hex/src/linux/input.rs

//! Linux dictation shortcuts: the one state machine every input feeds, the
//! X11 key grabs, the Wayland shortcuts portal, and the `hex` commands a
//! desktop keybinding runs. Dictation sees only [`HotkeyEvent`]s.

use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::mpsc::{self, Receiver, SyncSender, TrySendError};
use std::sync::{Arc, Mutex};
use std::thread::{self, JoinHandle};
use std::time::{Duration, Instant};

use color_eyre::eyre::{Result, WrapErr, eyre};
use serde::{Deserialize, Serialize};
use x11rb::connection::Connection;
use x11rb::errors::ReplyError;
use x11rb::protocol::ErrorKind;
use x11rb::protocol::Event;
use x11rb::protocol::xproto::{ButtonIndex, ConnectionExt, EventMask, GrabMode, ModMask, Window};
use x11rb::rust_connection::RustConnection;

use crate::app_settings::{HotkeyBinding, HotkeyKey, HotkeyModifiers, ModifierSide};
use crate::desktop::host::{DesktopGrantedShortcut, DesktopShortcut, DesktopShortcuts};
use crate::dictation::DictationFlavour;
use crate::linux::session::LinuxSession;

#[path = "input/x11.rs"]
mod x11;
pub(crate) use x11::{Keymap, MouseCapture, connect_x11};

/// A shortcut as X11 grabs and the portal see it: held modifiers and a
/// named key. Settings store it as a portable `HotkeyBinding`.
#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
#[serde(default)]
pub(crate) struct LinuxHotkey {
    pub(crate) control: bool,
    pub(crate) alt: bool,
    pub(crate) shift: bool,
    pub(crate) super_key: bool,
    pub(crate) key: String,
}

impl Default for LinuxHotkey {
    fn default() -> Self {
        Self {
            control: false,
            alt: true,
            shift: false,
            super_key: false,
            key: "space".into(),
        }
    }
}

/// Linux names Command the Super key and Option Alt; keys go by name.
impl From<&HotkeyBinding> for LinuxHotkey {
    fn from(binding: &HotkeyBinding) -> Self {
        Self {
            control: binding.modifiers.control.is_some(),
            alt: binding.modifiers.option.is_some(),
            shift: binding.modifiers.shift.is_some(),
            super_key: binding.modifiers.command.is_some(),
            key: binding
                .key
                .as_ref()
                .map(HotkeyKey::name)
                .unwrap_or_default(),
        }
    }
}

impl From<&LinuxHotkey> for HotkeyBinding {
    fn from(hotkey: &LinuxHotkey) -> Self {
        let side = |held: bool| held.then_some(ModifierSide::Either);
        Self {
            modifiers: HotkeyModifiers {
                control: side(hotkey.control),
                option: side(hotkey.alt),
                shift: side(hotkey.shift),
                command: side(hotkey.super_key),
                function: false,
            },
            key: (!hotkey.key.trim().is_empty()).then(|| HotkeyKey::named(&hotkey.key)),
        }
    }
}

impl TryFrom<DesktopShortcut> for LinuxHotkey {
    type Error = color_eyre::Report;

    fn try_from(shortcut: DesktopShortcut) -> Result<Self> {
        if shortcut.function {
            return Err(eyre!("the Fn modifier cannot be registered on Linux"));
        }
        Ok(Self {
            control: shortcut.control,
            alt: shortcut.alt,
            shift: shortcut.shift,
            super_key: shortcut.platform,
            key: if shortcut.key == " " {
                "space".into()
            } else {
                shortcut.key.to_ascii_lowercase()
            },
        })
    }
}

/// Logical numbering is consistent with macOS/Windows; X11 reserves 4–7
/// for scroll wheels and puts auxiliary buttons at 8 and above.
pub(crate) fn mouse_button(name: &str) -> Option<u8> {
    Some(match HotkeyKey::mouse_number(name)? {
        1 => 1,
        2 => 3,
        3 => 2,
        number => (number + 4) as u8,
    })
}

pub(crate) fn mouse_name(button: u8) -> Option<String> {
    let number = match button {
        1 => 1,
        2 => 3,
        3 => 2,
        8..=36 => u16::from(button) - 4,
        _ => return None,
    };
    Some(format!("mouse{number}"))
}

impl LinuxHotkey {
    pub(crate) fn validate(&self) -> Result<()> {
        if self.key.trim().is_empty() {
            return Err(eyre!("Linux hotkeys require a non-modifier key"));
        }
        Ok(())
    }

    pub(crate) fn label(&self) -> String {
        HotkeyBinding::from(self).keycaps().join("+")
    }

    /// The trigger the shortcuts portal asks the desktop for, in the
    /// XDG shortcuts format: `CTRL+ALT+space`.
    pub(crate) fn portal_trigger(&self) -> Result<String> {
        if mouse_button(&self.key).is_some() {
            return Err(eyre!(
                "Wayland's shortcuts portal cannot request mouse buttons; bind the hex commands in the desktop settings"
            ));
        }
        let key = keysym_name(&self.key)?;
        let mut parts = Vec::new();
        for (held, name) in [
            (self.control, "CTRL"),
            (self.alt, "ALT"),
            (self.shift, "SHIFT"),
            (self.super_key, "LOGO"),
        ] {
            if held {
                parts.push(name);
            }
        }
        parts.push(&key);
        Ok(parts.join("+"))
    }

    pub(crate) fn modifier_mask(
        &self,
        connection: &RustConnection,
        keymap: &Keymap,
    ) -> Result<ModMask> {
        let mut result = ModMask::default();
        for (enabled, symbols) in [
            (self.control, &[XK_CONTROL_L, XK_CONTROL_R][..]),
            (self.alt, &[XK_ALT_L, XK_ALT_R][..]),
            (self.shift, &[XK_SHIFT_L, XK_SHIFT_R][..]),
            (self.super_key, &[XK_SUPER_L, XK_SUPER_R][..]),
        ] {
            if enabled {
                result |= keymap.modifier_for(connection, symbols)?;
            }
        }
        Ok(result)
    }
}

/// The xkb keysym name of a key Settings records.
fn keysym_name(key: &str) -> Result<String> {
    let key = key.to_ascii_lowercase();
    let name = match key.as_str() {
        "space" | " " => "space",
        "enter" | "return" => "Return",
        "tab" => "Tab",
        "backspace" => "BackSpace",
        "-" | "minus" => "minus",
        "=" | "equal" => "equal",
        "[" | "bracketleft" => "bracketleft",
        "]" | "bracketright" => "bracketright",
        ";" | "semicolon" => "semicolon",
        "'" | "apostrophe" => "apostrophe",
        "`" | "grave" => "grave",
        "\\" | "backslash" => "backslash",
        "," | "comma" => "comma",
        "." | "period" => "period",
        "/" | "slash" => "slash",
        // Labs › Special keys alone; settings hold these only while it's on.
        "menu" => "Menu",
        "pause" => "Pause",
        "scroll lock" | "scrolllock" | "scroll_lock" => "Scroll_Lock",
        // The ISO key left of 1; alone only with Labs › Section key alone.
        "§" | "section" => "section",
        key if key.len() == 1 && key.as_bytes()[0].is_ascii_alphanumeric() => key,
        key if key.starts_with('f')
            && key[1..]
                .parse::<u32>()
                .is_ok_and(|number| (1..=24).contains(&number)) =>
        {
            return Ok(key.to_ascii_uppercase());
        }
        // A portal shortcut holds its key from every app, so the portal
        // never binds Escape (#786).
        "escape" => {
            return Err(eyre!(
                "the shortcuts portal can't bind Escape; it would take Escape from every app"
            ));
        }
        // Navigation and editing keys, named as GNOME's accelerators name
        // them, so both Linux paths accept the same keys (#846).
        key => match crate::linux::gnome_shortcuts::named_keysym(key) {
            Some(name) => name,
            None => return Err(eyre!("unsupported shortcut key: {key}")),
        },
    };
    Ok(name.into())
}

const XK_SPACE: u32 = 0x20;
const XK_ESCAPE: u32 = 0xff1b;
pub(crate) const XK_SHIFT_L: u32 = 0xffe1;
pub(crate) const XK_SHIFT_R: u32 = 0xffe2;
pub(crate) const XK_CONTROL_L: u32 = 0xffe3;
pub(crate) const XK_CONTROL_R: u32 = 0xffe4;
pub(crate) const XK_ALT_L: u32 = 0xffe9;
pub(crate) const XK_ALT_R: u32 = 0xffea;
pub(crate) const XK_SUPER_L: u32 = 0xffeb;
pub(crate) const XK_SUPER_R: u32 = 0xffec;
const XK_NUM_LOCK: u32 = 0xff7f;
pub(crate) const KEY_PRESS: u8 = 2;
pub(crate) const KEY_RELEASE: u8 = 3;
const RELEASE_GRACE: Duration = Duration::from_millis(50);
pub(crate) const DOUBLE_TAP_WINDOW: Duration = Duration::from_millis(300);
/// Labs › Tap or hold: a Toggle press held this long is a hold, as macOS's
/// hold threshold.
const TAP_OR_HOLD_THRESHOLD: Duration = Duration::from_millis(300);
/// Desktops that repeat a held shortcut's press (KWin) repeat it sooner
/// than this, so a press after a longer gap is a new press.
const KEY_REPEAT_GAP: Duration = Duration::from_secs(1);
/// How often an X11 monitor checks timed shortcut state while a key is down
/// or a release is settling.
const POLL_INTERVAL: Duration = Duration::from_millis(5);
/// How long a listening portal waits for the desktop's next signal: a press
/// wakes it at once, and this only bounds how long a queued `hex` command
/// waits behind it.
const PORTAL_WAIT: Duration = Duration::from_millis(50);
/// How long a monitor without a portal sleeps: a `hex` command wakes it, and
/// its next portal check is due much later than this.
const COMMAND_WAIT: Duration = Duration::from_millis(250);
/// Binding through the portal can wait for the user to approve a dialog.
const PORTAL_READY_TIMEOUT: Duration = Duration::from_secs(65);

#[derive(Clone, Debug, Eq, PartialEq)]
pub(crate) enum HotkeyEvent {
    /// `flavour` is the shortcut that started the capture: dictation,
    /// Dictate without processing, Labs › Terminal paste, or Labs › Second
    /// dictation.
    Start {
        flavour: DictationFlavour,
    },
    Finish,
    /// `hex dictation stop --print` finished the dictation: its transcript
    /// goes to the reply instead of being pasted.
    FinishPrinting(crate::control::PrintReply),
    Cancel,
    PasteLast,
    /// Labs › Transform typed text: the focused field's text is processed
    /// and replaced, while nothing records.
    TypedText,
    /// The Annotate key went down: nothing recording, a capture starts;
    /// recording, the capture host waits to tell a tap from a hold.
    Capture,
    /// It came up: a tap stops the recording, a hold stops drawing.
    CaptureUp,
}

/// What a `hex` command asks of the running listener. Each one is
/// idempotent: starting while recording or stopping while idle does nothing.
#[derive(Clone, Copy, Debug, Eq, PartialEq, Serialize, Deserialize)]
pub(crate) enum ShortcutCommand {
    DictationStart,
    DictationStop,
    DictationToggle,
    /// `hex dictation cancel`: discards whatever records, in any mode.
    DictationCancel,
    PasteLast,
    /// `hex typed-text`: the typed-text shortcut's one job.
    TypedText,
    /// `hex dictation start --raw` and `toggle --raw`.
    DictationStartRaw,
    DictationToggleRaw,
}

/// What the listener's command queue carries: a `hex` command, or a
/// printing stop with the reply only its own connection waits on.
#[derive(Debug, Eq, PartialEq)]
pub(crate) enum ListenerCommand {
    Shortcut(ShortcutCommand),
    StopAndPrint(crate::control::PrintReply),
}

impl From<ShortcutCommand> for ListenerCommand {
    fn from(command: ShortcutCommand) -> Self {
        Self::Shortcut(command)
    }
}

/// How the dictation shortcut behaves, and the shortcuts registered
/// beside it.
#[derive(Clone, Debug, Default, PartialEq)]
pub(crate) struct HotkeyOptions {
    pub(crate) double_tap: bool,
    /// Only a double-tap starts recording, which then stays locked.
    pub(crate) double_tap_only: bool,
    pub(crate) toggle: bool,
    /// Labs › Tap or hold, in Toggle mode: a press held at least
    /// [`TAP_OR_HOLD_THRESHOLD`] finishes its capture when it lifts.
    pub(crate) tap_or_hold: bool,
    pub(crate) paste_last: Option<LinuxHotkey>,
    /// Dictate without processing, while it is bound.
    pub(crate) raw_dictation: Option<LinuxHotkey>,
    /// Labs › Transform typed text, while its lab is on and it is bound.
    pub(crate) typed_text: Option<LinuxHotkey>,
    /// Labs › Terminal paste shortcut, while the lab is on and it is bound.
    pub(crate) terminal_paste: Option<LinuxHotkey>,
    /// Labs › Second dictation shortcut, while the lab is on and it is bound:
    /// another key that dictates exactly like the dictation shortcut.
    pub(crate) second_dictation: Option<LinuxHotkey>,
    /// Annotate's one key, while Annotate is on: tap to start and stop,
    /// hold to draw.
    pub(crate) capture: Option<LinuxHotkey>,
    /// Toggle mode's cancel shortcut, which Hex takes only while a
    /// recording runs; `None` in Hold mode, which has no cancel.
    pub(crate) cancel: Option<LinuxHotkey>,
}

/// Whether Annotate draws now, so Escape is Hex's (it stops drawing).
fn annotate_drawing() -> bool {
    #[cfg(hex_capture)]
    return crate::capture_host::drawing();
    #[cfg(not(hex_capture))]
    false
}

