minicrossterm/src/common/screen/screen.rs

146 lines
5.0 KiB
Rust

use super::{AlternateScreen,RawScreen};
use TerminalOutput;
use std::io::Write;
use std::io::Result;
use std::sync::Arc;
/// This type represents an screen.
/// This screen has an stdout which is used by the program to write to or to execute commands with.
///
/// You have to make sure that you pass the correct `Screen` to the modules `cursor, terminal, color, input, style`.
/// Most of the time you just have one screen so you could get an instance of that screen with: `Screen::default()`.
///
/// Also this screen has an buffer where you can write to. When you want to write the buffer to the screen you could flush the screen.
///
/// ```rust
/// // create default screen.
/// let screen = Screen::default();
/// // create raw screen.
/// let mut screen = Screen::new(true);
///
/// // write some text to the internal buffer of this type.
/// screen.write(b"Some text");
/// screen.write(b"Some more text");
/// screen.write(b"Some more text");
///
/// // write the above text by flushing the internal buffer of this type.
/// screen.flush();
///
/// let screen = Screen::new(false);
///
/// // create raw alternate screen from normal screen.
/// if let Ok(alternate_screen) = screen.enable_alternate_modes(true)
/// {
/// let crossterm = Crossterm::new(&alternate_screen.screen);
///
/// // make sure to pass in the screen of the AlternateScreen.
/// crossterm.cursor();
/// }
/// ```
///
pub struct Screen
{
buffer: Vec<u8>,
pub stdout: Arc<TerminalOutput>,
drop: bool,
}
impl Screen
{
/// Create new instance of the Screen also specify if the current screen should be in raw mode or normal mode. Check out `RawScreen` type for more info.
/// If you are not sure what raw mode is then pass false or use the `Screen::default()` to create an instance.
pub fn new(raw_mode: bool) -> Screen
{
if raw_mode
{
let screen = Screen { stdout: Arc::new(TerminalOutput::new(true)), buffer: Vec::new(), drop: true };
RawScreen::into_raw_mode().unwrap();
return screen;
}
return Screen::default();
}
/// Switch to alternate screen. This function will return an `AlternateScreen` instance. If everything went well this type will give you control over the `AlternateScreen`.
///
/// The bool 'raw_mode' specifies whether the alternate screen should be raw mode or not.
///
/// # What is Alternate screen?
/// *Nix style applications often utilize an alternate screen buffer, so that they can modify the entire contents of the buffer, without affecting the application that started them.
/// The alternate buffer is exactly the dimensions of the window, without any scrollback region.
/// For an example of this behavior, consider when vim is launched from bash.
/// Vim uses the entirety of the screen to edit the file, then returning to bash leaves the original buffer unchanged.
pub fn enable_alternate_modes(&self, raw_mode: bool) -> Result<AlternateScreen> {
let stdout = TerminalOutput::new(raw_mode);
let alternate_screen = AlternateScreen::to_alternate_screen(stdout, raw_mode)?;
return Ok(alternate_screen);
}
/// Write buffer to an internal buffer. When you want to write the buffer to screen use `flush()`.
///
/// This function is useful if you want to build up some output and when you are ready you could flush the output to the screen.
pub fn write_buf(&mut self, buf: &[u8]) -> Result<usize> {
self.buffer.write(buf);
Ok(buf.len())
}
/// Flush the internal buffer to the screen.
pub fn flush_buf(&mut self) -> Result<()> {
self.stdout.write_buf(&self.buffer);
self.stdout.flush()
}
/// This will disable the drop which will cause raw modes not to be undone on drop of `Screen`.
pub fn disable_drop(&mut self)
{
self.drop = false;
}
}
impl From<TerminalOutput> for Screen
{
/// Create an screen with the given `Stdout`
fn from(stdout: TerminalOutput) -> Self {
return Screen { stdout: Arc::new(stdout), buffer: Vec::new(), drop: true};
}
}
impl From<Arc<TerminalOutput>> for Screen
{
/// Create an screen with the given 'Arc<Stdout>'
fn from(stdout: Arc<TerminalOutput>) -> Self {
return Screen { stdout: stdout, buffer: Vec::new(), drop: true};
}
}
impl Default for Screen
{
/// Create an new screen which will not be in raw mode or alternate mode.
fn default() -> Self {
return Screen { stdout: Arc::new(TerminalOutput::new(false)), buffer: Vec::new(), drop: true};
}
}
impl Drop for Screen
{
/// If the current screen is in raw mode whe need to disable it when the instance goes out of scope.
fn drop(&mut self) {
if self.stdout.is_in_raw_mode && self.drop
{
RawScreen::disable_raw_modes();
}
}
}
impl Write for Screen
{
fn write(&mut self, buf: &[u8]) -> Result<usize> {
self.stdout.write_buf(buf)
}
fn flush(&mut self) -> Result<()> {
self.stdout.flush()
}
}