### Class

# Gtk IMContext

#### Description [src]

    abstract class Gtk.IMContext : GObject.Object {
      parent_instance: GObject
    }

`GtkIMContext` defines the interface for GTK input methods.

`GtkIMContext` is used by GTK text input widgets like `GtkText` to map from key events to Unicode character strings.

By default, GTK uses a platform-dependent default input method. On Windows, the default implementation is IME-based and on Wayland, it is using the Wayland text protocol. The choice can be overridden programmatically via the `GtkSettings:gtk-im-module` setting. Users may set the `GTK_IM_MODULE` environment variable to override the default.

Text widgets have a :im-module property (e.g. `GtkTextView:im-module`) that may also be used to set input methods for specific widget instances. For instance, a certain entry widget might be expected to contain certain characters which would be easier to input with a specific input method.

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.

For instance, the built-in GTK input method `GtkIMContextSimple` 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”.

#### Hierarchy

#### Ancestors

- GObject

#### Instance methods

###### gtk_im_context_delete_surrounding

Asks the widget that the input context is attached to delete characters around the cursor position by emitting the GtkIMContext::delete_surrounding signal.

###### gtk_im_context_filter_key

Allow an input method to forward key press and release events to another input methodm without necessarily having a `GdkEvent` available.

###### gtk_im_context_filter_keypress

Allow an input method to internally handle key press and release events.

###### gtk_im_context_focus_in

Notify the input method that the widget to which this input context corresponds has gained focus.

###### gtk_im_context_focus_out

Notify the input method that the widget to which this input context corresponds has lost focus.

###### gtk_im_context_get_preedit_string

Retrieve the current preedit string for the input context, and a list of attributes to apply to the string.

###### gtk_im_context_get_surrounding

Retrieves context around the insertion point.

Deprecated since: 4.2

###### gtk_im_context_get_surrounding_with_selection

Retrieves context around the insertion point.

Available since: 4.2

###### gtk_im_context_reset

Notify the input method that a change such as a change in cursor position has been made.

###### gtk_im_context_set_client_widget

Set the client widget for the input context.

###### gtk_im_context_set_cursor_location

Notify the input method that a change in cursor position has been made.

###### gtk_im_context_set_surrounding

Sets surrounding context around the insertion point and preedit string.

Deprecated since: 4.2

###### gtk_im_context_set_surrounding_with_selection

Sets surrounding context around the insertion point and preedit string. This function is expected to be called in response to the GtkIMContext::retrieve_surrounding signal, and will likely have no effect if called at other times.

Available since: 4.2

###### gtk_im_context_set_use_preedit

Sets whether the IM context should use the preedit string to display feedback.

#### Properties

###### Gtk.IMContext:input-hints

No description available.

###### Gtk.IMContext:input-purpose

No description available.

#### Signals

###### Gtk.IMContext::commit

The ::commit signal is emitted when a complete input sequence has been entered by the user. This can be a single character immediately after a key press or the final result of preediting.

###### Gtk.IMContext::delete-surrounding

The ::delete-surrounding signal is emitted when the input method needs to delete all or part of the context surrounding the cursor.

###### Gtk.IMContext::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 gtk_im_context_get_preedit_string() returns the empty string.

###### Gtk.IMContext::preedit-end

The ::preedit-end signal is emitted when a preediting sequence has been completed or canceled.

###### Gtk.IMContext::preedit-start

The ::preedit-start signal is emitted when a new preediting sequence starts.

###### Gtk.IMContext::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 gtk_im_context_set_surrounding() method.

#### Class structure

    struct GtkIMContextClass {
      void (* preedit_start) (
        GtkIMContext* context
      );
      void (* preedit_end) (
        GtkIMContext* context
      );
      void (* preedit_changed) (
        GtkIMContext* context
      );
      void (* commit) (
        GtkIMContext* context,
        const char* str
      );
      gboolean (* retrieve_surrounding) (
        GtkIMContext* context
      );
      gboolean (* delete_surrounding) (
        GtkIMContext* context,
        int offset,
        int n_chars
      );
      void (* set_client_widget) (
        GtkIMContext* context,
        GtkWidget* widget
      );
      void (* get_preedit_string) (
        GtkIMContext* context,
        char** str,
        PangoAttrList** attrs,
        int* cursor_pos
      );
      gboolean (* filter_keypress) (
        GtkIMContext* context,
        GdkEvent* event
      );
      void (* focus_in) (
        GtkIMContext* context
      );
      void (* focus_out) (
        GtkIMContext* context
      );
      void (* reset) (
        GtkIMContext* context
      );
      void (* set_cursor_location) (
        GtkIMContext* context,
        GdkRectangle* area
      );
      void (* set_use_preedit) (
        GtkIMContext* context,
        gboolean use_preedit
      );
      void (* set_surrounding) (
        GtkIMContext* context,
        const char* text,
        int len,
        int cursor_index
      );
      gboolean (* get_surrounding) (
        GtkIMContext* context,
        char** text,
        int* cursor_index
      );
      void (* set_surrounding_with_selection) (
        GtkIMContext* context,
        const char* text,
        int len,
        int cursor_index,
        int anchor_index
      );
      gboolean (* get_surrounding_with_selection) (
        GtkIMContext* context,
        char** text,
        int* cursor_index,
        int* anchor_index
      );
      void (* _gtk_reserved1) (
    void
      );
      void (* _gtk_reserved2) (
    void
      );
      void (* _gtk_reserved3) (
    void
      );
      void (* _gtk_reserved4) (
    void
      );
      void (* _gtk_reserved5) (
    void
      );

