// Pure layout computation extracted from `WindowManager::arrange_views()`.
 //
 // Functions here take plain-data snapshots and return placement plans; the
 // mechanism side (`window_manager.rs`) builds the snapshots from FFI state and
 // applies the plans to the scene graph. `arrange()` is the whole frame in one
 // call — the future `Policy::arrange` entry point — composed from the
 // per-section functions below it.
 
 use super::api::{DecorationSpec, Rect, WindowRole};
 use super::tiling::TilingMode;
 
 /// `CCE_ARRANGE_DEBUG=1` — status-bar placement tracing. These sites were
 /// `info!`, so they wrote on every arrange regardless of log level, and a
 /// status-bar commit runs an arrange every second. Mirrors the mechanism-side
 /// switch of the same name in the compositor's `window_manager.rs`.
 fn arrange_debug() -> bool {
     static FLAG: std::sync::OnceLock<bool> = std::sync::OnceLock::new();
     *FLAG.get_or_init(|| std::env::var_os("CCE_ARRANGE_DEBUG").is_some())
 }
 
 /// Which screen edge/region a status-bar window docks to.
 /// Set from the app_id suffix or config; `Unspecified` resolves to `TopLeft`.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum StatusEdge {
     Unspecified,
     TopLeft,
     TopCenter,
     TopRight,
     BottomLeft,
     BottomCenter,
     BottomRight,
     Left,
     Right,
 }
 
 /// Snapshot of one status-bar window, in `self.windows` iteration order.
 /// Windows being interactively dragged are excluded before layout.
 pub struct StatusBarItem {
     pub app_id: String,
     pub edge: StatusEdge,
     /// The segment's length along the bar axis. While a segment is expanded
     /// (see [`Self::expanded`]) the mechanism supplies the FROZEN collapsed
     /// length, so the slot the segment occupies — and every neighbor —
     /// stays put while the surface itself grows.
     pub prev_len: i32,
     /// The segment's committed thickness (perpendicular to the bar axis)
     /// exceeds the bar height: the client has grown its surface into an
     /// in-surface menu. The layout keeps the segment's slot but stops
     /// enforcing its size ([`StatusBarPlacement::enforce_size`]).
     pub expanded: bool,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub struct StatusBarPlacement {
     pub x: i32,
     pub y: i32,
     /// Slot size. Only applied when [`Self::enforce_size`] is set.
     pub width: u32,
     pub height: u32,
     /// False for an expanded segment: position it, but leave its size to the
     /// client (the surface currently IS an open menu; configuring it back to
     /// the slot size would fight the client every commit).
     pub enforce_size: bool,
 }
 
 pub struct StatusBarLayoutParams {
     /// The output's layout box.
     pub output: Rect,
     pub bar_height: u32,
     pub hide_mode: bool,
     /// Pixels of bar left peeking when hide_mode pushes top bars offscreen.
     pub hide_mode_preview: i32,
     /// Gap between adjacent status segments (the bar's `module { spacing }`;
     /// [`DEFAULT_STATUS_MODULE_SPACING`] when unconfigured).
     pub spacing: i32,
     /// Local time as a fraction of the day (0 = midnight, 0.5 = noon).
     /// Some(_) sends the light_source segment traveling the screen
     /// perimeter — noon at top-center, counterclockwise (the sun's path:
     /// morning up the right edge, evening down the left), midnight at
     /// bottom-center. None keeps it in its configured edge group.
     pub day_fraction: Option<f64>,
 }
 
 /// The usable (tileable) area of an output: the layout box, shrunk by the
 /// layer-shell non-exclusive area and by one bar-height per screen edge that
 /// has a status bar docked to it. Top bars reserve no space in hide mode.
 ///
 /// `non_exclusive` is relative to the output box; a zero-sized rect means no
 /// layer-shell exclusion. `status_edges` holds the raw edge of every live
 /// status-bar window (`Unspecified` resolves to `TopLeft`).
 pub fn compute_usable_area(
     output: Rect,
     non_exclusive: Rect,
     bar_height: i32,
     status_hide_mode: bool,
     status_edges: &[StatusEdge],
 ) -> Rect {
     let mut usable = output;
 
     if non_exclusive.width > 0 && non_exclusive.height > 0 {
         usable.x = output.x + non_exclusive.x;
         usable.y = output.y + non_exclusive.y;
         usable.width = non_exclusive.width;
         usable.height = non_exclusive.height;
     }
 
     let mut has_top = false;
     let mut has_bottom = false;
     let mut has_left = false;
     let mut has_right = false;
 
