add simple modal text editor example

Cargo.toml

@@ -58,6 +58,10 @@ required-features = ["crossterm"]
 name = "variable"
 required-features = ["crossterm"]
 
+[[example]]
+name = "modal"
+required-features = ["crossterm"]
+
 [workspace]
 members = [
     "bench",

README.md

@@ -82,6 +82,14 @@ cargo run --example variable
 
 Simple textarea with variable height following the number of lines.
 
+### [`modal`](./examples/modal.rs)
+
+```sh
+cargo run --example modal
+```
+
+Simple modal text editor like `vi`.
+
 ## Installation
 
 Add `tui-textarea` crate to dependencies in your `Cargo.toml`. This enables crossterm backend support by default.
@@ -448,50 +456,12 @@ loop {
             Input { key: Key::Char('j'), .. } => textarea.move_cursor(CursorMove::Down),
             Input { key: Key::Char('k'), .. } => textarea.move_cursor(CursorMove::Up),
             Input { key: Key::Char('l'), .. } => textarea.move_cursor(CursorMove::Forward),
-            Input { key: Key::Char('w'), .. } => textarea.move_cursor(CursorMove::WordForward),
+            Input { key: Key::Char('i'), .. } => mode = Mode::Insert, // Enter insert mode
-            Input { key: Key::Char('b'), ctrl: false, .. } => textarea.move_cursor(CursorMove::WordBack),
+            // ...Add more mappings
-            Input { key: Key::Char('^'), .. } => textarea.move_cursor(CursorMove::Head),
-            Input { key: Key::Char('$'), .. } => textarea.move_cursor(CursorMove::End),
-            Input { key: Key::Char('D'), .. } => { textarea.delete_line_by_end(); }
-            Input { key: Key::Char('C'), .. } => {
-                textarea.delete_line_by_end();
-                mode = Mode::Insert;
-            }
-            Input { key: Key::Char('p'), .. } => { textarea.paste(); }
-            Input { key: Key::Char('u'), ctrl: false, .. } => { textarea.undo(); },
-            Input { key: Key::Char('r'), ctrl: true, .. } => { textarea.redo(); },
-            Input { key: Key::Char('x'), .. } => { textarea.delete_next_char(); },
-            Input { key: Key::Char('i'), .. } => mode = Mode::Insert,
-            Input { key: Key::Char('a'), .. } => {
-                textarea.move_cursor(CursorMove::Forward);
-                mode = Mode::Insert;
-            }
-            Input { key: Key::Char('A'), .. } => {
-                textarea.move_cursor(CursorMove::End);
-                mode = Mode::Insert;
-            }
-            Input { key: Key::Char('I'), .. } => {
-                textarea.move_cursor(CursorMove::Head);
-                mode = Mode::Insert;
-            }
-            Input { key: Key::Char('/'), .. } => {
-                let pat = ...;
-                textarea.set_search_pattern(pat)?;
-            }
-            Input { key: Key::Esc, .. } => textarea.set_search_pattern("").unwrap(),
-            Input { key: Key::Char('n'), .. } => textarea.search_forward(),
-            Input { key: Key::Char('N'), .. } => textarea.search_back(),
-            Input { key: Key::Char('e'), ctrl: true, .. } => textarea.scroll((1, 0)),
-            Input { key: Key::Char('y'), ctrl: true, .. } => textarea.scroll((-1, 0)),
-            Input { key: Key::Char('d'), ctrl: true, .. } => textarea.scroll(Scrolling::HalfPageDown),
-            Input { key: Key::Char('u'), ctrl: true, .. } => textarea.scroll(Scrolling::HalfPageUp),
-            Input { key: Key::Char('f'), ctrl: true, .. } => textarea.scroll(Scrolling::PageDown),
-            Input { key: Key::Char('b'), ctrl: true, .. } => textarea.scroll(Scrolling::PageUp),
             _ => {},
         },
         Mode::Insert => match read()?.into() {
-            Input { key: Key::Esc, .. }
+            Input { key: Key::Esc, .. } => {
-            | Input { key: Key::Char('c'), ctrl: true, .. } => {
                 mode = Mode::Normal; // Back to normal mode with Esc or Ctrl+C
             }
             input => {
@@ -502,6 +472,8 @@ loop {
 }
 ```
 
+See [`modal` example](./examples/modal.rs) for working example. It implements more Vim-like key mappings.
+
 If you don't want to use default key mappings, `TextArea::input_without_shortcuts()` method can be used instead of
 `TextArea::input()`. The method only handles very basic operations such as inserting/deleting single characters, tabs,
