//! cce-terminal — terminal emulator for the cce desktop.
 //!
 //! VT emulation is `alacritty_terminal`'s `Term` fed by its `vte` parser; this
 //! crate owns the pty ([`pty`]), the palette mapping ([`colors`]), and the
 //! rendering onto cce-ui's display-list path: cell backgrounds and decorations
 //! as quads, foreground text batched into per-style runs, everything on the
 //! DE's standard window plate. Key input encodes to terminal bytes
 //! (APP_CURSOR-aware); the wheel scrolls the scrollback (or synthesizes
 //! arrows on the alternate screen); OSC titles flow to the xdg toplevel via
 //! the engine's `settings().title` poll.
 //!
 //! Selection follows the X/Wayland convention: click-drag (double = word,
 //! triple = line) highlights and copies to PRIMARY on release; middle-click
 //! pastes PRIMARY; Ctrl+Shift+C / Ctrl+Shift+V are the regular clipboard,
 //! with bracketed paste when the app enables it. OSC 52 stores are honored.
 //!
 //! Mouse reporting: TUIs that enable a mouse mode (1000/1002/1003, with SGR
 //! 1006 / UTF-8 1005 / legacy encodings) get button, drag-motion, and wheel
 //! reports at cell coordinates, plus focus in/out (1004); holding Shift
 //! bypasses reporting so selection stays reachable, per convention.
 //!
 //! The window plate carries the DE's corner control ([`plate_menu`]): the
 //! circular trigger on the top-right that cce-designer's panes wear, opening
 //! a menu of the actions a menubar-less terminal has nowhere else to put —
 //! copy/paste, text zoom, scrollback and terminal resets, a new window, and
 //! the tabs. A tab ([`Tab`]) is one shell on one pty with its own `Term`,
 //! title, view offset and bell; the window shows the active one and the
 //! menu lists them as a radio group (the designer's dock-tab language) with
 //! New Tab / Close Tab. There is no tab bar: the title carries `[i/n]` while
 //! more than one is open. Rebindable chords (`cce-terminal` domain in
 //! input.kdl): `new_tab`, `close_tab`, `next_tab`, `prev_tab`.
 //!
 //! Config (KDL, live-reloaded on file change): a `terminal { … }` section in
 //! the shared `~/.config/cce/config.kdl` or the per-app
 //! `~/.config/cce/cce-terminal/config.kdl` (app file wins) with `font_size`,
 //! `scrollback`, and a `colors { … }` block naming `foreground`, `background`,
 //! `cursor`, `selection`, and the 16 ANSI slots (`black` … `bright_white`)
 //! as hex strings. The font family comes from the shared config's
 //! `fonts { terminal }` key, like the rest of the DE's font routing.
 //!
 //! Not yet: measured cell metrics (0.60 em / 1.2 em estimates — exact for
 //! Berkeley Mono in practice).
 
 mod clip;
 mod colors;
 mod plate_menu;
 mod pty;
 
 use std::io::{Read, Write};
 use std::path::{Path, PathBuf};
 use std::time::{Duration, Instant};
 
 use alacritty_terminal::event::{Event as TermEvent, EventListener, WindowSize};
 use alacritty_terminal::grid::{Dimensions, Scroll};
 use alacritty_terminal::index::{Column, Line, Point, Side};
 use alacritty_terminal::selection::{Selection, SelectionType};
 use alacritty_terminal::term::cell::Flags;
 use alacritty_terminal::term::{ClipboardType, Config as TermConfig, Term, TermMode};
 use alacritty_terminal::vte::ansi::{
     Color as AnsiColor, CursorShape, NamedColor, Processor, Rgb,
 };
 use cce_ui::engine::{Application, EngineState, LogicalPosition, LogicalSize, WindowSettings};
 use cce_ui::scene::layout::Rect;
 use cce_ui::scene::paint::{DisplayList, PaintCtx, TextAttrs};
 use cce_ui::widget::{Bounds, ElementState, Key, KeyEvent, MouseButton, MouseScrollDelta, NamedKey, ScrollMotion};
 use wayland_client::QueueHandle;
 
 const INIT_W: u32 = 840;
 const INIT_H: u32 = 520;
 /// Wheel notches → scrollback lines.
 const SCROLL_LINES_PER_NOTCH: f32 = 3.0;
 /// Presses in the same cell within this window escalate Simple → Semantic →
 /// Lines selection.
 const MULTI_CLICK_WINDOW: Duration = Duration::from_millis(400);
 
 /// The KDL-configurable knobs (`terminal { … }` in the shared config.kdl or
 /// the per-app `~/.config/cce/cce-terminal/config.kdl`, app file winning) and
 /// the cell metrics derived from them. Toolkit conventions for the metrics:
 /// ceil(font_size × 1.2) line height (`text_leaf_height`), 0.60 × font_size
 /// mono advance (`estimate_label_width_helper`).
 #[derive(Clone, Copy, PartialEq)]
 struct Settings {
     font_size: f32,
     line_h: f32,
     cell_w: f32,
     scrollback: usize,
     palette: colors::Palette,
 }
 
 impl Settings {
     /// `zoom_steps` is the corner menu's text zoom: one point per step over
     /// the configured size, session-only (a config edit keeps the zoom).
     fn load(font_family: &str, zoom_steps: i32) -> Self {
         let font_size = (cce_ui::config::get_f32("/terminal/font_size", 14.0) + zoom_steps as f32)
             .clamp(6.0, 72.0);
         let scrollback =
             cce_ui::config::get_i64("/terminal/scrollback", 5000).clamp(0, 200_000) as usize;
         // Measure the real glyph advance; the 0.60 em toolkit estimate is the
         // fallback (and the sanity band — a broken measurement won't wreck
         // the grid).
         let estimate = font_size * 0.60;
         let cell_w = measure_advance(font_family, font_size)
             .filter(|w| (0.5 * estimate..2.0 * estimate).contains(w))
             .unwrap_or(estimate);
         if std::env::var_os("CCE_TERM_DEBUG").is_some() {
             eprintln!("[metrics] family={font_family} size={font_size} cell_w={cell_w} (estimate {estimate})");
         }
         Settings {
             font_size,
             line_h: (font_size * 1.2).ceil(),
             cell_w,
             scrollback,
             palette: colors::Palette::from_config(),
         }
     }
 }
 
 /// Shape a long run of one ASCII glyph in the terminal font and divide out
 /// the per-cell advance. Uses an app-side bundled-fonts `FontSystem` (the
 /// documented pattern for measurement), cached across config reloads.
 fn measure_advance(font_family: &str, font_size: f32) -> Option<f32> {
     use std::sync::{Mutex, OnceLock};
     static FONT_SYSTEM: OnceLock<Mutex<cce_ui::cosmic_text::FontSystem>> = OnceLock::new();
     const RUN: usize = 64;
     let fs = FONT_SYSTEM.get_or_init(|| Mutex::new(cce_ui::create_font_system()));
     let mut fs = fs.lock().ok()?;
     let mut buffer = cce_ui::cosmic_text::Buffer::new(
         &mut fs,
         cce_ui::cosmic_text::Metrics::new(font_size, (font_size * 1.2).ceil()),
     );
     buffer.set_size(&mut fs, None, None);
     buffer.set_text(
         &mut fs,
         &"M".repeat(RUN),
         cce_ui::cosmic_text::Attrs::new().family(cce_ui::cosmic_text::Family::Name(font_family)),
         cce_ui::cosmic_text::Shaping::Advanced,
     );
     let advance = buffer.layout_runs().next()?.line_w / RUN as f32;
     (advance.is_finite() && advance > 0.0).then_some(advance)
 }
 
 /// The app's rebindable shortcuts, resolved once at startup from input.kdl
 /// (domain `cce-terminal`, falling back to `cce-ui` then these defaults).
 struct Keys {
     copy: String,
     paste: String,
     scroll_up: String,
     scroll_down: String,
     new_tab: String,
     close_tab: String,
     next_tab: String,
     prev_tab: String,
 }
 
 impl Keys {
     fn load() -> Self {
         let get = cce_ui::input::app_chord;
         Keys {
             copy: get("copy", "ctrl+shift+c"),
             paste: get("paste", "ctrl+shift+v"),
             scroll_up: get("scroll_up", "shift+pageup"),
             scroll_down: get("scroll_down", "shift+pagedown"),
             // The gnome-terminal chords; Ctrl+PageUp/Down are taken from the
             // shell (they would encode as CSI 5;5~ / 6;5~ otherwise).
             new_tab: get("new_tab", "ctrl+shift+t"),
             close_tab: get("close_tab", "ctrl+shift+w"),
             next_tab: get("next_tab", "ctrl+pagedown"),
             prev_tab: get("prev_tab", "ctrl+pageup"),
         }
     }
 }
 