     for &edge in status_edges {
         let edge = if edge == StatusEdge::Unspecified { StatusEdge::TopLeft } else { edge };
         match edge {
             StatusEdge::Unspecified | StatusEdge::TopLeft | StatusEdge::TopCenter | StatusEdge::TopRight => {
                 if !status_hide_mode {
                     has_top = true;
                 }
             }
             StatusEdge::BottomLeft | StatusEdge::BottomCenter | StatusEdge::BottomRight => {
                 has_bottom = true;
             }
             StatusEdge::Left => {
                 has_left = true;
             }
             StatusEdge::Right => {
                 has_right = true;
             }
         }
     }
 
     if has_top {
         usable.y += bar_height;
         usable.height -= bar_height;
     }
     if has_bottom {
         usable.height -= bar_height;
     }
     if has_left {
         usable.x += bar_height;
         usable.width -= bar_height;
     }
     if has_right {
         usable.width -= bar_height;
     }
 
     usable
 }
 
 /// How `arrange_views` treats a window this frame. `Background`/`StatusBar`
 /// windows get fixed geometry regardless of visibility; `Hidden` windows are
 /// disabled in the scene; `Overlay` windows get the overlay slot unless they
 /// are mid-drag (then they arrange as `Normal`).
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum WindowClass {
     Background,
     StatusBar,
     /// The world-anchored grid client (role `Grid`): placed at its patch's
     /// virtual origin with scale `zoom / patch.scale`.
     Grid,
     Hidden,
     Overlay,
     Normal,
 }
 
 pub fn classify_window(
     role: WindowRole,
     minimized: bool,
     closing_or_init: bool,
     mode: TilingMode,
     is_moving: bool,
 ) -> WindowClass {
     match role {
         WindowRole::Background => WindowClass::Background,
         WindowRole::StatusBar => WindowClass::StatusBar,
         WindowRole::Grid => {
             if closing_or_init {
                 WindowClass::Hidden
             } else {
                 WindowClass::Grid
             }
         }
         _ => {
             if minimized || closing_or_init {
                 WindowClass::Hidden
             } else if mode == TilingMode::Overlay && !is_moving {
                 WindowClass::Overlay
             } else {
                 WindowClass::Normal
             }
         }
     }
 }
 
 /// Overlay windows keep 16px clear above for decorations.
 const OVERLAY_DEC_H: i32 = 16;
 
 /// Windows further than this many pixels outside the output are culled.
 const OFFSCREEN_MARGIN: f64 = 50.0;
 
 /// Opacity of an unfocused window's scene tree. Both are 1.0 — the same as
 /// focused — since 2026-09-03. They used to be 0.85 (overlay) and 0.90
 /// (normal), and on a translucent root plate that dimming did not read as
 /// "dimmer": it thinned the plate's tint, so the blurred backdrop showed
 /// through with more contrast and the window looked LESS frosted than the
 /// focused one, which then appeared to gain blur on every focus click. The
 /// blur radius never changed. Keep the knob (and `opacity_enabled`) so the
 /// level can be re-tuned without re-plumbing.
 pub const OVERLAY_UNFOCUSED_OPACITY: f32 = 1.0;
 pub const NORMAL_UNFOCUSED_OPACITY: f32 = 1.0;
 
 pub fn window_opacity(is_focused: bool, opacity_enabled: bool, unfocused: f32) -> f32 {
     if is_focused || !opacity_enabled { 1.0 } else { unfocused }
 }
 
 /// Per-output placement context: the physical box, the usable area from
 /// `compute_usable_area`, and the desktop viewport (pan/zoom).
 pub struct PlacementCtx {
     pub phys: Rect,
     pub usable: Rect,
     pub pan_x: f64,
     pub pan_y: f64,
     pub zoom: f64,
 }
 
 impl PlacementCtx {
     /// Rounds to the nearest pixel, the same way the background grid places
     /// its lattice (`background::grid_frame`). It used to truncate toward
     /// zero: a systematic half-pixel disagreement with the grid, flipping
     /// sign across the origin, so the lattice slid a pixel against window
     /// edges as the camera moved — and the client grid patch (placed through
     /// this same function) landed a pixel off the fallback lattice at every
     /// swap.
     fn virtual_to_screen(&self, vx: f64, vy: f64) -> (i32, i32) {
         (
             self.phys.x + ((vx - self.pan_x) * self.zoom).round() as i32,
             self.phys.y + ((vy - self.pan_y) * self.zoom).round() as i32,
         )
     }
 
     fn is_offscreen(&self, x: i32, y: i32, scaled_w: f64, scaled_h: f64) -> bool {
         let viewport_w = self.phys.width as f64;
         let viewport_h = self.phys.height as f64;
         (x as f64 + scaled_w + OFFSCREEN_MARGIN) < self.phys.x as f64
             || (x as f64 - OFFSCREEN_MARGIN) > (self.phys.x as f64 + viewport_w)
             || (y as f64 + scaled_h + OFFSCREEN_MARGIN) < self.phys.y as f64
             || (y as f64 - OFFSCREEN_MARGIN) > (self.phys.y as f64 + viewport_h)
     }
 }
 
