Module crossterm::event

A module to read events.

Event

The event module provides the functionality to read keyboard, mouse and terminal resize events.

• The read function returns an Event immediately (if available) or blocks until an Event is available.

• The poll function allows you to check if there is or isn't an Event available within the given period of time. In other words - if subsequent call to the read function will block or not.

It's not allowed to call these functions from different threads or combine them with the EventStream. You're allowed to either:

• use the read & poll functions on any, but same, thread
• or the EventStream.

Mouse Events

Mouse events are not enabled by default. You have to enable them with the EnableMouseCapture command. See Command API for more information.

Examples

Blocking read:

use crossterm::event::{read, Event};

fn print_events() -> crossterm::Result<()> {
    loop {
        // `read()` blocks until an `Event` is available
        match read()? {
            Event::Key(event) => println!("{:?}", event),
            Event::Mouse(event) => println!("{:?}", event),
            Event::Resize(width, height) => println!("New size {}x{}", width, height),
        }
    }
    Ok(())
}

Non-blocking read:

use std::time::Duration;

use crossterm::event::{poll, read, Event};

fn print_events() -> crossterm::Result<()> {
    loop {
        // `poll()` waits for an `Event` for a given time period
        if poll(Duration::from_millis(500))? {
            // It's guaranteed that the `read()` won't block when the `poll()`
            // function returns `true`
            match read()? {
                Event::Key(event) => println!("{:?}", event),
                Event::Mouse(event) => println!("{:?}", event),
                Event::Resize(width, height) => println!("New size {}x{}", width, height),
            }
        } else {
            // Timeout expired and no `Event` is available
        }
    }
    Ok(())
}

Check the examples folder for more of them (event-*).

Structs

DisableMouseCapture	A command that disables mouse event capturing.
EnableMouseCapture	A command that enables mouse event capturing.
EventStream	A stream of Result<Event>.
KeyEvent	Represents a key event.
KeyModifiers	Represents key modifiers (shift, control, alt).

Enums

Event	Represents an event.
KeyCode	Represents a key.
MouseButton	Represents a mouse button.
MouseEvent	Represents a mouse event.

Functions

poll	Checks if there is an Event available.
read	Reads a single Event.