 /// A tab's identity for its lifetime. Messages from the pty reader thread
 /// and the Term's event proxy are keyed on it rather than on a `Vec` index,
 /// which shifts when an earlier tab closes.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 struct TabId(u64);
 
 #[derive(Clone)]
 enum Msg {
     Pty(TabId, Vec<u8>),
     PtyClosed(TabId),
     Term(TabId, TermEvent),
 }
 
 /// The terminal's grid dimensions, for `Term::new`/`resize`.
 #[derive(Clone, Copy)]
 struct TermDims {
     cols: u16,
     rows: u16,
 }
 
 impl Dimensions for TermDims {
     fn total_lines(&self) -> usize {
         self.rows as usize
     }
     fn screen_lines(&self) -> usize {
         self.rows as usize
     }
     fn columns(&self) -> usize {
         self.cols as usize
     }
 }
 
 /// Forwards a tab's `Term` events (pty write-backs, title changes …) into
 /// the engine's message channel, tagged with the tab; handled in `update`.
 struct EventProxy {
     sender: calloop::channel::Sender<Msg>,
     id: TabId,
 }
 
 impl EventListener for EventProxy {
     fn send_event(&self, event: TermEvent) {
         let _ = self.sender.send(Msg::Term(self.id, event));
     }
 }
 
 /// One shell on one pty: the VT state and everything that is per-view
 /// rather than per-window. Gesture state (selection drag, multi-click,
 /// wheel remainders) stays on the app: it belongs to the pointer, and a
 /// tab switch simply drops it.
 struct Tab {
     id: TabId,
     term: Term<EventProxy>,
     parser: Processor,
     pty: pty::Pty,
     writer: std::fs::File,
     /// OSC title; the active tab's is polled by the engine through
     /// `settings().title`, every tab's names its menu row.
     title: Option<String>,
     /// Scrollback view motion in LINE units: `y.pos()` is the float display
     /// offset — a notch glides it, a trackpad tracks it 1:1 and its flick
     /// coasts (cce-ui's ScrollMotion) — and each frame the Term is stepped to
     /// its rounding. Drawing stays line-quantized; only the offset is smooth.
     scroll_motion: ScrollMotion,
     /// Bell flash intensity, 1.0 → 0 over ~a quarter second (decayed in tick).
     bell: f32,
     /// Cell of the last motion report — motion is per-cell, not per-pixel.
     last_mouse_cell: Option<(usize, usize)>,
 }
 
 impl Tab {
     /// Spawn a shell (or `command`) on a fresh pty sized to the grid, start
     /// its reader thread, and build the Term that will parse it.
     fn spawn(
         id: TabId,
         cols: u16,
         rows: u16,
         settings: &Settings,
         sender: &calloop::channel::Sender<Msg>,
         command: Option<&[String]>,
         cwd: Option<&Path>,
     ) -> std::io::Result<Tab> {
         let pty = pty::spawn_shell(cols, rows, command, cwd)?;
         let writer = pty.dup_handle()?;
         let mut reader = pty.dup_handle()?;
         let pty_sender = sender.clone();
         std::thread::spawn(move || {
             let mut buf = [0u8; 8192];
             loop {
                 match reader.read(&mut buf) {
                     Ok(0) => break,
                     Ok(n) => {
                         if pty_sender.send(Msg::Pty(id, buf[..n].to_vec())).is_err() {
                             return;
                         }
                     }
                     Err(e) if e.kind() == std::io::ErrorKind::Interrupted => continue,
                     // EIO when the last slave fd closes: the normal exit path.
                     Err(_) => break,
                 }
             }
             let _ = pty_sender.send(Msg::PtyClosed(id));
         });
 
         let config =
             TermConfig { scrolling_history: settings.scrollback, ..TermConfig::default() };
         let term = Term::new(
             config,
             &TermDims { cols, rows },
             EventProxy { sender: sender.clone(), id },
         );
         Ok(Tab {
             id,
             term,
             parser: Processor::new(),
             pty,
             writer,
             title: None,
             scroll_motion: ScrollMotion::new(),
             bell: 0.0,
             last_mouse_cell: None,
         })
     }
 
     /// The shell's current directory (via /proc), so a new tab can start
     /// where this one is. The shell itself, not its foreground job: that is
     /// where the next prompt will be.
     fn cwd(&self) -> Option<PathBuf> {
         std::fs::read_link(format!("/proc/{}/cwd", self.pty.child.id())).ok()
     }
 
     /// The tab's menu row text: its title, or "Tab n" before one arrives,
     /// clipped so a long OSC title does not stretch the menu.
     fn label(&self, n: usize) -> String {
         const MAX: usize = 32;
         let title = match &self.title {
             Some(t) if !t.trim().is_empty() => t.trim().to_string(),
             _ => return format!("Tab {}", n + 1),
         };
         if title.chars().count() <= MAX {
             title
         } else {
             let head: String = title.chars().take(MAX - 1).collect();
             format!("{head}…")
         }
     }
 
     /// Kill the shell and reap it. Closing a tab, not the shell exiting on
     /// its own — that arrives as `Msg::PtyClosed` from the reader thread.
     fn kill(&mut self) {
         let _ = self.pty.child.kill();
         let _ = self.pty.child.wait();
     }
 }
 
 struct TerminalApp {
     /// The engine's message channel, kept so new tabs can spawn onto it.
     sender: calloop::channel::Sender<Msg>,
     /// Never empty while the app runs: the last shell exiting exits the app.
     tabs: Vec<Tab>,
     active: usize,
     next_tab_id: u64,
     font: String,
     pad: f32,
     cols: u16,
     rows: u16,
     /// Fractional wheel remainder for the whole-line wheel protocols (mouse
     /// reports, alternate-scroll arrows), where a trackpad's pixel deltas
     /// have to add up to a line before anything is sent.
     scroll_accum: f32,
     focused: bool,
     /// Left button held: pointer moves extend the selection.
     selecting: bool,
     /// Multi-click escalation state: last press instant + cell.
     last_click: Option<(Instant, Point)>,
     click_count: u8,
     settings: Settings,
     keys: Keys,
     /// Config-file mtime at the last (re)load — tick polls it so palette and
     /// font-size edits apply live, per the DE's edit-the-file convention.
     config_stamp: Option<std::time::SystemTime>,
     /// Last pointer position (any state) — tick's autoscroll reads it while a
     /// selection drag holds the pointer in the frame's edge padding.
     last_pointer: LogicalPosition,
     autoscroll_accum: f32,
     /// Current window size (for grid re-derivation on config reload and
     /// selection edge-autoscroll bounds).
     win_w: f32,
     win_h: f32,
     /// Modifier state tracked from key events (mouse handlers receive no
     /// modifiers). Shift bypasses mouse reporting; ctrl/alt ride report codes.
     shift_down: bool,
     ctrl_down: bool,
     alt_down: bool,
     /// Held buttons for drag-motion reports: bit 0 left, 1 middle, 2 right.
     mouse_buttons: u8,
     /// Corner-menu text zoom, in points over the configured font size.
     zoom_steps: i32,
     /// Rows of the OPEN corner menu (empty = not open); see [`plate_menu`].
     plate_menu_actions: Vec<plate_menu::PlateMenuAction>,
 }
 
 impl TerminalApp {
     fn tab(&self) -> &Tab {
         &self.tabs[self.active]
     }
 
     fn tab_mut(&mut self) -> &mut Tab {
         &mut self.tabs[self.active]
     }
 
     fn tab_index(&self, id: TabId) -> Option<usize> {
         self.tabs.iter().position(|t| t.id == id)
     }
 
     /// Open a new tab after the active one, in the active shell's directory,
     /// and switch to it.
     fn new_tab(&mut self) {
         let id = TabId(self.next_tab_id);
         self.next_tab_id += 1;
         let cwd = self.tab().cwd();
         match Tab::spawn(id, self.cols, self.rows, &self.settings, &self.sender, None, cwd.as_deref()) {
             Ok(tab) => {
                 let at = self.active + 1;
                 self.tabs.insert(at, tab);
                 self.show_tab(at);
             }
             Err(e) => log::warn!("cce-terminal: failed to spawn a new tab: {e}"),
         }
     }
 
     /// Make tab `i` the visible one. Apps tracking focus (1004) in either
     /// tab see the switch as focus leaving one and reaching the other.
     fn show_tab(&mut self, i: usize) {
         if i >= self.tabs.len() || i == self.active {
             return;
         }
         if self.focused && self.tab().term.mode().contains(TermMode::FOCUS_IN_OUT) {
             self.write_pty(b"\x1b[O");
         }
         self.active = i;
         // Pointer gestures do not survive the switch: they were about the
         // old tab's cells.
         self.selecting = false;
         self.last_click = None;
         self.click_count = 0;
         self.scroll_accum = 0.0;
         self.autoscroll_accum = 0.0;
         if self.focused && self.tab().term.mode().contains(TermMode::FOCUS_IN_OUT) {
             self.write_pty(b"\x1b[I");
         }
     }
 
     fn show_tab_by_id(&mut self, id: TabId) {
         if let Some(i) = self.tab_index(id) {
             self.show_tab(i);
         }
     }
 