 pub struct OverlaySnapshot {
     pub box_geom: Rect,
     pub min_width: i32,
     pub is_cloud: bool,
     pub ssd: bool,
     pub decorations_size: (i32, i32),
 }
 
 pub struct OverlayParams {
     pub overlay_width: i32,
     pub border_gap: i32,
     /// Server-side border width. Placement no longer insets by it (the border
     /// overhangs the content box); it only sets a floor on the decoration
     /// strip height reserved above the overlay slot.
     pub border_width: i32,
     pub position_right: bool,
     pub cloud_position_default: Option<[i32; 2]>,
 }
 
 pub struct OverlayPlacement {
     pub pos: (i32, i32),
     /// Persistent geometry to store back on the window, if placement chose it.
     pub box_geom_write: Option<Rect>,
     pub virtual_pos: (f64, f64),
     pub size: (u32, u32),
 }
 
 /// Place the primary overlay window: fresh windows get the configured overlay
 /// slot (left or right edge, full usable height); cloud windows snap to their
 /// configured default position; anything else keeps its stored geometry.
 ///
 /// The fresh slot is content-aligned: the content box sits directly on the
 /// configured gaps and the border, which draws outside it, overhangs them.
 /// Stored geometry behaves the same way.
 pub fn place_overlay_window(
     snap: &OverlaySnapshot,
     p: &OverlayParams,
     ctx: &PlacementCtx,
 ) -> OverlayPlacement {
     let bw = p.border_width.max(0);
     let g = p.border_gap;
     let dec_h = std::cmp::max(bw, OVERLAY_DEC_H);
 
     let mut sp_x = snap.box_geom.x;
     let mut sp_y = snap.box_geom.y;
     let mut sp_w = snap.box_geom.width;
     let mut sp_h = snap.box_geom.height;
     let mut box_geom_write = None;
 
     if sp_w == 0 || sp_h == 0 {
         sp_w = if snap.min_width > 32 {
             std::cmp::max(p.overlay_width, snap.min_width)
         } else {
             p.overlay_width
         };
         sp_h = (ctx.usable.height - dec_h - 2 * g).max(1);
 
         sp_x = if p.position_right {
             ctx.usable.x + ctx.usable.width - sp_w - g
         } else {
             ctx.usable.x + g
         };
         sp_y = ctx.usable.y + dec_h + g;
 
         box_geom_write = Some(Rect { x: sp_x, y: sp_y, width: sp_w, height: sp_h });
     } else if snap.is_cloud {
         if let Some(pos) = p.cloud_position_default {
             sp_x = ctx.usable.x + pos[0];
             sp_y = ctx.usable.y + pos[1];
             box_geom_write = Some(Rect { x: sp_x, y: sp_y, width: sp_w, height: sp_h });
         }
     }
 
     let vx = ctx.pan_x + (sp_x - ctx.phys.x) as f64 / ctx.zoom;
     let vy = ctx.pan_y + (sp_y - ctx.phys.y) as f64 / ctx.zoom;
 
     let mut target_w = sp_w;
     let mut target_h = sp_h;
     if !snap.ssd {
         let (dec_w, dec_h) = snap.decorations_size;
         target_w = (sp_w - dec_w).max(1);
         target_h = (sp_h - dec_h).max(1);
     }
 
     OverlayPlacement {
         pos: (sp_x, sp_y),
         box_geom_write,
         virtual_pos: (vx, vy),
         size: (target_w as u32, target_h as u32),
     }
 }
 
 /// State-machine step for entering/leaving Tiled mode. `Enter` tells the
 /// mechanism to save the given restore size (plus the window's current virtual
 /// position) and set `was_tiled`; `Exit` restores the saved geometry — the
 /// client-unmaximize path. (A geometric demotion — dragging a tiled window
 /// off-grid — clears `was_tiled` mechanism-side without an Exit, so the
 /// window stays where it was dropped.) Leaving with an invalid saved size
 /// does nothing (`was_tiled` stays set).
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum TiledTransition {
     Enter { width: i32, height: i32 },
     Exit { width: i32, height: i32, virtual_x: f64, virtual_y: f64 },
 }
 
 pub fn tiled_transition(
     is_tiled_mode: bool,
     was_tiled: bool,
     box_size: (i32, i32),
     min_size: (i32, i32),
     saved_size: (i32, i32),
     saved_virtual: (f64, f64),
 ) -> Option<TiledTransition> {
     if is_tiled_mode && !was_tiled {
         let mut w = box_size.0;
         let mut h = box_size.1;
         if w <= 0 {
             w = if min_size.0 > 32 { min_size.0 } else { 800 };
         }
         if h <= 0 {
             h = if min_size.1 > 32 { min_size.1 } else { 600 };
         }
         Some(TiledTransition::Enter { width: w, height: h })
     } else if !is_tiled_mode && was_tiled {
         if saved_size.0 > 0 && saved_size.1 > 0 {
             Some(TiledTransition::Exit {
                 width: saved_size.0,
                 height: saved_size.1,
                 virtual_x: saved_virtual.0,
                 virtual_y: saved_virtual.1,
             })
         } else {
             None
         }
     } else {
         None
     }
 }
 