/// What the running listener reports about its shortcuts.
#[derive(Clone, Debug, Default)]
pub(crate) struct HotkeyStatus {
    shortcuts: Arc<Mutex<DesktopShortcuts>>,
    /// Whether the shortcuts portal can show the desktop's dialog for them.
    configurable: Arc<AtomicBool>,
    /// Settings asked for that dialog.
    configure: Arc<AtomicBool>,
    /// The person disabled Hex: clear its shortcuts from the desktop's list
    /// when the listener stops.
    forget: Arc<AtomicBool>,
    keys: ShortcutKeys,
}

impl HotkeyStatus {
    pub(crate) fn shortcuts(&self) -> DesktopShortcuts {
        self.shortcuts
            .lock()
            .unwrap_or_else(|error| error.into_inner())
            .clone()
    }

    /// When the shortcut that asked for a paste has let go of its keys.
    pub(crate) fn keys(&self) -> ShortcutKeys {
        self.keys.clone()
    }

    pub(crate) fn configurable(&self) -> bool {
        self.configurable.load(Ordering::Acquire)
    }

    /// Opens the desktop's dialog for Hex's shortcuts, when it has one.
    pub(crate) fn configure(&self) {
        self.configure.store(true, Ordering::Release);
    }

    /// Clears Hex's shortcuts from the desktop's list once the listener
    /// stops, as Disable does; a restart for a settings change keeps them.
    pub(crate) fn forget_on_stop(&self) {
        self.forget.store(true, Ordering::Release);
    }

    fn set_shortcuts(&self, shortcuts: DesktopShortcuts) {
        *self
            .shortcuts
            .lock()
            .unwrap_or_else(|error| error.into_inner()) = shortcuts;
    }
}

/// How long after a Wayland shortcut's last event its modifiers may still be
/// down. Hex cannot see them there, so this is the bounded estimate.
const MODIFIER_GRACE: Duration = Duration::from_millis(250);
/// The longest a press without its release holds a paste back, for desktops
/// that drop the release.
const HELD_LIMIT: Duration = Duration::from_secs(2);

/// When the keys of a Hex shortcut may still be down. Some Wayland
/// compositors (Hyprland) add every held physical modifier to virtual
/// keyboard input, turning a paste's Ctrl+V into Ctrl+Alt+V. Hex reads no
/// input devices, so the paste waits on the shortcut's own events: until a
/// modifier shortcut's release (portal Deactivated) plus [`MODIFIER_GRACE`],
/// and [`MODIFIER_GRACE`] after a `hex` command, whose keybinding is unknown.
#[derive(Clone, Debug, Default)]
pub(crate) struct ShortcutKeys(Arc<Mutex<HeldKeys>>);

#[derive(Debug, Default)]
struct HeldKeys {
    /// Modifier shortcuts pressed without their release, by [`Shortcut::index`].
    held: u8,
    last: Option<Instant>,
}

impl HeldKeys {
    /// When a paste may send its shortcut, or `None` for now.
    fn quiet_at(&self) -> Option<Instant> {
        let last = self.last?;
        Some(
            last + if self.held != 0 {
                HELD_LIMIT
            } else {
                MODIFIER_GRACE
            },
        )
    }
}

impl ShortcutKeys {
    fn update(&self, change: impl FnOnce(&mut HeldKeys)) {
        let mut keys = self.0.lock().unwrap_or_else(|error| error.into_inner());
        change(&mut keys);
        keys.last = Some(Instant::now());
    }

    fn pressed(&self, shortcut: Shortcut) {
        self.update(|keys| keys.held |= 1 << shortcut.index());
    }

    fn released(&self, shortcut: Shortcut) {
        self.update(|keys| keys.held &= !(1 << shortcut.index()));
    }

    fn command(&self) {
        self.update(|_| {});
    }

    fn released_all(&self) {
        self.0
            .lock()
            .unwrap_or_else(|error| error.into_inner())
            .held = 0;
    }

    /// Whether a Hex shortcut is down now (pressed without its release), so
    /// a newer capture owns the modifiers a paste sees held.
    pub(crate) fn any_held(&self) -> bool {
        self.0
            .lock()
            .unwrap_or_else(|error| error.into_inner())
            .held
            != 0
    }

    /// Waits until the shortcut that asked for a paste has plausibly let
    /// go of its modifiers, or a release ends the wait early.
    pub(crate) fn settle(&self, stop: &AtomicBool) -> Result<()> {
        loop {
            if stop.load(Ordering::Acquire) {
                return Err(eyre!("paste cancelled while stopping the listener"));
            }
            let quiet_at = self
                .0
                .lock()
                .unwrap_or_else(|error| error.into_inner())
                .quiet_at();
            let Some(wait) = quiet_at.and_then(|at| at.checked_duration_since(Instant::now()))
            else {
                return Ok(());
            };
            thread::sleep(wait.min(Duration::from_millis(20)));
        }
    }
}

/// Whether a portal trigger holds modifiers: the one the desktop granted,
/// else the one Hex asked for.
fn trigger_has_modifiers(granted: Option<&str>, requested: &LinuxHotkey) -> bool {
    match granted.map(str::trim).filter(|trigger| !trigger.is_empty()) {
        Some(trigger) => crate::linux::portal::readable_trigger(trigger).contains('+'),
        None => requested.control || requested.alt || requested.shift || requested.super_key,
    }
}

/// The portal id of a shortcut asking for `trigger`. A desktop keeps the
/// trigger it stored for an id and ignores a later `preferred_trigger`
/// (GNOME, KDE), so a shortcut changed in Hex gets a new id, which the
/// desktop binds to the new trigger (#575). An unchanged shortcut keeps its
/// id, and with it any trigger the user assigned in the desktop.
///
/// With `desktop_assigns` (Hyprland), the desktop ignores the trigger and
/// the user binds the id by name in its config, so the id is the bare
/// `base`: recording another key in Hex must not leave that bind pointing
/// at a name Hex no longer listens to (#1376).
fn portal_shortcut_id(base: &str, trigger: &str, desktop_assigns: bool) -> String {
    if desktop_assigns {
        return base.to_string();
    }
    format!("{base}-{}", trigger.replace('+', "-"))
}

/// The name Hex 3.3 and earlier gave `shortcut` on Hyprland, the trigger in
/// the id (`dictation-ALT-space`), which configs written then still bind.
/// Hex binds it beside the bare id so those binds keep working while the
/// recorded key is the one they were written for. Only the shortcuts 3.3
/// had get one.
fn hyprland_legacy_id(shortcut: Shortcut, trigger: &str) -> Option<String> {
    matches!(
        shortcut,
        Shortcut::Dictation | Shortcut::PasteLast | Shortcut::Capture | Shortcut::RawDictation
    )
    .then(|| portal_shortcut_id(shortcut.portal_id().0, trigger, false))
}

/// The trigger the desktop granted a shortcut, by the id Hex bound it under.
fn granted_trigger<'a>(
    granted: &'a std::collections::HashMap<String, Option<String>>,
    ids: &[Option<String>; Shortcut::ALL.len()],
    shortcut: Shortcut,
) -> Option<&'a str> {
    ids[shortcut.index()]
        .as_deref()
        .and_then(|id| granted.get(id))
        .and_then(Option::as_deref)
}

/// What the desktop granted, as Settings shows it: each shortcut Hex asked
/// for. With `desktop_assigns` (Hyprland), a shortcut without a trigger is
/// unconfirmed rather than refused.
fn project_grants(
    granted: &std::collections::HashMap<String, Option<String>>,
    requested: &[Option<(Shortcut, &LinuxHotkey)>],
    ids: &[Option<String>; Shortcut::ALL.len()],
    desktop_assigns: bool,
) -> Vec<DesktopGrantedShortcut> {
    requested
        .iter()
        .flatten()
        .map(|(shortcut, _)| {
            let trigger = granted_trigger(granted, ids, *shortcut)
                .map(crate::linux::portal::readable_trigger);
            DesktopGrantedShortcut {
                name: shortcut.portal_id().1.into(),
                unconfirmed: desktop_assigns && trigger.is_none(),
                trigger,
            }
        })
        .collect()
}

/// A shortcut a backend reports pressed or released.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
enum Shortcut {
    Dictation,
    PasteLast,
    TypedText,
    Capture,
    RawDictation,
    TerminalPaste,
    /// Labs › Second dictation shortcut.
    SecondDictation,
}

impl Shortcut {
    const ALL: [Self; 7] = [
        Self::Dictation,
        Self::PasteLast,
        Self::TypedText,
        Self::Capture,
        Self::RawDictation,
        Self::TerminalPaste,
        Self::SecondDictation,
    ];

    fn index(self) -> usize {
        self as usize
    }

    /// The dictation flavour a shortcut starts captures with; `None` for
    /// the shortcuts that start no dictation.
    fn flavour(self) -> Option<DictationFlavour> {
        match self {
            Self::Dictation => Some(DictationFlavour::Normal),
            Self::RawDictation => Some(DictationFlavour::Raw),
            Self::TerminalPaste => Some(DictationFlavour::TerminalPaste),
            Self::SecondDictation => Some(DictationFlavour::Second),
            Self::PasteLast | Self::TypedText | Self::Capture => None,
        }
    }

    /// The dictation shortcut that starts captures with `flavour`.
    fn for_flavour(flavour: DictationFlavour) -> Self {
        match flavour {
            DictationFlavour::Normal => Self::Dictation,
            DictationFlavour::Raw => Self::RawDictation,
            DictationFlavour::TerminalPaste => Self::TerminalPaste,
            DictationFlavour::Second => Self::SecondDictation,
        }
    }

    /// The portal's stable id and the description desktops show.
    fn portal_id(self) -> (&'static str, &'static str) {
        match self {
            Self::Dictation => ("dictation", "Dictation"),
            Self::PasteLast => ("paste-last", "Paste last dictation"),
            Self::TypedText => ("typed-text", "Transform typed text"),
            Self::Capture => ("capture", "Annotate"),
            Self::RawDictation => ("raw-dictation", "Dictate without processing"),
            Self::TerminalPaste => ("terminal-paste", "Terminal paste shortcut"),
            Self::SecondDictation => ("second-dictation", "Second dictation shortcut"),
        }
    }
}

#[derive(Clone, Copy, Debug, Eq, PartialEq)]
enum Input {
    Pressed(Shortcut),
    Released(Shortcut),
    /// Escape, which only stops Annotate's drawing (#786).
    Escape,
    /// The cancel shortcut, pressed while Hex held it.
    Cancel,
    /// The backend can no longer tell which keys are down.
    Lost,
    Command(ShortcutCommand),
}

#[derive(Clone, Copy, Debug, PartialEq)]
enum Capture {
    Idle,
    /// Double-tap-only: the first tap is down and waits for the second.
    Armed,
    Held {
        second_tap: bool,
    },
    Locked,
}

/// The shortcut rules every input shares: hold, double-tap lock, toggle,
/// double-tap only, Toggle's cancel, Paste Last, and commands.
struct ShortcutState {
    double_tap: bool,
    double_tap_only: bool,
    /// Every press acts as the second tap of a double-tap: releasing locks.
    toggle: bool,
    /// Labs › Tap or hold in Toggle mode: a long press finishes on release.
    tap_or_hold: bool,
    /// Toggle mode has a cancel shortcut.
    cancels: bool,
    capture: Capture,
    last_release: Option<Instant>,
    last_press: Option<Instant>,
    /// When the press that started the held capture went down (its
    /// repeats don't move it).
    held_since: Option<Instant>,
    /// The dictation shortcut was pressed and its release hasn't arrived.
    down: bool,
    /// The desktop repeated the held press (GNOME, KWin), so repeats that
    /// stop mean its keys came up.
    repeating: bool,
    /// The shortcut that owns the capture (or the last one): dictation,
    /// Dictate without processing, Labs › Terminal paste, or Labs › Second
    /// dictation.
    flavour: DictationFlavour,
}

impl ShortcutState {
    fn new(options: &HotkeyOptions) -> Self {
        Self {
            double_tap: options.double_tap,
            double_tap_only: options.double_tap_only,
            toggle: options.toggle,
            tap_or_hold: options.toggle && options.tap_or_hold,
            cancels: options.toggle && options.cancel.is_some(),
            capture: Capture::Idle,
            last_release: None,
            last_press: None,
            held_since: None,
            down: false,
            repeating: false,
            flavour: DictationFlavour::Normal,
        }
    }

    fn idle(&self) -> bool {
        matches!(self.capture, Capture::Idle | Capture::Armed)
    }

    /// Whether the cancel shortcut is Hex's now: only in Toggle mode, and
    /// only while something records, so the key stays with every app
    /// otherwise.
    fn wants_cancel(&self) -> bool {
        self.cancels && matches!(self.capture, Capture::Held { .. } | Capture::Locked)
    }

    /// Whatever records ends unfinished: the backend lost track of the
    /// keys, or the person cancelled it.
    fn cancel(&mut self) -> Option<HotkeyEvent> {
        let active = matches!(self.capture, Capture::Held { .. } | Capture::Locked);
        self.capture = Capture::Idle;
        self.last_release = None;
        active.then_some(HotkeyEvent::Cancel)
    }

    fn start_dictation(&mut self, flavour: DictationFlavour) -> Option<HotkeyEvent> {
        if !self.idle() {
            return None;
        }
        // Like a locked capture: a shortcut press or `stop` finishes it.
        self.flavour = flavour;
        self.capture = Capture::Locked;
        self.last_release = None;
        Some(HotkeyEvent::Start { flavour })
    }