     /// Next/previous tab, wrapping.
     fn cycle_tab(&mut self, delta: i32) {
         let n = self.tabs.len() as i32;
         if n > 1 {
             self.show_tab(((self.active as i32 + delta).rem_euclid(n)) as usize);
         }
     }
 
     /// Close the active tab. The last tab is the window: killing its shell
     /// ends the pty, and the reader thread's `PtyClosed` exits the app the
     /// way a typed `exit` would, so there is never a tabless window.
     fn close_active_tab(&mut self) {
         if self.tabs.len() == 1 {
             self.tab_mut().kill();
             return;
         }
         let mut tab = self.tabs.remove(self.active);
         tab.kill();
         let i = self.active.min(self.tabs.len() - 1);
         // `show_tab` declines a same-index switch, so drop the gesture
         // state here — the tab under the pointer changed either way.
         self.active = i;
         self.selecting = false;
         self.last_click = None;
         self.click_count = 0;
     }
 
     fn grid_for(&self, w: f32, h: f32) -> (u16, u16) {
         grid_dims(w, h, self.pad, &self.settings)
     }
 
     fn write_pty(&mut self, bytes: &[u8]) {
         let _ = self.tab_mut().writer.write_all(bytes);
     }
 
     /// Resize every tab's pty and Term to the current grid.
     fn resize_tabs(&mut self, cols: u16, rows: u16) {
         self.cols = cols;
         self.rows = rows;
         for tab in &mut self.tabs {
             tab.pty.resize(cols, rows);
             tab.term.resize(TermDims { cols, rows });
         }
     }
 
     fn cell_rect(&self, row: usize, col: usize, width_cells: usize) -> Rect {
         Rect {
             x: self.pad + col as f32 * self.settings.cell_w,
             y: self.pad + row as f32 * self.settings.line_h,
             width: width_cells as f32 * self.settings.cell_w,
             height: self.settings.line_h,
         }
     }
 
     /// Pixel position → 0-based viewport cell (clamped).
     fn viewport_cell(&self, pos: LogicalPosition) -> (usize, usize) {
         let col = (((pos.x as f32 - self.pad) / self.settings.cell_w).max(0.0) as usize)
             .min(self.cols as usize - 1);
         let row = (((pos.y as f32 - self.pad) / self.settings.line_h).max(0.0) as usize)
             .min(self.rows as usize - 1);
         (col, row)
     }
 
     /// Pixel position → grid point (viewport-clamped; grid-space line, so
     /// scrolled history resolves to negative lines) plus which half of the
     /// cell was hit.
     fn grid_point(&self, pos: LogicalPosition) -> (Point, Side) {
         let (col, row) = self.viewport_cell(pos);
         let col_f = ((pos.x as f32 - self.pad) / self.settings.cell_w).max(0.0);
         let line = Line(row as i32 - self.tab().term.grid().display_offset() as i32);
         let side = if col_f.fract() > 0.5 { Side::Right } else { Side::Left };
         (Point::new(line, Column(col)), side)
     }
 
     /// Whether pointer events currently belong to the application rather than
     /// the selection machinery (Shift bypasses, per convention).
     fn mouse_reporting(&self) -> bool {
         self.tab().term.mode().intersects(TermMode::MOUSE_MODE) && !self.shift_down
     }
 
     /// Modifier bits added to every report's button code. Shift never
     /// arrives here (it bypasses reporting).
     fn report_mods(&self) -> u8 {
         (self.alt_down as u8) * 8 + (self.ctrl_down as u8) * 16
     }
 
     fn send_mouse_report(&mut self, code: u8, pressed: bool, col: usize, row: usize) {
         if let Some(bytes) = mouse_report_bytes(*self.tab().term.mode(), code, pressed, col, row) {
             self.write_pty(&bytes);
         }
     }
 
     /// Quantize wheel motion for the whole-line protocols, carrying the
     /// fractional remainder across events.
     fn take_whole_lines(&mut self, lines: f32) -> Option<i32> {
         self.scroll_accum += lines;
         let whole = self.scroll_accum as i32;
         if whole == 0 {
             return None;
         }
         self.scroll_accum -= whole as f32;
         Some(whole)
     }
 
     /// Adopt view moves made behind the motion's back — PageUp/PageDown, the
     /// snap to the bottom on a keypress or paste, new output pushing a held
     /// view up the history — so the motion resumes from where the view is.
     fn sync_scroll_motion(&mut self) {
         let tab = self.tab_mut();
         let offset = tab.term.grid().display_offset() as f32;
         if tab.scroll_motion.y.pos().round() != offset {
             tab.scroll_motion.y.jump_to(offset);
         }
     }
 
     /// How far a selection drag is holding the pointer past the top or
     /// bottom edge padding: 0 when it is inside, negative above, positive
     /// below. Drives the autoscroll rate in `tick`, and the frame cadence
     /// `idle_poll_interval` has to ask for while it is non-zero.
     fn autoscroll_overshoot(&self) -> f32 {
         if !self.selecting {
             return 0.0;
         }
         let y = self.last_pointer.y as f32;
         if y < self.pad {
             self.pad - y
         } else if y > self.win_h - self.pad {
             (self.win_h - self.pad) - y
         } else {
             0.0
         }
     }
 
     /// The scrollback offset's range: 0 (live bottom) ..= history length.
     fn scrollback_bounds(&self) -> Bounds {
         Bounds::max(self.tab().term.grid().history_size() as f32)
     }
 
     /// Step the Term to the motion's rounded offset; true if the view moved.
     fn apply_scroll_motion(&mut self) -> bool {
         let tab = self.tab_mut();
         let target = tab.scroll_motion.y.pos().round() as i32;
         let current = tab.term.grid().display_offset() as i32;
         if target == current {
             return false;
         }
         tab.term.scroll_display(Scroll::Delta(target - current));
         true
     }
 
     /// Swap in re-derived settings (a config edit, a zoom step) and reflow
     /// the grid and pty to match. `true` when anything changed.
     fn apply_settings(&mut self, reloaded: Settings) -> bool {
         let old = std::mem::replace(&mut self.settings, reloaded);
         if reloaded == old {
             return false;
         }
         let (cols, rows) = self.grid_for(self.win_w, self.win_h);
         if (cols, rows) != (self.cols, self.rows) {
             self.resize_tabs(cols, rows);
         }
         true
     }
 
     /// Send pasted text to the pty and snap the view to the bottom.
     fn paste(&mut self, text: &str) {
         let bracketed = self.tab().term.mode().contains(TermMode::BRACKETED_PASTE);
         let bytes = paste_bytes(text, bracketed);
         self.write_pty(&bytes);
         let term = &mut self.tab_mut().term;
         if term.grid().display_offset() != 0 {
             term.scroll_display(Scroll::Bottom);
         }
     }
 }
 
 /// Encode one mouse report. `code` is the xterm button code with modifier
 /// bits already applied (0/1/2 buttons, 64/65 wheel, +32 for motion);
 /// `col`/`row` are 0-based viewport cells. Picks the encoding the app
 /// negotiated: SGR (1006) > UTF-8 extended coords (1005) > legacy X10 bytes
 /// (coordinates saturate at their encodable maximum).
 fn mouse_report_bytes(
     mode: TermMode,
     code: u8,
     pressed: bool,
     col: usize,
     row: usize,
 ) -> Option<Vec<u8>> {
     if mode.contains(TermMode::SGR_MOUSE) {
         let suffix = if pressed { 'M' } else { 'm' };
         return Some(format!("\x1b[<{};{};{}{}", code, col + 1, row + 1, suffix).into_bytes());
     }
     // Non-SGR encodings can't distinguish which button released.
     let byte = 32 + if pressed { code } else { 3 | (code & !0b11) };
     let mut bytes = vec![0x1b, b'[', b'M', byte];
     if mode.contains(TermMode::UTF8_MOUSE) {
         for coord in [col, row] {
             let n = (coord + 1 + 32).min(2015) as u32;
             let mut buf = [0u8; 4];
             bytes.extend_from_slice(
                 char::from_u32(n).unwrap_or(' ').encode_utf8(&mut buf).as_bytes(),
             );
         }
     } else {
         bytes.push((col + 1 + 32).min(255) as u8);
         bytes.push((row + 1 + 32).min(255) as u8);
     }
     Some(bytes)
 }
 