 pub struct NormalSnapshot {
     pub mode: TilingMode,
     pub box_geom: Rect,
     pub min_size: (i32, i32),
     pub virtual_pos: (f64, f64),
     /// Live interactive-resize dimensions, if a resize op is in progress.
     pub active_resize: Option<(u32, u32)>,
     pub is_cloud: bool,
 }
 
 pub struct NormalParams {
     pub gap_right: i32,
     pub gap_top: i32,
     pub cloud_position_default: Option<[i32; 2]>,
     /// Desktop grid cell width/height (each axis's period is cell + gap).
     pub desktop_cell_w: f64,
     pub desktop_cell_h: f64,
     /// Desktop grid gap between cells.
     pub desktop_gap_width: f64,
     /// Visual inset of a cell's edge (the fade inset); Tiled windows
     /// snap to the visible cell edges like interactive snapping does.
     pub desktop_cell_inset: f64,
 }
 
 pub struct NormalPlacement {
     pub pos: (i32, i32),
     pub scale: f64,
     pub size: (u32, u32),
     /// Fullscreen windows report all edges tiled to the client.
     pub tiled_all_edges: bool,
     /// Offscreen-culling result; `None` leaves the window's flag untouched.
     pub hidden: Option<bool>,
     /// Tiled grid-snap moves the window's virtual position.
     pub virtual_write: Option<(f64, f64)>,
 }
 
 /// Place a non-overlay window according to its tiling mode: `Popup` docks to
 /// the usable area's top-right (or the cloud default position), `Fullscreen`
 /// covers the physical output, `Tiled` snaps to cover every desktop-grid
 /// cell its current geometry touches, and everything else pans on the virtual
 /// surface under the current viewport.
 pub fn place_normal_window(
     snap: &NormalSnapshot,
     p: &NormalParams,
     ctx: &PlacementCtx,
 ) -> NormalPlacement {
     match snap.mode {
         TilingMode::Popup => {
             let fw = if snap.box_geom.width > 0 {
                 snap.box_geom.width
             } else if snap.min_size.0 > 32 {
                 snap.min_size.0
             } else {
                 360
             };
             let fh = if snap.box_geom.height > 0 {
                 snap.box_geom.height
             } else if snap.min_size.1 > 32 {
                 snap.min_size.1
             } else {
                 100
             };
 
             // The dock slot is content-aligned: the content box sits on the
             // configured gaps and the border overhangs them. Explicit cloud
             // positions are taken as content positions verbatim.
             let (fx, fy) = if snap.is_cloud && p.cloud_position_default.is_some() {
                 let pos = p.cloud_position_default.unwrap();
                 (ctx.usable.x + pos[0], ctx.usable.y + pos[1])
             } else {
                 (ctx.usable.x + ctx.usable.width - fw - p.gap_right, ctx.usable.y + p.gap_top)
             };
 
             NormalPlacement {
                 pos: (fx, fy),
                 scale: 1.0,
                 size: (fw as u32, fh as u32),
                 tiled_all_edges: false,
                 hidden: None,
                 virtual_write: None,
             }
         }
         TilingMode::Fullscreen => NormalPlacement {
             pos: (ctx.phys.x, ctx.phys.y),
             scale: 1.0,
             size: (ctx.phys.width as u32, ctx.phys.height as u32),
             tiled_all_edges: true,
             hidden: None,
             virtual_write: None,
         },
         TilingMode::Tiled => {
             // Cover the VISIBLE edges of every desktop-grid cell the current
             // geometry touches — the same cell-edge geometry as interactive
             // grid snapping (snap::tiled_span). A tiled window's geometry
             // is already cell-aligned (that's what makes it tiled), so this
             // is normally the identity; it aligns a client-requested maximize
             // and absorbs drift.
             let x1 = snap.virtual_pos.0;
             let y1 = snap.virtual_pos.1;
             let x2 = x1 + snap.box_geom.width.max(1) as f64;
             let y2 = y1 + snap.box_geom.height.max(1) as f64;
 
             let (low_x, high_x) = crate::snap::tiled_span(
                 x1, x2, p.desktop_cell_w, p.desktop_gap_width, p.desktop_cell_inset,
             );
             let (low_y, high_y) = crate::snap::tiled_span(
                 y1, y2, p.desktop_cell_h, p.desktop_gap_width, p.desktop_cell_inset,
             );
 