 newlines.

examples/modal.rs

@@ -0,0 +1,263 @@
+use crossterm::event::{DisableMouseCapture, EnableMouseCapture};
+use crossterm::terminal::{
+    disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen,
+};
+use std::env;
+use std::fmt;
+use std::fs;
+use std::io;
+use std::io::BufRead;
+use tui::backend::CrosstermBackend;
+use tui::layout::{Constraint, Direction, Layout};
+use tui::style::{Modifier, Style};
+use tui::text::{Span, Spans};
+use tui::widgets::{Block, Borders, Paragraph};
+use tui::Terminal;
+use tui_textarea::{CursorMove, Input, Key, Scrolling, TextArea};
+
+enum Mode {
+    Normal,
+    Insert,
+}
+
+impl fmt::Display for Mode {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
+        match self {
+            Self::Normal => write!(f, "NORMAL"),
+            Self::Insert => write!(f, "INSERT"),
+        }
+    }
+}
+
+fn main() -> io::Result<()> {
+    let stdout = io::stdout();
+    let mut stdout = stdout.lock();
+
+    enable_raw_mode()?;
+    crossterm::execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    let backend = CrosstermBackend::new(stdout);
+    let mut term = Terminal::new(backend)?;
+
+    let mut textarea = if let Some(path) = env::args().nth(1) {
+        let file = fs::File::open(path)?;
+        io::BufReader::new(file)
+            .lines()
+            .collect::<io::Result<_>>()?
+    } else {
+        TextArea::default()
+    };
+
+    textarea.set_block(
+        Block::default()
+            .borders(Borders::ALL)
+            .title("Modal Example"),
+    );
+
+    let layout = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(1), Constraint::Length(1)].as_ref());
+    let mut mode = Mode::Normal;
+    loop {
+        term.draw(|f| {
+            let chunks = layout.split(f.size());
+
+            f.render_widget(textarea.widget(), chunks[0]);
+
+            let (row, col) = textarea.cursor();
+            let help = if let Mode::Normal = mode {
+                " type q for quit, type i to enter insert mode"
+            } else {
+                " type Esc to leave insert mode"
+            };
+            let status = Paragraph::new(Spans::from(vec![
+                Span::styled(
+                    format!(" {} {},{} ", mode, row, col),
+                    Style::default().add_modifier(Modifier::REVERSED),
+                ),
+                Span::raw(help),
+            ]));
+            f.render_widget(status, chunks[1]);
+        })?;
+
+        let input = crossterm::event::read()?.into();
+        match mode {
+            Mode::Normal => match input {
+                // Mappings in normal mode
+                Input {
+                    key: Key::Char('h'),
+                    ..
+                } => textarea.move_cursor(CursorMove::Back),
+                Input {
+                    key: Key::Char('j'),
+                    ..
+                } => textarea.move_cursor(CursorMove::Down),
+                Input {
+                    key: Key::Char('k'),
+                    ..
+                } => textarea.move_cursor(CursorMove::Up),
+                Input {
+                    key: Key::Char('l'),
+                    ..
+                } => textarea.move_cursor(CursorMove::Forward),
+                Input {
+                    key: Key::Char('w'),
+                    ..
+                } => textarea.move_cursor(CursorMove::WordForward),
+                Input {
+                    key: Key::Char('b'),
+                    ctrl: false,
+                    ..
+                } => textarea.move_cursor(CursorMove::WordBack),
+                Input {
+                    key: Key::Char('^'),
+                    ..
+                } => textarea.move_cursor(CursorMove::Head),
+                Input {
+                    key: Key::Char('$'),
+                    ..
+                } => textarea.move_cursor(CursorMove::End),
+                Input {
+                    key: Key::Char('D'),
+                    ..
+                } => {
+                    textarea.delete_line_by_end();
+                }
+                Input {
+                    key: Key::Char('C'),
+                    ..
+                } => {
+                    textarea.delete_line_by_end();
+                    mode = Mode::Insert;