 /// Paste encoding: bracketed when the app asked for it (end-marker
 /// occurrences stripped so a paste can't fake the terminator),
 /// newline-normalized to CR otherwise.
 fn paste_bytes(text: &str, bracketed: bool) -> Vec<u8> {
     if bracketed {
         let mut bytes = b"\x1b[200~".to_vec();
         bytes.extend_from_slice(text.replace("\x1b[201~", "").as_bytes());
         bytes.extend_from_slice(b"\x1b[201~");
         bytes
     } else {
         text.replace("\r\n", "\r").replace('\n', "\r").into_bytes()
     }
 }
 
 fn grid_dims(w: f32, h: f32, pad: f32, settings: &Settings) -> (u16, u16) {
     let cols = (((w - 2.0 * pad) / settings.cell_w).floor() as i64).clamp(2, u16::MAX as i64);
     let rows = (((h - 2.0 * pad) / settings.line_h).floor() as i64).clamp(1, u16::MAX as i64);
     (cols as u16, rows as u16)
 }
 
 /// Terminal-space RGB → cce-ui quad color (the geometry pipeline is linear;
 /// terminal colors are sRGB).
 fn quad_color(rgb: Rgb, alpha: f32) -> [f32; 4] {
     [
         cce_ui::color::srgb_to_linear(rgb.r as f32 / 255.0),
         cce_ui::color::srgb_to_linear(rgb.g as f32 / 255.0),
         cce_ui::color::srgb_to_linear(rgb.b as f32 / 255.0),
         alpha,
     ]
 }
 
 /// Terminal byte encoding for a key press; `None` = nothing to send. Honors
 /// DECCKM (application cursor keys) and the xterm modifier parameter
 /// (`1 + shift + 2·alt + 4·ctrl`) on CSI keys; alt prefixes ESC everywhere
 /// else (readline's alt-b / alt-backspace family).
 fn encode_key(ev: &KeyEvent, mode: TermMode) -> Option<Vec<u8>> {
     let app = mode.contains(TermMode::APP_CURSOR);
     let m = 1 + ev.shift as u8 + 2 * ev.alt as u8 + 4 * ev.ctrl as u8;
 
     enum Enc {
         /// `ESC[<final>` / `ESCO<final>` (app mode) / `ESC[1;<m><final>`.
         Csi(char),
         /// `ESC[<n>~` / `ESC[<n>;<m>~`.
         Tilde(u8),
         /// Raw bytes, ESC-prefixed when alt is held.
         Plain(&'static [u8]),
     }
 
     match &ev.logical_key {
         Key::Named(k) => {
             let enc = match k {
                 NamedKey::ArrowUp => Enc::Csi('A'),
                 NamedKey::ArrowDown => Enc::Csi('B'),
                 NamedKey::ArrowRight => Enc::Csi('C'),
                 NamedKey::ArrowLeft => Enc::Csi('D'),
                 NamedKey::Home => Enc::Csi('H'),
                 NamedKey::End => Enc::Csi('F'),
                 NamedKey::PageUp => Enc::Tilde(5),
                 NamedKey::PageDown => Enc::Tilde(6),
                 NamedKey::Delete => Enc::Tilde(3),
                 NamedKey::F5 => Enc::Tilde(15),
                 NamedKey::Enter => Enc::Plain(b"\r"),
                 NamedKey::Backspace => Enc::Plain(b"\x7f"),
                 NamedKey::Tab if ev.shift => return Some(b"\x1b[Z".to_vec()),
                 NamedKey::Tab => Enc::Plain(b"\t"),
                 NamedKey::Escape => Enc::Plain(b"\x1b"),
                 NamedKey::Space if ev.ctrl => Enc::Plain(b"\x00"),
                 NamedKey::Space => Enc::Plain(b" "),
                 _ => return None,
             };
             Some(match enc {
                 Enc::Csi(c) if m > 1 => format!("\x1b[1;{m}{c}").into_bytes(),
                 Enc::Csi(c) if app => format!("\x1bO{c}").into_bytes(),
                 Enc::Csi(c) => format!("\x1b[{c}").into_bytes(),
                 Enc::Tilde(n) if m > 1 => format!("\x1b[{n};{m}~").into_bytes(),
                 Enc::Tilde(n) => format!("\x1b[{n}~").into_bytes(),
                 Enc::Plain(b) => {
                     let mut bytes = Vec::with_capacity(b.len() + 1);
                     if ev.alt {
                         bytes.push(0x1b);
                     }
                     bytes.extend_from_slice(b);
                     bytes
                 }
             })
         }
         Key::Character(s) => {
             let mut bytes: Vec<u8> = if ev.ctrl {
                 match s.chars().next()?.to_ascii_lowercase() {
                     c @ 'a'..='z' => vec![c as u8 - b'a' + 1],
                     '[' => vec![0x1b],
                     '\\' => vec![0x1c],
                     ']' => vec![0x1d],
                     _ => return None,
                 }
             } else if let Some(t) = &ev.text {
                 t.as_bytes().to_vec()
             } else {
                 s.as_bytes().to_vec()
             };
             if ev.alt {
                 bytes.insert(0, 0x1b);
             }
             Some(bytes)
         }
     }
 }
 
 /// A run of contiguous same-style cells on one row, batched into a single
 /// text prim (valid because the grid is monospace-cell-addressed).
 struct TextRun {
     row: usize,
     col: usize,
     next_col: usize,
     text: String,
     fg: Rgb,
     bold: bool,
     italic: bool,
 }
 
 impl Application for TerminalApp {
     type Message = Msg;
 
     fn new(
         _qh: &QueueHandle<EngineState<Self>>,
         sender: calloop::channel::Sender<Self::Message>,
     ) -> Self {
         // The window-edge inset: the root plate's roll plus one padding.
         let pad = cce_ui::layout::root_plate_inset();
         // `.3` is the `fonts { terminal }` family (this was the 7-tuple's
         // fontconfig `terminal` alias before the DE's fonts moved into the
         // shared KDL config), falling back to Noto Sans Mono.
         let font = cce_ui::layout::read_preferred_fonts().3;
         let settings = Settings::load(&font, 0);
         let config_stamp = cce_ui::config::config_files_modified();
         let (cols, rows) = grid_dims(INIT_W as f32, INIT_H as f32, pad, &settings);
 
         // A command instead of $SHELL: `cce-terminal -e <cmd> [args…]`
         // (xterm-style), or bare trailing args (foot-style) — the launcher
         // hosts `Terminal=true` entries positionally (`term sh -c …`), so
         // both conventions must work.
         let argv: Vec<String> = std::env::args().skip(1).collect();
         let command: Option<Vec<String>> = match argv.first().map(String::as_str) {
             Some("-e") => Some(argv[1..].to_vec()).filter(|c| !c.is_empty()),
             Some(_) => Some(argv.clone()),
             None => None,
         };
 
         // The first tab runs the command (later tabs are plain shells) and
         // inherits the terminal's own directory.
         let first = Tab::spawn(TabId(0), cols, rows, &settings, &sender, command.as_deref(), None)
             .expect("cce-terminal: failed to spawn shell on pty");
 
         TerminalApp {
             sender,
             tabs: vec![first],
             active: 0,
             next_tab_id: 1,
             font,
             pad,
             cols,
             rows,
             scroll_accum: 0.0,
             focused: true,
             selecting: false,
             last_click: None,
             click_count: 0,
             settings,
             keys: Keys::load(),
             config_stamp,
             last_pointer: LogicalPosition::new(0.0, 0.0),
             autoscroll_accum: 0.0,
             win_w: INIT_W as f32,
             win_h: INIT_H as f32,
             shift_down: false,
             ctrl_down: false,
             alt_down: false,
             mouse_buttons: 0,
             zoom_steps: 0,
             plate_menu_actions: Vec::new(),
         }
     }
 
     fn settings(&self) -> WindowSettings {
         // The active tab's title; with several tabs and no tab bar, the
         // title is where "which one, of how many" shows.
         let mut title = self.tab().title.clone().unwrap_or_else(|| "cce-terminal".to_string());
         if self.tabs.len() > 1 {
             title = format!("{title} [{}/{}]", self.active + 1, self.tabs.len());
         }
         WindowSettings {
             title,
             app_id: "cce-terminal".to_string(),
             width: INIT_W,
             height: INIT_H,
             fullscreen: false,
             min_size: Some((240, 140)),
         }
     }
 
