docs(terminal): add docs for terminal module (#486)

- moves the impl Terminal block up to be closer to the type definition
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Josh McKinney 2023-09-11 18:39:15 -07:00 committed by GitHub
parent 1414fbcc05
commit 42f816999e
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3 changed files with 280 additions and 101 deletions

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@ -191,6 +191,7 @@ pub mod terminal;
pub mod text;
pub mod widgets;
pub use self::terminal::{Frame, Terminal, TerminalOptions, Viewport};
#[doc(inline)]
pub use self::terminal::{CompletedFrame, Frame, Terminal, TerminalOptions, Viewport};
pub mod prelude;

View file

@ -29,6 +29,6 @@ pub use crate::{
layout::{self, Alignment, Constraint, Corner, Direction, Layout, Margin, Rect},
style::{self, Color, Modifier, Style, Styled, Stylize},
symbols::{self, Marker},
terminal::{self, Frame, Terminal, TerminalOptions, Viewport},
terminal::{CompletedFrame, Frame, Terminal, TerminalOptions, Viewport},
text::{self, Line, Masked, Span, Text},
};

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@ -1,3 +1,34 @@
#![deny(missing_docs)]
//! Provides the [`Terminal`], [`Frame`] and related types.
//!
//! The [`Terminal`] is the main interface of this library. It is responsible for drawing and
//! maintaining the state of the different widgets that compose your application.
//!
//! The [`Frame`] is a consistent view into the terminal state for rendering. It is obtained via
//! the closure argument of [`Terminal::draw`]. It is used to render widgets to the terminal and
//! control the cursor position.
//!
//! # Example
//!
//! ```rust,no_run
//! use std::io::stdout;
//! use ratatui::{prelude::*, widgets::Paragraph};
//!
//! let backend = CrosstermBackend::new(stdout());
//! let mut terminal = Terminal::new(backend)?;
//! terminal.draw(|frame| {
//! let area = frame.size();
//! frame.render_widget(Paragraph::new("Hello world!"), area);
//! })?;
//! # std::io::Result::Ok(())
//! ```
//!
//! [Crossterm]: https://crates.io/crates/crossterm
//! [Termion]: https://crates.io/crates/termion
//! [Termwiz]: https://crates.io/crates/termwiz
//! [`backend`]: crate::backend
//! [`Backend`]: crate::backend::Backend
//! [`Buffer`]: crate::buffer::Buffer
use std::{fmt, io};
use crate::{
@ -7,11 +38,29 @@ use crate::{
widgets::{StatefulWidget, Widget},
};
/// Represents the viewport of the terminal. The viewport is the area of the terminal that is
/// currently visible to the user. It can be either fullscreen, inline or fixed.
///
/// When the viewport is fullscreen, the whole terminal is used to draw the application.
///
/// When the viewport is inline, it is drawn inline with the rest of the terminal. The height of
/// the viewport is fixed, but the width is the same as the terminal width.
///
/// When the viewport is fixed, it is drawn in a fixed area of the terminal. The area is specified
/// by a [`Rect`].
///
/// See [`Terminal::with_options`] for more information.
#[derive(Debug, Default, Clone, Eq, PartialEq, Hash)]
pub enum Viewport {
/// The viewport is fullscreen
#[default]
Fullscreen,
/// The viewport is inline with the rest of the terminal.
///
/// The viewport's height is fixed and specified in number of lines. The width is the same as
/// the terminal's width. The viewport is drawn below the cursor position.
Inline(u16),
/// The viewport is drawn in a fixed area of the terminal. The area is specified by a [`Rect`].
Fixed(Rect),
}
@ -32,12 +81,55 @@ pub struct TerminalOptions {
pub viewport: Viewport,
}
/// Interface to the terminal backed by a [`Backend`].
/// An interface that Ratatui to interact and draw [`Frame`]s on the user's terminal.
///
/// This is the main entry point for Ratatui. It is responsible for drawing and maintaining the
/// state of the buffers, cursor and viewport.
///
/// The [`Terminal`] is generic over a [`Backend`] implementation which is used to interface with
/// the underlying terminal library. The [`Backend`] trait is implemented for three popular Rust
/// terminal libraries: [Crossterm], [Termion] and [Termwiz]. See the [`backend`] module for more
/// information.
///
/// The terminal has two buffers that are used to draw the application. The first buffer is the
/// current buffer and the second buffer is the previous buffer. The two buffers are compared at
/// the end of each draw pass to output only the changes to the terminal.
///
/// The terminal also has a viewport which is the area of the terminal that is currently visible to
/// the user. It can be either fullscreen, inline or fixed. See [`Viewport`] for more information.
