Provide a way to set cursor area for IME cursor

Rename `Window::set_ime_position` to `Window::set_ime_cursor_area`
adding a way to create cursor exclusive zone.

Fixes #2886.

src/platform_impl/android/mod.rs

@@ -872,7 +872,7 @@ impl Window {
 
     pub fn set_window_icon(&self, _window_icon: Option<crate::icon::Icon>) {}
 
-    pub fn set_ime_position(&self, _position: Position) {}
+    pub fn set_ime_cursor_area(&self, _position: Position, _size: Size) {}
 
     pub fn set_ime_allowed(&self, _allowed: bool) {}
 

src/platform_impl/ios/window.rs

@@ -295,8 +295,8 @@ impl Inner {
         warn!("`Window::set_window_icon` is ignored on iOS")
     }
 
-    pub fn set_ime_position(&self, _position: Position) {
-        warn!("`Window::set_ime_position` is ignored on iOS")
+    pub fn set_ime_cursor_area(&self, _position: Position, _size: Size) {
+        warn!("`Window::set_ime_cursor_area` is ignored on iOS")
     }
 
     pub fn set_ime_allowed(&self, _allowed: bool) {

src/platform_impl/linux/mod.rs

@@ -512,8 +512,8 @@ impl Window {
     }
 
     #[inline]
-    pub fn set_ime_position(&self, position: Position) {
-        x11_or_wayland!(match self; Window(w) => w.set_ime_position(position))
+    pub fn set_ime_cursor_area(&self, position: Position, size: Size) {
+        x11_or_wayland!(match self; Window(w) => w.set_ime_cursor_area(position, size))
     }
 
     #[inline]

src/platform_impl/linux/wayland/window/mod.rs

@@ -534,12 +534,13 @@ impl Window {
     }
 
     #[inline]
-    pub fn set_ime_position(&self, position: Position) {
+    pub fn set_ime_cursor_area(&self, position: Position, size: Size) {
         let window_state = self.window_state.lock().unwrap();
         if window_state.ime_allowed() {
             let scale_factor = window_state.scale_factor();
             let position = position.to_logical(scale_factor);
-            window_state.set_ime_position(position);
+            let size = size.to_logical(scale_factor);
+            window_state.set_ime_cursor_area(position, size);
         }
     }
 

src/platform_impl/linux/wayland/window/state.rs

@@ -741,13 +741,14 @@ impl WindowState {
     }
 
     /// Set the IME position.
-    pub fn set_ime_position(&self, position: LogicalPosition<u32>) {
+    pub fn set_ime_cursor_area(&self, position: LogicalPosition<u32>, size: LogicalSize<u32>) {
         // XXX This won't fly unless user will have a way to request IME window per seat, since
         // the ime windows will be overlapping, but winit doesn't expose API to specify for
         // which seat we're setting IME position.
         let (x, y) = (position.x as i32, position.y as i32);
+        let (width, height) = (size.width as i32, size.height as i32);
         for text_input in self.text_inputs.iter() {
-            text_input.set_cursor_rectangle(x, y, 0, 0);
+            text_input.set_cursor_rectangle(x, y, width, height);
             text_input.commit();
         }
     }

src/platform_impl/linux/x11/window.rs

@@ -1510,7 +1510,7 @@ impl UnownedWindow {
     }
 
     #[inline]
-    pub fn set_ime_position(&self, spot: Position) {
+    pub fn set_ime_cursor_area(&self, spot: Position, _size: Size) {
         let (x, y) = spot.to_physical::<i32>(self.scale_factor()).into();
         let _ = self
             .ime_sender

src/platform_impl/macos/util/async.rs

@@ -202,11 +202,15 @@ pub(crate) fn close_sync(window: &NSWindow) {
     });
 }
 
-pub(crate) fn set_ime_position_sync(window: &WinitWindow, logical_spot: LogicalPosition<f64>) {
+pub(crate) fn set_ime_cursor_area_sync(
+    window: &WinitWindow,
+    logical_spot: LogicalPosition<f64>,
+    size: LogicalSize<f64>,
+) {
     let window = MainThreadSafe(window);
     run_on_main(move || {
         // TODO(madsmtm): Remove the need for this
-        unsafe { Id::from_shared(window.view()) }.set_ime_position(logical_spot);
+        unsafe { Id::from_shared(window.view()) }.set_ime_cursor_area(logical_spot, size);
     });
 }
 