             // The content fills the covered cells edge to edge; the border
             // draws outside it and overhangs into the grid gap.
             let content_x = low_x;
             let content_y = low_y;
             let fw = (high_x - low_x).max(1.0);
             let fh = (high_y - low_y).max(1.0);
 
             let (final_x, final_y) = ctx.virtual_to_screen(content_x, content_y);
 
             NormalPlacement {
                 pos: (final_x, final_y),
                 scale: ctx.zoom,
                 size: (fw as u32, fh as u32),
                 tiled_all_edges: false,
                 hidden: Some(ctx.is_offscreen(final_x, final_y, fw * ctx.zoom, fh * ctx.zoom)),
                 virtual_write: Some((content_x, content_y)),
             }
         }
         _ => {
             // A fresh floating spawn (no established box, no resize in
             // flight) gets the xdg "you choose" size 0x0 instead of a guess:
             // the client maps at its natural size and the acked-commit path
             // adopts that as the box. Guessing from the min-size hint locked
             // self-sizing clients (every cce-ui app) to their minimum — they
             // obey any nonzero configure, so the guess became the box forever.
             if matches!(snap.mode, TilingMode::Floating | TilingMode::Utility)
                 && snap.active_resize.is_none()
                 && snap.box_geom.width <= 0
                 && snap.box_geom.height <= 0
             {
                 let (final_x, final_y) = ctx.virtual_to_screen(snap.virtual_pos.0, snap.virtual_pos.1);
                 return NormalPlacement {
                     pos: (final_x, final_y),
                     scale: ctx.zoom,
                     size: (0, 0),
                     tiled_all_edges: false,
                     // Unmapped until its first buffer; sizeless culling would
                     // be meaningless, so leave the flag untouched.
                     hidden: None,
                     virtual_write: None,
                 };
             }
 
             // Regular pannable window on the virtual surface.
             let fw = if let Some(resize_size) = snap.active_resize {
                 resize_size.0 as i32
             } else if snap.box_geom.width > 0 {
                 snap.box_geom.width
             } else if snap.min_size.0 > 32 {
                 snap.min_size.0
             } else {
                 800
             };
             let fh = if let Some(resize_size) = snap.active_resize {
                 resize_size.1 as i32
             } else if snap.box_geom.height > 0 {
                 snap.box_geom.height
             } else if snap.min_size.1 > 32 {
                 snap.min_size.1
             } else {
                 600
             };
 
             let (final_x, final_y) = ctx.virtual_to_screen(snap.virtual_pos.0, snap.virtual_pos.1);
 
             // A Utility window's size is the client's alone: the plan restates
             // the "you choose" 0x0 on EVERY pass, so the compositor never
             // dictates a size to it — not from a restore, not after an output
             // or scale change (the client re-commits at the new scale and the
             // commit path adopts that as the box). The cull still uses the
             // real box; only the configure size is withheld.
             let size = if snap.mode == TilingMode::Utility {
                 (0, 0)
             } else {
                 (fw as u32, fh as u32)
             };
 
             NormalPlacement {
                 pos: (final_x, final_y),
                 scale: ctx.zoom,
                 size,
                 tiled_all_edges: false,
                 hidden: Some(ctx.is_offscreen(final_x, final_y, fw as f64 * ctx.zoom, fh as f64 * ctx.zoom)),
                 virtual_write: None,
             }
         }
     }
 }
 
 /// Default gap between adjacent status segments — the fallback for
 /// [`StatusBarLayoutParams::spacing`] / [`ArrangeParams::status_module_spacing`].
 pub const DEFAULT_STATUS_MODULE_SPACING: i32 = 12;
 const MARGIN: i32 = 12;
 
 const LEFT_ORDER: &[&str] = &["viewport", "window"];
 // `stats` is the bar's combined readout segment (cpu, memory, brightness,
 // volume and battery in one bubble, 2026-09-16); the five single names stay
 // valid for a bar that still runs them separately.
 const RIGHT_ORDER: &[&str] = &["tray", "stats", "cpu", "memory", "brightness", "volume", "battery", "clock"];
 
 fn left_sort_key(app_id: &str) -> usize {
     let name = app_id.strip_prefix("cce-status-interface-left-")
         .or_else(|| app_id.strip_prefix("cce-status-left-"))
         .unwrap_or(app_id);
     LEFT_ORDER.iter().position(|&m| m == name).unwrap_or(99)
 }
 
 fn right_sort_key(app_id: &str) -> usize {
     let name = app_id.strip_prefix("cce-status-interface-right-")
         .or_else(|| app_id.strip_prefix("cce-status-right-"))
         .unwrap_or(app_id);
     RIGHT_ORDER.iter().position(|&m| m == name).unwrap_or(99)
 }
 
