multiline_input

Terminal multiline input with rich editing capabilities

Scope

Responsibility:

• Terminal multiline input widget with rich editing capabilities
• ENTER to submit, CTRL+ENTER for newlines (optimized for AI assistants)
• Raw terminal mode with visual feedback and validation
• Cross-platform support (Linux, macOS, Windows)

In Scope:

• Multiline text input widget
• Line editing (cursor movement, backspace, delete)
• Terminal manipulation (raw mode, key event capture)
• Visual feedback (line numbers, status line, colors)
• Validation (min/max length, custom validators)
• Builder API for configuration
• Pre-filled text editing
• Key bindings (ENTER, CTRL+ENTER, ESC, arrows, Home, End)
• Cross-platform terminal support

Out of Scope:

• ❌ Wizard framework → delegated to terminal_wizard crate
• ❌ CLI applications → individual binaries use this as library
• ❌ Scrolling for large texts → future work
• ❌ Undo/redo → future work
• ❌ Clipboard integration → future work

Features

• ENTER to submit input
• CTRL+ENTER to insert newline (multiline support)
• Rich line editing (cursor movement, backspace, delete)
• Visual feedback (line numbers, status line, colors)
• Validation (min/max length, custom validators)
• Cross-platform (Linux, macOS, Windows)
• Zero-config defaults

Quick Start

use multiline_input::collect;

fn main() {
  match collect("Enter your message:") {
    Ok(Some(text)) => println!("You entered:\n{}", text),
    Ok(None) => println!("Cancelled"),
    Err(e) => eprintln!("Error: {}", e),
  }
}

Key Bindings

Advanced Usage

With Builder Pattern

use multiline_input::Builder;

let editor = Builder::new()
  .prompt("Enter commit message:")
  .min_length(10)
  .max_length(500)
  .show_line_numbers(true)
  .show_status(true)
  .color(true)
  .build();

match editor.collect() {
  Ok(Some(msg)) => println!("Commit:\n{}", msg),
  Ok(None) => println!("Cancelled"),
  Err(e) => eprintln!("Error: {}", e),
}

With Validation

use multiline_input::Builder;

let editor = Builder::new()
  .prompt("Enter message:")
  .validator(|text| {
    if text.contains("spam") {
      Err("Message contains prohibited content".to_string())
    } else {
      Ok(())
    }
  })
  .build();

match editor.collect() {
  Ok(Some(text)) => println!("Valid: {}", text),
  Ok(None) => println!("Cancelled"),
  Err(e) => eprintln!("Error: {}", e),
}

Pre-filled Text

use multiline_input::Builder;

let editor = Builder::new()
  .prompt("Edit TODO:")
  .initial_text("- Task 1\n- Task 2\n- Task 3")
  .show_line_numbers(true)
  .build();

match editor.collect() {
  Ok(Some(text)) => println!("Updated:\n{}", text),
  Ok(None) => println!("Cancelled"),
  Err(e) => eprintln!("Error: {}", e),
}

Configuration Options

Examples

See examples/ directory for more usage examples:

• basic_usage.rs - Simple input collection
• with_validation.rs - Custom validation
• with_config.rs - Full configuration demo
• pre_filled.rs - Edit existing text

Run examples:

cargo run --example basic_usage

How It Works

1. Enters raw terminal mode to capture individual key events
2. Parses key combinations (ENTER, CTRL+ENTER, arrows, etc.)
3. Updates text buffer with insertions/deletions
4. Renders to screen with visual feedback
5. Returns collected text on ENTER or None on ESC/CTRL+C

Platform Support

• ✅ Linux: Full support (all terminals)
• ✅ macOS: Full support (Terminal.app, iTerm2)
• ⚠️ Windows:
  • Windows Terminal: Full support
  • cmd.exe: Limited (CTRL+ENTER may not work)
  • ConEmu: Full support

Implementation Status

• Core input collection
• Key event handling (ENTER, CTRL+ENTER, ESC, arrows)
• Text buffer with cursor management
• Basic rendering
• Builder API
• Validation (min/max, custom)
• Visual enhancements (line numbers, status, colors)
• Scrolling for large texts
• Undo/redo
• Clipboard integration

Documentation

For complete specification and implementation details, see spec.md.

For API documentation: cargo doc --open

Testing

# Run tests
cargo test

# Run with coverage
cargo tarpaulin --out Html

Contributing

Contributions welcome! Please:

1. Read spec.md for architecture details
2. Write tests for new features
3. Follow existing code style
4. Update documentation

License

MIT License - see LICENSE for details

Related Projects

• dialoguer - CLI prompts library
• inquire - Interactive prompts
• rustyline - Readline implementation

Difference: multiline_input focuses specifically on multiline text collection with ENTER to submit and CTRL+ENTER for newlines, optimized for AI assistant integration and commit message editing.