pub struct CrosstermBackend<W: Write> { /* private fields */ }
crossterm
only.Expand description
A Backend
implementation that uses Crossterm to render to the terminal.
The CrosstermBackend
struct is a wrapper around a writer implementing Write
, which is
used to send commands to the terminal. It provides methods for drawing content, manipulating
the cursor, and clearing the terminal screen.
Most applications should not call the methods on CrosstermBackend
directly, but will instead
use the Terminal
struct, which provides a more ergonomic interface.
Usually applications will enable raw mode and switch to alternate screen mode after creating
a CrosstermBackend
. This is done by calling crossterm::terminal::enable_raw_mode
and
crossterm::terminal::EnterAlternateScreen
(and the corresponding disable/leave functions
when the application exits). This is not done automatically by the backend because it is
possible that the application may want to use the terminal for other purposes (like showing
help text) before entering alternate screen mode.
§Example
use std::io::{stderr, stdout};
use crossterm::{
terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
ExecutableCommand,
};
use ratatui::{backend::CrosstermBackend, Terminal};
let mut backend = CrosstermBackend::new(stdout());
// or
let backend = CrosstermBackend::new(stderr());
let mut terminal = Terminal::new(backend)?;
enable_raw_mode()?;
stdout().execute(EnterAlternateScreen)?;
terminal.clear()?;
terminal.draw(|frame| {
// -- snip --
})?;
stdout().execute(LeaveAlternateScreen)?;
disable_raw_mode()?;
See the the Examples directory for more examples. See the backend
module documentation
for more details on raw mode and alternate screen.
Implementations§
Source§impl<W> CrosstermBackend<W>where
W: Write,
impl<W> CrosstermBackend<W>where
W: Write,
Sourcepub const fn writer(&self) -> &W
Available on crate feature unstable-backend-writer
only.
pub const fn writer(&self) -> &W
unstable-backend-writer
only.Gets the writer.
§Availability
This API is marked as unstable and is only available when the unstable-backend-writer
crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.
The tracking issue is: https://github.com/ratatui/ratatui/pull/991
Sourcepub fn writer_mut(&mut self) -> &mut W
Available on crate feature unstable-backend-writer
only.
pub fn writer_mut(&mut self) -> &mut W
unstable-backend-writer
only.Gets the writer as a mutable reference.
Note: writing to the writer may cause incorrect output after the write. This is due to the way that the Terminal implements diffing Buffers.
§Availability
This API is marked as unstable and is only available when the unstable-backend-writer
crate feature is enabled. This comes with no stability guarantees, and could be changed or removed at any time.
The tracking issue is: https://github.com/ratatui/ratatui/pull/991
Trait Implementations§
Source§impl<W> Backend for CrosstermBackend<W>where
W: Write,
impl<W> Backend for CrosstermBackend<W>where
W: Write,
Source§fn draw<'a, I>(&mut self, content: I) -> Result<()>
fn draw<'a, I>(&mut self, content: I) -> Result<()>
Source§fn get_cursor_position(&mut self) -> Result<Position>
fn get_cursor_position(&mut self) -> Result<Position>
Source§fn set_cursor_position<P: Into<Position>>(&mut self, position: P) -> Result<()>
fn set_cursor_position<P: Into<Position>>(&mut self, position: P) -> Result<()>
Source§fn append_lines(&mut self, n: u16) -> Result<()>
fn append_lines(&mut self, n: u16) -> Result<()>
n
line breaks to the terminal screen. Read moreSource§fn window_size(&mut self) -> Result<WindowSize>
fn window_size(&mut self) -> Result<WindowSize>
WindowSize
. Read moreSource§fn scroll_region_up(&mut self, region: Range<u16>, amount: u16) -> Result<()>
fn scroll_region_up(&mut self, region: Range<u16>, amount: u16) -> Result<()>
scrolling-regions
only.Source§fn scroll_region_down(&mut self, region: Range<u16>, amount: u16) -> Result<()>
fn scroll_region_down(&mut self, region: Range<u16>, amount: u16) -> Result<()>
scrolling-regions
only.Source§impl<W: Clone + Write> Clone for CrosstermBackend<W>
impl<W: Clone + Write> Clone for CrosstermBackend<W>
1.0.0 · Source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moreSource§impl<W> Write for CrosstermBackend<W>where
W: Write,
impl<W> Write for CrosstermBackend<W>where
W: Write,
Source§fn write(&mut self, buf: &[u8]) -> Result<usize>
fn write(&mut self, buf: &[u8]) -> Result<usize>
Writes a buffer of bytes to the underlying buffer.
