Remove `Backend::get_cursor`

It is unused and cannot be used on some terminal hosts like `conhost`
that do not respond to VT queries. This doesn't have any affect on
behavior - I'm removing it so that we don't rely on it in the future.

helix-tui/src/backend/mod.rs

@@ -21,7 +21,6 @@ pub trait Backend {
         I: Iterator<Item = (u16, u16, &'a Cell)>;
     fn hide_cursor(&mut self) -> Result<(), io::Error>;
     fn show_cursor(&mut self, kind: CursorKind) -> Result<(), io::Error>;
-    fn get_cursor(&mut self) -> Result<(u16, u16), io::Error>;
     fn set_cursor(&mut self, x: u16, y: u16) -> Result<(), io::Error>;
     fn clear(&mut self) -> Result<(), io::Error>;
     fn size(&self) -> Result<Rect, io::Error>;

helix-tui/src/backend/termina.rs

@@ -511,25 +511,6 @@ impl Backend for TerminaBackend {
         self.flush()
     }
 
-    fn get_cursor(&mut self) -> Result<(u16, u16), io::Error> {
-        write!(
-            self.terminal,
-            "{}",
-            csi::Csi::Cursor(csi::Cursor::RequestActivePositionReport),
-        )?;
-        self.terminal.flush()?;
-        let event = self.terminal.read(|event| {
-            matches!(
-                event,
-                Event::Csi(Csi::Cursor(csi::Cursor::ActivePositionReport { .. }))
-            )
-        })?;
-        let Event::Csi(Csi::Cursor(csi::Cursor::ActivePositionReport { line, col })) = event else {
-            unreachable!();
-        };
-        Ok((line.get_zero_based(), col.get_zero_based()))
-    }
-
     fn set_cursor(&mut self, x: u16, y: u16) -> io::Result<()> {
         let col = OneBased::from_zero_based(x);
         let line = OneBased::from_zero_based(y);

helix-tui/src/backend/test.rs

@@ -139,10 +139,6 @@ impl Backend for TestBackend {
         Ok(())
     }
 
-    fn get_cursor(&mut self) -> Result<(u16, u16), io::Error> {
-        Ok(self.pos)
-    }
-
     fn set_cursor(&mut self, x: u16, y: u16) -> Result<(), io::Error> {
         self.pos = (x, y);
         Ok(())

helix-tui/src/terminal.rs

@@ -216,10 +216,6 @@ where
         Ok(())
     }
 
-    pub fn get_cursor(&mut self) -> io::Result<(u16, u16)> {
-        self.backend.get_cursor()
-    }
-
     pub fn set_cursor(&mut self, x: u16, y: u16) -> io::Result<()> {
         self.backend.set_cursor(x, y)
     }