KeyState uses flag to determine event type instead of seperate parameter

added is_down method to KeyState
added more tests
add get_flag and has_one_bit_set functions to lib.rs
change main.rs to use is_down instead of w_param for checking event type

src/key/keystate.rs

@@ -1,7 +1,8 @@
 use std::ffi::OsString;
 
-use winapi::um::winuser::{GetKeyNameTextW, KBDLLHOOKSTRUCT, LLKHF_EXTENDED};
+use winapi::um::winuser::{GetKeyNameTextW, KBDLLHOOKSTRUCT, LLKHF_EXTENDED, LLKHF_UP};
 use wio::wide::FromWide;
+use crate::get_flag;
 
 #[allow(clippy::struct_excessive_bools)]
 pub struct KeyState {
@@ -31,7 +32,8 @@ impl KeyState {
     }
 
     /// `key_down` if the event was a keydown event, this should be true. if it was keyup it should be false
-    pub fn update(&mut self, key: KBDLLHOOKSTRUCT, key_down: bool) {
+    pub fn update(&mut self, key: KBDLLHOOKSTRUCT) {
+        let key_down = !get_flag(key.flags, LLKHF_UP);
         self.kbdllstruct = key;
 
         match key.vkCode {
@@ -40,7 +42,7 @@ impl KeyState {
             164 | 165 => self.alt_down = key_down,
             91 => self.win_down = key_down,
             _ => {},
-        }
+        };
     }
 
     /// true if the key is an auxiliary key like shift, control or the windows key
@@ -48,22 +50,28 @@ impl KeyState {
         matches!(self.kbdllstruct.vkCode, 160..=165 | 91)
     }
 
-    #[no_mangle]
+    #[no_mangle] //required to not get garbage from native call
     pub fn name(&self) -> String {
         unsafe {
-            #[allow(clippy::if_not_else)] //clippy wrongfully assumes the != here is unecessary
-            let flags = if self.kbdllstruct.flags & LLKHF_EXTENDED != 0 { 1 << 24 } else { 0 };
+            let flags = if get_flag(self.kbdllstruct.flags, LLKHF_EXTENDED) { 1 << 24 } else { 0 };
+
             let mut out = [0_u16; 128];
             GetKeyNameTextW((self.kbdllstruct.scanCode << 16 | flags /*this distinguishes special keys by setting a flag. yes only microsoft thinks that input and flags in 1 param is a good idea*/) as i32, (&mut out).as_mut_ptr(), 128);
             let null_pos = out.iter().position(|x| *x == b'\0' as u16).unwrap_or_else(|| out.len());
             OsString::from_wide(&out[..null_pos]).to_str().unwrap().to_owned()
         }
     }
+
+    ///true if this event is keydown, otherwise false
+    pub fn is_down(&self) -> bool {
+        !get_flag(self.kbdllstruct.flags, LLKHF_UP)
+    }
 }
 
 #[cfg(test)]
 mod tests {
     use crate::key::keystate::KeyState;
+    use winapi::um::winuser::LLKHF_UP;
 
     #[test]
     fn is_aux_key() {
@@ -71,4 +79,17 @@ mod tests {
         k.kbdllstruct.vkCode = 160;
         assert!(k.is_aux_key());
     }
+
+    #[test]
+    fn is_down() {
+        let mut k = KeyState::new();
+
+        k.kbdllstruct.flags = LLKHF_UP;
+
+        assert!(!k.is_down());
+
+        k.kbdllstruct.flags = 0;
+
+        assert!(k.is_down());
+    }
 }

src/lib.rs

@@ -4,10 +4,46 @@
 //disable silly rules
 #![allow(
 clippy::module_name_repetitions, //complains about function names which makes no sense, so disabled
-clippy::must_use_candidate, //no i dont wannt to add the must_use attribute to everything
+clippy::must_use_candidate, //no i dont want to add the must_use attribute to everything
 clippy::cast_lossless, clippy::cast_possible_wrap, //lossy casts are required to work with garbage WinApi
 )]
 //endregion
 
 pub mod logging;
 pub mod key;
+
+///gets the flag at the position of `flag`. `flag` must have exactly 1 bit set
+fn get_flag(val: u32, flag: u32) -> bool {
+    if has_one_bit_set(flag) {
+        val & flag != 0
+    } else {
+        panic!("flag must have 1 bit set")
+    }
+}
+
+///true if exactly 1 bit of the given number is set
+fn has_one_bit_set(n: u32) -> bool {
+    //Dont ask me why this works! its mathgic!
+    n > 0 && !(n & (n - 1) > 0)
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn get_flag() {
+        assert!(super::get_flag(5, 1 << 2));
+        assert!(!super::get_flag(3, 1 << 2));
+    }
+
+    #[test]
+    #[should_panic]
+    fn get_flag_panic() {
+        super::get_flag(0, 3);
+    }
+
+    #[test]
+    fn has_one_bit_set() {
+        assert!(super::has_one_bit_set(1));
+        assert!(!super::has_one_bit_set(3));
+    }
+}

src/main.rs

@@ -21,12 +21,12 @@ fn main() {
     }
 }
 
-unsafe extern "system" fn hook_callback(_code: i32, w_param: usize, l_param: isize) -> isize {
+unsafe extern "system" fn hook_callback(_code: i32, _w_param: usize, l_param: isize) -> isize {
     let mut state = KEYSTATE.lock().unwrap();
     let key = *(l_param as PKBDLLHOOKSTRUCT);
-    state.update(key, w_param == 256);
+    state.update(key);
     //Check if keydown and not aux key
-    if w_param != 256 || state.is_aux_key() { return 0; }
+    if state.is_down() || state.is_aux_key() { return 0; }
     LOGGER.log(&state);
     0
 }