support ratatui crate by editor and termion example

examples/editor.rs

@@ -1,3 +1,6 @@
+#[cfg(feature = "ratatui-crossterm")]
+use crossterm_026 as crossterm;
+
 use crossterm::event::{DisableMouseCapture, EnableMouseCapture};
 use crossterm::terminal::{
     disable_raw_mode, enable_raw_mode, is_raw_mode_enabled, EnterAlternateScreen,
@@ -10,14 +13,27 @@ use std::fs;
 use std::io;
 use std::io::{BufRead, Write};
 use std::path::PathBuf;
-use tui::backend::CrosstermBackend;
-use tui::layout::{Constraint, Direction, Layout};
-use tui::style::{Color, Modifier, Style};
-use tui::text::{Span, Spans};
-use tui::widgets::{Block, Borders, Paragraph};
-use tui::Terminal;
 use tui_textarea::{CursorMove, Input, Key, TextArea};
 
+#[cfg(feature = "ratatui-crossterm")]
+use ratatui::{
+    backend::CrosstermBackend,
+    layout::{Constraint, Direction, Layout},
+    style::{Color, Modifier, Style},
+    text::{Span, Spans},
+    widgets::{Block, Borders, Paragraph},
+    Terminal,
+};
+#[cfg(not(feature = "ratatui-crossterm"))]
+use tui::{
+    backend::CrosstermBackend,
+    layout::{Constraint, Direction, Layout},
+    style::{Color, Modifier, Style},
+    text::{Span, Spans},
+    widgets::{Block, Borders, Paragraph},
+    Terminal,
+};
+
 macro_rules! error {
     ($fmt: expr $(, $args:tt)*) => {{
         Err(io::Error::new(io::ErrorKind::Other, format!($fmt $(, $args)*)))

examples/termion.rs

@@ -1,3 +1,6 @@
+#[cfg(all(not(feature = "termion"), not(feature = "ratatui-termion")))]
+compile_error!("termion example requires \"termion\" feature or \"ratatui-termion\" feature. see https://github.com/rhysd/tui-textarea");
+
 use std::error::Error;
 use std::io;
 use std::sync::mpsc;
@@ -7,11 +10,21 @@ use termion::event::Event as TermEvent;
 use termion::input::{MouseTerminal, TermRead};
 use termion::raw::IntoRawMode;
 use termion::screen::AlternateScreen;
-use tui::backend::TermionBackend;
-use tui::widgets::{Block, Borders};
-use tui::Terminal;
 use tui_textarea::{Input, Key, TextArea};
 
+#[cfg(feature = "ratatui-termion")]
+use ratatui::{
+    backend::TermionBackend,
+    widgets::{Block, Borders},
+    Terminal,
+};
+#[cfg(feature = "termion")]
+use tui::{
+    backend::TermionBackend,
+    widgets::{Block, Borders},
+    Terminal,
+};
+
 enum Event {
     Term(TermEvent),
     Tick,