 /// Bar length to use: previous major length, or 100 for a fresh bar.
 fn bar_len(prev_len: i32) -> u32 {
     if prev_len > 0 { prev_len as u32 } else { 100 }
 }
 
 fn is_light_source(app_id: &str) -> bool {
     app_id.ends_with("light_source")
 }
 
 /// A point on the output-rect perimeter for the traveling light_source
 /// segment, plus the edge it lies on (0 top, 1 left, 2 bottom, 3 right).
 /// `day` is the local day fraction (0 = midnight); the path runs
 /// counterclockwise from top-center at noon.
 fn sun_perimeter_point(output: Rect, day: f64) -> (f64, f64, u8) {
     let bw = output.width as f64;
     let bh = output.height as f64;
     // Perimeter fraction from top-center: noon → 0, 18:00 → ¼ (mid left
     // edge), midnight → ½ (bottom center), 06:00 → ¾ (mid right edge).
     let f = (day + 0.5).fract();
     let mut s = f * 2.0 * (bw + bh);
     if s < bw / 2.0 {
         return (bw / 2.0 - s, 0.0, 0);
     }
     s -= bw / 2.0;
     if s < bh {
         return (0.0, s, 1);
     }
     s -= bh;
     if s < bw {
         return (s, bh, 2);
     }
     s -= bw;
     if s < bh {
         return (bw, bh - s, 3);
     }
     s -= bh;
     (bw - s, 0.0, 0)
 }
 
 /// Lay out status-bar windows on one output: horizontal groups on the top and
 /// bottom edges (left/center/right within each), vertical stacks on the left
 /// and right edges, and full-width bars across the top.
 ///
 /// Returns one placement per item, index-aligned with `items`.
 pub fn layout_status_bars(
     items: &[StatusBarItem],
     p: &StatusBarLayoutParams,
 ) -> Vec<Option<StatusBarPlacement>> {
     let wlr_box = p.output;
     let bar_h = p.bar_height;
     let spacing = p.spacing;
     let margin = MARGIN;
 
     let mut top_left: Vec<usize> = Vec::new();
     let mut top_center: Vec<usize> = Vec::new();
     let mut top_right: Vec<usize> = Vec::new();
     let mut bottom_left: Vec<usize> = Vec::new();
     let mut bottom_center: Vec<usize> = Vec::new();
     let mut bottom_right: Vec<usize> = Vec::new();
     let mut left_side: Vec<usize> = Vec::new();
     let mut right_side: Vec<usize> = Vec::new();
     let mut full_top: Vec<usize> = Vec::new();
     let mut sun_track: Vec<usize> = Vec::new();
 
     for (idx, item) in items.iter().enumerate() {
         // The light_source segment ignores edge groups: it travels the
         // screen perimeter with the time of day (see sun_perimeter_point).
         if p.day_fraction.is_some() && is_light_source(&item.app_id) {
             sun_track.push(idx);
             continue;
         }
         let edge = if item.edge == StatusEdge::Unspecified {
             StatusEdge::TopLeft
         } else {
             item.edge
         };
         match edge {
             StatusEdge::TopLeft => top_left.push(idx),
             StatusEdge::TopCenter => top_center.push(idx),
             StatusEdge::TopRight => top_right.push(idx),
             StatusEdge::BottomLeft => bottom_left.push(idx),
             StatusEdge::BottomCenter => bottom_center.push(idx),
             StatusEdge::BottomRight => bottom_right.push(idx),
             StatusEdge::Left => left_side.push(idx),
             StatusEdge::Right => right_side.push(idx),
             _ => full_top.push(idx),
         }
     }
 
     if arrange_debug() {
         log::debug!("[ArrangeStatus] top_left_len={}, top_center_len={}, top_right_len={}, left_side_len={}", top_left.len(), top_center.len(), top_right.len(), left_side.len());
     }
 
     let sort_left = |list: &mut Vec<usize>| {
         list.sort_by_key(|&i| left_sort_key(&items[i].app_id));
     };
     let sort_right = |list: &mut Vec<usize>| {
         list.sort_by_key(|&i| right_sort_key(&items[i].app_id));
     };
 
     sort_left(&mut top_left);
     sort_left(&mut top_center);
     sort_right(&mut top_right);
     sort_left(&mut bottom_left);
     sort_left(&mut bottom_center);
     sort_right(&mut bottom_right);
 
     let mut placements: Vec<Option<StatusBarPlacement>> = vec![None; items.len()];
 
     // 1. Top Edge
     let status_y_top = if p.hide_mode {
         wlr_box.y - (bar_h as i32 - p.hide_mode_preview)
     } else {
         wlr_box.y
     };
 
     let mut top_right_width_needed = 0;
     for &i in &top_right {
         let w = bar_len(items[i].prev_len);
         top_right_width_needed += w as i32 + spacing;
     }
     let top_right_boundary = wlr_box.x + wlr_box.width - margin - top_right_width_needed;
 