Source§fn is_write_vectored(&self) -> bool
fn is_write_vectored(&self) -> bool
can_vector
)1.0.0 · Source§fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>
fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>
Source§fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>
fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>
write_all_vectored
)impl<W: Eq + Write> Eq for CrosstermBackend<W>
impl<W: Write> StructuralPartialEq for CrosstermBackend<W>
Auto Trait Implementations§
impl<W> Freeze for CrosstermBackend<W>where
W: Freeze,
impl<W> RefUnwindSafe for CrosstermBackend<W>where
W: RefUnwindSafe,
impl<W> Send for CrosstermBackend<W>where
W: Send,
impl<W> Sync for CrosstermBackend<W>where
W: Sync,
impl<W> Unpin for CrosstermBackend<W>where
W: Unpin,
impl<W> UnwindSafe for CrosstermBackend<W>where
W: UnwindSafe,
Blanket Implementations§
Source§impl<S, D, Swp, Dwp, T> AdaptInto<D, Swp, Dwp, T> for Swhere
T: Real + Zero + Arithmetics + Clone,
Swp: WhitePoint<T>,
Dwp: WhitePoint<T>,
D: AdaptFrom<S, Swp, Dwp, T>,
impl<S, D, Swp, Dwp, T> AdaptInto<D, Swp, Dwp, T> for Swhere
T: Real + Zero + Arithmetics + Clone,
Swp: WhitePoint<T>,
Dwp: WhitePoint<T>,
D: AdaptFrom<S, Swp, Dwp, T>,
Source§fn adapt_into_using<M>(self, method: M) -> Dwhere
M: TransformMatrix<T>,
fn adapt_into_using<M>(self, method: M) -> Dwhere
M: TransformMatrix<T>,
Source§fn adapt_into(self) -> D
fn adapt_into(self) -> D
Source§impl<T, C> ArraysFrom<C> for Twhere
C: IntoArrays<T>,
impl<T, C> ArraysFrom<C> for Twhere
C: IntoArrays<T>,
Source§fn arrays_from(colors: C) -> T
fn arrays_from(colors: C) -> T
Source§impl<T, C> ArraysInto<C> for Twhere
C: FromArrays<T>,
impl<T, C> ArraysInto<C> for Twhere
C: FromArrays<T>,
Source§fn arrays_into(self) -> C
fn arrays_into(self) -> C
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Source§impl<WpParam, T, U> Cam16IntoUnclamped<WpParam, T> for Uwhere
T: FromCam16Unclamped<WpParam, U>,
impl<WpParam, T, U> Cam16IntoUnclamped<WpParam, T> for Uwhere
T: FromCam16Unclamped<WpParam, U>,
Source§type Scalar = <T as FromCam16Unclamped<WpParam, U>>::Scalar
type Scalar = <T as FromCam16Unclamped<WpParam, U>>::Scalar
parameters
when converting.Source§fn cam16_into_unclamped(
self,
parameters: BakedParameters<WpParam, <U as Cam16IntoUnclamped<WpParam, T>>::Scalar>,
) -> T
fn cam16_into_unclamped( self, parameters: BakedParameters<WpParam, <U as Cam16IntoUnclamped<WpParam, T>>::Scalar>, ) -> T
self
into C
, using the provided parameters.Source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
Source§impl<T, C> ComponentsFrom<C> for Twhere
C: IntoComponents<T>,
impl<T, C> ComponentsFrom<C> for Twhere
C: IntoComponents<T>,
Source§fn components_from(colors: C) -> T
fn components_from(colors: C) -> T
Source§impl<W> DetectColors for Wwhere
W: Write,
impl<W> DetectColors for Wwhere
W: Write,
Source§impl<W> DetectCursorPos for Wwhere
W: Write,
impl<W> DetectCursorPos for Wwhere
W: Write,
Source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
Source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.Source§impl<T> ExecutableCommand for T
impl<T> ExecutableCommand for T
Source§fn execute(&mut self, command: impl Command) -> Result<&mut T, Error>
fn execute(&mut self, command: impl Command) -> Result<&mut T, Error>
Executes the given command directly.
