Match key events using macros

src/ui/input.rs

@@ -0,0 +1,48 @@
+use crossterm::event::{KeyCode, KeyModifiers};
+
+/// A key event data type that is a bit easier to pattern match on than
+/// [`crossterm::event::KeyEvent`].
+#[derive(Debug, Clone, Copy)]
+pub struct KeyEvent {
+    pub code: KeyCode,
+    pub shift: bool,
+    pub ctrl: bool,
+    pub alt: bool,
+}
+
+impl From<crossterm::event::KeyEvent> for KeyEvent {
+    fn from(event: crossterm::event::KeyEvent) -> Self {
+        Self {
+            code: event.code,
+            shift: event.modifiers.contains(KeyModifiers::SHIFT),
+            ctrl: event.modifiers.contains(KeyModifiers::CONTROL),
+            alt: event.modifiers.contains(KeyModifiers::ALT),
+        }
+    }
+}
+
+#[rustfmt::skip]
+macro_rules! key {
+    // key!('a')
+    (        $key:literal ) => { KeyEvent { code: KeyCode::Char($key), shift: _, ctrl: false, alt: false, } };
+    ( Ctrl + $key:literal ) => { KeyEvent { code: KeyCode::Char($key), shift: _, ctrl: true,  alt: false, } };
+    (  Alt + $key:literal ) => { KeyEvent { code: KeyCode::Char($key), shift: _, ctrl: false, alt: true,  } };
+
+    // key!(Char(xyz))
+    (        Char $key:pat ) => { KeyEvent { code: KeyCode::Char($key), shift: _, ctrl: false, alt: false, } };
+    ( Ctrl + Char $key:pat ) => { KeyEvent { code: KeyCode::Char($key), shift: _, ctrl: true,  alt: false, } };
+    (  Alt + Char $key:pat ) => { KeyEvent { code: KeyCode::Char($key), shift: _, ctrl: false, alt: true,  } };
+
+    // key!(F(n))
+    (         F $key:pat ) => { KeyEvent { code: KeyCode::F($key), shift: false, ctrl: false, alt: false, } };
+    ( Shift + F $key:pat ) => { KeyEvent { code: KeyCode::F($key), shift: true,  ctrl: false, alt: false, } };
+    (  Ctrl + F $key:pat ) => { KeyEvent { code: KeyCode::F($key), shift: false, ctrl: true,  alt: false, } };
+    (   Alt + F $key:pat ) => { KeyEvent { code: KeyCode::F($key), shift: false, ctrl: false, alt: true,  } };
+
+    // key!(other)
+    (         $key:ident ) => { KeyEvent { code: KeyCode::$key, shift: false, ctrl: false, alt: false, } };
+    ( Shift + $key:ident ) => { KeyEvent { code: KeyCode::$key, shift: true,  ctrl: false, alt: false, } };
+    (  Ctrl + $key:ident ) => { KeyEvent { code: KeyCode::$key, shift: false, ctrl: true,  alt: false, } };
+    (   Alt + $key:ident ) => { KeyEvent { code: KeyCode::$key, shift: false, ctrl: false, alt: true,  } };
+}
+pub(crate) use key;