     // 1a. Left Group (TopLeft / nw)
     let mut cur_left_x = wlr_box.x + margin;
     for &i in &top_left {
         let mut w = bar_len(items[i].prev_len);
         let max_allowed_w = top_right_boundary - cur_left_x - spacing;
         if w as i32 > max_allowed_w {
             w = std::cmp::max(max_allowed_w, 20) as u32;
         }
         if arrange_debug() {
             log::debug!("[TopLeftLayout] app_id={} x={}, w={}", items[i].app_id, cur_left_x, w);
         }
         placements[i] = Some(StatusBarPlacement { x: cur_left_x, y: status_y_top, width: w, height: bar_h, enforce_size: !items[i].expanded });
         cur_left_x += w as i32 + spacing;
     }
 
     // 1b. Center Group (TopCenter / n)
     let mut top_center_width_needed = 0;
     for &i in &top_center {
         let w = bar_len(items[i].prev_len);
         top_center_width_needed += w as i32 + spacing;
     }
     if top_center_width_needed > 0 {
         top_center_width_needed -= spacing;
     }
     let center_start_x = wlr_box.x + (wlr_box.width - top_center_width_needed) / 2;
     let mut cur_center_x = std::cmp::max(center_start_x, cur_left_x + spacing);
 
     for &i in &top_center {
         let mut w = bar_len(items[i].prev_len);
         let max_allowed_w = top_right_boundary - cur_center_x - spacing;
         if w as i32 > max_allowed_w {
             w = std::cmp::max(max_allowed_w, 20) as u32;
         }
         log::info!("[TopCenterLayout] app_id={} x={}, w={}", items[i].app_id, cur_center_x, w);
         placements[i] = Some(StatusBarPlacement { x: cur_center_x, y: status_y_top, width: w, height: bar_h, enforce_size: !items[i].expanded });
         cur_center_x += w as i32 + spacing;
     }
 
     // 1c. Right Group (TopRight / ne)
     let mut cur_right_x = wlr_box.x + wlr_box.width - margin;
     for &i in top_right.iter().rev() {
         let w = bar_len(items[i].prev_len);
         let x = cur_right_x - w as i32;
         placements[i] = Some(StatusBarPlacement { x, y: status_y_top, width: w, height: bar_h, enforce_size: !items[i].expanded });
         cur_right_x = x - spacing;
     }
 
     for &i in &full_top {
         placements[i] = Some(StatusBarPlacement { x: wlr_box.x, y: status_y_top, width: wlr_box.width as u32, height: bar_h, enforce_size: !items[i].expanded });
     }
 
     // 2. Bottom Edge
     let status_y_bottom = wlr_box.y + wlr_box.height - bar_h as i32;
 
     let mut bottom_right_width_needed = 0;
     for &i in &bottom_right {
         let w = bar_len(items[i].prev_len);
         bottom_right_width_needed += w as i32 + spacing;
     }
     let bottom_right_boundary = wlr_box.x + wlr_box.width - margin - bottom_right_width_needed;
 
     // 2a. Left Group (BottomLeft / sw)
     let mut cur_left_x = wlr_box.x + margin;
     for &i in &bottom_left {
         let mut w = bar_len(items[i].prev_len);
         let max_allowed_w = bottom_right_boundary - cur_left_x - spacing;
         if w as i32 > max_allowed_w {
             w = std::cmp::max(max_allowed_w, 20) as u32;
         }
         placements[i] = Some(StatusBarPlacement { x: cur_left_x, y: status_y_bottom, width: w, height: bar_h, enforce_size: !items[i].expanded });
         cur_left_x += w as i32 + spacing;
     }
 
     // 2b. Center Group (BottomCenter / s)
     let mut bottom_center_width_needed = 0;
     for &i in &bottom_center {
         let w = bar_len(items[i].prev_len);
         bottom_center_width_needed += w as i32 + spacing;
     }
     if bottom_center_width_needed > 0 {
         bottom_center_width_needed -= spacing;
     }
     let center_start_x = wlr_box.x + (wlr_box.width - bottom_center_width_needed) / 2;
     let mut cur_center_x = std::cmp::max(center_start_x, cur_left_x + spacing);
 
     for &i in &bottom_center {
         let mut w = bar_len(items[i].prev_len);
         let max_allowed_w = bottom_right_boundary - cur_center_x - spacing;
         if w as i32 > max_allowed_w {
             w = std::cmp::max(max_allowed_w, 20) as u32;
         }
         placements[i] = Some(StatusBarPlacement { x: cur_center_x, y: status_y_bottom, width: w, height: bar_h, enforce_size: !items[i].expanded });
         cur_center_x += w as i32 + spacing;
     }
 