     fn update(&mut self, msg: Self::Message, needs_rebuild: &mut bool, exit: &mut bool) {
         // Every message names its tab; one from a tab already closed (its
         // reader thread outlives the kill by a moment) is simply dropped.
         // Background tabs keep parsing but never ask for a frame: nothing
         // of theirs is on screen except their menu label and the title.
         let (id, is_active) = match &msg {
             Msg::Pty(id, _) | Msg::PtyClosed(id) | Msg::Term(id, _) => {
                 let Some(i) = self.tab_index(*id) else { return };
                 (i, i == self.active)
             }
         };
         let window = WindowSize {
             num_lines: self.rows,
             num_cols: self.cols,
             cell_width: self.settings.cell_w as u16,
             cell_height: self.settings.line_h as u16,
         };
         let palette = self.settings.palette;
         let tab = &mut self.tabs[id];
         match msg {
             Msg::Pty(_, bytes) => {
                 tab.parser.advance(&mut tab.term, &bytes);
                 *needs_rebuild |= is_active;
             }
             Msg::PtyClosed(_) => {
                 let _ = tab.pty.child.wait();
                 if self.tabs.len() == 1 {
                     // The last shell exiting is the window closing — the
                     // tab stays in place so nothing observes an empty list.
                     *exit = true;
                     return;
                 }
                 self.tabs.remove(id);
                 if id < self.active {
                     self.active -= 1;
                 } else if self.active >= self.tabs.len() {
                     self.active = self.tabs.len() - 1;
                 }
                 if is_active {
                     self.selecting = false;
                     self.last_click = None;
                     self.click_count = 0;
                 }
                 *needs_rebuild = true;
             }
             Msg::Term(_, event) => match event {
                 TermEvent::PtyWrite(s) => {
                     let _ = tab.writer.write_all(s.as_bytes());
                 }
                 TermEvent::Title(t) => {
                     tab.title = Some(t);
                     *needs_rebuild |= is_active;
                 }
                 TermEvent::ResetTitle => {
                     tab.title = None;
                     *needs_rebuild |= is_active;
                 }
                 TermEvent::ColorRequest(index, format) => {
                     let rgb = tab.term.colors()[index]
                         .unwrap_or_else(|| colors::default_color(index, &palette));
                     let _ = tab.writer.write_all(format(rgb).as_bytes());
                 }
                 TermEvent::TextAreaSizeRequest(format) => {
                     let _ = tab.writer.write_all(format(window).as_bytes());
                 }
                 // OSC 52: programs storing to (or, if enabled in the term
                 // config, reading from) the system clipboards.
                 TermEvent::ClipboardStore(ty, text) => match ty {
                     ClipboardType::Clipboard => cce_ui::widget::clipboard::copy_to_clipboard(&text),
                     ClipboardType::Selection => clip::copy_primary(&text),
                 },
                 TermEvent::ClipboardLoad(ty, format) => {
                     let text = match ty {
                         ClipboardType::Clipboard => {
                             cce_ui::widget::clipboard::read_from_clipboard()
                         }
                         ClipboardType::Selection => clip::paste_primary(),
                     }
                     .unwrap_or_default();
                     let _ = tab.writer.write_all(format(&text).as_bytes());
                 }
                 TermEvent::Bell => {
                     tab.bell = 1.0;
                     *needs_rebuild |= is_active;
                 }
                 // Wakeup/cursor-blink: nothing to do.
                 _ => {}
             },
         }
     }
 
     /// Two things age in `tick` without redrawing anything the runner can
     /// see: a background tab's bell flash (only the active tab's decay asks
     /// for a frame) and selection autoscroll with the pointer held still in
     /// the edge padding (motion events stop at the edge). Both are real-time
     /// decays, and the runner's idle sleep clamps `dt` to one frame per
     /// wake — so ask for frame cadence while either is live, and nothing
     /// otherwise.
     fn idle_poll_interval(&self) -> Option<std::time::Duration> {
         let bell = self.tabs.iter().any(|t| t.bell > 0.0);
         (bell || self.autoscroll_overshoot() != 0.0)
             .then(|| std::time::Duration::from_millis(16))
     }
 
     fn tick(&mut self, dt: f32, needs_rebuild: &mut bool) {
         // Bell flash decay — every tab's, so a background tab's flash has
         // faded by the time it is shown rather than greeting the switch.
         for (i, tab) in self.tabs.iter_mut().enumerate() {
             if tab.bell > 0.0 {
                 tab.bell = (tab.bell - dt * 4.0).max(0.0);
                 *needs_rebuild |= i == self.active;
             }
         }
 
         // Wheel glide / trackpad coast through the scrollback: advance the
         // line-unit motion and step the Term to its rounded offset, asking
         // for frames while it is still moving.
         if self.tab().scroll_motion.is_animating() {
             self.sync_scroll_motion();
             if self.tab().scroll_motion.is_animating() {
                 let bounds = self.scrollback_bounds();
                 self.tab_mut().scroll_motion.tick(dt, Bounds::max(0.0), bounds);
                 if self.apply_scroll_motion() || self.tab().scroll_motion.is_animating() {
                     *needs_rebuild = true;
                 }
             }
         }
 
         // Selection autoscroll: while a drag holds the pointer in the top or
         // bottom edge padding, scroll at a rate scaling with the overshoot
         // (motion events stop at the edge, so this is time-driven).
         {
             let overshoot = self.autoscroll_overshoot();
             if overshoot != 0.0 {
                 let rate = 4.0 + overshoot.abs().min(24.0) * 2.0; // lines/sec
                 self.autoscroll_accum += dt * rate * overshoot.signum();
                 let lines = self.autoscroll_accum as i32;
                 if lines != 0 {
                     self.autoscroll_accum -= lines as f32;
                     self.tab_mut().term.scroll_display(Scroll::Delta(lines));
                     let (point, side) = self.grid_point(self.last_pointer);
                     if let Some(selection) = &mut self.tab_mut().term.selection {
                         selection.update(point, side);
                     }
                     *needs_rebuild = true;
                 }
             } else {
                 self.autoscroll_accum = 0.0;
             }
         }
 
         // Config edits apply live: poll the config files' mtime (the
         // toolkit's own getters stat them on every call anyway) and re-derive
         // settings, grid, and pty size on change. Scrollback capacity is the
         // exception — it's baked into the Term at startup.
         let stamp = cce_ui::config::config_files_modified();
         if stamp == self.config_stamp {
             return;
         }
         self.config_stamp = stamp;
         let font = self.font.clone();
         let reloaded = Settings::load(&font, self.zoom_steps);
         if self.apply_settings(reloaded) {
             *needs_rebuild = true;
         }
     }
 
     fn handle_resize(&mut self, width: f32, height: f32, _scale: f64) {
         self.win_w = width;
         self.win_h = height;
         let (cols, rows) = self.grid_for(width, height);
         if (cols, rows) != (self.cols, self.rows) {
             self.resize_tabs(cols, rows);
         }
     }
 
     fn display_list(&mut self, size: LogicalSize, _scale: f64) -> Option<DisplayList> {
         let (w, h) = (size.width, size.height);
         let mut pc = PaintCtx::new();
 
         // The standard root plate (cce-ui `PlateSpec::window`).
         pc.root_plate(w, h);
         let frame = Rect { x: 0.0, y: 0.0, width: w, height: h };
 
         let rows = self.rows as usize;
         let pad = self.pad;
         let font = self.font.clone();
         let bounds = [pad, 0.0, w - pad, h];
 
         let tab = self.tab();
         let bell = tab.bell;
         let content = tab.term.renderable_content();
         let display_offset = content.display_offset as i32;
         let overrides = content.colors;
         let cfg_palette = self.settings.palette;
 
         // One ordered pass over the viewport cells, batching backgrounds and
         // same-style text into runs. Emission order: bg quads → text →
         // decorations → cursor.
         let mut bg_runs: Vec<(usize, usize, usize, Rgb)> = Vec::new();
         let mut text_runs: Vec<TextRun> = Vec::new();
         // (row, col_start, col_end, color, is_strikeout)
         let mut deco_runs: Vec<(usize, usize, usize, Rgb, bool)> = Vec::new();
         // (row, col_start, col_end) — selection highlight spans.
         let mut sel_runs: Vec<(usize, usize, usize)> = Vec::new();
         let mut cur_bg: Option<(usize, usize, usize, Rgb)> = None;
         let mut cur_text: Option<TextRun> = None;
 
         for cell in content.display_iter {
             let row_i = cell.point.line.0 + display_offset;
             if row_i < 0 {
                 continue;
             }
             let row = row_i as usize;
             if row >= rows {
                 break;
             }
             let col = cell.point.column.0;
             let flags = cell.flags;
             if flags.intersects(Flags::WIDE_CHAR_SPACER | Flags::LEADING_WIDE_CHAR_SPACER) {
                 continue;
             }
             let width_cells = if flags.contains(Flags::WIDE_CHAR) { 2 } else { 1 };
             let (fg_color, bg_color) = if flags.contains(Flags::INVERSE) {
                 (cell.bg, cell.fg)
             } else {
                 (cell.fg, cell.bg)
             };
             let dim = flags.intersects(Flags::DIM);
             let fg = colors::resolve(fg_color, overrides, dim, &cfg_palette);
 
             // Selection highlight span.
             if content.selection.is_some_and(|sel| sel.contains(cell.point)) {
                 match sel_runs.last_mut() {
                     Some((r, _s, e)) if *r == row && *e == col => *e = col + width_cells,
                     _ => sel_runs.push((row, col, col + width_cells)),
                 }
             }
 