    /// Hands an idle state to the shortcut pressed, or reports that the
    /// other shortcut's capture owns its keys. A tap of one never counts
    /// toward the other's double tap.
    fn claim(&mut self, flavour: DictationFlavour) -> bool {
        if self.flavour == flavour {
            return true;
        }
        if !self.idle() {
            return false;
        }
        self.flavour = flavour;
        self.capture = Capture::Idle;
        self.last_release = None;
        self.last_press = None;
        self.down = false;
        self.repeating = false;
        true
    }

    /// A held press the desktop was repeating whose repeats stopped for
    /// longer than any repeat interval, with no release: GNOME's portal sends
    /// no deactivation when a modifier comes up before the key, so the keys
    /// are up and this counts as the release. Never the first tap of a
    /// double tap, since the release itself wasn't seen.
    fn expire(&mut self, now: Instant) -> Option<HotkeyEvent> {
        let stopped = self.down
            && self.repeating
            && self
                .last_press
                .is_some_and(|pressed| now.saturating_duration_since(pressed) >= KEY_REPEAT_GAP);
        if !stopped {
            return None;
        }
        let shortcut = Shortcut::for_flavour(self.flavour);
        let event = self.update(Input::Released(shortcut), now);
        self.last_release = None;
        event
    }

    fn stop_dictation(&mut self) -> Option<HotkeyEvent> {
        if !matches!(self.capture, Capture::Held { .. } | Capture::Locked) {
            return None;
        }
        self.capture = Capture::Idle;
        self.last_release = None;
        Some(HotkeyEvent::Finish)
    }

    fn update(&mut self, input: Input, now: Instant) -> Option<HotkeyEvent> {
        match input {
            // Escape while Annotate draws stops drawing, never the recording,
            // and it ends no dictation (#786).
            Input::Escape => {
                #[cfg(hex_capture)]
                crate::capture_host::exit_drawing();
                None
            }
            Input::Lost => {
                self.down = false;
                self.repeating = false;
                self.cancel()
            }
            Input::Cancel if self.wants_cancel() => self.cancel(),
            Input::Cancel => None,
            Input::Pressed(
                shortcut @ (Shortcut::Dictation
                | Shortcut::RawDictation
                | Shortcut::TerminalPaste
                | Shortcut::SecondDictation),
            ) => {
                let Some(flavour) = shortcut.flavour() else {
                    unreachable!("a dictation shortcut has a flavour");
                };
                if !self.claim(flavour) {
                    return None;
                }
                // A press with no release since the last one, sooner than a
                // new press could come, is the desktop repeating a held key.
                let repeat = self.down
                    && self.last_press.is_some_and(|pressed| {
                        now.saturating_duration_since(pressed) < KEY_REPEAT_GAP
                    });
                self.last_press = Some(now);
                self.down = true;
                self.repeating = repeat;
                if repeat {
                    return None;
                }
                match self.capture {
                    Capture::Locked => {
                        self.capture = Capture::Idle;
                        self.last_release = None;
                        Some(HotkeyEvent::Finish)
                    }
                    Capture::Idle => {
                        let second_tap = self.toggle
                            || self.last_release.take().is_some_and(|released| {
                                now.checked_duration_since(released)
                                    .is_some_and(|gap| gap < DOUBLE_TAP_WINDOW)
                            });
                        if self.double_tap_only && !second_tap {
                            self.capture = Capture::Armed;
                            return None;
                        }
                        self.capture = Capture::Held { second_tap };
                        self.held_since = Some(now);
                        Some(HotkeyEvent::Start {
                            flavour: self.flavour,
                        })
                    }
                    // The desktop never sent the release that would have
                    // finished or locked this capture (Hyprland's Lua binds and
                    // GNOME's portal drop it when the modifier comes up first),
                    // so this new press finishes it.
                    Capture::Held { .. } => {
                        self.capture = Capture::Idle;
                        self.last_release = None;
                        Some(HotkeyEvent::Finish)
                    }
                    Capture::Armed => None,
                }
            }
            Input::Released(
                shortcut @ (Shortcut::Dictation
                | Shortcut::RawDictation
                | Shortcut::TerminalPaste
                | Shortcut::SecondDictation),
            ) => {
                if shortcut.flavour() != Some(self.flavour) {
                    return None;
                }
                self.down = false;
                self.repeating = false;
                match self.capture {
                    Capture::Armed => {
                        self.capture = Capture::Idle;
                        self.last_release = Some(now);
                        None
                    }
                    // Labs › Tap or hold: a Toggle press held long enough
                    // dictates only while held, as Hold does.
                    Capture::Held { second_tap: true }
                        if self.tap_or_hold
                            && self.held_since.is_some_and(|pressed| {
                                now.saturating_duration_since(pressed) >= TAP_OR_HOLD_THRESHOLD
                            }) =>
                    {
                        self.capture = Capture::Idle;
                        self.last_release = None;
                        Some(HotkeyEvent::Finish)
                    }
                    Capture::Held { second_tap: true } => {
                        self.capture = Capture::Locked;
                        self.last_release = None;
                        None
                    }
                    Capture::Held { second_tap: false } => {
                        self.capture = Capture::Idle;
                        self.last_release = self.double_tap.then_some(now);
                        Some(HotkeyEvent::Finish)
                    }
                    Capture::Idle | Capture::Locked => None,
                }
            }
            Input::Pressed(Shortcut::PasteLast) | Input::Command(ShortcutCommand::PasteLast) => {
                self.idle().then_some(HotkeyEvent::PasteLast)
            }
            Input::Released(Shortcut::PasteLast) => None,
            // The typed-text job owns no capture state: pressing its shortcut
            // or sending `hex typed-text` while idle asks for one job, and
            // while recording it does nothing at all.
            Input::Pressed(Shortcut::TypedText) | Input::Command(ShortcutCommand::TypedText) => {
                self.idle().then_some(HotkeyEvent::TypedText)
            }
            Input::Released(Shortcut::TypedText) => None,
            Input::Pressed(Shortcut::Capture) => Some(HotkeyEvent::Capture),
            Input::Released(Shortcut::Capture) => Some(HotkeyEvent::CaptureUp),
            Input::Command(command) => match command {
                ShortcutCommand::DictationStart => self.start_dictation(DictationFlavour::Normal),
                ShortcutCommand::DictationStartRaw => self.start_dictation(DictationFlavour::Raw),
                ShortcutCommand::DictationStop => self.stop_dictation(),
                ShortcutCommand::DictationToggle => self
                    .stop_dictation()
                    .or_else(|| self.start_dictation(DictationFlavour::Normal)),
                ShortcutCommand::DictationToggleRaw => self
                    .stop_dictation()
                    .or_else(|| self.start_dictation(DictationFlavour::Raw)),
                ShortcutCommand::DictationCancel => self.cancel(),
                ShortcutCommand::PasteLast | ShortcutCommand::TypedText => {
                    unreachable!("handled above")
                }
            },
        }
    }
}

/// `hex` commands for whichever monitor runs now. The listener keeps one
/// queue while it registers its shortcuts again after a settings change.
#[derive(Clone)]
pub(crate) struct CommandQueue {
    commands: Arc<Mutex<Receiver<ListenerCommand>>>,
    /// Whether `hex` commands reach this listener: they go to the service,
    /// never to a foreground `hex dictate` process.
    connected: bool,
}

impl From<Receiver<ListenerCommand>> for CommandQueue {
    fn from(receiver: Receiver<ListenerCommand>) -> Self {
        Self {
            commands: Arc::new(Mutex::new(receiver)),
            connected: true,
        }
    }
}

impl CommandQueue {
    /// A queue nothing sends to: the foreground `hex dictate` listener.
    pub(crate) fn disconnected() -> Self {
        Self {
            commands: Arc::new(Mutex::new(mpsc::channel().1)),
            connected: false,
        }
    }

    /// Whether this listener's `hex` commands arrive through this queue.
    pub(crate) fn connected(&self) -> bool {
        self.connected
    }
}

/// The monitor thread's side: the state machine and its outputs. Backends
/// feed inputs, then [`Dispatcher::flush`].
struct Dispatcher {
    state: ShortcutState,
    sender: SyncSender<HotkeyEvent>,
    commands: CommandQueue,
    keys: ShortcutKeys,
    pending: Vec<HotkeyEvent>,
}

impl Dispatcher {
    fn new(
        options: &HotkeyOptions,
        sender: SyncSender<HotkeyEvent>,
        commands: CommandQueue,
        keys: ShortcutKeys,
    ) -> Self {
        Self {
            state: ShortcutState::new(options),
            sender,
            commands,
            keys,
            pending: Vec::new(),
        }
    }

    fn input(&mut self, input: Input) {
        self.pending
            .extend(self.state.update(input, Instant::now()));
    }

    /// Releases a held dictation shortcut whose desktop stopped repeating it
    /// without sending its release (see [`ShortcutState::expire`]).
    fn expire(&mut self) {
        let was_down = self.state.down;
        let event = self.state.expire(Instant::now());
        if was_down && !self.state.down {
            tracing::info!(
                "the held dictation shortcut stopped repeating without a release; treating it as released"
            );
            self.keys
                .released(Shortcut::for_flavour(self.state.flavour));
        }
        self.pending.extend(event);
    }

    /// Feeds every queued `hex` command.
    fn commands(&mut self) {
        // `hex dictate` has no queue anything sends to: only shortcuts remain.
        if !self.commands.connected() {
            return;
        }
        let commands = self
            .commands
            .commands
            .lock()
            .unwrap_or_else(|error| error.into_inner());
        let queued: Vec<_> = commands.try_iter().collect();
        drop(commands);
        for command in queued {
            self.command(command);
        }
    }

    /// Waits up to `timeout` for a `hex` command, so a monitor with no
    /// shortcuts to watch sleeps until one arrives, then feeds it and any
    /// others already queued.
    fn wait_for_commands(&mut self, timeout: Duration) {
        let waiting = self
            .commands
            .commands
            .lock()
            .unwrap_or_else(|error| error.into_inner());
        let first = waiting.recv_timeout(timeout);
        drop(waiting);
        match first {
            Ok(command) => self.command(command),
            // Nothing can send another command; keep the loop from spinning
            // until it sees the listener's stop.
            Err(mpsc::RecvTimeoutError::Disconnected) => thread::sleep(POLL_INTERVAL),
            Err(mpsc::RecvTimeoutError::Timeout) => {}
        }
        self.commands();
    }

    fn command(&mut self, command: ListenerCommand) {
        self.keys.command();
        match command {
            ListenerCommand::Shortcut(command) => self.input(Input::Command(command)),
            // Recording stops now, so a following start isn't blocked.
            ListenerCommand::StopAndPrint(reply) => match self.state.stop_dictation() {
                Some(_) => self.pending.push(HotkeyEvent::FinishPrinting(reply)),
                None => reply.send(crate::control::PrintedTranscript::NotRecording),
            },
        }
    }

    /// Returns false once dictation stopped listening.
    fn flush(&mut self) -> Result<bool> {
        for event in self.pending.drain(..) {
            if !send_event(&self.sender, event)? {
                return Ok(false);
            }
        }
        Ok(true)
    }
}

pub(crate) struct LinuxHotkeyMonitor {
    pub(crate) events: Receiver<HotkeyEvent>,
    pub(crate) errors: Receiver<String>,
    stop: Arc<AtomicBool>,
    worker: Option<JoinHandle<()>>,
}

impl LinuxHotkeyMonitor {
    /// Registers the shortcuts on X11 or through the Wayland shortcuts
    /// portal; without the portal only `commands` drive dictation.
    pub(crate) fn start(
        binding: LinuxHotkey,
        options: HotkeyOptions,
        status: HotkeyStatus,
        commands: CommandQueue,
    ) -> Result<Self> {
        Self::start_for(binding, options, LinuxSession::detect(), status, commands)
    }

    fn start_for(
        binding: LinuxHotkey,
        options: HotkeyOptions,
        session: LinuxSession,
        status: HotkeyStatus,
        commands: CommandQueue,
    ) -> Result<Self> {
        let (sender, events) = mpsc::sync_channel(16);
        let (error_sender, errors) = mpsc::channel();
        let (ready_sender, ready_receiver) = mpsc::sync_channel(1);
        let stop = Arc::new(AtomicBool::new(false));
        let started = Arc::new(AtomicBool::new(false));
        let worker_stop = stop.clone();
        let worker_started = started.clone();
        let worker = thread::spawn(move || {
            let keys = status.keys();
            let backend = Backend {
                stop: worker_stop,
                ready: ready_sender.clone(),
                started: worker_started.clone(),
                status,
            };
            let dispatcher = Dispatcher::new(&options, sender, commands, keys);
            let result = match session {
                LinuxSession::X11 => backend.run_x11(dispatcher, binding, options),
                LinuxSession::Wayland => backend.run_wayland(dispatcher, binding, options),
            };
            if let Err(error) = result {
                let message = format!("{error:#}");
                if worker_started.load(Ordering::Acquire) {
                    let _ = error_sender.send(message);
                } else {
                    let _ = ready_sender.try_send(Err(eyre!(message)));
                }
            }
        });
        // Own the worker before waiting so every startup failure stops and joins it.
        let monitor = Self {
            events,
            errors,
            stop,
            worker: Some(worker),
        };
        let timeout = match session {
            LinuxSession::X11 => Duration::from_secs(2),
            LinuxSession::Wayland => PORTAL_READY_TIMEOUT,
        };
        ready_receiver
            .recv_timeout(timeout)
            .map_err(|_| eyre!("timed out registering the Linux dictation shortcut"))??;
        Ok(monitor)
    }
}

impl Drop for LinuxHotkeyMonitor {
    fn drop(&mut self) {
        self.stop.store(true, Ordering::Release);
        if let Some(worker) = self.worker.take() {
            let _ = worker.join();
        }
    }
}