    }

###### Class members

`preedit_start` |
    void (* preedit_start) (
        GtkIMContext* context
      )
| No description available.
`preedit_end` |
    void (* preedit_end) (
        GtkIMContext* context
      )
| No description available.
`preedit_changed` |
    void (* preedit_changed) (
        GtkIMContext* context
      )
| No description available.
`commit` |
    void (* commit) (
        GtkIMContext* context,
        const char* str
      )
| No description available.
`retrieve_surrounding` |
    gboolean (* retrieve_surrounding) (
        GtkIMContext* context
      )
| No description available.
`delete_surrounding` |
    gboolean (* delete_surrounding) (
        GtkIMContext* context,
        int offset,
        int n_chars
      )
| No description available.
`set_client_widget` |
    void (* set_client_widget) (
        GtkIMContext* context,
        GtkWidget* widget
      )
| No description available.
`get_preedit_string` |
    void (* get_preedit_string) (
        GtkIMContext* context,
        char** str,
        PangoAttrList** attrs,
        int* cursor_pos
      )
| No description available.
`filter_keypress` |
    gboolean (* filter_keypress) (
        GtkIMContext* context,
        GdkEvent* event
      )
| No description available.
`focus_in` |
    void (* focus_in) (
        GtkIMContext* context
      )
| No description available.
`focus_out` |
    void (* focus_out) (
        GtkIMContext* context
      )
| No description available.
`reset` |
    void (* reset) (
        GtkIMContext* context
      )
| No description available.
`set_cursor_location` |
    void (* set_cursor_location) (
        GtkIMContext* context,
        GdkRectangle* area
      )
| No description available.
`set_use_preedit` |
    void (* set_use_preedit) (
        GtkIMContext* context,
        gboolean use_preedit
      )
| No description available.
`set_surrounding` |
    void (* set_surrounding) (
        GtkIMContext* context,
        const char* text,
        int len,
        int cursor_index
      )
| No description available.
`get_surrounding` |
    gboolean (* get_surrounding) (
        GtkIMContext* context,
        char** text,
        int* cursor_index
      )
| No description available.
`set_surrounding_with_selection` |
    void (* set_surrounding_with_selection) (
        GtkIMContext* context,
        const char* text,
        int len,
        int cursor_index,
        int anchor_index
      )
| No description available.
`get_surrounding_with_selection` |
    gboolean (* get_surrounding_with_selection) (
        GtkIMContext* context,
        char** text,
        int* cursor_index,
        int* anchor_index
      )
| No description available.
`_gtk_reserved1` |
    void (* _gtk_reserved1) (
    void
      )
| No description available.
`_gtk_reserved2` |
    void (* _gtk_reserved2) (
    void
      )
| No description available.
`_gtk_reserved3` |
    void (* _gtk_reserved3) (
    void
      )
| No description available.
`_gtk_reserved4` |
    void (* _gtk_reserved4) (
    void
      )
| No description available.
`_gtk_reserved5` |
    void (* _gtk_reserved5) (
    void
      )
| No description available.

#### Virtual methods

###### Gtk.IMContextClass.commit

No description available.

###### Gtk.IMContextClass.delete_surrounding

Asks the widget that the input context is attached to delete characters around the cursor position by emitting the GtkIMContext::delete_surrounding signal.

###### Gtk.IMContextClass.filter_keypress

Allow an input method to internally handle key press and release events.

###### Gtk.IMContextClass.focus_in

Notify the input method that the widget to which this input context corresponds has gained focus.

###### Gtk.IMContextClass.focus_out

Notify the input method that the widget to which this input context corresponds has lost focus.

###### Gtk.IMContextClass.get_preedit_string

Retrieve the current preedit string for the input context, and a list of attributes to apply to the string.

###### Gtk.IMContextClass.get_surrounding

Retrieves context around the insertion point.

Deprecated since: 4.2

###### Gtk.IMContextClass.get_surrounding_with_selection

Retrieves context around the insertion point.

Available since: 4.2

###### Gtk.IMContextClass.preedit_changed

No description available.

###### Gtk.IMContextClass.preedit_end

No description available.

###### Gtk.IMContextClass.preedit_start

No description available.

###### Gtk.IMContextClass.reset

Notify the input method that a change such as a change in cursor position has been made.

###### Gtk.IMContextClass.retrieve_surrounding

No description available.

###### Gtk.IMContextClass.set_client_widget

Set the client widget for the input context.

###### Gtk.IMContextClass.set_cursor_location

Notify the input method that a change in cursor position has been made.

###### Gtk.IMContextClass.set_surrounding

Sets surrounding context around the insertion point and preedit string.

Deprecated since: 4.2

###### Gtk.IMContextClass.set_surrounding_with_selection

Sets surrounding context around the insertion point and preedit string. This function is expected to be called in response to the GtkIMContext::retrieve_surrounding signal, and will likely have no effect if called at other times.

Available since: 4.2

###### Gtk.IMContextClass.set_use_preedit

Sets whether the IM context should use the preedit string to display feedback.