             // Background run (skip the default background: the plate shows through).
             let bg = (bg_color != AnsiColor::Named(NamedColor::Background))
                 .then(|| colors::resolve(bg_color, overrides, false, &cfg_palette));
             match (&mut cur_bg, bg) {
                 (Some((r, _s, e, rgb)), Some(new)) if *r == row && *e == col && *rgb == new => {
                     *e = col + width_cells;
                 }
                 (run, bg) => {
                     if let Some(done) = run.take() {
                         bg_runs.push(done);
                     }
                     if let Some(new) = bg {
                         *run = Some((row, col, col + width_cells, new));
                     }
                 }
             }
 
             // Decoration runs (underline family collapses to underline).
             let underline = flags.intersects(
                 Flags::UNDERLINE
                     | Flags::DOUBLE_UNDERLINE
                     | Flags::UNDERCURL
                     | Flags::DOTTED_UNDERLINE
                     | Flags::DASHED_UNDERLINE,
             );
             let strikeout = flags.contains(Flags::STRIKEOUT);
             for (on, is_strike) in [(underline, false), (strikeout, true)] {
                 if !on {
                     continue;
                 }
                 if let Some(last) = deco_runs.last_mut() {
                     if last.0 == row && last.2 == col && last.4 == is_strike && last.3 == fg {
                         last.2 = col + width_cells;
                         continue;
                     }
                 }
                 deco_runs.push((row, col, col + width_cells, fg, is_strike));
             }
 
             // Text run: spaces and hidden cells only break runs, never render.
             let bold = flags.intersects(Flags::BOLD);
             let italic = flags.intersects(Flags::ITALIC);
             let renders = cell.c != ' ' && !flags.contains(Flags::HIDDEN);
             match &mut cur_text {
                 Some(run)
                     if renders
                         && run.row == row
                         && run.next_col == col
                         && run.fg == fg
                         && run.bold == bold
                         && run.italic == italic
                         && width_cells == 1 =>
                 {
                     run.text.push(cell.c);
                     run.next_col += 1;
                 }
                 run => {
                     if let Some(done) = run.take() {
                         text_runs.push(done);
                     }
                     if renders {
                         *run = Some(TextRun {
                             row,
                             col,
                             next_col: col + width_cells,
                             text: cell.c.to_string(),
                             fg,
                             bold,
                             italic,
                         });
                         // A wide char ends its run: the glyph's natural advance
                         // (~2 cells) is not guaranteed to match, so don't let
                         // drift accumulate into following cells.
                         if width_cells == 2 {
                             text_runs.push(run.take().unwrap());
                         }
                     }
                 }
             }
         }
         if let Some(run) = cur_bg.take() {
             bg_runs.push(run);
         }
         if let Some(run) = cur_text.take() {
             text_runs.push(run);
         }
 
         let cursor = content.cursor;
         let cursor_shape = cursor.shape;
         let cursor_row = cursor.point.line.0 + display_offset;
         let cursor_col = cursor.point.column.0;
         let cursor_rgb = colors::indexed(NamedColor::Cursor as usize, overrides, &cfg_palette);
         let mode = content.mode;
 
         for (row, start, end, rgb) in bg_runs {
             pc.quad(self.cell_rect(row, start, end - start), quad_color(rgb, 1.0));
         }
         for (row, start, end) in sel_runs {
             pc.quad(
                 self.cell_rect(row, start, end - start),
                 quad_color(cfg_palette.selection, 0.28),
             );
         }
         for run in text_runs {
             pc.text_attrs(
                 run.text,
                 pad + run.col as f32 * self.settings.cell_w,
                 pad + run.row as f32 * self.settings.line_h,
                 self.settings.font_size,
                 [run.fg.r, run.fg.g, run.fg.b],
                 Some(font.clone()),
                 Some(bounds),
                 TextAttrs { italic: run.italic, weight: run.bold.then_some(700) },
             );
         }
         for (row, start, end, rgb, is_strike) in deco_runs {
             let mut rect = self.cell_rect(row, start, end - start);
             rect.y += if is_strike {
                 self.settings.line_h * 0.55
             } else {
                 self.settings.line_h - 2.0
             };
             rect.height = 1.0;
             pc.quad(rect, quad_color(rgb, 1.0));
         }
 
         // Cursor last, over the glyphs. Only when visible in the viewport
         // (scrolled history moves it off) and not hidden by DECTCEM.
         if cursor_shape != CursorShape::Hidden
             && mode.contains(TermMode::SHOW_CURSOR)
             && (0..rows as i32).contains(&cursor_row)
         {
             let rect = self.cell_rect(cursor_row as usize, cursor_col, 1);
             if !self.focused {
                 // Hollow outline while unfocused.
                 pc.border(
                     rect,
                     (0.0, 0.0, 0.0, 0.0),
                     [0.0, 0.0, 0.0, 0.0],
                     quad_color(cursor_rgb, 0.8),
                     1.0,
                 );
             } else {
                 match cursor_shape {
                     CursorShape::Beam => {
                         pc.quad(
                             Rect { width: 2.0, ..rect },
                             quad_color(cursor_rgb, 0.9),
                         );
                     }
                     CursorShape::Underline => {
                         pc.quad(
                             Rect { y: rect.y + self.settings.line_h - 2.0, height: 2.0, ..rect },
                             quad_color(cursor_rgb, 0.9),
                         );
                     }
                     // Block (and HollowBlock while focused): translucent
                     // overlay so the glyph beneath stays readable.
                     _ => pc.quad(rect, quad_color(cursor_rgb, 0.4)),
                 }
             }
         }
 
         // Visual bell: a brief foreground-tinted wash over the frame.
         if bell > 0.0 {
             pc.quad(frame, quad_color(cfg_palette.foreground, 0.12 * bell));
         }
 
         // The corner control over the grid, and its menu over everything.
         self.paint_plate_menu(&mut pc);
 
         Some(pc.finish())
     }
 
     fn display_list_text(&self) -> bool {
         true
     }
 
     fn handle_focus_change(&mut self, focused: bool, needs_rebuild: &mut bool) {
         if self.focused != focused {
             self.focused = focused;
             *needs_rebuild = true;
             // Modifier releases are lost while unfocused — start clean.
             self.shift_down = false;
             self.ctrl_down = false;
             self.alt_down = false;
             self.mouse_buttons = 0;
             if self.tab().term.mode().contains(TermMode::FOCUS_IN_OUT) {
                 self.write_pty(if focused { b"\x1b[I" } else { b"\x1b[O" });
             }
         }
     }
 
     fn handle_pointer_move(&mut self, pos: LogicalPosition, needs_rebuild: &mut bool) {
         if std::env::var_os("CCE_TERM_DEBUG").is_some() {
             eprintln!("[input] move ({:.1},{:.1}) selecting={}", pos.x, pos.y, self.selecting);
         }
         // The corner control's hover emphasis is a repaint; the open menu
         // takes the pointer exclusively (its own row hover).
         let was_on_corner = self.plate_corner_hit(self.last_pointer.x as f32, self.last_pointer.y as f32);
         self.last_pointer = pos;
         if self.plate_menu_open() {
             if cce_ui::widget::context_menu::cursor_moved(pos.x as f32, pos.y as f32) {
                 *needs_rebuild = true;
             }
             return;
         }
         if self.plate_corner_hit(pos.x as f32, pos.y as f32) != was_on_corner {
             *needs_rebuild = true;
         }
         if self.mouse_reporting() && !self.selecting {
             let mode = *self.tab().term.mode();
             let motion_wanted = mode.contains(TermMode::MOUSE_MOTION)
                 || (mode.contains(TermMode::MOUSE_DRAG) && self.mouse_buttons != 0);
             if motion_wanted {
                 let cell = self.viewport_cell(pos);
                 if self.tab().last_mouse_cell != Some(cell) {
                     self.tab_mut().last_mouse_cell = Some(cell);
                     // Lowest held button, or 3 (no button) for plain motion.
                     let button = (0..3).find(|b| self.mouse_buttons & (1 << b) != 0).unwrap_or(3);
                     let code = 32 + button + self.report_mods();
                     self.send_mouse_report(code, true, cell.0, cell.1);
                 }
             }
             return;
         }
         if !self.selecting {
             return;
         }
         // Edge overshoot scrolls on tick's autoscroll clock, not per event.
         let (point, side) = self.grid_point(pos);
         if let Some(selection) = &mut self.tab_mut().term.selection {
             selection.update(point, side);
             *needs_rebuild = true;
         }
     }
 
     fn handle_mouse_input(
         &mut self,
         button: MouseButton,
         state: ElementState,
         pos: LogicalPosition,
         needs_rebuild: &mut bool,
     ) -> Option<Self::Message> {
         if std::env::var_os("CCE_TERM_DEBUG").is_some() {
             eprintln!(
                 "[input] {:?} {:?} ({:.1},{:.1}) sel={} mode={:?} shift={}",
                 button,
                 state,
                 pos.x,
                 pos.y,
                 self.tab().term.selection.is_some(),
                 self.tab().term.mode(),
                 self.shift_down
             );
         }
         let button_bit = match button {
             MouseButton::Left => Some(0u8),
             MouseButton::Middle => Some(1),
             MouseButton::Right => Some(2),
             _ => None,
         };
         if let Some(bit) = button_bit {
             match state {
                 ElementState::Pressed => self.mouse_buttons |= 1 << bit,
                 ElementState::Released => self.mouse_buttons &= !(1 << bit),
             }
         }
 