/// The worker thread's lifecycle: stop flag, startup handshake, status.
struct Backend {
    stop: Arc<AtomicBool>,
    ready: SyncSender<Result<()>>,
    started: Arc<AtomicBool>,
    status: HotkeyStatus,
}

impl Backend {
    fn stopping(&self) -> bool {
        self.stop.load(Ordering::Acquire)
    }

    fn mark_ready(&self, shortcuts: DesktopShortcuts) {
        self.status.set_shortcuts(shortcuts);
        self.started.store(true, Ordering::Release);
        self.ready.try_send(Ok(())).ok();
    }

    fn run_wayland(
        self,
        mut dispatcher: Dispatcher,
        binding: LinuxHotkey,
        options: HotkeyOptions,
    ) -> Result<()> {
        let portal = match crate::linux::portal::Portal::connect(&self.stop)? {
            Some(portal) => portal,
            None => {
                tracing::warn!(
                    desktop = std::env::var("XDG_CURRENT_DESKTOP").unwrap_or_default(),
                    "{}",
                    crate::linux::portal::MISSING_SHORTCUTS_PORTAL
                );
                match self.wait_for_portal(&mut dispatcher, true)? {
                    Some(portal) => portal,
                    None => return Ok(()),
                }
            }
        };
        self.run_portal(portal, dispatcher, binding, options)
    }

    /// Serves `hex` commands, and with `probe` looks for the shortcuts
    /// portal again from time to time: a portal started before the desktop's
    /// session environment exposes none until it is restarted (#875).
    /// Returns the portal once it appears, or `None` when the listener stops.
    fn wait_for_portal(
        &self,
        dispatcher: &mut Dispatcher,
        probe: bool,
    ) -> Result<Option<crate::linux::portal::Portal>> {
        self.mark_ready(DesktopShortcuts::Commands);
        let mut probe = probe.then(|| crate::linux::portal::PortalProbe::new(self.stop.clone()));
        while !self.stopping() {
            // No portal: `hex` commands are the only input, so wait on their
            // queue; the probe is due far less often than this.
            dispatcher.wait_for_commands(COMMAND_WAIT);
            if !dispatcher.flush()? {
                return Ok(None);
            }
            if let Some(probe) = probe.as_mut()
                && let Some(portal) = probe.poll()?
            {
                return Ok(Some(portal));
            }
        }
        Ok(None)
    }

    fn run_portal(
        self,
        mut portal: crate::linux::portal::Portal,
        mut dispatcher: Dispatcher,
        binding: LinuxHotkey,
        options: HotkeyOptions,
    ) -> Result<()> {
        let requested = [
            Some((Shortcut::Dictation, &binding)),
            options
                .paste_last
                .as_ref()
                .map(|key| (Shortcut::PasteLast, key)),
            options.capture.as_ref().map(|key| (Shortcut::Capture, key)),
            options
                .raw_dictation
                .as_ref()
                .map(|key| (Shortcut::RawDictation, key)),
            options
                .typed_text
                .as_ref()
                .map(|key| (Shortcut::TypedText, key)),
            options
                .terminal_paste
                .as_ref()
                .map(|key| (Shortcut::TerminalPaste, key)),
            options
                .second_dictation
                .as_ref()
                .map(|key| (Shortcut::SecondDictation, key)),
        ];
        let desktop_assigns = crate::linux::portal::desktop_assigns_triggers();
        let mut shortcuts = Vec::new();
        let mut ids: [Option<String>; Shortcut::ALL.len()] = Default::default();
        let mut legacy_ids: [Option<String>; Shortcut::ALL.len()] = Default::default();
        for (shortcut, key) in requested.into_iter().flatten() {
            let (base, description) = shortcut.portal_id();
            // Keep keyboard shortcuts usable after moving X11 settings to
            // Wayland. Mouse actions remain available through the CLI.
            if mouse_button(&key.key).is_some() {
                continue;
            }
            let trigger = key.portal_trigger()?;
            let id = portal_shortcut_id(base, &trigger, desktop_assigns);
            ids[shortcut.index()] = Some(id.clone());
            shortcuts.push(crate::linux::portal::Shortcut {
                id,
                description,
                trigger: Some(trigger.clone()),
            });
            if desktop_assigns && let Some(legacy) = hyprland_legacy_id(shortcut, &trigger) {
                legacy_ids[shortcut.index()] = Some(legacy.clone());
                shortcuts.push(crate::linux::portal::Shortcut {
                    id: legacy,
                    description,
                    trigger: Some(trigger),
                });
            }
        }
        // Every shortcut goes in this one bind: a second bind would replace
        // the set on KDE. Escape is never among them (#786).
        // On KDE, ids of shortcuts changed since keep holding their keys,
        // which a new id could then never take; they go first (#898).
        let keep = shortcuts
            .iter()
            .map(|shortcut| shortcut.id.as_str())
            .collect::<Vec<_>>();
        if let Err(error) = portal.forget_legacy_kde_shortcuts(&keep) {
            tracing::warn!(
                error = format!("{error:#}"),
                "could not remove Hex's old shortcuts from KDE"
            );
        }
        // GNOME asks for approval whenever Hex binds shortcuts it hasn't
        // approved, as after a shortcut change; dismissing that dialog fails
        // the bind (#723), and Enable binds again, so the dialog returns.
        let granted = match portal.bind(&shortcuts, &self.stop) {
            Ok(granted) => granted,
            Err(error) if self.stopping() => return Err(error),
            // The backend failed the bind rather than the person refusing it
            // (niri with the GNOME backend and no GNOME Shell, #1014): treat
            // the desktop as having no usable shortcuts portal. Binding again
            // would fail the same way, so this run doesn't look for it again;
            // a listener restart (Enable, a settings change) tries once more.
            Err(error) if crate::linux::portal::is_backend_failure(&error) => {
                tracing::warn!(
                    error = format!("{error:#}"),
                    desktop = std::env::var("XDG_CURRENT_DESKTOP").unwrap_or_default(),
                    "the shortcuts portal's backend could not bind Hex's shortcuts; dictation follows the hex commands, which reach the service listener (`hex start`) but not a foreground `hex dictate`"
                );
                drop(portal);
                self.wait_for_portal(&mut dispatcher, false)?;
                return Ok(());
            }
            Err(error) => {
                return Err(error.wrap_err(
                    "the desktop did not approve Hex's shortcuts; choose Enable to ask again",
                ));
            }
        };
        let project = |granted: &std::collections::HashMap<String, Option<String>>| {
            project_grants(granted, &requested, &ids, desktop_assigns)
        };
        let modifiers = |granted: &std::collections::HashMap<String, Option<String>>| {
            Shortcut::ALL.map(|shortcut| {
                requested.iter().flatten().any(|(requested, key)| {
                    *requested == shortcut
                        && trigger_has_modifiers(granted_trigger(granted, &ids, shortcut), key)
                })
            })
        };
        let mut with_modifiers = modifiers(&granted);
        let granted = project(&granted);
        for shortcut in &granted {
            match &shortcut.trigger {
                None if shortcut.unconfirmed => {
                    tracing::info!(
                        name = %shortcut.name,
                        "the desktop assigns this Hex shortcut's key itself; Hex cannot confirm it"
                    );
                }
                None => {
                    tracing::warn!(
                        name = %shortcut.name,
                        "the desktop did not grant a Hex shortcut"
                    );
                }
                Some(_) => {}
            }
        }
        self.status
            .configurable
            .store(portal.configurable(), Ordering::Release);
        self.status.configure.store(false, Ordering::Release);
        self.mark_ready(DesktopShortcuts::Portal(granted));
        let shortcut_for = |id: &str| {
            Shortcut::ALL.into_iter().find(|shortcut| {
                ids[shortcut.index()].as_deref() == Some(id)
                    || legacy_ids[shortcut.index()].as_deref() == Some(id)
            })
        };
        while !self.stopping() {
            // Wakes on the desktop's signals; the timeout only lets queued
            // `hex` commands through while nothing is pressed.
            for event in portal.wait_events(PORTAL_WAIT) {
                let input = match event {
                    crate::linux::portal::Event::Pressed(id) => match shortcut_for(&id) {
                        Some(shortcut) => {
                            if with_modifiers[shortcut.index()] {
                                dispatcher.keys.pressed(shortcut);
                            }
                            Input::Pressed(shortcut)
                        }
                        None => continue,
                    },
                    crate::linux::portal::Event::Released(id) => match shortcut_for(&id) {
                        Some(shortcut) => {
                            if with_modifiers[shortcut.index()] {
                                dispatcher.keys.released(shortcut);
                            }
                            Input::Released(shortcut)
                        }
                        None => continue,
                    },
                    crate::linux::portal::Event::Changed(changed) => {
                        with_modifiers = modifiers(&changed);
                        self.status
                            .set_shortcuts(DesktopShortcuts::Portal(project(&changed)));
                        continue;
                    }
                    crate::linux::portal::Event::Closed => {
                        dispatcher.keys.released_all();
                        dispatcher.input(Input::Lost);
                        let _ = dispatcher.flush();
                        return Err(eyre!("the desktop closed Hex's shortcuts portal session"));
                    }
                };
                dispatcher.input(input);
            }
            dispatcher.expire();
            dispatcher.commands();
            if self.status.configure.swap(false, Ordering::AcqRel)
                && let Err(error) = portal.configure()
            {
                // The portal advertises ConfigureShortcuts even when the
                // desktop's backend lacks it (GNOME, #723), so the call
                // fails and opens nothing. Settings then drops its Open
                // button rather than keep one that does nothing.
                self.status.configurable.store(false, Ordering::Release);
                tracing::warn!(
                    error = format!("{error:#}"),
                    "could not open the desktop's shortcut settings"
                );
            }
            if !dispatcher.flush()? {
                break;
            }
        }
        if self.status.forget.load(Ordering::Acquire)
            && let Err(error) = portal.forget()
        {
            tracing::warn!(
                error = format!("{error:#}"),
                "could not clear Hex's shortcuts from the desktop"
            );
        }
        Ok(())
    }
}
pub(crate) fn send_event(sender: &SyncSender<HotkeyEvent>, event: HotkeyEvent) -> Result<bool> {
    match sender.try_send(event) {
        Ok(()) => Ok(true),
        Err(TrySendError::Full(_)) => Err(eyre!("Linux hotkey event queue overflow")),
        Err(TrySendError::Disconnected(_)) => Ok(false),
    }
}

#[cfg(test)]
mod tests {
    use super::x11::*;
    use super::*;
    use HotkeyEvent::{Cancel, Finish, PasteLast};
    const START: HotkeyEvent = HotkeyEvent::Start {
        flavour: DictationFlavour::Normal,
    };
    use ShortcutCommand as Command;

    struct Test {
        state: ShortcutState,
        now: Instant,
        events: Vec<HotkeyEvent>,
    }

    impl Test {
        fn new(double_tap: bool) -> Self {
            Self::with(HotkeyOptions {
                double_tap,
                ..HotkeyOptions::default()
            })
        }

        fn with(options: HotkeyOptions) -> Self {
            Self {
                state: ShortcutState::new(&options),
                now: Instant::now(),
                events: Vec::new(),
            }
        }

        fn input(&mut self, input: Input) {
            if let Some(event) = self.state.update(input, self.now) {
                self.events.push(event);
            }
        }

        fn press(&mut self, shortcut: Shortcut) {
            self.input(Input::Pressed(shortcut));
        }

        fn release(&mut self, shortcut: Shortcut) {
            self.input(Input::Released(shortcut));
        }

        fn command(&mut self, command: ShortcutCommand) {
            self.input(Input::Command(command));
        }

        fn expire(&mut self) {
            if let Some(event) = self.state.expire(self.now) {
                self.events.push(event);
            }
        }

        fn tap(&mut self) {
            self.press(Shortcut::Dictation);
            self.release(Shortcut::Dictation);
        }

        fn lock(&mut self) {
            self.tap();
            self.now += Duration::from_millis(20);
            self.tap();
            assert_eq!(self.events, [START, Finish, START]);
            assert_eq!(self.state.capture, Capture::Locked);
            self.events.clear();
        }
    }

    #[test]
    fn raw_dictation_owns_the_capture_it_starts() {
        const RAW: HotkeyEvent = HotkeyEvent::Start {
            flavour: DictationFlavour::Raw,
        };
        let mut test = Test::new(true);
        test.press(Shortcut::RawDictation);
        // The dictation shortcut can't finish or join another's capture.
        test.tap();
        test.release(Shortcut::RawDictation);
        assert_eq!(test.events, [RAW, Finish]);
        // A dictation tap right after a raw one is not its second tap.
        test.now += Duration::from_millis(20);
        test.tap();
        assert_eq!(test.events, [RAW, Finish, START, Finish]);
        assert_eq!(test.state.capture, Capture::Idle);
        test.command(Command::DictationToggleRaw);
        test.command(Command::DictationToggleRaw);
        assert_eq!(test.events, [RAW, Finish, START, Finish, RAW, Finish]);
    }

    #[test]
    fn terminal_paste_shortcut_owns_the_capture_it_starts() {
        const TERMINAL: HotkeyEvent = HotkeyEvent::Start {
            flavour: DictationFlavour::TerminalPaste,
        };
        let mut test = Test::new(true);
        test.press(Shortcut::TerminalPaste);
        // The dictation and raw shortcuts can't finish or join another's
        // capture.
        test.tap();
        test.press(Shortcut::RawDictation);
        test.release(Shortcut::RawDictation);
        test.release(Shortcut::TerminalPaste);
        assert_eq!(test.events, [TERMINAL, Finish]);
        // A dictation tap right after is not its second tap.
        test.now += Duration::from_millis(20);
        test.tap();
        assert_eq!(test.events, [TERMINAL, Finish, START, Finish]);
        // A later held press starts and finishes a plain capture.
        test.now += Duration::from_millis(400);
        test.press(Shortcut::TerminalPaste);
        test.release(Shortcut::TerminalPaste);
        assert_eq!(
            test.events,
            [TERMINAL, Finish, START, Finish, TERMINAL, Finish]
        );
    }

