fn retrieve_keycode()

in src/platform_impl/macos/view.rs [629:650]

• 12 lines of code
• 4 McCabe index (conditional complexity)

fn retrieve_keycode(event: id) -> Option<VirtualKeyCode> {
    #[inline]
    fn get_code(ev: id, raw: bool) -> Option<VirtualKeyCode> {
        let characters = get_characters(ev, raw);
        characters.chars().next().and_then(|c| char_to_keycode(c))
    }

    // Cmd switches Roman letters for Dvorak-QWERTY layout, so we try modified characters first.
    // If we don't get a match, then we fall back to unmodified characters.
    let code = get_code(event, false).or_else(|| get_code(event, true));

    // We've checked all layout related keys, so fall through to scancode.
    // Reaching this code means that the key is layout-independent (e.g. Backspace, Return).
    //
    // We're additionally checking here for F21-F24 keys, since their keycode
    // can vary, but we know that they are encoded
    // in characters property.
    code.or_else(|| {
        let scancode = get_scancode(event);
        scancode_to_keycode(scancode).or_else(|| check_function_keys(&get_characters(event, true)))
    })
}