Trait gtk4::subclass::im_context::IMContextImpl

pub trait IMContextImpl: IMContextImplExt + ObjectImpl {
    // Provided methods
    fn commit(&self, string: &str) { ... }
    fn delete_surrounding(&self, offset: i32, n_chars: i32) -> bool { ... }
    fn filter_keypress(&self, event: &Event) -> bool { ... }
    fn focus_in(&self) { ... }
    fn focus_out(&self) { ... }
    fn preedit_string(&self) -> (GString, AttrList, i32) { ... }
    fn surrounding(&self) -> Option<(GString, i32)> { ... }
    fn preedit_changed(&self) { ... }
    fn preedit_end(&self) { ... }
    fn preedit_start(&self) { ... }
    fn reset(&self) { ... }
    fn retrieve_surrounding(&self) -> bool { ... }
    fn set_client_widget<P: IsA<Widget>>(&self, widget: Option<&P>) { ... }
    fn set_cursor_location(&self, area: &Rectangle) { ... }
    fn set_surrounding(&self, text: &str, cursor_index: i32) { ... }
    fn set_use_preedit(&self, use_preedit: bool) { ... }
    fn activate_osk(&self) { ... }
    fn activate_osk_with_event(&self, event: Option<&Event>) -> bool { ... }
}

Provided Methods

fn commit(&self, string: &str)

Default handler of the commit signal.

fn delete_surrounding(&self, offset: i32, n_chars: i32) -> bool

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.

In order to use this function, you should first call IMContextExt::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.

fn filter_keypress(&self, event: &Event) -> bool

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.

fn focus_in(&self)

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.

fn focus_out(&self)

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.

fn preedit_string(&self) -> (GString, AttrList, i32)

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.

fn surrounding(&self) -> Option<(GString, i32)>

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 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 IMContextExt::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 IMContextExt::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.

fn preedit_changed(&self)

Default handler of the preedit-changed signal.

fn preedit_end(&self)

Default handler of the preedit-end signal.

fn preedit_start(&self)

Default handler of the preedit-start signal.

fn reset(&self)

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.

fn retrieve_surrounding(&self) -> bool

Default handler of the retrieve-surrounding signal.

fn set_client_widget<P: IsA<Widget>>(&self, widget: Option<&P>)

Set the client widget for the input context.

This is the 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.

fn set_cursor_location(&self, area: &Rectangle)

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

The location is relative to the client widget.

area

new location

fn set_surrounding(&self, text: &str, cursor_index: i32)

👎Deprecated: Since 4.2

Sets surrounding context around the insertion point and preedit string.

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

Deprecated since 4.2

Use IMContextExt::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.

fn set_use_preedit(&self, use_preedit: bool)

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.

fn activate_osk(&self)

Available on crate feature v4_10 only.

fn activate_osk_with_event(&self, event: Option<&Event>) -> bool

Available on crate feature v4_14 only.

Object Safety

This trait is not object safe.

Implementors