    #[test]
    fn second_dictation_shortcut_owns_the_capture_it_starts() {
        const SECOND: HotkeyEvent = HotkeyEvent::Start {
            flavour: DictationFlavour::Second,
        };
        let mut test = Test::new(true);
        test.press(Shortcut::SecondDictation);
        // The dictation and raw shortcuts can't finish or join its capture.
        test.tap();
        test.press(Shortcut::RawDictation);
        test.release(Shortcut::RawDictation);
        test.release(Shortcut::SecondDictation);
        assert_eq!(test.events, [SECOND, Finish]);
        // A dictation tap right after is not its second tap either, and the
        // second shortcut starts and finishes a later capture of its own.
        test.now += Duration::from_millis(20);
        test.tap();
        assert_eq!(test.events, [SECOND, Finish, START, Finish]);
        test.now += Duration::from_millis(400);
        test.press(Shortcut::SecondDictation);
        test.release(Shortcut::SecondDictation);
        assert_eq!(test.events, [SECOND, Finish, START, Finish, SECOND, Finish]);
    }

    /// #786: only the shortcuts Hex asked for show; a key the desktop still
    /// keeps for the removed Cancel dictation stays out.
    #[test]
    fn only_requested_shortcuts_are_shown() {
        let binding = LinuxHotkey::default();
        let requested = [
            Some((Shortcut::Dictation, &binding)),
            None,
            None,
            None,
            None,
        ];
        let mut ids: [Option<String>; Shortcut::ALL.len()] = Default::default();
        ids[Shortcut::Dictation.index()] = Some("dictation-ALT-space".into());
        let granted = std::collections::HashMap::from([
            (
                "dictation-ALT-space".to_string(),
                Some("Alt+Space".to_string()),
            ),
            ("cancel-dictation".to_string(), Some("Esc".to_string())),
        ]);
        let names = project_grants(&granted, &requested, &ids, false)
            .into_iter()
            .map(|grant| (grant.name, grant.trigger))
            .collect::<Vec<_>>();
        assert_eq!(
            names,
            [("Dictation".to_string(), Some("Alt+Space".to_string()))]
        );
    }

    /// #635: Hyprland's portal names no trigger for any shortcut, since its
    /// config assigns the keys, so a missing one there is unconfirmed, not
    /// refused; elsewhere it stays a refusal.
    #[test]
    fn a_missing_trigger_is_unconfirmed_where_the_desktop_assigns_keys() {
        let binding = LinuxHotkey::default();
        let requested = [
            Some((Shortcut::Dictation, &binding)),
            None,
            None,
            None,
            None,
        ];
        let mut ids: [Option<String>; Shortcut::ALL.len()] = Default::default();
        ids[Shortcut::Dictation.index()] = Some("dictation-ALT-space".into());
        let granted = std::collections::HashMap::from([("dictation-ALT-space".to_string(), None)]);
        let unconfirmed = |desktop_assigns| {
            project_grants(&granted, &requested, &ids, desktop_assigns)
                .into_iter()
                .map(|grant| (grant.name, grant.trigger, grant.unconfirmed))
                .collect::<Vec<_>>()
        };
        assert_eq!(unconfirmed(true), [("Dictation".to_string(), None, true)]);
        assert_eq!(unconfirmed(false), [("Dictation".to_string(), None, false)]);
        let bound = std::collections::HashMap::from([(
            "dictation-ALT-space".to_string(),
            Some("Alt+Space".to_string()),
        )]);
        assert!(
            !project_grants(&bound, &requested, &ids, true)[0].unconfirmed,
            "a named trigger is confirmed"
        );
    }

    #[test]
    fn mouse_numbering_skips_wheel_buttons_and_round_trips() {
        for (name, native) in [
            ("mouse1", 1),
            ("mouse2", 3),
            ("mouse3", 2),
            ("mouse4", 8),
            ("mouse5", 9),
            ("mouse32", 36),
        ] {
            assert_eq!(mouse_button(name), Some(native));
            assert_eq!(mouse_name(native).as_deref(), Some(name));
            let key = LinuxHotkey {
                key: name.into(),
                ..LinuxHotkey::default()
            };
            assert_eq!(LinuxHotkey::from(&HotkeyBinding::from(&key)), key);
            assert!(
                key.portal_trigger().is_err(),
                "the XDG portal has no mouse trigger syntax"
            );
        }
        for wheel in 4..=7 {
            assert_eq!(mouse_name(wheel), None);
        }
        assert_eq!(mouse_button("mouse33"), None);
    }

    #[test]
    #[ignore = "requires an isolated X11 server (Xvfb)"]
    fn x11_mouse_grab_delivers_hold_and_release() {
        let harness = X11TestHarness::new();
        let binding = LinuxHotkey {
            control: false,
            alt: false,
            shift: false,
            super_key: false,
            key: "mouse4".into(),
        };
        let (monitor, _commands) = x11_monitor(binding, double_tap(), Default::default());
        send_key(&harness.connection, harness.root, 4, 8);
        assert_eq!(
            recv_event(&monitor),
            HotkeyEvent::Start {
                flavour: DictationFlavour::Normal
            }
        );
        send_key(&harness.connection, harness.root, 5, 8);
        assert_eq!(recv_event(&monitor), HotkeyEvent::Finish);
    }

    #[test]
    #[ignore = "requires an isolated X11 server (Xvfb)"]
    fn x11_mouse_recorder_captures_auxiliary_button_and_releases_its_grab() {
        use x11rb::protocol::xproto::{
            AtomEnum, CreateWindowAux, InputFocus, PropMode, WindowClass,
        };
        use x11rb::wrapper::ConnectionExt as _;
        let harness = X11TestHarness::new();
        let c = &harness.connection;
        let window = c.generate_id().unwrap();
        c.create_window(
            x11rb::COPY_DEPTH_FROM_PARENT,
            window,
            harness.root,
            0,
            0,
            200,
            200,
            0,
            WindowClass::INPUT_OUTPUT,
            0,
            &CreateWindowAux::new(),
        )
        .unwrap()
        .check()
        .unwrap();
        let atom = c
            .intern_atom(false, b"_NET_WM_PID")
            .unwrap()
            .reply()
            .unwrap()
            .atom;
        c.change_property32(
            PropMode::REPLACE,
            window,
            atom,
            AtomEnum::CARDINAL,
            &[std::process::id()],
        )
        .unwrap()
        .check()
        .unwrap();
        c.map_window(window).unwrap().check().unwrap();
        c.set_input_focus(InputFocus::PARENT, window, x11rb::CURRENT_TIME)
            .unwrap()
            .check()
            .unwrap();
        c.warp_pointer(x11rb::NONE, window, 0, 0, 0, 0, 50, 50)
            .unwrap()
            .check()
            .unwrap();
        send_key(c, harness.root, 4, 1);
        let mut capture = MouseCapture::start().unwrap();
        assert!(capture.poll().unwrap().is_none());
        assert!(
            !capture.grabbed,
            "the opening click must not become the binding"
        );
        send_key(c, harness.root, 5, 1);
        assert!(capture.poll().unwrap().is_none());
        assert!(capture.grabbed);
        send_key(c, harness.root, 4, 9);
        let deadline = Instant::now() + Duration::from_secs(1);
        let captured = loop {
            if let Some(binding) = capture.poll().unwrap() {
                break binding;
            }
            assert!(Instant::now() < deadline);
            thread::sleep(Duration::from_millis(5));
        };
        assert_eq!(captured.key, "mouse5");
        send_key(c, harness.root, 5, 9);
        drop(capture);
        let status = c
            .grab_pointer(
                false,
                window,
                EventMask::BUTTON_PRESS,
                GrabMode::ASYNC,
                GrabMode::ASYNC,
                x11rb::NONE,
                x11rb::NONE,
                x11rb::CURRENT_TIME,
            )
            .unwrap()
            .reply()
            .unwrap()
            .status;
        assert_eq!(status, x11rb::protocol::xproto::GrabStatus::SUCCESS);
        c.ungrab_pointer(x11rb::CURRENT_TIME)
            .unwrap()
            .check()
            .unwrap();
        c.destroy_window(window).unwrap().check().unwrap();
    }

    #[test]
    fn default_binding_is_alt_space() {
        assert_eq!(LinuxHotkey::default().label(), "Alt+Space");
    }

    #[test]
    fn modifier_only_bindings_are_rejected() {
        let binding = LinuxHotkey {
            key: String::new(),
            ..LinuxHotkey::default()
        };
        assert!(binding.validate().is_err());
        assert!(binding.portal_trigger().is_err());
    }

    #[test]
    fn standalone_function_keys_are_accepted() {
        let binding = LinuxHotkey {
            alt: false,
            key: "f12".into(),
            ..LinuxHotkey::default()
        };
        assert_eq!(binding.label(), "F12");
        assert!(binding.validate().is_ok());
    }

    /// Issue 767: Menu, Pause, and Scroll Lock, as a saved binding names
    /// them, reach the portal and X11 under their xkb names.
    #[test]
    fn special_keys_have_portal_and_x11_names() {
        for (name, portal, keysym_value) in [
            ("menu", "Menu", 0xff67),
            ("pause", "Pause", 0xff13),
            ("scrolllock", "Scroll_Lock", 0xff14),
        ] {
            let saved = HotkeyBinding {
                modifiers: HotkeyModifiers::default(),
                key: Some(HotkeyKey::named(name)),
            };
            let hotkey = LinuxHotkey::from(&saved);
            assert!(hotkey.validate().is_ok());
            assert_eq!(hotkey.portal_trigger().unwrap(), portal);
            assert_eq!(keysym(&hotkey.key).unwrap(), keysym_value);
            assert_eq!(HotkeyBinding::from(&hotkey), saved);
        }
    }

    /// Issue 1050: the § key, saved as `§` or named `section`, reaches the
    /// portal as `section` and X11 as XK_section, and shows as §.
    #[test]
    fn the_section_key_has_portal_and_x11_names() {
        for name in ["§", "section"] {
            let saved = HotkeyBinding {
                modifiers: HotkeyModifiers::default(),
                key: Some(HotkeyKey::named(name)),
            };
            let hotkey = LinuxHotkey::from(&saved);
            assert!(hotkey.validate().is_ok());
            assert_eq!(hotkey.label(), "§");
            assert_eq!(hotkey.portal_trigger().unwrap(), "section");
            assert_eq!(keysym(&hotkey.key).unwrap(), 0xa7);
            assert_eq!(HotkeyBinding::from(&hotkey), saved);
        }
    }

    /// #846: navigation and editing keys GNOME's accelerators accept reach
    /// the portal under the same xkb names, alone or with modifiers.
    #[test]
    fn navigation_keys_have_portal_triggers() {
        for (name, portal) in [
            ("home", "Home"),
            ("end", "End"),
            ("pageup", "Page_Up"),
            ("pagedown", "Page_Down"),
            ("up", "Up"),
            ("down", "Down"),
            ("left", "Left"),
            ("right", "Right"),
            ("insert", "Insert"),
            ("delete", "Delete"),
            ("print", "Print"),
        ] {
            let saved = HotkeyBinding {
                modifiers: HotkeyModifiers::default(),
                key: Some(HotkeyKey::named(name)),
            };
            let hotkey = LinuxHotkey::from(&saved);
            assert!(hotkey.validate().is_ok());
            assert_eq!(hotkey.portal_trigger().unwrap(), portal);
            assert_eq!(
                crate::linux::gnome_shortcuts::named_keysym(name),
                Some(portal)
            );
            assert_eq!(HotkeyBinding::from(&hotkey), saved);
            let with_control = LinuxHotkey {
                control: true,
                ..hotkey
            };
            assert_eq!(
                with_control.portal_trigger().unwrap(),
                format!("CTRL+{portal}")
            );
        }
    }

    #[test]
    fn hotkeys_round_trip_through_the_portable_binding() {
        let hotkey = LinuxHotkey {
            control: true,
            super_key: true,
            key: "f12".into(),
            ..LinuxHotkey::default()
        };
        assert_eq!(LinuxHotkey::from(&HotkeyBinding::from(&hotkey)), hotkey);
    }

    #[test]
    fn portal_triggers_use_xdg_modifiers_and_xkb_key_names() {
        let trigger = |control, alt, shift, super_key, key: &str| {
            LinuxHotkey {
                control,
                alt,
                shift,
                super_key,
                key: key.into(),
            }
            .portal_trigger()
            .unwrap()
        };
        assert_eq!(trigger(false, true, false, false, "space"), "ALT+space");
        assert_eq!(
            trigger(true, true, true, true, "f9"),
            "CTRL+ALT+SHIFT+LOGO+F9"
        );
        assert_eq!(trigger(true, false, false, false, "-"), "CTRL+minus");
        assert_eq!(trigger(true, false, false, false, "enter"), "CTRL+Return");
        assert_eq!(trigger(false, false, false, true, "Q"), "LOGO+q");
        assert_eq!(trigger(false, false, false, false, "7"), "7");
        for unsupported in ["f25", "escape", "é"] {
            assert!(
                LinuxHotkey {
                    key: unsupported.into(),
                    ..LinuxHotkey::default()
                }
                .portal_trigger()
                .is_err()
            );
        }
    }

