296 lines
10 KiB
Rust
296 lines
10 KiB
Rust
use std::fmt;
|
|
use std::io::{self, Write};
|
|
|
|
use crate::terminal::{BeginSynchronizedUpdate, EndSynchronizedUpdate};
|
|
|
|
/// An interface for a command that performs an action on the terminal.
|
|
///
|
|
/// Crossterm provides a set of commands,
|
|
/// and there is no immediate reason to implement a command yourself.
|
|
/// In order to understand how to use and execute commands,
|
|
/// it is recommended that you take a look at [Command API](./index.html#command-api) chapter.
|
|
pub trait Command {
|
|
/// Write an ANSI representation of this command to the given writer.
|
|
/// An ANSI code can manipulate the terminal by writing it to the terminal buffer.
|
|
/// However, only Windows 10 and UNIX systems support this.
|
|
///
|
|
/// This method does not need to be accessed manually, as it is used by the crossterm's [Command API](./index.html#command-api)
|
|
fn write_ansi(&self, f: &mut impl fmt::Write) -> fmt::Result;
|
|
|
|
/// Execute this command.
|
|
///
|
|
/// Windows versions lower than windows 10 do not support ANSI escape codes,
|
|
/// therefore a direct WinAPI call is made.
|
|
///
|
|
/// This method does not need to be accessed manually, as it is used by the crossterm's [Command API](./index.html#command-api)
|
|
#[cfg(windows)]
|
|
fn execute_winapi(&self) -> io::Result<()>;
|
|
|
|
/// Returns whether the ANSI code representation of this command is supported by windows.
|
|
///
|
|
/// A list of supported ANSI escape codes
|
|
/// can be found [here](https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences).
|
|
#[cfg(windows)]
|
|
fn is_ansi_code_supported(&self) -> bool {
|
|
super::ansi_support::supports_ansi()
|
|
}
|
|
}
|
|
|
|
impl<T: Command + ?Sized> Command for &T {
|
|
fn write_ansi(&self, f: &mut impl fmt::Write) -> fmt::Result {
|
|
(**self).write_ansi(f)
|
|
}
|
|
|
|
#[inline]
|
|
#[cfg(windows)]
|
|
fn execute_winapi(&self) -> io::Result<()> {
|
|
T::execute_winapi(self)
|
|
}
|
|
|
|
#[cfg(windows)]
|
|
#[inline]
|
|
fn is_ansi_code_supported(&self) -> bool {
|
|
T::is_ansi_code_supported(self)
|
|
}
|
|
}
|
|
|
|
/// An interface for types that can queue commands for further execution.
|
|
pub trait QueueableCommand {
|
|
/// Queues the given command for further execution.
|
|
fn queue(&mut self, command: impl Command) -> io::Result<&mut Self>;
|
|
}
|
|
|
|
/// An interface for types that can directly execute commands.
|
|
pub trait ExecutableCommand {
|
|
/// Executes the given command directly.
|
|
fn execute(&mut self, command: impl Command) -> io::Result<&mut Self>;
|
|
}
|
|
|
|
impl<T: Write + ?Sized> QueueableCommand for T {
|
|
/// 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 implementing `io::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
|
|
///
|
|
/// - [Command](./trait.Command.html)
|
|
///
|
|
/// The command that you want to queue for later execution.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use std::io::{self, Write};
|
|
/// use keyfork_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](./index.html#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](./trait.ExecutableCommand.html)
|
|
/// and [queue](./trait.QueueableCommand.html) for those old Windows versions.
|
|
fn queue(&mut self, command: impl Command) -> io::Result<&mut Self> {
|
|
#[cfg(windows)]
|
|
if !command.is_ansi_code_supported() {
|
|
// There may be queued commands in this writer, but `execute_winapi` will execute the
|
|
// command immediately. To prevent commands being executed out of order we flush the
|
|
// writer now.
|
|
self.flush()?;
|
|
command.execute_winapi()?;
|
|
return Ok(self);
|
|
}
|
|
|
|
write_command_ansi(self, command)?;
|
|
Ok(self)
|
|
}
|
|
}
|
|
|
|
impl<T: Write + ?Sized> ExecutableCommand for T {
|
|
/// Executes the given command directly.
|
|
///
|
|
/// The given command its ANSI escape code will be written and flushed onto `Self`.
|
|
///
|
|
/// # Arguments
|
|
///
|
|
/// - [Command](./trait.Command.html)
|
|
///
|
|
/// The command that you want to execute directly.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```rust
|
|
/// use std::io;
|
|
/// use keyfork_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](./index.html#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](./trait.ExecutableCommand.html)
|
|
/// and [queue](./trait.QueueableCommand.html) for those old Windows versions.
|
|
fn execute(&mut self, command: impl Command) -> io::Result<&mut Self> {
|
|
self.queue(command)?;
|
|
self.flush()?;
|
|
Ok(self)
|
|
}
|
|
}
|
|
|
|
/// An interface for types that support synchronized updates.
|
|
pub trait SynchronizedUpdate {
|
|
/// Performs a set of actions against the given type.
|
|
fn sync_update<T>(&mut self, operations: impl FnOnce(&mut Self) -> T) -> io::Result<T>;
|
|
}
|
|
|
|
impl<W: std::io::Write + ?Sized> SynchronizedUpdate for W {
|
|
/// 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
|
|
///
|
|
/// ```rust
|
|
/// use std::io;
|
|
/// use keyfork_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.
|
|
///
|
|
fn sync_update<T>(&mut self, operations: impl FnOnce(&mut Self) -> T) -> io::Result<T> {
|
|
self.queue(BeginSynchronizedUpdate)?;
|
|
let result = operations(self);
|
|
self.execute(EndSynchronizedUpdate)?;
|
|
Ok(result)
|
|
}
|
|
}
|
|
/// Writes the ANSI representation of a command to the given writer.
|
|
fn write_command_ansi<C: Command>(
|
|
io: &mut (impl io::Write + ?Sized),
|
|
command: C,
|
|
) -> io::Result<()> {
|
|
struct Adapter<T> {
|
|
inner: T,
|
|
res: io::Result<()>,
|
|
}
|
|
|
|
impl<T: Write> fmt::Write for Adapter<T> {
|
|
fn write_str(&mut self, s: &str) -> fmt::Result {
|
|
self.inner.write_all(s.as_bytes()).map_err(|e| {
|
|
self.res = Err(e);
|
|
fmt::Error
|
|
})
|
|
}
|
|
}
|
|
|
|
let mut adapter = Adapter {
|
|
inner: io,
|
|
res: Ok(()),
|
|
};
|
|
|
|
command
|
|
.write_ansi(&mut adapter)
|
|
.map_err(|fmt::Error| match adapter.res {
|
|
Ok(()) => panic!(
|
|
"<{}>::write_ansi incorrectly errored",
|
|
std::any::type_name::<C>()
|
|
),
|
|
Err(e) => e,
|
|
})
|
|
}
|
|
|
|
/// Executes the ANSI representation of a command, using the given `fmt::Write`.
|
|
pub(crate) fn execute_fmt(f: &mut impl fmt::Write, command: impl Command) -> fmt::Result {
|
|
#[cfg(windows)]
|
|
if !command.is_ansi_code_supported() {
|
|
return command.execute_winapi().map_err(|_| fmt::Error);
|
|
}
|
|
|
|
command.write_ansi(f)
|
|
}
|