         // The corner menu, ahead of everything: an open menu owns every
         // button event, and a left press on the control opens it (and never
         // reaches the grid — not as a selection, not as a mouse report).
         let (px, py) = (pos.x as f32, pos.y as f32);
         if self.handle_plate_menu_input(button, state, px, py) {
             *needs_rebuild = true;
             return None;
         }
         if button == MouseButton::Left
             && state == ElementState::Pressed
             && self.plate_corner_hit(px, py)
         {
             self.open_plate_menu();
             *needs_rebuild = true;
             return None;
         }
 
         // Application-owned pointer: report and stop — no selection, no
         // middle-paste (Shift bypasses via mouse_reporting).
         if self.mouse_reporting() && !self.selecting {
             if let Some(code) = button_bit {
                 let (col, row) = self.viewport_cell(pos);
                 let code = code + self.report_mods();
                 self.send_mouse_report(code, state == ElementState::Pressed, col, row);
                 if state == ElementState::Pressed {
                     self.tab_mut().last_mouse_cell = Some((col, row));
                 }
             }
             return None;
         }
 
         match (button, state) {
             (MouseButton::Left, ElementState::Pressed) => {
                 let (point, side) = self.grid_point(pos);
                 let now = Instant::now();
                 let repeat = self
                     .last_click
                     .is_some_and(|(t, p)| now - t < MULTI_CLICK_WINDOW && p == point);
                 self.click_count = if repeat { self.click_count % 3 + 1 } else { 1 };
                 self.last_click = Some((now, point));
                 let ty = match self.click_count {
                     2 => SelectionType::Semantic,
                     3 => SelectionType::Lines,
                     _ => SelectionType::Simple,
                 };
                 let had_selection = self.tab().term.selection.is_some();
                 self.tab_mut().term.selection = Some(Selection::new(ty, point, side));
                 self.selecting = true;
                 // Semantic/Lines are non-empty immediately; a fresh Simple
                 // press only needs a repaint if it cleared an old highlight.
                 *needs_rebuild = had_selection || ty != SelectionType::Simple;
             }
             (MouseButton::Left, ElementState::Released) => {
                 self.selecting = false;
                 // Empty selections (a plain click) drop; real ones go to
                 // PRIMARY, per the select-then-middle-click convention.
                 match self.tab().term.selection_to_string() {
                     Some(text) if !text.is_empty() => clip::copy_primary(&text),
                     _ => {
                         if self.tab_mut().term.selection.take().is_some() {
                             *needs_rebuild = true;
                         }
                     }
                 }
             }
             (MouseButton::Middle, ElementState::Pressed) => {
                 if let Some(text) = clip::paste_primary() {
                     if !text.is_empty() {
                         self.paste(&text);
                     }
                 }
             }
             _ => {}
         }
         None
     }
 
     fn handle_mouse_wheel(
         &mut self,
         delta: &MouseScrollDelta,
         pos: LogicalPosition,
         needs_rebuild: &mut bool,
     ) {
         // Lines, signed like the display offset: up is positive.
         let lines = delta.notches_y() * SCROLL_LINES_PER_NOTCH;
 
         // Wheel reports take precedence over alternate-scroll arrows. Both
         // are whole-line protocols and stay quantized.
         if self.mouse_reporting() {
             let Some(lines) = self.take_whole_lines(lines) else { return };
             let (col, row) = self.viewport_cell(pos);
             let code = if lines > 0 { 64 } else { 65 } + self.report_mods();
             for _ in 0..lines.unsigned_abs() {
                 self.send_mouse_report(code, true, col, row);
             }
             return;
         }
 
         let mode = *self.tab().term.mode();
         if mode.contains(TermMode::ALT_SCREEN) && mode.contains(TermMode::ALTERNATE_SCROLL) {
             // Full-screen apps without mouse reporting get arrow keys.
             let Some(lines) = self.take_whole_lines(lines) else { return };
             let key: &[u8] = if lines > 0 { b"\x1b[A" } else { b"\x1b[B" };
             let bytes = key.repeat(lines.unsigned_abs() as usize);
             self.write_pty(&bytes);
             return;
         }
 
         // Scrollback: feed the line-unit motion. `apply_px` rather than
         // `apply` — that one's sign flip and 1:1 pixel path are for pixel
         // offsets, whereas here up grows the offset and the delta is already
         // in lines. A finger lift arrives as a zero delta and must reach the
         // motion (it is what starts the coast), so no early return on zero.
         self.sync_scroll_motion();
         let bounds = self.scrollback_bounds();
         let discrete = matches!(delta, MouseScrollDelta::LineDelta(..));
         let moved =
             self.tab_mut().scroll_motion.apply_px(0.0, lines, discrete, Bounds::max(0.0), bounds);
         if moved && self.apply_scroll_motion() {
             *needs_rebuild = true;
         }
         if self.tab().scroll_motion.is_animating() {
             // A notch only moved the target; tick glides the view there.
             *needs_rebuild = true;
         }
     }
 
     fn handle_key_input(&mut self, event: &KeyEvent, needs_rebuild: &mut bool) -> Option<Self::Message> {
         // Modifier state for mouse reporting (both edges, ahead of the
         // pressed-only gate).
         match &event.logical_key {
             Key::Named(NamedKey::Shift) => self.shift_down = event.state == ElementState::Pressed,
             Key::Named(NamedKey::Control) => {
                 self.ctrl_down = event.state == ElementState::Pressed
             }
             Key::Named(NamedKey::Alt) => self.alt_down = event.state == ElementState::Pressed,
             _ => {}
         }
         if event.state != ElementState::Pressed {
             return None;
         }
 
         // Escape dismisses the corner menu instead of reaching the shell.
         if self.plate_menu_open() && matches!(event.logical_key, Key::Named(NamedKey::Escape)) {
             self.close_plate_menu();
             *needs_rebuild = true;
             return None;
         }
 
         // App shortcuts (input.kdl-rebindable), ahead of terminal encoding —
         // a bare Ctrl+C must still reach the shell as SIGINT.
         use cce_ui::widget::match_key_shortcut;
         if match_key_shortcut(event, &self.keys.copy) {
             if let Some(text) = self.tab().term.selection_to_string() {
                 if !text.is_empty() {
                     cce_ui::widget::clipboard::copy_to_clipboard(&text);
                 }
             }
             return None;
         }
         // Tabs: the same operations the corner menu offers, by chord.
         if match_key_shortcut(event, &self.keys.new_tab) {
             self.new_tab();
             *needs_rebuild = true;
             return None;
         }
         if match_key_shortcut(event, &self.keys.close_tab) {
             self.close_active_tab();
             *needs_rebuild = true;
             return None;
         }
         if match_key_shortcut(event, &self.keys.next_tab) {
             self.cycle_tab(1);
             *needs_rebuild = true;
             return None;
         }
         if match_key_shortcut(event, &self.keys.prev_tab) {
             self.cycle_tab(-1);
             *needs_rebuild = true;
             return None;
         }
         if match_key_shortcut(event, &self.keys.paste) {
             if let Some(text) = cce_ui::widget::clipboard::read_from_clipboard() {
                 if !text.is_empty() {
                     self.paste(&text);
                 }
             }
             return None;
         }
         if match_key_shortcut(event, &self.keys.scroll_up) {
             self.tab_mut().term.scroll_display(Scroll::PageUp);
             *needs_rebuild = true;
             return None;
         }
         if match_key_shortcut(event, &self.keys.scroll_down) {
             self.tab_mut().term.scroll_display(Scroll::PageDown);
             *needs_rebuild = true;
             return None;
         }
 
         if let Some(bytes) = encode_key(event, *self.tab().term.mode()) {
             self.write_pty(&bytes);
             let term = &mut self.tab_mut().term;
             if term.selection.take().is_some() {
                 *needs_rebuild = true;
             }
             if term.grid().display_offset() != 0 {
                 term.scroll_display(Scroll::Bottom);
                 *needs_rebuild = true;
             }
         }
         None
     }
 
     fn clear_color(&self) -> [f32; 4] {
         [0.0, 0.0, 0.0, 0.0]
     }
 }
 
 fn main() {
     // cce-ui logs its own fatal paths (Wayland dispatch / protocol errors that
     // end the event loop) through `log`, which is a no-op sink unless the app
     // installs a logger — without this, an app that dies with its compositor
     // connection leaves no explanation behind.
     env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("info")).init();
     log::info!("cce-terminal starting (pid {})", std::process::id());
     cce_ui::engine::run::<TerminalApp>();
     log::info!("cce-terminal event loop returned; exiting");
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
     use alacritty_terminal::event::VoidListener;
     use alacritty_terminal::index::{Column, Line};
 
     fn term_with(bytes: &[u8]) -> Term<VoidListener> {
         let mut term = Term::new(
             TermConfig::default(),
             &TermDims { cols: 20, rows: 5 },
             VoidListener,
         );
         let mut parser: Processor = Processor::new();
         parser.advance(&mut term, bytes);
         term
     }
 