    #[test]
    fn a_changed_portal_trigger_gets_a_new_shortcut_id() {
        let id =
            |trigger: &str| portal_shortcut_id(Shortcut::Dictation.portal_id().0, trigger, false);
        assert_eq!(id("ALT+space"), "dictation-ALT-space");
        assert_eq!(id("ALT+space"), id("ALT+space"));
        assert_ne!(id("ALT+space"), id("CTRL+ALT+space"));
        let granted = std::collections::HashMap::from([
            (
                "dictation".to_string(),
                Some("Press <alt>space".to_string()),
            ),
            (id("CTRL+F9"), Some("Press <ctrl>F9".to_string())),
        ]);
        let mut ids: [Option<String>; Shortcut::ALL.len()] = Default::default();
        ids[Shortcut::Dictation.index()] = Some(id("CTRL+F9"));
        assert_eq!(
            granted_trigger(&granted, &ids, Shortcut::Dictation),
            Some("Press <ctrl>F9")
        );
        assert_eq!(granted_trigger(&granted, &ids, Shortcut::PasteLast), None);
    }

    /// #1376: Hyprland binds Hex's shortcuts by name in its config and
    /// ignores the trigger, so a key recorded in Hex keeps the same name.
    #[test]
    fn a_desktop_that_assigns_keys_keeps_one_shortcut_id() {
        let id = |shortcut: Shortcut, trigger: &str| {
            portal_shortcut_id(shortcut.portal_id().0, trigger, true)
        };
        assert_eq!(id(Shortcut::Dictation, "ALT+space"), "dictation");
        assert_eq!(id(Shortcut::Dictation, "CTRL+ALT+j"), "dictation");
        assert_eq!(id(Shortcut::PasteLast, "CTRL+ALT+v"), "paste-last");
        assert_eq!(id(Shortcut::Capture, "F9"), "capture");
        assert_eq!(id(Shortcut::RawDictation, "CTRL+r"), "raw-dictation");
        assert_eq!(
            id(Shortcut::TerminalPaste, "CTRL+SHIFT+t"),
            "terminal-paste"
        );
    }

    /// A config written for 3.3 binds `anomaly.hex:dictation-ALT-space`;
    /// Hex binds that name too, for the key it was written for.
    #[test]
    fn hyprland_keeps_the_names_3_3_bound() {
        assert_eq!(
            hyprland_legacy_id(Shortcut::Dictation, "ALT+space").as_deref(),
            Some("dictation-ALT-space")
        );
        assert_eq!(
            hyprland_legacy_id(Shortcut::PasteLast, "CTRL+ALT+v").as_deref(),
            Some("paste-last-CTRL-ALT-v")
        );
        assert_eq!(
            hyprland_legacy_id(Shortcut::RawDictation, "F9").as_deref(),
            Some("raw-dictation-F9")
        );
        // Shortcuts 3.3 didn't have were never bound by the old names.
        assert_eq!(hyprland_legacy_id(Shortcut::TerminalPaste, "CTRL+t"), None);
        assert_eq!(hyprland_legacy_id(Shortcut::SecondDictation, "F10"), None);
    }

    #[test]
    fn hold_starts_on_press_and_finishes_on_release() {
        let mut test = Test::new(false);
        test.press(Shortcut::Dictation);
        test.now += Duration::from_millis(500);
        test.release(Shortcut::Dictation);
        test.now += Duration::from_millis(20);
        test.tap();
        assert_eq!(test.events, [START, Finish, START, Finish]);
    }

    #[test]
    fn duplicate_presses_and_releases_do_not_start_finish_or_lock() {
        let mut test = Test::new(true);
        test.press(Shortcut::Dictation);
        test.press(Shortcut::Dictation);
        test.release(Shortcut::Dictation);
        test.now += Duration::from_secs(1);
        test.release(Shortcut::Dictation);
        assert_eq!(test.events, [START, Finish]);
    }

    #[test]
    fn double_tap_window_has_an_explicit_boundary() {
        for (delay, expected) in [
            (299, vec![START, Finish, START]),
            (300, vec![START, Finish, START, Finish]),
        ] {
            let mut test = Test::new(true);
            test.tap();
            test.now += Duration::from_millis(delay);
            test.tap();
            assert_eq!(test.events, expected);
        }
    }

    #[test]
    fn second_tap_locks_until_the_shortcut_is_pressed_again() {
        let mut test = Test::new(true);
        test.lock();
        test.release(Shortcut::Dictation);
        assert!(test.events.is_empty());
        test.press(Shortcut::Dictation);
        assert_eq!(test.events, [Finish]);
        // The release of the finishing press does nothing.
        test.release(Shortcut::Dictation);
        test.now += Duration::from_secs(1);
        test.tap();
        assert_eq!(test.events, [Finish, START, Finish]);
    }

    #[test]
    fn double_tap_only_ignores_a_single_hold_and_locks_on_the_second_tap() {
        let mut test = Test::with(HotkeyOptions {
            double_tap: true,
            double_tap_only: true,
            ..HotkeyOptions::default()
        });
        test.press(Shortcut::Dictation);
        test.now += Duration::from_millis(600);
        test.release(Shortcut::Dictation);
        assert!(test.events.is_empty(), "a hold alone never records");
        test.now += Duration::from_secs(1);
        test.tap();
        test.now += Duration::from_millis(20);
        test.tap();
        assert_eq!(test.events, [START]);
        assert_eq!(test.state.capture, Capture::Locked);
        test.tap();
        assert_eq!(test.events, [START, Finish]);
    }

    #[test]
    fn toggle_mode_starts_on_a_tap_and_finishes_on_the_next() {
        for double_tap in [false, true] {
            let mut test = Test::with(HotkeyOptions {
                double_tap,
                toggle: true,
                ..HotkeyOptions::default()
            });
            test.tap();
            assert_eq!(test.events, [START]);
            assert_eq!(test.state.capture, Capture::Locked);
            test.now += Duration::from_secs(5);
            test.tap();
            assert_eq!(test.events, [START, Finish]);
            // A quick third tap starts a fresh capture rather than locking a double tap.
            test.now += Duration::from_millis(20);
            test.tap();
            assert_eq!(test.events, [START, Finish, START]);
            test.input(Input::Escape);
            assert_eq!(test.events, [START, Finish, START]);
            assert_eq!(test.state.capture, Capture::Locked);
        }
    }

    #[test]
    fn a_capture_that_would_lock_finishes_when_the_desktop_drops_its_release() {
        // Hyprland's Lua binds send no release when Alt comes up before Z.
        for toggle in [true, false] {
            let mut test = Test::with(HotkeyOptions {
                double_tap: !toggle,
                toggle,
                ..HotkeyOptions::default()
            });
            if !toggle {
                test.tap();
                test.now += Duration::from_millis(20);
            }
            test.press(Shortcut::Dictation);
            assert_eq!(test.state.capture, Capture::Held { second_tap: true });
            test.events.clear();
            test.now += Duration::from_secs(5);
            test.press(Shortcut::Dictation);
            assert_eq!(test.events, [Finish]);
            assert_eq!(test.state.capture, Capture::Idle);
            test.release(Shortcut::Dictation);
            test.now += Duration::from_secs(1);
            test.press(Shortcut::Dictation);
            assert_eq!(test.events, [Finish, START]);
        }
    }

    #[test]
    fn a_hold_whose_release_never_arrives_finishes_on_the_next_new_press() {
        // GNOME's portal repeats a held shortcut's activation and sends no
        // deactivation when Ctrl comes up before Space.
        for double_tap in [false, true] {
            let mut test = Test::new(double_tap);
            test.press(Shortcut::Dictation);
            for _ in 0..20 {
                test.now += Duration::from_millis(33);
                test.press(Shortcut::Dictation);
            }
            assert_eq!(test.events, [START], "repeats never finish the hold");
            assert_eq!(test.state.capture, Capture::Held { second_tap: false });
            // Ctrl up first: the repeats stop and no release comes.
            test.now += Duration::from_secs(3);
            test.press(Shortcut::Dictation);
            assert_eq!(test.events, [START, Finish]);
            // The finishing press's own repeats and release start nothing.
            for _ in 0..20 {
                test.now += Duration::from_millis(33);
                test.press(Shortcut::Dictation);
            }
            test.release(Shortcut::Dictation);
            assert_eq!(test.events, [START, Finish]);
            assert_eq!(test.state.capture, Capture::Idle);
            test.now += Duration::from_secs(1);
            test.tap();
            assert_eq!(test.events, [START, Finish, START, Finish]);
        }
    }

    /// #1227: GNOME sends no release when a modifier comes up first, so a
    /// hold whose repeats stop finishes by itself, and a press right after
    /// starts a fresh capture rather than locking a double tap.
    #[test]
    fn a_hold_whose_repeats_stop_without_a_release_finishes_by_itself() {
        for double_tap in [false, true] {
            let mut test = Test::new(double_tap);
            test.press(Shortcut::Dictation);
            for _ in 0..20 {
                test.now += Duration::from_millis(33);
                test.press(Shortcut::Dictation);
            }
            test.now += Duration::from_millis(500);
            test.expire();
            assert_eq!(test.events, [START], "repeats may still come");
            test.now += Duration::from_millis(500);
            test.expire();
            assert_eq!(test.events, [START, Finish]);
            assert_eq!(test.state.capture, Capture::Idle);
            test.expire();
            assert_eq!(test.events, [START, Finish]);
            // A quick press after it is a new capture, never a lock.
            test.now += Duration::from_millis(100);
            test.tap();
            assert_eq!(test.events, [START, Finish, START, Finish]);
            assert_eq!(test.state.capture, Capture::Idle);
            // A hold that never repeated has nothing to go on: it waits for
            // its release or the next press.
            test.now += Duration::from_secs(1);
            test.press(Shortcut::Dictation);
            test.now += Duration::from_secs(5);
            test.expire();
            assert_eq!(test.events, [START, Finish, START, Finish, START]);
            test.release(Shortcut::Dictation);
            assert_eq!(test.events, [START, Finish, START, Finish, START, Finish]);
        }
    }

    #[test]
    fn a_balanced_release_finishes_a_repeating_hold() {
        // Space first, or both together: the desktop sends the release.
        let mut test = Test::new(false);
        test.press(Shortcut::Dictation);
        for _ in 0..20 {
            test.now += Duration::from_millis(33);
            test.press(Shortcut::Dictation);
        }
        test.release(Shortcut::Dictation);
        assert_eq!(test.events, [START, Finish]);
        // A quick new press after a release is a press, not a repeat.
        test.now += Duration::from_millis(100);
        test.press(Shortcut::Dictation);
        assert_eq!(test.events, [START, Finish, START]);
    }

    #[test]
    fn a_repeating_held_press_never_finishes_the_capture() {
        // KWin repeats a held global shortcut's press.
        let mut test = Test::with(HotkeyOptions {
            toggle: true,
            ..HotkeyOptions::default()
        });
        test.press(Shortcut::Dictation);
        test.now += Duration::from_millis(900);
        for _ in 0..100 {
            test.press(Shortcut::Dictation);
            test.now += Duration::from_millis(40);
        }
        test.release(Shortcut::Dictation);
        assert_eq!(test.events, [START]);
        assert_eq!(test.state.capture, Capture::Locked);
    }

    fn tap_or_hold() -> HotkeyOptions {
        HotkeyOptions {
            toggle: true,
            tap_or_hold: true,
            ..HotkeyOptions::default()
        }
    }

    /// #1144: with Labs › Tap or hold, a held Toggle press dictates until it
    /// lifts, and a short tap still locks until the next press.
    #[test]
    fn tap_or_hold_finishes_a_held_press_and_locks_a_tap() {
        let mut test = Test::with(tap_or_hold());
        test.press(Shortcut::Dictation);
        test.now += Duration::from_millis(600);
        test.release(Shortcut::Dictation);
        assert_eq!(test.events, [START, Finish]);
        assert_eq!(test.state.capture, Capture::Idle);

        test.now += Duration::from_secs(1);
        test.press(Shortcut::Dictation);
        test.now += Duration::from_millis(299);
        test.release(Shortcut::Dictation);
        assert_eq!(test.events, [START, Finish, START]);
        assert_eq!(test.state.capture, Capture::Locked);
        test.now += Duration::from_secs(2);
        test.press(Shortcut::Dictation);
        test.now += Duration::from_millis(600);
        test.release(Shortcut::Dictation);
        assert_eq!(test.events, [START, Finish, START, Finish]);
        assert_eq!(test.state.capture, Capture::Idle);
    }

    /// Off, or in Hold mode, a held Toggle press still locks as before.
    #[test]
    fn without_tap_or_hold_a_held_toggle_press_locks() {
        for options in [
            HotkeyOptions {
                tap_or_hold: false,
                ..tap_or_hold()
            },
            HotkeyOptions {
                toggle: false,
                double_tap: true,
                ..tap_or_hold()
            },
        ] {
            let toggle = options.toggle;
            let mut test = Test::with(options);
            if !toggle {
                test.tap();
                test.now += Duration::from_millis(20);
            }
            test.events.clear();
            test.press(Shortcut::Dictation);
            test.now += Duration::from_millis(600);
            test.release(Shortcut::Dictation);
            assert_eq!(test.events, [START]);
            assert_eq!(test.state.capture, Capture::Locked);
        }
    }

    /// Repeats of a held press neither finish early nor restart the hold,
    /// and a dropped release leaves the capture recording until a new press.
    #[test]
    fn tap_or_hold_survives_repeats_and_dropped_releases() {
        let mut test = Test::with(tap_or_hold());
        test.press(Shortcut::Dictation);
        for _ in 0..20 {
            test.now += Duration::from_millis(33);
            test.press(Shortcut::Dictation);
        }
        assert_eq!(test.events, [START]);
        test.release(Shortcut::Dictation);
        assert_eq!(
            test.events,
            [START, Finish],
            "held 660 ms from the first press"
        );

        test.now += Duration::from_secs(1);
        test.press(Shortcut::Dictation);
        test.now += Duration::from_secs(5);
        assert_eq!(test.state.capture, Capture::Held { second_tap: true });
        test.press(Shortcut::Dictation);
        assert_eq!(test.events, [START, Finish, START, Finish]);
        test.release(Shortcut::Dictation);
        assert_eq!(test.events, [START, Finish, START, Finish]);
        assert_eq!(test.state.capture, Capture::Idle);
    }