+                }
+                Input {
+                    key: Key::Char('p'),
+                    ..
+                } => {
+                    textarea.paste();
+                }
+                Input {
+                    key: Key::Char('u'),
+                    ctrl: false,
+                    ..
+                } => {
+                    textarea.undo();
+                }
+                Input {
+                    key: Key::Char('r'),
+                    ctrl: true,
+                    ..
+                } => {
+                    textarea.redo();
+                }
+                Input {
+                    key: Key::Char('x'),
+                    ..
+                } => {
+                    textarea.delete_next_char();
+                }
+                Input {
+                    key: Key::Char('i'),
+                    ..
+                } => mode = Mode::Insert,
+                Input {
+                    key: Key::Char('a'),
+                    ..
+                } => {
+                    textarea.move_cursor(CursorMove::Forward);
+                    mode = Mode::Insert;
+                }
+                Input {
+                    key: Key::Char('A'),
+                    ..
+                } => {
+                    textarea.move_cursor(CursorMove::End);
+                    mode = Mode::Insert;
+                }
+                Input {
+                    key: Key::Char('o'),
+                    ..
+                } => {
+                    textarea.move_cursor(CursorMove::End);
+                    textarea.insert_newline();
+                    mode = Mode::Insert;
+                }
+                Input {
+                    key: Key::Char('O'),
+                    ..
+                } => {
+                    textarea.move_cursor(CursorMove::Head);
+                    textarea.insert_newline();
+                    textarea.move_cursor(CursorMove::Up);
+                    mode = Mode::Insert;
+                }
+                Input {
+                    key: Key::Char('I'),
+                    ..
+                } => {
+                    textarea.move_cursor(CursorMove::Head);
+                    mode = Mode::Insert;
+                }
+                Input {
+                    key: Key::Char('q'),
+                    ..
+                } => break,
+                Input {
+                    key: Key::Char('e'),
+                    ctrl: true,
+                    ..
+                } => textarea.scroll((1, 0)),
+                Input {
+                    key: Key::Char('y'),
+                    ctrl: true,
+                    ..
+                } => textarea.scroll((-1, 0)),
+                Input {
+                    key: Key::Char('d'),
+                    ctrl: true,
+                    ..
+                } => textarea.scroll(Scrolling::HalfPageDown),
+                Input {
+                    key: Key::Char('u'),
+                    ctrl: true,
+                    ..
+                } => textarea.scroll(Scrolling::HalfPageUp),
+                Input {
+                    key: Key::Char('f'),
+                    ctrl: true,
+                    ..
+                } => textarea.scroll(Scrolling::PageDown),
+                Input {
+                    key: Key::Char('b'),
+                    ctrl: true,
+                    ..
+                } => textarea.scroll(Scrolling::PageUp),
+                _ => {}
+            },
+            Mode::Insert => match input {
+                Input { key: Key::Esc, .. }
+                | Input {
+                    key: Key::Char('c'),
+                    ctrl: true,
+                    ..
+                } => {
+                    mode = Mode::Normal; // Back to normal mode with Esc or Ctrl+C
+                }
+                input => {
+                    textarea.input(input); // Use default key mappings in insert mode
+                }
+            },
+        }
+    }
+
+    disable_raw_mode()?;
+    crossterm::execute!(
+        term.backend_mut(),
+        LeaveAlternateScreen,
+        DisableMouseCapture
+    )?;
+    term.show_cursor()?;
+
+    println!("Lines: {:?}", textarea.lines());
+
+    Ok(())
+}