static IMContext> = None

Trait Implementations

impl Clone for IMContext

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for IMContext

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for IMContext

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl HasParamSpec for IMContext

type ParamSpec = ParamSpecObject

type SetValue = IMContext

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(_: &str) -> ParamSpecObjectBuilder<'_, IMContext>

fn param_spec_builder() -> Self::BuilderFn

impl Hash for IMContext

fn hash<H>(&self, state: &mut H)where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: IMContextImpl> IsSubclassable<T> for IMContext

fn class_init(class: &mut Class<Self>)

Override the virtual methods of this class for the given subclass and do other class initialization.

fn instance_init(instance: &mut InitializingObject<T>)

Instance specific initialization.

impl Ord for IMContext

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl ParentClassIs for IMContext

type Parent = Object

impl<OT: ObjectType> PartialEq<OT> for IMContext

fn eq(&self, other: &OT) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<OT: ObjectType> PartialOrd<OT> for IMContext

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for IMContext

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for IMContext

impl IsA<IMContext> for IMContextSimple

impl IsA<IMContext> for IMMulticontext