///
/// Applications should detect terminal resizes and call [`Terminal::draw`] to redraw the
/// application with the new size. This will automatically resize the internal buffers to match the
/// new size for inline and fullscreen viewports. Fixed viewports are not resized automatically.
///
/// # Examples
///
/// ```rust,no_run
/// use std::io::stdout;
/// use ratatui::{prelude::*, widgets::Paragraph};
///
/// let backend = CrosstermBackend::new(stdout());
/// let mut terminal = Terminal::new(backend)?;
/// terminal.draw(|frame| {
/// let area = frame.size();
/// frame.render_widget(Paragraph::new("Hello World!"), area);
/// frame.set_cursor(0, 0);
/// })?;
/// # std::io::Result::Ok(())
/// ```
///
/// [Crossterm]: https://crates.io/crates/crossterm
/// [Termion]: https://crates.io/crates/termion
/// [Termwiz]: https://crates.io/crates/termwiz
/// [`backend`]: crate::backend
/// [`Backend`]: crate::backend::Backend
/// [`Buffer`]: crate::buffer::Buffer
#[derive(Debug, Default, Clone, Eq, PartialEq, Hash)]
pub struct Terminal<B>
where
B: Backend,
{
/// The backend used to interface with the terminal
backend: B,
/// Holds the results of the current and previous draw calls. The two are compared at the end
/// of each draw pass to output the necessary updates to the terminal
@ -48,6 +140,7 @@ where
hidden_cursor: bool,
/// Viewport
viewport: Viewport,
/// Area of the viewport
viewport_area: Rect,
/// Last known size of the terminal. Used to detect if the internal buffers have to be resized.
last_known_size: Rect,
@ -56,99 +149,6 @@ where
last_known_cursor_pos: (u16, u16),
}
/// Represents a consistent terminal interface for rendering.
#[derive(Debug, Hash)]
pub struct Frame<'a, B: 'a>
where
B: Backend,
{
terminal: &'a mut Terminal<B>,
/// Where should the cursor be after drawing this frame?
///
/// If `None`, the cursor is hidden and its position is controlled by the backend. If `Some((x,
/// y))`, the cursor is shown and placed at `(x, y)` after the call to `Terminal::draw()`.
cursor_position: Option<(u16, u16)>,
}
impl<'a, B> Frame<'a, B>
where
B: Backend,
{
/// Frame size, guaranteed not to change when rendering.
pub fn size(&self) -> Rect {
self.terminal.viewport_area
}
/// Render a [`Widget`] to the current buffer using [`Widget::render`].
///
/// # Examples
///
/// ```rust
/// # use ratatui::{backend::TestBackend, prelude::*, widgets::*};
/// # let backend = TestBackend::new(5, 5);
/// # let mut terminal = Terminal::new(backend).unwrap();
/// let block = Block::default();
/// let area = Rect::new(0, 0, 5, 5);
/// let mut frame = terminal.get_frame();
/// frame.render_widget(block, area);
/// ```
pub fn render_widget<W>(&mut self, widget: W, area: Rect)
where
W: Widget,
{
widget.render(area, self.terminal.current_buffer_mut());
}
/// Render a [`StatefulWidget`] to the current buffer using [`StatefulWidget::render`].
///
/// The last argument should be an instance of the [`StatefulWidget::State`] associated to the
/// given [`StatefulWidget`].
///
/// # Examples
///
/// ```rust
/// # use ratatui::{backend::TestBackend, prelude::*, widgets::*};
/// # let backend = TestBackend::new(5, 5);
/// # let mut terminal = Terminal::new(backend).unwrap();
/// let mut state = ListState::default();
/// state.select(Some(1));
/// let items = vec![
/// ListItem::new("Item 1"),
/// ListItem::new("Item 2"),
/// ];
/// let list = List::new(items);
/// let area = Rect::new(0, 0, 5, 5);
/// let mut frame = terminal.get_frame();
/// frame.render_stateful_widget(list, area, &mut state);
/// ```
pub fn render_stateful_widget<W>(&mut self, widget: W, area: Rect, state: &mut W::State)
where
W: StatefulWidget,
{
widget.render(area, self.terminal.current_buffer_mut(), state);
}
/// After drawing this frame, make the cursor visible and put it at the specified (x, y)
/// coordinates. If this method is not called, the cursor will be hidden.
///
/// Note that this will interfere with calls to `Terminal::hide_cursor()`,
/// `Terminal::show_cursor()`, and `Terminal::set_cursor()`. Pick one of the APIs and stick
/// with it.
pub fn set_cursor(&mut self, x: u16, y: u16) {
self.cursor_position = Some((x, y));
}
}
/// `CompletedFrame` represents the state of the terminal after all changes performed in the last
/// [`Terminal::draw`] call have been applied. Therefore, it is only valid until the next call to
/// [`Terminal::draw`].
