leyoda/winit
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

winit-core: add surrounding_text for IME

Browse source 
Allow communicating surrounding text to IME to better handle user input
and account for content around for preedit.
This commit is contained in:
DorotaC 2025-07-13 07:57:10 +02:00 • committed by GitHub
parent eb66c25980
commit e7a6034b55
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
3 changed files with 250 additions and 17 deletions
Download patch file Download diff file Expand all files Collapse all files

58
examples/application.rs
View file

@ -40,8 +40,8 @@ use winit::platform::web::{ActiveEventLoopExtWeb, WindowAttributesWeb};
#[cfg(x11_platform)]
use winit::platform::x11::{ActiveEventLoopExtX11, WindowAttributesX11};
use winit::window::{
CursorGrabMode, ImeCapabilities, ImeEnableRequest, ImePurpose, ImeRequestData, ResizeDirection,
Theme, Window, WindowAttributes, WindowId,
CursorGrabMode, ImeCapabilities, ImeEnableRequest, ImePurpose, ImeRequestData,
ImeSurroundingText, ResizeDirection, Theme, Window, WindowAttributes, WindowId,
};
use winit_core::application::macos::ApplicationHandlerExtMacOS;
use winit_core::window::ImeRequest;
@ -518,7 +518,12 @@ impl ApplicationHandler for Application {
info!("Preedit: {}, with caret at {:?}", text, caret_pos);
},
Ime::Commit(text) => {
window.text_field_contents.0.push_str(&text);
window.text_field_contents.1 += text.len();
info!("Committed: {}", text);
let request_data = window.get_ime_update();
window.window.request_ime_update(ImeRequest::Update(request_data)).unwrap();
},
Ime::Disabled => info!("IME disabled for Window={window_id:?}"),
},
@ -611,6 +616,9 @@ impl ApplicationHandlerExtMacOS for Application {
/// State of the window.
struct WindowState {
ime_enabled: bool,
/// The contents of the emulated text field for IME purposes (not displayed).
/// (text, cursor position in bytes).
text_field_contents: (String, usize),
/// Render surface.
///
/// NOTE: This surface must be dropped before the `Window`.
@ -668,9 +676,10 @@ impl WindowState {
// Allow IME out of the box.
let request_data = ImeRequestData::default()
.with_purpose(ImePurpose::Normal)
.with_cursor_area(LogicalPosition { x: 0, y: 0 }.into(), IME_CURSOR_SIZE.into());
.with_cursor_area(LogicalPosition { x: 0, y: 0 }.into(), IME_CURSOR_SIZE.into())
.with_surrounding_text(ImeSurroundingText::new(String::new(), 0, 0).unwrap());
let enable_request = ImeEnableRequest::new(
ImeCapabilities::new().with_purpose().with_cursor_area(),
ImeCapabilities::new().with_purpose().with_cursor_area().with_surrounding_text(),
request_data,
)
.unwrap();
@ -695,6 +704,7 @@ impl WindowState {
#[cfg(not(android_platform))]
start_time: Instant::now(),
ime_enabled: true,
text_field_contents: (String::new(), 0),
cursor_position: Default::default(),
cursor_hidden: Default::default(),
modifiers: Default::default(),
@ -708,20 +718,42 @@ impl WindowState {
Ok(state)
}
pub fn get_ime_update(&self) -> ImeRequestData {
let (text, cursor) = &self.text_field_contents;
// A rudimentary text field emulation: the caret moves right by a constant amount for each
// code point.
let text_before_caret = if text.is_char_boundary(*cursor) { &text[..*cursor] } else { "" };
let chars_before_caret = text_before_caret.chars().count();
let cursor_pos = LogicalPosition { x: 10 * chars_before_caret as u32, y: 0 }.into();
// Limit text field size
const MAX_BYTES: usize = ImeSurroundingText::MAX_TEXT_BYTES;
let minimal_offset = cursor / MAX_BYTES * MAX_BYTES;
let first_char_boundary =
(minimal_offset..*cursor).find(|off| text.is_char_boundary(*off)).unwrap_or(*cursor);
let last_char_boundary = (*cursor..(first_char_boundary + MAX_BYTES))
.rev()
.find(|off| text.is_char_boundary(*off))
.unwrap_or(*cursor);
let surrounding_text = &text[first_char_boundary..last_char_boundary];
let relative_cursor = cursor - first_char_boundary;
let surrounding_text =
ImeSurroundingText::new(surrounding_text.into(), relative_cursor, relative_cursor)
.expect("Bug in example: bad byte calculations");
ImeRequestData::default()
.with_purpose(ImePurpose::Normal)
.with_cursor_area(cursor_pos, IME_CURSOR_SIZE.into())
.with_surrounding_text(surrounding_text)
}
pub fn toggle_ime(&mut self) {
if self.ime_enabled {
self.window.request_ime_update(ImeRequest::Disable).expect("disable can not fail");
} else {
let cursor_pos = self
.cursor_position
.map(Into::into)
.unwrap_or(LogicalPosition { x: 0, y: 0 }.into());
let request_data = ImeRequestData::default()
.with_purpose(ImePurpose::Normal)
.with_cursor_area(cursor_pos, IME_CURSOR_SIZE.into());
let enable_request = ImeEnableRequest::new(
ImeCapabilities::new().with_purpose().with_cursor_area(),
request_data,
ImeCapabilities::new().with_purpose().with_cursor_area().with_surrounding_text(),
self.get_ime_update(),
)
.unwrap();
self.window.request_ime_update(ImeRequest::Enable(enable_request)).unwrap();