macos: try to set the IME cursor position a bit better

Use the current terminal cursor position as the basis for the position
of the IME.

src/frontend/gui/termwindow.rs

@@ -291,6 +291,9 @@ impl WindowCallbacks for TermWindow {
                 return;
             }
         };
+
+        self.update_text_cursor(&tab);
+
         let start = std::time::Instant::now();
         if let Err(err) = self.paint_tab(&tab, ctx) {
             if let Some(&OutOfTextureSpace { size }) = err.downcast_ref::<OutOfTextureSpace>() {
@@ -323,6 +326,7 @@ impl WindowCallbacks for TermWindow {
                 return;
             }
         };
+        self.update_text_cursor(&tab);
         let start = std::time::Instant::now();
         if let Err(err) = self.paint_tab_opengl(&tab, frame) {
             if let Some(&OutOfTextureSpace { size }) = err.downcast_ref::<OutOfTextureSpace>() {
@@ -486,6 +490,21 @@ impl TermWindow {
         }
     }
 
+    fn update_text_cursor(&mut self, tab: &Rc<dyn Tab>) {
+        let term = tab.renderer();
+        let cursor = term.get_cursor_position();
+        if let Some(win) = self.window.as_ref() {
+            let r = Rect::new(
+                Point::new(
+                    cursor.x.max(0) as isize * self.render_metrics.cell_size.width,
+                    cursor.y.max(0) as isize * self.render_metrics.cell_size.height,
+                ),
+                self.render_metrics.cell_size,
+            );
+            win.set_text_cursor_position(r);
+        }
+    }
+
     fn activate_tab(&mut self, tab_idx: usize) -> Fallible<()> {
         let mux = Mux::get().unwrap();
         let mut window = mux

window/src/lib.rs

@@ -172,6 +172,11 @@ pub trait WindowOps {
     /// Resize the inner or client area of the window
     fn set_inner_size(&self, width: usize, height: usize);
 
+    /// inform the windowing system of the current textual
+    /// cursor input location.  This is used primarily for
+    /// the platform specific input method editor
+    fn set_text_cursor_position(&self, _cursor: Rect) {}
+
     /// Schedule a callback on the data associated with the window.
     /// The `Any` that is passed in corresponds to the WindowCallbacks
     /// impl you passed to `new_window`, pre-converted to Any so that
@@ -214,4 +219,9 @@ pub trait WindowOpsMut {
 
     /// Resize the inner or client area of the window
     fn set_inner_size(&self, width: usize, height: usize);
+
+    /// inform the windowing system of the current textual
+    /// cursor input location.  This is used primarily for
+    /// the platform specific input method editor
+    fn set_text_cursor_position(&mut self, _cursor: Rect) {}
 }

window/src/os/macos/window.rs

@@ -7,7 +7,7 @@ use crate::connection::ConnectionOps;
 use crate::os::macos::bitmap::BitmapRef;
 use crate::{
     BitmapImage, Color, Connection, Dimensions, KeyCode, KeyEvent, Modifiers, MouseButtons,
-    MouseCursor, MouseEvent, MouseEventKind, MousePress, Operator, PaintContext, Point, Rect,
+    MouseCursor, MouseEvent, MouseEventKind, MousePress, Operator, PaintContext, Point, Rect, Size,
     WindowCallbacks, WindowOps, WindowOpsMut,
 };
 use cocoa::appkit::{
@@ -281,6 +281,7 @@ impl Window {
                 window_id,
                 #[cfg(feature = "opengl")]
                 gl_context_pair: None,
+                text_cursor_position: Rect::new(Point::new(0, 0), Size::new(0, 0)),
             }));
 
             let window = StrongPtr::new(
@@ -364,6 +365,10 @@ impl WindowOps for Window {
         Connection::with_window_inner(self.0, move |inner| inner.set_inner_size(width, height));
     }
 
+    fn set_text_cursor_position(&self, cursor: Rect) {
+        Connection::with_window_inner(self.0, move |inner| inner.set_text_cursor_position(cursor));
+    }
+
     fn apply<F: Send + 'static + Fn(&mut dyn Any, &dyn WindowOps)>(&self, func: F)
     where
         Self: Sized,
@@ -462,6 +467,16 @@ impl WindowOpsMut for WindowInner {
             );
         }
     }
+
+    fn set_text_cursor_position(&mut self, cursor: Rect) {
+        if let Some(window_view) = WindowView::get_this(unsafe { &**self.view }) {
+            window_view.inner.borrow_mut().text_cursor_position = cursor;
+        }
+        unsafe {
+            let input_context: id = msg_send![&**self.view, inputContext];
+            let () = msg_send![input_context, invalidateCharacterCoordinates];
+        }
+    }
 }
 
 struct Inner {
@@ -470,6 +485,7 @@ struct Inner {
     window_id: usize,
     #[cfg(feature = "opengl")]
     gl_context_pair: Option<opengl::GlContextPair>,
+    text_cursor_position: Rect,
 }
 
 const CLS_NAME: &str = "WezTermWindowView";
@@ -727,9 +743,29 @@ impl WindowView {
             "firstRectForCharacterRange: range:{:?} actual:{:?}",
             range, actual
         );
-        unsafe {
+        let frame = unsafe {
             let window: id = msg_send![this, window];
-            let frame = NSWindow::frame(window);
+            NSWindow::frame(window)
+        };
+        let backing_frame: NSRect = unsafe { msg_send![this, convertRectToBacking: frame] };
+        let scale = frame.size.width / backing_frame.size.width;
+
+        if let Some(this) = Self::get_this(this) {
+            let cursor_pos = this
+                .inner
+                .borrow()
+                .text_cursor_position
+                .to_f64()
+                .scale(scale, scale);
+
+            NSRect::new(
+                NSPoint::new(
+                    frame.origin.x + cursor_pos.origin.x,
+                    frame.origin.y + frame.size.height - cursor_pos.origin.y,
+                ),
+                NSSize::new(cursor_pos.size.width, cursor_pos.size.height),
+            )
+        } else {
             frame
         }
     }