     #[test]
     fn sgr_colors_land_in_grid() {
         let term = term_with(b"\x1b[31mred\x1b[0m ok");
         let grid = term.grid();
         assert_eq!(grid[Line(0)][Column(0)].c, 'r');
         assert_eq!(grid[Line(0)][Column(0)].fg, AnsiColor::Named(NamedColor::Red));
         assert_eq!(grid[Line(0)][Column(4)].c, 'o');
         assert_eq!(grid[Line(0)][Column(4)].fg, AnsiColor::Named(NamedColor::Foreground));
     }
 
     #[test]
     fn cursor_addressing_works() {
         // CUP to row 3 col 5, write X — the stub couldn't do this.
         let term = term_with(b"\x1b[3;5HX");
         assert_eq!(term.grid()[Line(2)][Column(4)].c, 'X');
         assert_eq!(term.grid().cursor.point.line, Line(2));
     }
 
     fn key(logical_key: Key, ctrl: bool, shift: bool, alt: bool) -> KeyEvent {
         let text = match &logical_key {
             Key::Character(s) if !ctrl && !alt => Some(s.clone()),
             _ => None,
         };
         KeyEvent { state: ElementState::Pressed, logical_key, text, repeat: false, ctrl, shift, alt }
     }
 
     #[test]
     fn app_cursor_mode_switches_arrow_encoding() {
         let ev = key(Key::Named(NamedKey::ArrowUp), false, false, false);
         assert_eq!(encode_key(&ev, TermMode::empty()).unwrap(), b"\x1b[A");
         assert_eq!(encode_key(&ev, TermMode::APP_CURSOR).unwrap(), b"\x1bOA");
     }
 
     #[test]
     fn modifier_parameters_on_csi_keys() {
         let up = |c, s, a| key(Key::Named(NamedKey::ArrowUp), c, s, a);
         // alt = +2, ctrl = +4, shift = +1 on the xterm modifier parameter.
         assert_eq!(encode_key(&up(false, false, true), TermMode::empty()).unwrap(), b"\x1b[1;3A");
         assert_eq!(encode_key(&up(true, false, false), TermMode::empty()).unwrap(), b"\x1b[1;5A");
         assert_eq!(encode_key(&up(true, true, true), TermMode::empty()).unwrap(), b"\x1b[1;8A");
         // Modified keys keep CSI form even in app-cursor mode.
         assert_eq!(
             encode_key(&up(true, false, false), TermMode::APP_CURSOR).unwrap(),
             b"\x1b[1;5A"
         );
         // Tilde keys carry the parameter after their number.
         let del = key(Key::Named(NamedKey::Delete), false, false, true);
         assert_eq!(encode_key(&del, TermMode::empty()).unwrap(), b"\x1b[3;3~");
     }
 
     #[test]
     fn alt_prefixes_esc() {
         let b = key(Key::Character("b".into()), false, false, true);
         assert_eq!(encode_key(&b, TermMode::empty()).unwrap(), b"\x1bb");
         // ctrl+alt compose: ESC then the ctrl byte.
         let w = key(Key::Character("w".into()), true, false, true);
         assert_eq!(encode_key(&w, TermMode::empty()).unwrap(), vec![0x1b, 0x17]);
         // alt+backspace: readline backward-kill-word.
         let bs = key(Key::Named(NamedKey::Backspace), false, false, true);
         assert_eq!(encode_key(&bs, TermMode::empty()).unwrap(), vec![0x1b, 0x7f]);
         // shift+tab is backtab regardless of other state.
         let tab = key(Key::Named(NamedKey::Tab), false, true, false);
         assert_eq!(encode_key(&tab, TermMode::empty()).unwrap(), b"\x1b[Z");
     }
 
     #[test]
     fn selection_extracts_text() {
         let mut term = term_with(b"hello world\r\nsecond line");
         // Word-select "world": semantic selection from a point inside it.
         term.selection = Some(Selection::new(
             SelectionType::Semantic,
             Point::new(Line(0), Column(8)),
             Side::Left,
         ));
         assert_eq!(term.selection_to_string().as_deref(), Some("world"));
         // Line-select the second row.
         term.selection = Some(Selection::new(
             SelectionType::Lines,
             Point::new(Line(1), Column(3)),
             Side::Left,
         ));
         // Line selections carry their trailing newline.
         assert_eq!(term.selection_to_string().as_deref(), Some("second line\n"));
         // Simple drag across the first word.
         let mut sel =
             Selection::new(SelectionType::Simple, Point::new(Line(0), Column(0)), Side::Left);
         sel.update(Point::new(Line(0), Column(4)), Side::Right);
         term.selection = Some(sel);
         assert_eq!(term.selection_to_string().as_deref(), Some("hello"));
     }
 
     #[test]
     fn mouse_report_encodings() {
         let sgr = TermMode::MOUSE_REPORT_CLICK | TermMode::SGR_MOUSE;
         // SGR: press 'M', release 'm', same button code, 1-based coords.
         assert_eq!(mouse_report_bytes(sgr, 0, true, 4, 2).unwrap(), b"\x1b[<0;5;3M");
         assert_eq!(mouse_report_bytes(sgr, 2, false, 0, 0).unwrap(), b"\x1b[<2;1;1m");
         // Legacy: +32 bytes, release collapses the button to 3.
         let legacy = TermMode::MOUSE_REPORT_CLICK;
         assert_eq!(
             mouse_report_bytes(legacy, 0, true, 4, 2).unwrap(),
             vec![0x1b, b'[', b'M', 32, 37, 35]
         );
         assert_eq!(
             mouse_report_bytes(legacy, 0, false, 4, 2).unwrap(),
             vec![0x1b, b'[', b'M', 35, 37, 35]
         );
         // Legacy coordinate saturation at byte 255.
         assert_eq!(mouse_report_bytes(legacy, 0, true, 300, 2).unwrap()[4], 255);
         // UTF-8 extended coords: col 200 → 233 → two-byte UTF-8.
         let utf8 = TermMode::MOUSE_REPORT_CLICK | TermMode::UTF8_MOUSE;
         let bytes = mouse_report_bytes(utf8, 0, true, 199, 0).unwrap();
         assert_eq!(&bytes[4..], "\u{e8}\u{21}".to_string().as_bytes());
     }
 
     #[test]
     fn mouse_modes_land_from_escapes() {
         let term = term_with(b"\x1b[?1002h\x1b[?1006h");
         assert!(term.mode().contains(TermMode::MOUSE_DRAG));
         assert!(term.mode().contains(TermMode::SGR_MOUSE));
         assert!(term.mode().intersects(TermMode::MOUSE_MODE));
     }
 
     #[test]
     fn paste_encoding() {
         assert_eq!(paste_bytes("a\nb\r\nc", false), b"a\rb\rc");
         assert_eq!(
             paste_bytes("hi\x1b[201~!", true),
             b"\x1b[200~hi!\x1b[201~"
         );
     }
 
     #[test]
     fn measured_advance_is_sane() {
         // Depends on the bundled fonts being present ($CCE_FONTS_DIR /
         // ~/Dropbox/Fonts); when they are, the measured advance must sit in
         // the mono band around the 0.60 em estimate.
         if let Some(adv) = measure_advance("Berkeley Mono", 14.0) {
             assert!((5.0..=14.0).contains(&adv), "advance {adv} out of band");
         }
     }
 
     #[test]
     fn shortcut_matching_honors_alt() {
         let ev = key(Key::Character("c".into()), true, true, false);
         assert!(cce_ui::widget::match_key_shortcut(&ev, "ctrl+shift+c"));
         assert!(!cce_ui::widget::match_key_shortcut(&ev, "ctrl+alt+c"));
         let alt_ev = key(Key::Character("c".into()), false, false, true);
         assert!(cce_ui::widget::match_key_shortcut(&alt_ev, "alt+c"));
         assert!(!cce_ui::widget::match_key_shortcut(&alt_ev, "c"));
     }
 
     #[test]
     fn ctrl_chars_encode() {
         let c = key(Key::Character("c".into()), true, false, false);
         assert_eq!(encode_key(&c, TermMode::empty()).unwrap(), vec![0x03]);
         let a = key(Key::Character("a".into()), false, false, false);
         assert_eq!(encode_key(&a, TermMode::empty()).unwrap(), b"a");
     }
 }