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
57
58
59
60
61
62

use std::collections::HashMap;
use std::mem;
use winapi::shared::windef::HWND;
use winapi::um::winuser;

pub mod modifiers {
    use winapi::um::winuser;
    pub const ALT: u32 = winuser::MOD_ALT as u32;
    pub const CONTROL: u32 = winuser::MOD_CONTROL as u32;
    pub const SHIFT: u32 = winuser::MOD_SHIFT as u32;
    pub const SUPER: u32 = winuser::MOD_WIN as u32;
}

pub type ListenerID = i32;

pub struct Listener {
    last_id: i32,
    handlers: HashMap<ListenerID, Box<dyn Fn()>>,
}

impl Listener {
    pub fn new() -> Listener {
        Listener {
            last_id: 0,
            handlers: HashMap::new(),
        }
    }

    pub fn register_hotkey<CB: 'static + Fn()>(
        &mut self,
        modifiers: u32,
        key: u32,
        handler: CB,
    ) -> Result<ListenerID, String> {
        unsafe {
            self.last_id += 1;
            let id = self.last_id;
            let result = winuser::RegisterHotKey(0 as HWND, id, modifiers, key);
            if result == 0 {
                return Err("Failed to register hotkey".to_string());
            }

            self.handlers.insert(id, Box::new(handler));
            Ok(id)
        }
    }

    pub fn listen(self) {
        unsafe {
            loop {
                let mut msg = mem::MaybeUninit::uninit().assume_init();
                while winuser::GetMessageW(&mut msg, 0 as HWND, 0, 0) > 0 {
                    if msg.wParam != 0 {
                        if let Some(handler) = self.handlers.get(&(msg.wParam as i32)) {
                            handler();
                        }
                    }
                }
            }
        }
    }
}