#[derive(Debug, Clone, Eq, PartialEq, Hash)]
pub struct CompletedFrame<'a> {
pub buffer: &'a Buffer,
pub area: Rect,
}
impl<B> Drop for Terminal<B>
where
B: Backend,
@ -167,8 +167,17 @@ impl<B> Terminal<B>
where
B: Backend,
{
/// Wrapper around Terminal initialization. Each buffer is initialized with a blank string and
/// default colors for the foreground and the background
/// Creates a new [`Terminal`] with the given [`Backend`] with a full screen viewport.
///
/// # Example
///
/// ```rust,no_run
/// # use std::io::stdout;
/// # use ratatui::prelude::*;
/// let backend = CrosstermBackend::new(stdout());
/// let terminal = Terminal::new(backend)?;
/// # std::io::Result::Ok(())
/// ```
pub fn new(backend: B) -> io::Result<Terminal<B>> {
Terminal::with_options(
backend,
@ -178,6 +187,21 @@ where
)
}
/// Creates a new [`Terminal`] with the given [`Backend`] and [`TerminalOptions`].
///
/// # Example
///
/// ```rust
/// # use std::io::stdout;
/// # use ratatui::{prelude::*, backend::TestBackend};
/// let backend = CrosstermBackend::new(stdout());
/// let viewport = Viewport::Fixed(Rect::new(0, 0, 10, 10));
/// let terminal = Terminal::with_options(
/// backend,
/// TerminalOptions { viewport },
/// )?;
/// # std::io::Result::Ok(())
/// ```
pub fn with_options(mut backend: B, options: TerminalOptions) -> io::Result<Terminal<B>> {
let size = match options.viewport {
Viewport::Fullscreen | Viewport::Inline(_) => backend.size()?,
@ -208,14 +232,17 @@ where
}
}
/// Gets the current buffer as a mutable reference.
pub fn current_buffer_mut(&mut self) -> &mut Buffer {
&mut self.buffers[self.current]
}
/// Gets the backend
pub fn backend(&self) -> &B {
&self.backend
}
/// Gets the backend as a mutable reference
pub fn backend_mut(&mut self) -> &mut B {
&mut self.backend
}
@ -232,9 +259,10 @@ where
self.backend.draw(updates.into_iter())
}
/// Updates the Terminal so that internal buffers match the requested size. Requested size will
/// be saved so the size can remain consistent when rendering.
/// This leads to a full clear of the screen.
/// Updates the Terminal so that internal buffers match the requested size.
///
/// Requested size will be saved so the size can remain consistent when rendering. This leads
/// to a full clear of the screen.
pub fn resize(&mut self, size: Rect) -> io::Result<()> {
let next_area = match self.viewport {
Viewport::Fullscreen => size,
@ -274,6 +302,23 @@ where
/// Synchronizes terminal size, calls the rendering closure, flushes the current internal state
/// and prepares for the next draw call.
///
/// This is the main entry point for drawing to the terminal.
///
/// # Examples
///
/// ```rust,no_run
/// # use std::io::stdout;
/// # use ratatui::{prelude::*, widgets::Paragraph};
/// let backend = CrosstermBackend::new(stdout());
/// let mut terminal = Terminal::new(backend)?;
/// terminal.draw(|frame| {
/// let area = frame.size();
/// frame.render_widget(Paragraph::new("Hello World!"), area);
/// frame.set_cursor(0, 0);
/// })?;
/// # std::io::Result::Ok(())
/// ```
pub fn draw<F>(&mut self, f: F) -> io::Result<CompletedFrame>
where
F: FnOnce(&mut Frame<B>),
@ -311,22 +356,29 @@ where
})
}
/// Hides the cursor.
pub fn hide_cursor(&mut self) -> io::Result<()> {
self.backend.hide_cursor()?;
self.hidden_cursor = true;
Ok(())
}
/// Shows the cursor.
pub fn show_cursor(&mut self) -> io::Result<()> {
self.backend.show_cursor()?;
self.hidden_cursor = false;
Ok(())
}
/// Gets the current cursor position.
///
/// This is the position of the cursor after the last draw call and is returned as a tuple of
/// `(x, y)` coordinates.
pub fn get_cursor(&mut self) -> io::Result<(u16, u16)> {
self.backend.get_cursor()
}
/// Sets the cursor position.
pub fn set_cursor(&mut self, x: u16, y: u16) -> io::Result<()> {
self.backend.set_cursor(x, y)?;
self.last_known_cursor_pos = (x, y);
@ -488,6 +540,132 @@ fn compute_inline_size<B: Backend>(
))
}
/// A consistent view into the terminal state for rendering a single frame.
