toss/src/terminal.rs

86 lines
2.4 KiB
Rust

use std::io::Write;
use std::{io, mem};
use crossterm::cursor::MoveTo;
use crossterm::style::{PrintStyledContent, StyledContent};
use crossterm::terminal::{Clear, ClearType, EnterAlternateScreen, LeaveAlternateScreen};
use crossterm::{ExecutableCommand, QueueableCommand};
use crate::buffer::{Buffer, Size};
pub struct Terminal {
out: Box<dyn Write>,
/// Currently visible on screen.
prev_buffer: Buffer,
/// Buffer to render to.
curr_buffer: Buffer,
/// When the screen is updated next, it must be cleared and redrawn fully
/// instead of performing an incremental update.
full_redraw: bool,
}
impl Drop for Terminal {
fn drop(&mut self) {
let _ = self.out.execute(LeaveAlternateScreen);
let _ = crossterm::terminal::disable_raw_mode();
}
}
impl Terminal {
pub fn new(out: Box<dyn Write>) -> io::Result<Self> {
let mut result = Self {
out,
prev_buffer: Buffer::new(),
curr_buffer: Buffer::new(),
full_redraw: true,
};
crossterm::terminal::enable_raw_mode()?;
result.out.execute(EnterAlternateScreen)?;
Ok(result)
}
pub fn buffer(&mut self) -> &mut Buffer {
&mut self.curr_buffer
}
pub fn autoresize(&mut self) -> io::Result<()> {
let (width, height) = crossterm::terminal::size()?;
let size = Size { width, height };
if size != self.curr_buffer.size() {
self.prev_buffer.resize(size);
self.curr_buffer.resize(size);
self.full_redraw = true;
}
Ok(())
}
/// Display the contents of the buffer on the screen and prepare rendering
/// the next frame.
pub fn present(&mut self) -> io::Result<()> {
if self.full_redraw {
io::stdout().queue(Clear(ClearType::All))?;
self.prev_buffer.reset();
self.full_redraw = false;
}
self.draw_differences()?;
self.out.flush()?;
mem::swap(&mut self.prev_buffer, &mut self.curr_buffer);
Ok(())
}
fn draw_differences(&mut self) -> io::Result<()> {
// TODO Only draw the differences
for (x, y, cell) in self.curr_buffer.cells() {
let content = StyledContent::new(cell.style, &cell.content as &str);
self.out
.queue(MoveTo(x, y))?
.queue(PrintStyledContent(content))?;
}
Ok(())
}
}