src/platform_impl/macos/view.rs

@@ -122,6 +122,7 @@ fn get_left_modifier_code(key: &Key) -> KeyCode {
 pub(super) struct ViewState {
     pub cursor_state: Mutex<CursorState>,
     ime_position: LogicalPosition<f64>,
+    ime_size: LogicalSize<f64>,
     pub(super) modifiers: Modifiers,
     phys_modifiers: HashMap<Key, ModLocationMask>,
     tracking_rect: Option<NSTrackingRectTag>,
@@ -167,6 +168,7 @@ declare_class!(
                 let state = ViewState {
                     cursor_state: Default::default(),
                     ime_position: LogicalPosition::new(0.0, 0.0),
+                    ime_size: Default::default(),
                     modifiers: Default::default(),
                     phys_modifiers: Default::default(),
                     tracking_rect: None,
@@ -416,11 +418,8 @@ declare_class!(
             let base_y = (content_rect.origin.y + content_rect.size.height) as f64;
             let x = base_x + self.state.ime_position.x;
             let y = base_y - self.state.ime_position.y;
-            // This is not ideal: We _should_ return a different position based on
-            // the currently selected character (which varies depending on the type
-            // and size of the character), but in the current `winit` API there is
-            // no way to express this. Same goes for the `NSSize`.
-            NSRect::new(NSPoint::new(x as _, y as _), NSSize::new(0.0, 0.0))
+            let LogicalSize { width, height } = self.state.ime_size;
+            NSRect::new(NSPoint::new(x as _, y as _), NSSize::new(width, height))
         }
 
         #[sel(insertText:replacementRange:)]
@@ -871,8 +870,13 @@ impl WinitView {
         }
     }
 
-    pub(super) fn set_ime_position(&mut self, position: LogicalPosition<f64>) {
+    pub(super) fn set_ime_cursor_area(
+        &mut self,
+        position: LogicalPosition<f64>,
+        size: LogicalSize<f64>,
+    ) {
         self.state.ime_position = position;
+        self.state.ime_size = size;
         let input_context = self.inputContext().expect("input context");
         input_context.invalidateCharacterCoordinates();
     }

src/platform_impl/macos/window.rs

@@ -1161,10 +1161,11 @@ impl WinitWindow {
     }
 
     #[inline]
-    pub fn set_ime_position(&self, spot: Position) {
+    pub fn set_ime_cursor_area(&self, spot: Position, size: Size) {
         let scale_factor = self.scale_factor();
         let logical_spot = spot.to_logical(scale_factor);
-        util::set_ime_position_sync(self, logical_spot);
+        let size = size.to_logical(scale_factor);
+        util::set_ime_cursor_area_sync(self, logical_spot, size);
     }
 
     #[inline]

src/platform_impl/orbital/window.rs

@@ -324,7 +324,7 @@ impl Window {
     pub fn set_window_icon(&self, _window_icon: Option<crate::icon::Icon>) {}
 
     #[inline]
-    pub fn set_ime_position(&self, _position: Position) {}
+    pub fn set_ime_cursor_area(&self, _position: Position, _size: Size) {}
 
     #[inline]
     pub fn set_ime_allowed(&self, _allowed: bool) {}

src/platform_impl/web/window.rs

@@ -327,7 +327,7 @@ impl Window {
     }
 
     #[inline]
-    pub fn set_ime_position(&self, _position: Position) {
+    pub fn set_ime_cursor_area(&self, _position: Position, _size: Size) {
         // Currently a no-op as it does not seem there is good support for this on web
     }
 

src/platform_impl/windows/ime.rs

@@ -1,12 +1,11 @@
 use std::{
     ffi::{c_void, OsString},
-    mem::zeroed,
     os::windows::prelude::OsStringExt,
     ptr::null_mut,
 };
 
 use windows_sys::Win32::{
-    Foundation::POINT,
+    Foundation::{POINT, RECT},
     Globalization::HIMC,
     UI::{
         Input::Ime::{
@@ -19,7 +18,10 @@ use windows_sys::Win32::{
     },
 };
 
-use crate::{dpi::Position, platform::windows::HWND};
+use crate::{
+    dpi::{Position, Size},
+    platform::windows::HWND,
+};
 
 pub struct ImeContext {
     hwnd: HWND,
@@ -109,17 +111,24 @@ impl ImeContext {
         }
     }
 
-    pub unsafe fn set_ime_position(&self, spot: Position, scale_factor: f64) {
+    pub unsafe fn set_ime_cursor_area(&self, spot: Position, size: Size, scale_factor: f64) {
         if !ImeContext::system_has_ime() {
             return;
         }
 
         let (x, y) = spot.to_physical::<i32>(scale_factor).into();
+        let (width, height): (i32, i32) = size.to_physical::<i32>(scale_factor).into();
+        let rc_area = RECT {
+            left: x,
+            top: y,
+            right: x + width,
+            bottom: y - height,
+        };
         let candidate_form = CANDIDATEFORM {
             dwIndex: 0,
             dwStyle: CFS_EXCLUDE,
             ptCurrentPos: POINT { x, y },
-            rcArea: zeroed(),
+            rcArea: rc_area,
         };
 
         ImmSetCandidateWindow(self.himc, &candidate_form);

src/platform_impl/windows/window.rs

@@ -722,9 +722,9 @@ impl Window {
     }
 
     #[inline]
-    pub fn set_ime_position(&self, spot: Position) {
+    pub fn set_ime_cursor_area(&self, spot: Position, size: Size) {
         unsafe {
-            ImeContext::current(self.hwnd()).set_ime_position(spot, self.scale_factor());
+            ImeContext::current(self.hwnd()).set_ime_cursor_area(spot, size, self.scale_factor());
         }
     }