Class: Gtk::IMContext

Inherits:
Object
  • Object
show all
Defined in:
(unknown)

Instance Method Summary collapse

Instance Method Details

#activate_osk(event) ⇒ Boolean

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.

Parameters:

  • event (Gdk::Event) —

    a [classGdk.Event]

Returns:

  • (Boolean) —

    true if an on-screen keyboard could be requested to the platform.

#client_widget=(widget) ⇒ nil

Set the client widget for the input context.

This is the GtkWidget 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.

Parameters:

  • widget (Gtk::Widget) —

    the client widget. This may be nil to indicate that the previous client widget no longer exists.

Returns:

  • (nil)

#cursor_location=(area) ⇒ nil

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

The location is relative to the client widget.

Parameters:

  • area (Gdk::Rectangle) —

    new location

Returns:

  • (nil)

#delete_surrounding(offset, n_chars) ⇒ Boolean

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 GtkIMContext.

In order to use this function, you should first call [methodGtk.IMContext.get_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.

Parameters:

  • offset (Integer) —

    offset from cursor position in chars; a negative value means start before the cursor.

  • n_chars (Integer) —

    number of characters to delete.

Returns:

  • (Boolean) —

    true if the signal was handled.

#filter_key(press, surface, device, time, keycode, state, group) ⇒ Boolean

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

Parameters:

  • press (Boolean) —

    whether to forward a key press or release event

  • surface (Gdk::Surface) —

    the surface the event is for

  • device (Gdk::Device) —

    the device that the event is for

  • time (Integer) —

    the timestamp for the event

  • keycode (Integer) —

    the keycode for the event

  • state (Gdk::ModifierType) —

    modifier state for the event

  • group (Integer) —

    the active keyboard group for the event

Returns:

  • (Boolean) —

    true if the input method handled the key event.

#filter_keypress(event) ⇒ Boolean

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.

Parameters:

  • event (Gdk::Event) —

    the key event

Returns:

  • (Boolean) —

    true if the input method handled the key event.

#focus_in ⇒ nil

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.

Returns:

  • (nil)

#focus_out ⇒ nil

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.

Returns:

  • (nil)

#get_preedit_string(str, attrs, cursor_pos) ⇒ nil

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.

Parameters:

  • str (String) —

    location to store the retrieved string. The string retrieved must be freed with g_free().

  • attrs (Pango::AttrList) —

    location to store the retrieved attribute list. When you are done with this list, you must unreference it with [methodPango.AttrList.unref].

  • cursor_pos (Integer) —

    location to store position of cursor (in characters) within the preedit string.

Returns:

  • (nil)

#get_surrounding(text, cursor_index) ⇒ Boolean

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 [signalGtk.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 [methodGtk.IMContext.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.

Parameters:

  • text (String) —

    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 (Integer) —

    location to store byte index of the insertion cursor within text.

Returns:

  • (Boolean) —

    TRUE if surrounding text was provided; in this case you must free the result stored in text.

#get_surrounding_with_selection(text, cursor_index, anchor_index) ⇒ Boolean

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 [signalGtk.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 [methodGtk.IMContext.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.

Parameters:

  • text (String) —

    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 (Integer) —

    location to store byte index of the insertion cursor within text.

  • anchor_index (Integer) —

    location to store byte index of the selection bound within text

Returns:

  • (Boolean) —

    TRUE if surrounding text was provided; in this case you must free the result stored in text.

#input_hints ⇒ Gtk::InputHints

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

Returns:

#input_hints=(input_hints) ⇒ Gtk::InputHints

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

Parameters:

Returns:

#input_purpose ⇒ Gtk::InputPurpose

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.

Returns:

#input_purpose=(input_purpose) ⇒ Gtk::InputPurpose

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.

Parameters:

Returns:

#reset ⇒ nil

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.

Returns:

  • (nil)

#set_surrounding(text, len, cursor_index) ⇒ nil

Sets surrounding context around the insertion point and preedit string.

This function is expected to be called in response to the [signalGtk.IMContext::retrieve-surrounding] signal, and will likely have no effect if called at other times.

Parameters:

  • text (String) —

    text surrounding the insertion point, as UTF-8. the preedit string should not be included within text

  • len (Integer) —

    the length of text, or -1 if text is nul-terminated

  • cursor_index (Integer) —

    the byte index of the insertion cursor within text.

Returns:

  • (nil)

#set_surrounding_with_selection(text, len, cursor_index, anchor_index) ⇒ nil

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

Parameters:

  • text (String) —

    text surrounding the insertion point, as UTF-8. the preedit string should not be included within text

  • len (Integer) —

    the length of text, or -1 if text is nul-terminated

  • cursor_index (Integer) —

    the byte index of the insertion cursor within text

  • anchor_index (Integer) —

    the byte index of the selection bound within text

Returns:

  • (nil)

#use_preedit=(use_preedit) ⇒ nil

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.

Parameters:

  • use_preedit (Boolean) —

    whether the IM context should use the preedit string.

Returns:

  • (nil)