The given command its ANSI escape code will be written and flushed onto Self
.
§Arguments
-
The command that you want to execute directly.
§Example
use std::io;
use crossterm::{ExecutableCommand, style::Print};
fn main() -> io::Result<()> {
// will be executed directly
io::stdout()
.execute(Print("sum:\n".to_string()))?
.execute(Print(format!("1 + 1= {} ", 1 + 1)))?;
Ok(())
// ==== Output ====
// sum:
// 1 + 1 = 2
}
Have a look over at the Command API for more details.
§Notes
- In the case of UNIX and Windows 10, ANSI codes are written to the given ‘writer’.
- In case of Windows versions lower than 10, a direct WinAPI call will be made.
The reason for this is that Windows versions lower than 10 do not support ANSI codes,
and can therefore not be written to the given
writer
. Therefore, there is no difference between execute and queue for those old Windows versions.
Source§impl<T> FromAngle<T> for T
impl<T> FromAngle<T> for T
Source§fn from_angle(angle: T) -> T
fn from_angle(angle: T) -> T
angle
.Source§impl<T, U> FromStimulus<U> for Twhere
U: IntoStimulus<T>,
impl<T, U> FromStimulus<U> for Twhere
U: IntoStimulus<T>,
Source§fn from_stimulus(other: U) -> T
fn from_stimulus(other: U) -> T
other
into Self
, while performing the appropriate scaling,
rounding and clamping.Source§impl<W> IntoAlternateScreen for Wwhere
W: Write,
impl<W> IntoAlternateScreen for Wwhere
W: Write,
Source§fn into_alternate_screen(self) -> Result<AlternateScreen<Self>, Error>
fn into_alternate_screen(self) -> Result<AlternateScreen<Self>, Error>
AlternateScreen
returned by this function is
dropped.Source§impl<T, U> IntoAngle<U> for Twhere
U: FromAngle<T>,
impl<T, U> IntoAngle<U> for Twhere
U: FromAngle<T>,
Source§fn into_angle(self) -> U
fn into_angle(self) -> U
T
.Source§impl<WpParam, T, U> IntoCam16Unclamped<WpParam, T> for Uwhere
T: Cam16FromUnclamped<WpParam, U>,
impl<WpParam, T, U> IntoCam16Unclamped<WpParam, T> for Uwhere
T: Cam16FromUnclamped<WpParam, U>,
Source§type Scalar = <T as Cam16FromUnclamped<WpParam, U>>::Scalar
type Scalar = <T as Cam16FromUnclamped<WpParam, U>>::Scalar
parameters
when converting.Source§fn into_cam16_unclamped(
self,
parameters: BakedParameters<WpParam, <U as IntoCam16Unclamped<WpParam, T>>::Scalar>,
) -> T
fn into_cam16_unclamped( self, parameters: BakedParameters<WpParam, <U as IntoCam16Unclamped<WpParam, T>>::Scalar>, ) -> T
self
into C
, using the provided parameters.Source§impl<T, U> IntoColor<U> for Twhere
U: FromColor<T>,
impl<T, U> IntoColor<U> for Twhere
U: FromColor<T>,
Source§fn into_color(self) -> U
fn into_color(self) -> U
Source§impl<T, U> IntoColorUnclamped<U> for Twhere
U: FromColorUnclamped<T>,
impl<T, U> IntoColorUnclamped<U> for Twhere
U: FromColorUnclamped<T>,
Source§fn into_color_unclamped(self) -> U
fn into_color_unclamped(self) -> U
Source§impl<T> IntoEither for T
impl<T> IntoEither for T
Source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moreSource§impl<T> IntoStimulus<T> for T
impl<T> IntoStimulus<T> for T
Source§fn into_stimulus(self) -> T
fn into_stimulus(self) -> T
self
into T
, while performing the appropriate scaling,
rounding and clamping.Source§impl<T> QueueableCommand for T
impl<T> QueueableCommand for T
Source§fn queue(&mut self, command: impl Command) -> Result<&mut T, Error>
fn queue(&mut self, command: impl Command) -> Result<&mut T, Error>
Queues the given command for further execution.
