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/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]