basic navigation & character insert

src/editor.rs

@@ -0,0 +1,142 @@
+use std::{
+	io::{stdin, stdout, Write},
+	ops::Range,
+};
+use termion::{
+	clear, cursor,
+	event::{Event, Key},
+	input::TermRead,
+	raw::IntoRawMode,
+};
+
+pub struct Editor {
+	text: String,
+	lines: Vec<Line>,
+	cursor: Cursor,
+	quit: bool,
+}
+
+struct Cursor {
+	line: usize,
+	column: usize,
+}
+
+// #[derive(Clone, Copy)]
+type Line = Range<usize>;
+
+impl Editor {
+	pub fn new() -> Self {
+		Editor {
+			// text: String::new(),
+			text: include_str!("editor.rs").into(),
+			lines: Vec::new(),
+			cursor: Cursor { line: 0, column: 0 },
+			quit: false,
+		}
+	}
+
+	pub fn run(mut self) {
+		println!("{}", clear::All);
+		stdout().flush().unwrap();
+		let _t = stdout().into_raw_mode().unwrap();
+
+		while !self.quit {
+			self.find_lines();
+			self.draw();
+			self.input();
+		}
+		println!("{}", clear::All);
+		stdout().flush().unwrap();
+		// self.term.suspend_raw_mode().unwrap();
+	}
+
+	fn input(&mut self) {
+		for event in stdin().events().take(1).flatten() {
+			// dbg!(&event);
+			if let Event::Key(key) = event {
+				match key {
+					Key::Esc => self.quit = true,
+					Key::Char(char) => self.insert_char(char),
+					Key::Left => self.move_left(),
+					Key::Right => self.move_right(),
+					Key::Up => self.move_up(),
+					Key::Down => self.move_down(),
+					_ => (),
+				}
+			}
+		}
+	}
+
+	fn move_left(&mut self) {
+		if self.cursor.column > 0 {
+			self.cursor.column -= 1;
+		} else if self.cursor.line > 0 {
+			self.cursor.line -= 1;
+			self.cursor.column = self.current_line().len();
+		}
+	}
+
+	fn move_right(&mut self) {
+		if self.cursor.column < self.current_line().len() {
+			self.cursor.column += 1;
+		} else if self.cursor.line < self.lines.len() {
+			self.cursor.line += 1;
+			self.cursor.column = 0;
+		}
+	}
+
+	fn move_up(&mut self) {
+		if self.cursor.line > 0 {
+			self.cursor.line -= 1;
+			self.cursor.column = self.cursor.column.min(self.current_line().len());
+		}
+	}
+
+	fn move_down(&mut self) {
+		if self.cursor.line < self.lines.len() {
+			self.cursor.line += 1;
+			self.cursor.column = self.cursor.column.min(self.current_line().len());
+		}
+	}
+
+	fn current_line(&self) -> &Line {
+		self.lines.get(self.cursor.line).unwrap_or(&(0..0))
+	}
+
+	fn find_lines(&mut self) {
+		self.lines.clear();
+		let mut this_line = 0..0;
+		for (index, char) in self.text.chars().enumerate() {
+			if char == '\n' {
+				this_line.end = index;
+				self.lines.push(this_line.clone());
+				this_line.start = index + 1;
+			}
+		}
+	}
+
+	fn draw(&self) {
+		print!("{}", clear::All);
+
+		for (row, line) in self.lines.iter().enumerate() {
+			let text = &self.text[line.clone()];
+			print!(
+				"{}{}",
+				cursor::Goto(1, row as u16 + 1),
+				text.replace('\t', "    ")
+			);
+		}
+		print!(
+			"{}",
+			cursor::Goto(self.cursor.column as u16 + 1, self.cursor.line as u16 + 1)
+		);
+		stdout().flush().unwrap();
+	}
+
+	fn insert_char(&mut self, ch: char) {
+		let index = self.current_line().start + self.cursor.column;
+		self.text.insert(index, ch);
+		self.move_right();
+		self.find_lines();
+	}
+}

src/main.rs

@@ -0,0 +1,6 @@
+mod editor;
+use editor::Editor;
+
+fn main() {
+	Editor::new().run();
+}