Queued commands will be executed in the following cases:
- When
flush
is called manually on the given type implementingio::Write
. - The terminal will
flush
automatically if the buffer is full. - Each line is flushed in case of
stdout
, because it is line buffered.
§Arguments
-
The command that you want to queue for later execution.
§Examples
use std::io::{self, Write};
use crossterm::{QueueableCommand, style::Print};
fn main() -> io::Result<()> {
let mut stdout = io::stdout();
// `Print` will executed executed when `flush` is called.
stdout
.queue(Print("foo 1\n".to_string()))?
.queue(Print("foo 2".to_string()))?;
// some other code (no execution happening here) ...
// when calling `flush` on `stdout`, all commands will be written to the stdout and therefore executed.
stdout.flush()?;
Ok(())
// ==== Output ====
// foo 1
// foo 2
}
Have a look over at the Command API for more details.
§Notes
- In the case of UNIX and Windows 10, ANSI codes are written to the given ‘writer’.
- In case of Windows versions lower than 10, a direct WinAPI call will be made.
The reason for this is that Windows versions lower than 10 do not support ANSI codes,
and can therefore not be written to the given
writer
. Therefore, there is no difference between execute and queue for those old Windows versions.
Source§impl<W> SynchronizedUpdate for W
impl<W> SynchronizedUpdate for W
Source§fn sync_update<T>(
&mut self,
operations: impl FnOnce(&mut W) -> T,
) -> Result<T, Error>
fn sync_update<T>( &mut self, operations: impl FnOnce(&mut W) -> T, ) -> Result<T, Error>
Performs a set of actions within a synchronous update.
Updates will be suspended in the terminal, the function will be executed against self, updates will be resumed, and a flush will be performed.
§Arguments
-
Function
A function that performs the operations that must execute in a synchronized update.
§Examples
use std::io;
use crossterm::{ExecutableCommand, SynchronizedUpdate, style::Print};
fn main() -> io::Result<()> {
let mut stdout = io::stdout();
stdout.sync_update(|stdout| {
stdout.execute(Print("foo 1\n".to_string()))?;
stdout.execute(Print("foo 2".to_string()))?;
// The effects of the print command will not be present in the terminal
// buffer, but not visible in the terminal.
std::io::Result::Ok(())
})?;
// The effects of the commands will be visible.
Ok(())
// ==== Output ====
// foo 1
// foo 2
}
§Notes
This command is performed only using ANSI codes, and will do nothing on terminals that do not support ANSI codes, or this specific extension.
When rendering the screen of the terminal, the Emulator usually iterates through each visible grid cell and renders its current state. With applications updating the screen a at higher frequency this can cause tearing.
This mode attempts to mitigate that.
When the synchronization mode is enabled following render calls will keep rendering the last rendered state. The terminal Emulator keeps processing incoming text and sequences. When the synchronized update mode is disabled again the renderer may fetch the latest screen buffer state again, effectively avoiding the tearing effect by unintentionally rendering in the middle a of an application screen update.
Source§impl<T, C> TryComponentsInto<C> for Twhere
C: TryFromComponents<T>,
impl<T, C> TryComponentsInto<C> for Twhere
C: TryFromComponents<T>,
Source§type Error = <C as TryFromComponents<T>>::Error
type Error = <C as TryFromComponents<T>>::Error
try_into_colors
fails to cast.Source§fn try_components_into(self) -> Result<C, <T as TryComponentsInto<C>>::Error>
fn try_components_into(self) -> Result<C, <T as TryComponentsInto<C>>::Error>
Source§impl<T, U> TryIntoColor<U> for Twhere
U: TryFromColor<T>,
impl<T, U> TryIntoColor<U> for Twhere
U: TryFromColor<T>,
Source§fn try_into_color(self) -> Result<U, OutOfBounds<U>>
fn try_into_color(self) -> Result<U, OutOfBounds<U>>
OutOfBounds
error is returned which contains
the unclamped color. Read more