    /// Dictate without processing follows Tap or hold for its own capture,
    /// and commands are unchanged.
    #[test]
    fn tap_or_hold_applies_to_raw_dictation_but_not_commands() {
        const RAW: HotkeyEvent = HotkeyEvent::Start {
            flavour: DictationFlavour::Raw,
        };
        let mut test = Test::with(tap_or_hold());
        test.press(Shortcut::RawDictation);
        test.now += Duration::from_millis(500);
        test.tap();
        test.release(Shortcut::RawDictation);
        assert_eq!(test.events, [RAW, Finish]);
        test.now += Duration::from_secs(1);
        test.command(Command::DictationStart);
        test.now += Duration::from_secs(1);
        test.command(Command::DictationStop);
        assert_eq!(test.events, [RAW, Finish, START, Finish]);
    }

    /// #786: Escape ends no dictation, held, locked, or idle.
    #[test]
    fn escape_never_ends_a_dictation() {
        let mut test = Test::new(true);
        test.input(Input::Escape);
        assert!(test.events.is_empty());
        test.press(Shortcut::Dictation);
        test.input(Input::Escape);
        test.release(Shortcut::Dictation);
        assert_eq!(test.events, [START, Finish]);

        let mut test = Test::new(true);
        test.lock();
        test.input(Input::Escape);
        assert_eq!(test.state.capture, Capture::Locked);
        test.tap();
        assert_eq!(test.events, [Finish]);
    }

    fn toggle_with_cancel() -> HotkeyOptions {
        HotkeyOptions {
            toggle: true,
            cancel: Some(LinuxHotkey {
                alt: false,
                key: "escape".into(),
                ..LinuxHotkey::default()
            }),
            ..HotkeyOptions::default()
        }
    }

    /// Toggle's cancel discards the recording, while the shortcut is still
    /// down or after it locked, and the next press starts afresh.
    #[test]
    fn cancel_discards_a_toggled_recording() {
        let mut test = Test::with(toggle_with_cancel());
        test.press(Shortcut::Dictation);
        assert!(test.state.wants_cancel());
        test.input(Input::Cancel);
        test.release(Shortcut::Dictation);
        assert_eq!(test.events, [START, Cancel]);
        assert_eq!(test.state.capture, Capture::Idle);
        assert!(!test.state.wants_cancel());

        test.tap();
        assert_eq!(test.state.capture, Capture::Locked);
        test.input(Input::Cancel);
        test.input(Input::Cancel);
        assert_eq!(test.events, [START, Cancel, START, Cancel]);
        test.tap();
        test.tap();
        assert_eq!(test.events, [START, Cancel, START, Cancel, START, Finish]);
    }

    /// Hold mode has no cancel: the key is never Hex's, even while a
    /// recording runs, and a press of it ends nothing.
    #[test]
    fn cancel_is_ignored_in_hold_mode() {
        let mut test = Test::with(HotkeyOptions {
            toggle: false,
            double_tap: true,
            ..toggle_with_cancel()
        });
        test.press(Shortcut::Dictation);
        assert!(!test.state.wants_cancel());
        test.input(Input::Cancel);
        test.release(Shortcut::Dictation);
        assert_eq!(test.events, [START, Finish]);
        test.events.clear();
        test.now += Duration::from_millis(20);
        test.tap();
        test.input(Input::Cancel);
        assert_eq!(test.state.capture, Capture::Locked);
        assert!(test.events.iter().all(|event| *event != Cancel));
    }

    /// While nothing records, Hex doesn't take the cancel key, so it stays
    /// with the app in front.
    #[test]
    fn cancel_is_not_taken_while_idle() {
        let mut test = Test::with(toggle_with_cancel());
        assert!(!test.state.wants_cancel());
        test.input(Input::Cancel);
        assert!(test.events.is_empty());
        test.tap();
        test.tap();
        assert!(!test.state.wants_cancel());
        assert_eq!(test.events, [START, Finish]);
        // Toggle without a cancel shortcut never takes one either.
        let mut test = Test::with(HotkeyOptions {
            cancel: None,
            ..toggle_with_cancel()
        });
        test.tap();
        assert!(!test.state.wants_cancel());
    }

    #[test]
    fn lost_input_cancels_and_forgets_taps() {
        for locked in [false, true] {
            let mut test = Test::new(true);
            if locked {
                test.lock();
            } else {
                test.press(Shortcut::Dictation);
                test.events.clear();
            }
            test.input(Input::Lost);
            assert_eq!(test.events, [Cancel]);
            assert_eq!(test.state.capture, Capture::Idle);
            assert!(test.state.last_release.is_none());
            test.release(Shortcut::Dictation);
            test.tap();
            assert_eq!(test.events, [Cancel, START, Finish]);
        }
    }

    #[test]
    fn paste_last_fires_only_while_idle() {
        let mut test = Test::new(true);
        test.press(Shortcut::PasteLast);
        test.release(Shortcut::PasteLast);
        test.command(Command::PasteLast);
        assert_eq!(test.events, [PasteLast, PasteLast]);
        test.press(Shortcut::Dictation);
        test.press(Shortcut::PasteLast);
        test.command(Command::PasteLast);
        assert_eq!(test.events, [PasteLast, PasteLast, START]);
    }

    #[test]
    fn typed_text_fires_only_while_idle_and_changes_no_capture_state() {
        let mut test = Test::new(true);
        test.press(Shortcut::TypedText);
        test.release(Shortcut::TypedText);
        test.command(Command::TypedText);
        assert_eq!(
            test.events,
            [HotkeyEvent::TypedText, HotkeyEvent::TypedText]
        );
        assert_eq!(test.state.capture, Capture::Idle);
        // Recording owns the shortcut and `hex typed-text`: no job and no
        // state change.
        test.press(Shortcut::Dictation);
        test.events.clear();
        test.press(Shortcut::TypedText);
        test.release(Shortcut::TypedText);
        test.command(Command::TypedText);
        assert!(test.events.is_empty());
        assert!(matches!(test.state.capture, Capture::Held { .. }));
        assert_eq!(
            Shortcut::TypedText.portal_id(),
            ("typed-text", "Transform typed text")
        );
    }

    #[test]
    fn dictation_commands_are_idempotent() {
        let mut test = Test::new(true);
        test.command(Command::DictationStop);
        assert!(test.events.is_empty(), "stopping while idle does nothing");
        test.command(Command::DictationStart);
        test.command(Command::DictationStart);
        assert_eq!(
            test.events,
            [START],
            "starting while recording does nothing"
        );
        test.command(Command::DictationStop);
        test.command(Command::DictationStop);
        assert_eq!(test.events, [START, Finish]);
        // A stop never counts as the first tap of a double-tap.
        test.tap();
        assert_eq!(test.events, [START, Finish, START, Finish]);
    }

    #[test]
    fn dictation_toggle_commands() {
        let mut test = Test::new(false);
        test.command(Command::DictationToggle);
        test.command(Command::DictationToggle);
        test.command(Command::DictationToggle);
        test.command(Command::DictationCancel);
        test.command(Command::DictationCancel);
        assert_eq!(test.events, [START, Finish, START, Cancel]);
    }

    #[test]
    fn commands_and_shortcuts_share_one_capture() {
        let mut test = Test::new(true);
        // A shortcut press finishes a capture a command started.
        test.command(Command::DictationStart);
        test.tap();
        // A stop command finishes a held shortcut.
        test.now += Duration::from_secs(1);
        test.press(Shortcut::Dictation);
        test.command(Command::DictationStop);
        test.release(Shortcut::Dictation);
        // A locked double-tap stops through toggle.
        test.now += Duration::from_secs(1);
        test.lock_from(&[START, Finish, START, Finish]);
        test.command(Command::DictationToggle);
        assert_eq!(
            test.events,
            [START, Finish, START, Finish, START, Finish, START, Finish]
        );
    }

    impl Test {
        fn lock_from(&mut self, before: &[HotkeyEvent]) {
            self.tap();
            self.now += Duration::from_millis(20);
            self.tap();
            let mut expected = before.to_vec();
            expected.extend([START, Finish, START]);
            assert_eq!(self.events, expected);
            assert_eq!(self.state.capture, Capture::Locked);
        }
    }

    #[test]
    fn x11_auto_repeat_pairs_never_release_the_shortcut() {
        let start = Instant::now();
        let mut keys = X11Keys::default();
        assert_eq!(
            keys.press(Shortcut::Dictation),
            Some(Input::Pressed(Shortcut::Dictation))
        );
        for repeat in 1..5 {
            let at = start + Duration::from_millis(30 * repeat);
            keys.release(Shortcut::Dictation, at);
            assert!(keys.expire(at + Duration::from_millis(10)).is_empty());
            assert_eq!(keys.press(Shortcut::Dictation), None);
        }
        // Detectable auto-repeat sends presses alone.
        assert_eq!(keys.press(Shortcut::Dictation), None);
        assert!(keys.held(Shortcut::Dictation));
    }

    #[test]
    fn x11_release_counts_after_the_grace_period() {
        let start = Instant::now();
        let mut keys = X11Keys::default();
        keys.press(Shortcut::Dictation);
        keys.release(Shortcut::Dictation, start);
        assert!(keys.expire(start + RELEASE_GRACE / 2).is_empty());
        assert_eq!(
            keys.expire(start + RELEASE_GRACE),
            [Input::Released(Shortcut::Dictation)]
        );
        assert!(keys.expire(start + RELEASE_GRACE * 2).is_empty());
        assert!(!keys.held(Shortcut::Dictation));
        assert_eq!(
            keys.press(Shortcut::Dictation),
            Some(Input::Pressed(Shortcut::Dictation))
        );
    }

    #[test]
    fn x11_ignores_releases_of_keys_it_never_saw_pressed() {
        let start = Instant::now();
        let mut keys = X11Keys::default();
        keys.release(Shortcut::PasteLast, start);
        assert!(keys.expire(start + Duration::from_secs(1)).is_empty());
    }

    #[test]
    fn x11_shortcuts_track_independently() {
        let start = Instant::now();
        let mut keys = X11Keys::default();
        keys.press(Shortcut::Dictation);
        keys.press(Shortcut::PasteLast);
        keys.release(Shortcut::PasteLast, start);
        assert_eq!(
            keys.expire(start + RELEASE_GRACE),
            [Input::Released(Shortcut::PasteLast)]
        );
        assert!(keys.held(Shortcut::Dictation));
    }

    /// #638: with detectable auto-repeat, a release under 50 ms before the
    /// next press still counts, so a fast double tap starts double-tap-only
    /// dictation; a held key's repeated presses stay ignored.
    #[test]
    fn x11_detectable_repeat_releases_at_once_for_fast_double_taps() {
        let mut keys = X11Keys {
            detectable_repeat: true,
            ..X11Keys::default()
        };
        let mut test = Test::with(HotkeyOptions {
            double_tap: true,
            double_tap_only: true,
            ..HotkeyOptions::default()
        });
        let feed = |input: Option<Input>, test: &mut Test| {
            if let Some(input) = input {
                test.input(input);
            }
        };
        feed(keys.press(Shortcut::Dictation), &mut test);
        test.now += Duration::from_millis(40);
        let released = keys.release(Shortcut::Dictation, test.now);
        assert_eq!(released, Some(Input::Released(Shortcut::Dictation)));
        feed(released, &mut test);
        test.now += Duration::from_millis(20);
        feed(keys.press(Shortcut::Dictation), &mut test);
        assert_eq!(test.events, [START]);
        // Held: the server repeats only the press.
        for _ in 0..5 {
            test.now += Duration::from_millis(30);
            assert_eq!(keys.press(Shortcut::Dictation), None);
        }
        assert!(keys.expire(test.now + RELEASE_GRACE).is_empty());
        feed(keys.release(Shortcut::Dictation, test.now), &mut test);
        assert_eq!(test.events, [START]);
        assert_eq!(test.state.capture, Capture::Locked);
    }

    use std::sync::MutexGuard;
    use x11rb::protocol::xtest;

    static X11_TEST_LOCK: Mutex<()> = Mutex::new(());

    struct X11TestHarness {
        _guard: MutexGuard<'static, ()>,
        connection: RustConnection,
        root: Window,
        keymap: Keymap,
        alt: u8,
        space: u8,
        escape: u8,
    }

    impl X11TestHarness {
        fn new() -> Self {
            let guard = X11_TEST_LOCK
                .lock()
                .unwrap_or_else(|error| error.into_inner());
            let (connection, root, keymap) = connect_x11().unwrap();
            let alt = keymap.keycode(XK_ALT_L).unwrap();
            let space = keymap.keycode(XK_SPACE).unwrap();
            let escape = keymap.keycode(XK_ESCAPE).unwrap();
            Self {
                _guard: guard,
                connection,
                root,
                keymap,
                alt,
                space,
                escape,
            }
        }

        fn send_key(&self, type_: u8, key: u8) {
            send_key(&self.connection, self.root, type_, key);
        }

        fn tap_alt_space(&self) {
            for (type_, key) in [
                (KEY_PRESS, self.alt),
                (KEY_PRESS, self.space),
                (KEY_RELEASE, self.space),
                (KEY_RELEASE, self.alt),
            ] {
                self.send_key(type_, key);
            }
        }
    }

    fn recv_event(monitor: &LinuxHotkeyMonitor) -> HotkeyEvent {
        monitor.events.recv_timeout(Duration::from_secs(1)).unwrap()
    }

    fn send_key(connection: &RustConnection, root: Window, type_: u8, key: u8) {
        xtest::fake_input(connection, type_, key, 0, root, 0, 0, 0)
            .unwrap()
            .check()
            .unwrap();
        connection.flush().unwrap();
    }

    fn x11_monitor(
        binding: LinuxHotkey,
        options: HotkeyOptions,
        status: HotkeyStatus,
    ) -> (LinuxHotkeyMonitor, SyncSender<ListenerCommand>) {
        let (commands, receiver) = mpsc::sync_channel(4);
        let monitor = LinuxHotkeyMonitor::start_for(
            binding,
            options,
            LinuxSession::X11,
            status,
            receiver.into(),
        )
        .unwrap();
        (monitor, commands)
    }

    fn double_tap() -> HotkeyOptions {
        HotkeyOptions {
            double_tap: true,
            ..HotkeyOptions::default()
        }
    }

