Demonstrate using CrossTerm for a TUI

Cargo.toml

[package]
name = "rusterm"
version = "0.1.0"
edition = "2021"

[dependencies]
crokey = "0.5.1"
crossbeam = "0.8.2"
crossterm = "0.25.0"
notify = "5.0.0"
termimad = "0.20.3"
tokio = "1.21.2"

main.rs

// Copyright 2022 Google LLC.
// SPDX-License-Identifier: Apache-2.0
use std::{
    thread,
    time::{Duration, Instant},
};
use std::io::{stdout, Write};

use crossterm::{
    cursor::{MoveTo, SavePosition, RestorePosition},
    terminal::{Clear, ClearType},
    style::{Color, Print, ResetColor, SetBackgroundColor, SetForegroundColor},
    // ExecutableCommand,
    QueueableCommand, Result,
};

const TARGET_FPS: u64 = 2;
const MILLIS_PER_SECOND: u64 = 1000;
const TARGET_MILLIS: u64 = MILLIS_PER_SECOND/TARGET_FPS;

fn main() -> Result<()> {
    let start = Instant::now();
    stdout().queue(Clear(ClearType::All))?;
    let mut count = 0;
    loop {
        let wait_time = Duration::from_millis(TARGET_MILLIS);
        let frame_start = Instant::now();
        count += 1;
        let millis_per_frame = start.elapsed().as_millis().checked_div(count as u128).unwrap_or(0);
        let fps = (MILLIS_PER_SECOND as u128).checked_div(millis_per_frame).unwrap_or(0);

        let last_line = 5;

        stdout()
            // .queue(Clear(ClearType::All))?
            .queue(SavePosition)?
            .queue(MoveTo(0, last_line))?
            .queue(Clear(ClearType::FromCursorUp))?
            .queue(SetForegroundColor(Color::Blue))?
            .queue(SetBackgroundColor(Color::Red))?
            .queue(MoveTo(0, 0))?
            .queue(Print("Styled text here (1).\n"))?
            .queue(SetForegroundColor(Color::Red))?
            .queue(SetBackgroundColor(Color::Blue))?
            .queue(Print("Styled text here (2).\n"))?
            .queue(SetForegroundColor(Color::White))?
            .queue(SetBackgroundColor(Color::Black))?
            .queue(Print("Styled text here (3).\n"))?
            .queue(Print(&format!("Iterations: {}. Average FPS: {}.\n", count, fps)))?
            .queue(ResetColor)?
            .queue(RestorePosition)?;
        stdout().flush()?;

        let runtime = frame_start.elapsed();
        if let Some(remaining) = wait_time.checked_sub(runtime) {
            thread::sleep(remaining);
        }
    }
}