get/set cursor position

src/backend/crossterm.rs

@@ -69,6 +69,16 @@ impl Backend for CrosstermBackend {
         Ok(())
     }
 
+    fn get_cursor(&mut self) -> io::Result<(u16, u16)> {
+        let cursor = crossterm::cursor();
+        Ok(cursor.pos())
+    }
+
+    fn set_cursor(&mut self, x: u16, y: u16) -> io::Result<()> {
+        let cursor = crossterm::cursor();
+        cursor.goto(x, y).map_err(convert_error)
+    }
+
     fn size(&self) -> io::Result<Rect> {
         let terminal = crossterm::terminal();
         let (width, height) = terminal.terminal_size();

src/backend/mod.rs

@@ -27,6 +27,8 @@ pub trait Backend {
         I: Iterator<Item = (u16, u16, &'a Cell)>;
     fn hide_cursor(&mut self) -> Result<(), io::Error>;
     fn show_cursor(&mut self) -> 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>;
     fn flush(&mut self) -> Result<(), io::Error>;

src/backend/rustbox.rs

@@ -51,6 +51,13 @@ impl Backend for RustboxBackend {
     fn show_cursor(&mut self) -> Result<(), io::Error> {
         Ok(())
     }
+    fn get_cursor(&mut self) -> io::Result<(u16, u16)> {
+        Err(io::Error::from(io::ErrorKind::Other))
+    }
+    fn set_cursor(&mut self, x: u16, y: u16) -> io::Result<()> {
+        self.rustbox.set_cursor(x as isize, y as isize);
+        Ok(())
+    }
     fn clear(&mut self) -> Result<(), io::Error> {
         self.rustbox.clear();
         Ok(())

src/backend/termion.rs

@@ -59,6 +59,16 @@ where
         self.stdout.flush()
     }
 
+    /// Gets cursor position (0-based index)
+    fn get_cursor(&mut self) -> io::Result<(u16, u16)> {
+        termion::cursor::DetectCursorPos::cursor_pos(&mut self.stdout).map(|(x, y)| (x - 1, y - 1))
+    }
+
+    /// Sets cursor position (0-based index)
+    fn set_cursor(&mut self, x: u16, y: u16) -> io::Result<()> {
+        write!(self.stdout, "{}", termion::cursor::Goto(x + 1, y + 1))
+    }
+
     fn draw<'a, I>(&mut self, content: I) -> io::Result<()>
     where
         I: Iterator<Item = (u16, u16, &'a Cell)>,

src/backend/test.rs

@@ -9,6 +9,7 @@ pub struct TestBackend {
     buffer: Buffer,
     height: u16,
     cursor: bool,
+    pos: (u16, u16),
 }
 
 impl TestBackend {
@@ -18,6 +19,7 @@ impl TestBackend {
             height,
             buffer: Buffer::empty(Rect::new(0, 0, width, height)),
             cursor: false,
+            pos: (0, 0),
         }
     }
 
@@ -46,6 +48,13 @@ impl Backend for TestBackend {
         self.cursor = true;
         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(())
+    }
     fn clear(&mut self) -> Result<(), io::Error> {
         Ok(())
     }

src/terminal.rs

@@ -161,6 +161,12 @@ where
         self.hidden_cursor = false;
         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)
+    }
     pub fn clear(&mut self) -> io::Result<()> {
         self.backend.clear()
     }