    #[test]
    fn lock_variants_preserve_the_configured_modifier() {
        assert_eq!(
            lock_variants(ModMask::M1, ModMask::M2),
            [
                ModMask::M1,
                ModMask::M1 | ModMask::LOCK,
                ModMask::M1 | ModMask::M2,
                ModMask::M1 | ModMask::LOCK | ModMask::M2,
            ]
        );
    }

    #[test]
    fn standalone_f12_resolves_to_the_x11_keysym() {
        assert_eq!(keysym("f12").unwrap(), 0xffc9);
    }

    #[test]
    fn full_event_queue_returns_an_error_instead_of_blocking_the_worker() {
        let (sender, receiver) = mpsc::sync_channel(1);
        assert!(
            send_event(
                &sender,
                HotkeyEvent::Start {
                    flavour: DictationFlavour::Normal
                }
            )
            .unwrap()
        );
        assert!(send_event(&sender, HotkeyEvent::Finish).is_err());
        assert_eq!(
            receiver.try_recv().unwrap(),
            HotkeyEvent::Start {
                flavour: DictationFlavour::Normal
            }
        );
        drop(receiver);
        assert!(!send_event(&sender, HotkeyEvent::Cancel).unwrap());
    }

    fn grab_error(kind: ErrorKind) -> ReplyError {
        ReplyError::X11Error(x11rb::x11_utils::X11Error {
            error_kind: kind,
            error_code: 10,
            sequence: 12,
            bad_value: 1722,
            minor_opcode: 0,
            major_opcode: 33,
            extension_name: None,
            request_name: Some("GrabKey"),
        })
    }

    #[test]
    fn escape_grab_conflict_is_not_fatal() {
        assert!(is_grab_conflict(&grab_error(ErrorKind::Access)));
    }

    #[test]
    fn non_conflict_grab_errors_stay_fatal() {
        for kind in [ErrorKind::Value, ErrorKind::Window, ErrorKind::Match] {
            assert!(
                !is_grab_conflict(&grab_error(kind)),
                "{kind:?} must stay fatal"
            );
        }
    }

    #[test]
    fn a_paste_waits_for_a_modifier_shortcut_to_let_go() {
        let keys = HeldKeys::default();
        assert_eq!(keys.quiet_at(), None);
        let now = Instant::now();
        let held = HeldKeys {
            held: 1 << Shortcut::PasteLast.index(),
            last: Some(now),
        };
        assert_eq!(held.quiet_at(), Some(now + HELD_LIMIT));
        let released = HeldKeys {
            held: 0,
            last: Some(now),
        };
        assert_eq!(released.quiet_at(), Some(now + MODIFIER_GRACE));
    }

    #[test]
    fn granted_triggers_decide_whether_a_shortcut_holds_modifiers() {
        let alt_space = LinuxHotkey::default();
        assert!(trigger_has_modifiers(None, &alt_space));
        assert!(trigger_has_modifiers(Some(""), &alt_space));
        assert!(!trigger_has_modifiers(Some("Press End"), &alt_space));
        assert!(trigger_has_modifiers(
            Some("Press <ctrl><alt>v"),
            &alt_space
        ));
        let end = LinuxHotkey {
            control: false,
            alt: false,
            shift: false,
            super_key: false,
            key: "End".into(),
        };
        assert!(!trigger_has_modifiers(None, &end));
    }

    #[test]
    fn dropping_a_monitor_stops_and_joins_its_worker() {
        let (_, events) = mpsc::sync_channel(1);
        let (_, errors) = mpsc::channel();
        let stop = Arc::new(AtomicBool::new(false));
        let stopped = Arc::new(AtomicBool::new(false));
        let worker_stop = stop.clone();
        let worker_stopped = stopped.clone();
        let worker = thread::spawn(move || {
            while !worker_stop.load(Ordering::Acquire) {
                thread::yield_now();
            }
            worker_stopped.store(true, Ordering::Release);
        });
        drop(LinuxHotkeyMonitor {
            events,
            errors,
            stop,
            worker: Some(worker),
        });
        assert!(stopped.load(Ordering::Acquire));
    }

    #[test]
    fn commands_alone_drive_a_listener_without_shortcuts() {
        let (sender, events) = mpsc::sync_channel(4);
        let (commands, receiver) = mpsc::sync_channel(4);
        let (ready, readiness) = mpsc::sync_channel(1);
        let status = HotkeyStatus::default();
        let backend = Backend {
            stop: Arc::new(AtomicBool::new(false)),
            ready,
            started: Arc::new(AtomicBool::new(false)),
            status: status.clone(),
        };
        let stop = backend.stop.clone();
        // A starting listener claims no shortcut kind, not even X11's.
        assert_eq!(status.shortcuts(), DesktopShortcuts::Unregistered);
        let worker = thread::spawn(move || {
            // Stopped well before its first portal check.
            backend
                .wait_for_portal(
                    &mut Dispatcher::new(
                        &HotkeyOptions::default(),
                        sender,
                        receiver.into(),
                        ShortcutKeys::default(),
                    ),
                    true,
                )
                .map(|portal| assert!(portal.is_none()))
        });
        readiness.recv().unwrap().unwrap();
        assert_eq!(status.shortcuts(), DesktopShortcuts::Commands);
        commands.send(Command::DictationToggle.into()).unwrap();
        commands.send(Command::DictationToggle.into()).unwrap();
        let wait = || events.recv_timeout(Duration::from_secs(1)).unwrap();
        assert_eq!([wait(), wait()], [START, Finish]);
        stop.store(true, Ordering::Release);
        worker.join().unwrap().unwrap();
    }

    #[test]
    fn an_idle_monitor_wakes_at_once_for_a_hex_command() {
        let (sender, events) = mpsc::sync_channel(4);
        let (commands, receiver) = mpsc::sync_channel(4);
        let mut dispatcher = Dispatcher::new(
            &HotkeyOptions::default(),
            sender,
            receiver.into(),
            ShortcutKeys::default(),
        );
        let sent = thread::spawn(move || {
            thread::sleep(Duration::from_millis(20));
            commands.send(Command::DictationToggle.into()).unwrap();
        });
        let started = Instant::now();
        dispatcher.wait_for_commands(Duration::from_secs(5));
        assert!(dispatcher.flush().unwrap());
        assert_eq!(events.recv_timeout(Duration::from_secs(1)).unwrap(), START);
        assert!(started.elapsed() < Duration::from_secs(1));
        sent.join().unwrap();
    }

    #[test]
    fn a_printing_stop_rides_the_command_queue_with_its_reply() {
        use crate::control::{PrintReply, PrintedTranscript};
        let (sender, events) = mpsc::sync_channel(4);
        let (commands, receiver) = mpsc::sync_channel(4);
        let mut dispatcher = Dispatcher::new(
            &HotkeyOptions::default(),
            sender,
            receiver.into(),
            ShortcutKeys::default(),
        );
        // Nothing records: the reply is answered at once.
        let (reply, idle) = PrintReply::channel();
        commands.send(ListenerCommand::StopAndPrint(reply)).unwrap();
        dispatcher.commands();
        assert_eq!(idle.try_recv().unwrap(), PrintedTranscript::NotRecording);
        // The stop finishes in queue order and a later start isn't blocked.
        let (reply, printed) = PrintReply::channel();
        commands.send(Command::DictationStart.into()).unwrap();
        commands.send(ListenerCommand::StopAndPrint(reply)).unwrap();
        commands.send(Command::DictationStart.into()).unwrap();
        dispatcher.commands();
        assert!(dispatcher.flush().unwrap());
        let received: Vec<_> = events.try_iter().collect();
        assert!(matches!(
            received.as_slice(),
            [
                HotkeyEvent::Start {
                    flavour: DictationFlavour::Normal
                },
                HotkeyEvent::FinishPrinting(_),
                HotkeyEvent::Start {
                    flavour: DictationFlavour::Normal
                }
            ]
        ));
        // The listener owns the reply now; nothing has answered it yet.
        assert!(printed.try_recv().is_err());
        let Some(HotkeyEvent::FinishPrinting(reply)) = received.into_iter().nth(1) else {
            unreachable!()
        };
        reply.send(PrintedTranscript::Text("Ship it.".into()));
        assert_eq!(
            printed.try_recv().unwrap(),
            PrintedTranscript::Text("Ship it.".into())
        );
    }

    #[test]
    #[ignore = "requires the active X11 desktop"]
    fn grabbed_alt_space_delivers_press_and_release() {
        let harness = X11TestHarness::new();
        let (monitor, _commands) =
            x11_monitor(LinuxHotkey::default(), double_tap(), Default::default());
        harness.tap_alt_space();
        assert_eq!(
            recv_event(&monitor),
            HotkeyEvent::Start {
                flavour: DictationFlavour::Normal
            }
        );
        assert_eq!(recv_event(&monitor), HotkeyEvent::Finish);
    }

    #[test]
    #[ignore = "requires the active X11 desktop"]
    fn second_tap_locks_until_the_trigger_is_pressed_again() {
        let harness = X11TestHarness::new();
        let (monitor, _commands) =
            x11_monitor(LinuxHotkey::default(), double_tap(), Default::default());

        harness.tap_alt_space();
        assert_eq!(
            recv_event(&monitor),
            HotkeyEvent::Start {
                flavour: DictationFlavour::Normal
            }
        );
        assert_eq!(recv_event(&monitor), HotkeyEvent::Finish);
        harness.tap_alt_space();
        assert_eq!(
            recv_event(&monitor),
            HotkeyEvent::Start {
                flavour: DictationFlavour::Normal
            }
        );
        assert!(
            monitor
                .events
                .recv_timeout(Duration::from_millis(100))
                .is_err()
        );
        harness.tap_alt_space();
        assert_eq!(recv_event(&monitor), HotkeyEvent::Finish);
    }

    #[test]
    #[ignore = "requires the active X11 desktop"]
    fn standalone_function_key_delivers_press_and_release() {
        let harness = X11TestHarness::new();
        let binding = LinuxHotkey {
            alt: false,
            key: "f24".into(),
            ..LinuxHotkey::default()
        };
        let (monitor, _commands) =
            x11_monitor(binding, HotkeyOptions::default(), Default::default());
        let trigger = harness.keymap.keycode(keysym("f24").unwrap()).unwrap();
        harness.send_key(KEY_PRESS, trigger);
        harness.send_key(KEY_RELEASE, trigger);

        assert_eq!(
            recv_event(&monitor),
            HotkeyEvent::Start {
                flavour: DictationFlavour::Normal
            }
        );
        assert_eq!(recv_event(&monitor), HotkeyEvent::Finish);
    }

    #[test]
    #[ignore = "requires the active X11 desktop"]
    fn commands_and_grabs_share_the_x11_listener() {
        let harness = X11TestHarness::new();
        let (monitor, commands) =
            x11_monitor(LinuxHotkey::default(), double_tap(), Default::default());
        harness.send_key(KEY_PRESS, harness.alt);
        harness.send_key(KEY_PRESS, harness.space);
        assert_eq!(
            recv_event(&monitor),
            HotkeyEvent::Start {
                flavour: DictationFlavour::Normal
            }
        );
        commands.send(Command::DictationStop.into()).unwrap();
        assert_eq!(recv_event(&monitor), HotkeyEvent::Finish);
        // Releasing the held shortcut afterwards finishes nothing twice.
        harness.send_key(KEY_RELEASE, harness.space);
        harness.send_key(KEY_RELEASE, harness.alt);
        assert!(
            monitor
                .events
                .recv_timeout(Duration::from_millis(150))
                .is_err()
        );
        commands.send(Command::DictationStart.into()).unwrap();
        assert_eq!(
            recv_event(&monitor),
            HotkeyEvent::Start {
                flavour: DictationFlavour::Normal
            }
        );
        // Escape stays with applications while the capture records (#786).
        thread::sleep(Duration::from_millis(50));
        grab_variants(
            &harness.connection,
            harness.root,
            harness.escape,
            &[ModMask::ANY],
        )
        .unwrap();
        harness
            .connection
            .ungrab_key(harness.escape, harness.root, ModMask::ANY)
            .unwrap();
        commands.send(Command::DictationStop.into()).unwrap();
        assert_eq!(recv_event(&monitor), HotkeyEvent::Finish);
    }

    #[test]
    #[ignore = "requires an isolated X11 display"]
    fn conflicted_escape_fallback_releases_partial_grabs() {
        let harness = X11TestHarness::new();
        grab_variants(
            &harness.connection,
            harness.root,
            harness.escape,
            &[ModMask::LOCK],
        )
        .unwrap();
        let (connection, _) = RustConnection::connect(None).unwrap();
        let variants = lock_variants(ModMask::default(), ModMask::M2);
        assert!(
            grab_escape(&connection, harness.root, harness.escape, &variants)
                .unwrap()
                .is_empty()
        );
        // Plain Escape was grabbed before the lock variant failed. It must be freed.
        grab_variants(&harness.connection, harness.root, harness.escape, &variants).unwrap();
        assert!(grab_escape(&connection, 0, harness.escape, &variants).is_err());
    }
}