///
/// This is obtained via the closure argument of [`Terminal::draw`]. It is used to render widgets
/// to the terminal and control the cursor position.
///
/// The changes drawn to the frame are not immediately applied to the terminal. They are only
/// applied after the closure returns. This allows for widgets to be drawn in any order. The
/// changes are then compared to the previous frame and only the necessary updates are applied to
/// the terminal.
///
/// The [`Frame`] is generic over a [`Backend`] implementation which is used to interface with the
/// underlying terminal library. The [`Backend`] trait is implemented for three popular Rust
/// terminal libraries: [Crossterm], [Termion] and [Termwiz]. See the [`backend`] module for more
/// information.
///
/// [Crossterm]: https://crates.io/crates/crossterm
/// [Termion]: https://crates.io/crates/termion
/// [Termwiz]: https://crates.io/crates/termwiz
/// [`backend`]: crate::backend
/// [`Backend`]: crate::backend::Backend
/// [`Buffer`]: crate::buffer::Buffer
#[derive(Debug, Hash)]
pub struct Frame<'a, B: 'a>
where
B: Backend,
{
/// The terminal that this frame is associated with.
terminal: &'a mut Terminal<B>,
/// Where should the cursor be after drawing this frame?
///
/// If `None`, the cursor is hidden and its position is controlled by the backend. If `Some((x,
/// y))`, the cursor is shown and placed at `(x, y)` after the call to `Terminal::draw()`.
cursor_position: Option<(u16, u16)>,
}
impl<'a, B> Frame<'a, B>
where
B: Backend,
{
/// The size of the current frame
///
/// This is guaranteed not to change when rendering.
pub fn size(&self) -> Rect {
self.terminal.viewport_area
}
/// Render a [`Widget`] to the current buffer using [`Widget::render`].
///
/// Usually the area argument is the size of the current frame or a sub-area of the current
/// frame (which can be obtained using [`Layout`] to split the total area).
///
/// # Example
///
/// ```rust
/// # use ratatui::{backend::TestBackend, prelude::*, widgets::Block};
/// # let backend = TestBackend::new(5, 5);
/// # let mut terminal = Terminal::new(backend).unwrap();
/// # let mut frame = terminal.get_frame();
/// let block = Block::default();
/// let area = Rect::new(0, 0, 5, 5);
/// frame.render_widget(block, area);
/// ```
///
/// [`Layout`]: crate::layout::Layout
pub fn render_widget<W>(&mut self, widget: W, area: Rect)
where
W: Widget,
{
widget.render(area, self.terminal.current_buffer_mut());
}
/// Render a [`StatefulWidget`] to the current buffer using [`StatefulWidget::render`].
///
/// Usually the area argument is the size of the current frame or a sub-area of the current
/// frame (which can be obtained using [`Layout`] to split the total area).
///
/// The last argument should be an instance of the [`StatefulWidget::State`] associated to the
/// given [`StatefulWidget`].
///
/// # Examples
///
/// ```rust
/// # use ratatui::{backend::TestBackend, prelude::*, widgets::*};
/// # let backend = TestBackend::new(5, 5);
/// # let mut terminal = Terminal::new(backend).unwrap();
/// # let mut frame = terminal.get_frame();
/// let mut state = ListState::default().with_selected(Some(1));
/// let list = List::new(vec![
/// ListItem::new("Item 1"),
/// ListItem::new("Item 2"),
/// ]);
/// let area = Rect::new(0, 0, 5, 5);
/// frame.render_stateful_widget(list, area, &mut state);
/// ```
///
/// [`Layout`]: crate::layout::Layout
pub fn render_stateful_widget<W>(&mut self, widget: W, area: Rect, state: &mut W::State)
where
W: StatefulWidget,
{
widget.render(area, self.terminal.current_buffer_mut(), state);
}
/// After drawing this frame, make the cursor visible and put it at the specified (x, y)
/// coordinates. If this method is not called, the cursor will be hidden.
///
/// Note that this will interfere with calls to `Terminal::hide_cursor()`,
/// `Terminal::show_cursor()`, and `Terminal::set_cursor()`. Pick one of the APIs and stick
/// with it.
pub fn set_cursor(&mut self, x: u16, y: u16) {
self.cursor_position = Some((x, y));
}
}
/// `CompletedFrame` represents the state of the terminal after all changes performed in the last
/// [`Terminal::draw`] call have been applied. Therefore, it is only valid until the next call to
/// [`Terminal::draw`].
#[derive(Debug, Clone, Eq, PartialEq, Hash)]
pub struct CompletedFrame<'a> {
/// The buffer that was used to draw the last frame.
pub buffer: &'a Buffer,
/// The size of the last frame.
pub area: Rect,
}
#[cfg(test)]
mod tests {
use super::*;