Make reedline handling cursor shapes more configurable (#515)

Adds a struct to configure the cursor shape

Co-authored-by: sholderbach <sholderbach@users.noreply.github.com>
resolve https://github.com/nushell/reedline/issues/514

examples/demo.rs

@@ -12,6 +12,8 @@ use {
     },
 };
 
+use crossterm::cursor::CursorShape;
+use reedline::CursorConfig;
 #[cfg(not(any(feature = "sqlite", feature = "sqlite-dynlib")))]
 use reedline::FileBackedHistory;
 
@@ -58,11 +60,18 @@ fn main() -> Result<()> {
 
     let completer = Box::new(DefaultCompleter::new_with_wordlen(commands.clone(), 2));
 
+    let cursor_config = CursorConfig {
+        vi_insert: Some(CursorShape::Line),
+        vi_normal: Some(CursorShape::Block),
+        emacs: None,
+    };
+
     let mut line_editor = Reedline::create()
         .with_history(history)
         .with_completer(completer)
         .with_quick_completions(true)
         .with_partial_completions(true)
+        .with_cursor_config(cursor_config)
         .with_highlighter(Box::new(ExampleHighlighter::new(commands)))
         .with_hinter(Box::new(
             DefaultHinter::default().with_style(Style::new().fg(Color::DarkGray)),

src/edit_mode/cursors.rs

@@ -0,0 +1,13 @@
+use crossterm::cursor::CursorShape;
+
+/// Maps cursor shapes to each edit mode (emacs, vi normal & vi insert).
+/// If any of the fields is `None`, the cursor won't get changed by Reedline for that mode.
+#[derive(Default)]
+pub struct CursorConfig {
+    /// The cursor to be used when in vi insert mode
+    pub vi_insert: Option<CursorShape>,
+    /// The cursor to be used when in vi normal mode
+    pub vi_normal: Option<CursorShape>,
+    /// The cursor to be used when in emacs mode
+    pub emacs: Option<CursorShape>,
+}

src/edit_mode/mod.rs

@@ -1,9 +1,11 @@
 mod base;
+mod cursors;
 mod emacs;
 mod keybindings;
 mod vi;
 
 pub use base::EditMode;
+pub use cursors::CursorConfig;
 pub use emacs::{default_emacs_keybindings, Emacs};
 pub use keybindings::Keybindings;
 pub use vi::{default_vi_insert_keybindings, default_vi_normal_keybindings, Vi};

src/engine.rs

@@ -1,3 +1,4 @@
+use crate::CursorConfig;
 #[cfg(feature = "bashisms")]
 use crate::{
     history::SearchFilter,
@@ -128,6 +129,9 @@ pub struct Reedline {
     // Text editor used to open the line buffer for editing
     buffer_editor: Option<BufferEditor>,
 
+    // Use different cursors depending on the current edit mode
+    cursor_shapes: Option<CursorConfig>,
+
     #[cfg(feature = "external_printer")]
     external_printer: Option<ExternalPrinter<String>>,
 }
@@ -179,6 +183,7 @@ impl Reedline {
             use_ansi_coloring: true,
             menus: Vec::new(),
             buffer_editor: None,
+            cursor_shapes: None,
             #[cfg(feature = "external_printer")]
             external_printer: None,
         }
@@ -377,6 +382,14 @@ impl Reedline {
         self
     }
 
+    /// A builder that enables reedline changing the cursor shape based on the current edit mode.
+    /// The current implementation sets the cursor shape when drawing the prompt.
+    /// Do not use this if the cursor shape is set elsewhere, e.g. in the terminal settings or by ansi escape sequences.
+    pub fn with_cursor_config(mut self, cursor_shapes: CursorConfig) -> Self {
+        self.cursor_shapes = Some(cursor_shapes);
+        self
+    }
+
     /// Returns the corresponding expected prompt style for the given edit mode
     pub fn prompt_edit_mode(&self) -> PromptEditMode {
         self.edit_mode.edit_mode()
@@ -1393,6 +1406,7 @@ impl Reedline {
                 self.prompt_edit_mode(),
                 None,
                 self.use_ansi_coloring,
+                &self.cursor_shapes,
             )?;
         }
 
@@ -1460,6 +1474,7 @@ impl Reedline {
             self.prompt_edit_mode(),
             menu,
             self.use_ansi_coloring,
+            &self.cursor_shapes,
         )
     }
 

src/lib.rs

@@ -260,7 +260,7 @@ pub use prompt::{
 mod edit_mode;
 pub use edit_mode::{
     default_emacs_keybindings, default_vi_insert_keybindings, default_vi_normal_keybindings,
-    EditMode, Emacs, Keybindings, Vi,
+    CursorConfig, EditMode, Emacs, Keybindings, Vi,
 };
 
 mod highlighter;

src/painting/painter.rs

@@ -1,4 +1,4 @@
-use crate::PromptEditMode;
+use crate::{CursorConfig, PromptEditMode, PromptViMode};
 
 use {
     super::utils::{coerce_crlf, line_width},
@@ -137,6 +137,7 @@ impl Painter {
         prompt_mode: PromptEditMode,
         menu: Option<&ReedlineMenu>,
         use_ansi_coloring: bool,
+        cursor_config: &Option<CursorConfig>,
     ) -> Result<()> {
         self.stdout.queue(cursor::Hide)?;
 
@@ -175,13 +176,20 @@ impl Painter {
         // can print without overwriting the things written during the painting
         self.last_required_lines = required_lines;
 
-        self.stdout
+        self.stdout.queue(RestorePosition)?;
-            .queue(RestorePosition)?
+
-            .queue(cursor::SetCursorShape(match prompt_mode {
+        if let Some(shapes) = cursor_config {
-                PromptEditMode::Vi(crate::PromptViMode::Insert) => cursor::CursorShape::Line,
+            let shape = match &prompt_mode {
-                _ => cursor::CursorShape::Block,
+                PromptEditMode::Emacs => shapes.emacs,
-            }))?
+                PromptEditMode::Vi(PromptViMode::Insert) => shapes.vi_insert,
-            .queue(cursor::Show)?;
+                PromptEditMode::Vi(PromptViMode::Normal) => shapes.vi_normal,
+                _ => None,
+            };
+            if let Some(shape) = shape {
+                self.stdout.queue(cursor::SetCursorShape(shape))?;
+            }
+        }
+        self.stdout.queue(cursor::Show)?;
 
         self.stdout.flush()
     }