Add Kitty protocol keyboard enhancement support (#607)

* add use_kitty_protocol support option

* move pop key enhancement flags just before loop exit

* add pop keyboard flags pop on drop

* remove toggler functions' return

* move pop key enhancement flags beside other mode change

src/engine.rs

@@ -140,6 +140,9 @@ pub struct Reedline {
     // Indicate if global terminal have enabled BracketedPaste
     bracket_paste_enabled: bool,
 
+    // Use kitty protocol to handle escape code input or not
+    use_kitty_protocol: bool,
+
     #[cfg(feature = "external_printer")]
     external_printer: Option<ExternalPrinter<String>>,
 }
@@ -165,6 +168,9 @@ impl Drop for Reedline {
         if self.bracket_paste_enabled {
             let _ = execute!(io::stdout(), DisableBracketedPaste);
         }
+        if self.use_kitty_protocol {
+            let _ = execute!(io::stdout(), event::PopKeyboardEnhancementFlags);
+        }
     }
 }
 
@@ -210,6 +216,7 @@ impl Reedline {
             buffer_editor: None,
             cursor_shapes: None,
             bracket_paste_enabled: false,
+            use_kitty_protocol: false,
             #[cfg(feature = "external_printer")]
             external_printer: None,
         }
@@ -243,6 +250,25 @@ impl Reedline {
         res
     }
 
+    /// Return terminal support on keyboard enhancement
+    pub fn can_use_kitty_protocol(&mut self) -> bool {
+        if let Ok(b) = crossterm::terminal::supports_keyboard_enhancement() {
+            b
+        } else {
+            false
+        }
+    }
+
+    /// Enable keyboard enhancement to disambiguate escape code
+    pub fn enable_kitty_protocol(&mut self) {
+        self.use_kitty_protocol = true;
+    }
+
+    /// Disable keyboard enhancement to disambiguate escape code
+    pub fn disable_kitty_protocol(&mut self) {
+        self.use_kitty_protocol = false;
+    }
+
     /// Return the previously generated history session id
     pub fn get_history_session_id(&self) -> Option<HistorySessionId> {
         self.history_session_id
@@ -575,6 +601,11 @@ impl Reedline {
 
         #[cfg(not(target_os = "windows"))]
         self.disable_bracketed_paste()?;
+
+        if self.use_kitty_protocol {
+            let _ = execute!(io::stdout(), event::PopKeyboardEnhancementFlags);
+        }
+
         terminal::disable_raw_mode()?;
         result
     }
@@ -620,6 +651,31 @@ impl Reedline {
         let mut crossterm_events: Vec<ReedlineRawEvent> = vec![];
         let mut reedline_events: Vec<ReedlineEvent> = vec![];
 
+        if self.use_kitty_protocol {
+            if let Ok(true) = crossterm::terminal::supports_keyboard_enhancement() {
+                // enable kitty protocol
+                //
+                // Note that, currently, only the following support this protocol:
+                // * [kitty terminal](https://sw.kovidgoyal.net/kitty/)
+                // * [foot terminal](https://codeberg.org/dnkl/foot/issues/319)
+                // * [WezTerm terminal](https://wezfurlong.org/wezterm/config/lua/config/enable_kitty_keyboard.html)
+                // * [notcurses library](https://github.com/dankamongmen/notcurses/issues/2131)
+                // * [neovim text editor](https://github.com/neovim/neovim/pull/18181)
+                // * [kakoune text editor](https://github.com/mawww/kakoune/issues/4103)
+                // * [dte text editor](https://gitlab.com/craigbarnes/dte/-/issues/138)
+                //
+                // Refer to https://sw.kovidgoyal.net/kitty/keyboard-protocol/ if you're curious.
+                let _ = execute!(
+                    io::stdout(),
+                    event::PushKeyboardEnhancementFlags(
+                        event::KeyboardEnhancementFlags::DISAMBIGUATE_ESCAPE_CODES
+                    )
+                );
+            } else {
+                // TODO: Log or warning
+            }
+        }
+
         loop {
             let mut paste_enter_state = false;