device_query 4.0.1

A basic library for querying keyboard and mouse state on-demand without a window.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56

use crate::device_events::utils;
use std::ops::DerefMut;
use std::sync::{Arc, Mutex, Weak};
use Keycode;

/// Keyboard callback.
pub type KeyboardCallback = dyn Fn(&Keycode) + Sync + Send + 'static;

/// Keyboard callbacks.
#[derive(Default)]
pub(crate) struct KeyboardCallbacks {
    key_down: Mutex<Vec<Weak<KeyboardCallback>>>,
    key_up: Mutex<Vec<Weak<KeyboardCallback>>>,
}

impl KeyboardCallbacks {
    pub fn push_key_up(&self, callback: Arc<KeyboardCallback>) {
        if let Ok(mut key_down) = self.key_up.lock() {
            let callback = Arc::downgrade(&callback);
            key_down.push(callback)
        }
    }

    pub fn push_key_down(&self, callback: Arc<KeyboardCallback>) {
        if let Ok(mut key_down) = self.key_down.lock() {
            let callback = Arc::downgrade(&callback);
            key_down.push(callback)
        }
    }

    pub fn run_key_up(&self, key: &Keycode) {
        if let Ok(mut callbacks) = self.key_up.lock() {
            utils::DrainFilter::drain_filter(callbacks.deref_mut(), |callback| {
                callback.upgrade().is_none()
            });
            for callback in callbacks.iter() {
                if let Some(callback) = callback.upgrade() {
                    callback(key);
                }
            }
        }
    }

    pub fn run_key_down(&self, key: &Keycode) {
        if let Ok(mut callbacks) = self.key_down.lock() {
            utils::DrainFilter::drain_filter(callbacks.deref_mut(), |callback| {
                callback.upgrade().is_none()
            });
            for callback in callbacks.iter() {
                if let Some(callback) = callback.upgrade() {
                    callback(key);
                }
            }
        }
    }
}