Class

GtkIMContext

Description [src]

abstract class Gtk.IMContext : GObject.Object
{
  /* No available fields */
}

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.

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 GtkIMContext will emit GtkIMContext::preedit-start, GtkIMContext::preedit-changed and GtkIMContext::preedit-end signals.

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”.

To connect a widget to the users preferred input method, you should use GtkIMMulticontext.

Hierarchy

Ancestors

GObject

Descendants

Instance methods

gtk_im_context_activate_osk

Requests the platform to show an on-screen keyboard for user input.

since: 4.14

gtk_im_context_delete_surrounding

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

gtk_im_context_filter_key

Allow an input method to forward key press and release events to another input method 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: 4.2

gtk_im_context_get_surrounding_with_selection

Retrieves context around the insertion point.

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: 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.

since: 4.2

gtk_im_context_set_use_preedit

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

Methods inherited from GObject (43)

Please see GObject for a full list of methods.

Properties

Gtk.IMContext:input-hints

Additional hints that allow input methods to fine-tune their behaviour.

Gtk.IMContext:input-purpose

The purpose of the text field that the `GtkIMContext is connected to.

Signals

Gtk.IMContext::commit

The ::commit signal is emitted when a complete input sequence has been entered by the user.

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.

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.

Signals inherited from GObject (1)

GObject::notify

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.

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 (* activate_osk) (
    GtkIMContext* context
  );
  gboolean (* activate_osk_with_event) (
    GtkIMContext* context,
    GdkEvent* event
  );
  void (* _gtk_reserved2) (
void
  );
  void (* _gtk_reserved3) (
void
  );
  void (* _gtk_reserved4) (
void
  );
  
}

No description available.

Class members

preedit_start: void (* preedit_start) ( GtkIMContext* context ): Default handler of the GtkIMContext::preedit-start signal.
preedit_end: void (* preedit_end) ( GtkIMContext* context ): Default handler of the GtkIMContext::preedit-end signal.
preedit_changed: void (* preedit_changed) ( GtkIMContext* context ): Default handler of the GtkIMContext::preedit-changed signal.
commit: void (* commit) ( GtkIMContext* context, const char* str ): Default handler of the GtkIMContext::commit signal.
retrieve_surrounding: gboolean (* retrieve_surrounding) ( GtkIMContext* context ): Default handler of the GtkIMContext::retrieve-surrounding signal.
delete_surrounding: gboolean (* delete_surrounding) ( GtkIMContext* context, int offset, int n_chars ): Default handler of the GtkIMContext::delete-surrounding signal.
set_client_widget: void (* set_client_widget) ( GtkIMContext* context, GtkWidget* widget ): Called via gtk_im_context_set_client_widget() when the input window where the entered text will appear changes. Override this to keep track of the current input window, for instance for the purpose of positioning a status display of your input method.
get_preedit_string: void (* get_preedit_string) ( GtkIMContext* context, char** str, PangoAttrList** attrs, int* cursor_pos ): Called via gtk_im_context_get_preedit_string() to retrieve the text currently being preedited for display at the cursor position. Any input method which composes complex characters or any other compositions from multiple sequential key presses should override this method to provide feedback.
filter_keypress: gboolean (* filter_keypress) ( GtkIMContext* context, GdkEvent* event ): Called via gtk_im_context_filter_keypress() on every key press or release event. Every non-trivial input method needs to override this in order to implement the mapping from key events to text. A return value of TRUE indicates to the caller that the event was consumed by the input method. In that case, the GtkIMContext::commit signal should be emitted upon completion of a key sequence to pass the resulting text back to the input widget. Alternatively, FALSE may be returned to indicate that the event wasn’t handled by the input method. If a builtin mapping exists for the key, it is used to produce a character.
focus_in: void (* focus_in) ( GtkIMContext* context ): Called via gtk_im_context_focus_in() when the input widget has gained focus. May be overridden to keep track of the current focus.
focus_out: void (* focus_out) ( GtkIMContext* context ): Called via gtk_im_context_focus_out() when the input widget has lost focus. May be overridden to keep track of the current focus.
reset: void (* reset) ( GtkIMContext* context ): Called via gtk_im_context_reset() to signal a change such as a change in cursor position. An input method that implements preediting should override this method to clear the preedit state on reset.
set_cursor_location: void (* set_cursor_location) ( GtkIMContext* context, GdkRectangle* area ): Called via gtk_im_context_set_cursor_location() to inform the input method of the current cursor location relative to the client window. May be overridden to implement the display of popup windows at the cursor position.
set_use_preedit: void (* set_use_preedit) ( GtkIMContext* context, gboolean use_preedit ): Called via gtk_im_context_set_use_preedit() to control the use of the preedit string. Override this to display feedback by some other means if turned off.
set_surrounding: void (* set_surrounding) ( GtkIMContext* context, const char* text, int len, int cursor_index ): Called via gtk_im_context_set_surrounding() in response to GtkIMContext::retrieve-surrounding signal to update the input method’s idea of the context around the cursor. It is not necessary to override this method even with input methods which implement context-dependent behavior. The base implementation is sufficient for gtk_im_context_get_surrounding() to work.
get_surrounding: gboolean (* get_surrounding) ( GtkIMContext* context, char** text, int* cursor_index ): Called via gtk_im_context_get_surrounding() to update the context around the cursor location. It is not necessary to override this method even with input methods which implement context-dependent behavior. The base implementation emits GtkIMContext::retrieve-surrounding and records the context received by the subsequent invocation of Gtk.IMContextClass.get_surrounding.
set_surrounding_with_selection: void (* set_surrounding_with_selection) ( GtkIMContext* context, const char* text, int len, int cursor_index, int anchor_index ): Called via gtk_im_context_set_surrounding_with_selection() in response to the GtkIMContext::retrieve-surrounding signal to update the input method’s idea of the context around the cursor. It is not necessary to override this method even with input methods which implement context-dependent behavior. The base implementation is sufficient for gtk_im_context_get_surrounding() to work.
get_surrounding_with_selection: gboolean (* get_surrounding_with_selection) ( GtkIMContext* context, char** text, int* cursor_index, int* anchor_index ): Called via gtk_im_context_get_surrounding_with_selection() to update the context around the cursor location. It is not necessary to override this method even with input methods which implement context-dependent behavior. The base implementation emits GtkIMContext::retrieve-surrounding and records the context received by the subsequent invocation of Gtk.IMContextClass.get_surrounding.
activate_osk: void (* activate_osk) ( GtkIMContext* context ): No description available.
activate_osk_with_event: gboolean (* activate_osk_with_event) ( GtkIMContext* context, GdkEvent* event ): 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.