     // 2c. Right Group (BottomRight / se)
     let mut cur_right_x = wlr_box.x + wlr_box.width - margin;
     for &i in bottom_right.iter().rev() {
         let w = bar_len(items[i].prev_len);
         let x = cur_right_x - w as i32;
         placements[i] = Some(StatusBarPlacement { x, y: status_y_bottom, width: w, height: bar_h, enforce_size: !items[i].expanded });
         cur_right_x = x - spacing;
     }
 
     // 3. Left Edge (Vertical stacking)
     let mut left_total_height = 0;
     for &i in &left_side {
         let actual_h = bar_len(items[i].prev_len);
         left_total_height += actual_h as i32;
     }
     if !left_side.is_empty() {
         left_total_height += (left_side.len() as i32 - 1) * spacing;
     }
     let mut cur_left_y = wlr_box.y + (wlr_box.height - left_total_height) / 2;
 
     for &i in &left_side {
         let actual_h = bar_len(items[i].prev_len);
         placements[i] = Some(StatusBarPlacement { x: wlr_box.x, y: cur_left_y, width: bar_h, height: actual_h, enforce_size: !items[i].expanded });
         cur_left_y += actual_h as i32 + spacing;
     }
 
     // 4. Right Edge (Vertical stacking)
     let mut right_total_height = 0;
     for &i in &right_side {
         let actual_h = bar_len(items[i].prev_len);
         right_total_height += actual_h as i32;
     }
     if !right_side.is_empty() {
         right_total_height += (right_side.len() as i32 - 1) * spacing;
     }
     let mut cur_right_y = wlr_box.y + (wlr_box.height - right_total_height) / 2;
 
     for &i in &right_side {
         let actual_h = bar_len(items[i].prev_len);
         placements[i] = Some(StatusBarPlacement { x: wlr_box.x + wlr_box.width - bar_h as i32, y: cur_right_y, width: bar_h, height: actual_h, enforce_size: !items[i].expanded });
         cur_right_y += actual_h as i32 + spacing;
     }
 
     // 4. The traveling light_source segment: center the (always-horizontal)
     // segment box on the day-fraction perimeter point, clamped inside the
     // output so the corners are turned smoothly. In hide mode it slips off
     // its current edge like every other segment, leaving the same preview.
     if let Some(day) = p.day_fraction {
         for &i in &sun_track {
             let w = bar_len(items[i].prev_len) ;
             let (px, py, edge) = sun_perimeter_point(wlr_box, day);
             let mut x = (wlr_box.x as f64 + px - w as f64 / 2.0).round() as i32;
             let mut y = (wlr_box.y as f64 + py - bar_h as f64 / 2.0).round() as i32;
             x = x.clamp(wlr_box.x, wlr_box.x + wlr_box.width - w as i32);
             y = y.clamp(wlr_box.y, wlr_box.y + wlr_box.height - bar_h as i32);
             if p.hide_mode {
                 match edge {
                     0 => y = wlr_box.y - (bar_h as i32 - p.hide_mode_preview),
                     1 => x = wlr_box.x - (w as i32 - p.hide_mode_preview),
                     2 => y = wlr_box.y + wlr_box.height - p.hide_mode_preview,
                     _ => x = wlr_box.x + wlr_box.width - p.hide_mode_preview,
                 }
             }
             placements[i] = Some(StatusBarPlacement { x, y, width: w, height: bar_h, enforce_size: !items[i].expanded });
         }
     }
 
     placements
 }
 
 /// One enabled output, as `arrange` needs it.
 #[derive(Debug, Clone, Copy)]
 pub struct OutputSnapshot {
     /// The output's layout box.
     pub layout_box: Rect,
     /// Layer-shell non-exclusive area, relative to the layout box; a
     /// zero-sized rect means no exclusion.
     pub non_exclusive: Rect,
 }
 
 /// Everything `arrange` reads about one window. Built once per frame by the
 /// mechanism side; seat-dependent answers (`being_moved`, `active_resize`)
 /// are captured here so the pure pass never queries mid-computation.
 #[derive(Debug, Clone)]
 pub struct WindowSnapshot {
     pub app_id: Option<String>,
     /// Only used verbatim in log lines.
     pub title: Option<String>,
     pub role: WindowRole,
     pub minimized: bool,
     /// Window state is Closing or Init.
     pub closing_or_init: bool,
     /// Resolved tiling mode (`get_mode_for_window`).
     pub mode: TilingMode,
     /// Status segments only: the along-bar length last committed while the
     /// segment was at bar thickness, tracked by the mechanism. Keeps the
     /// segment's slot stable while it is EXPANDED (surface grown into an
     /// in-surface menu); 0 when never collapsed-committed (fall back to the
     /// live box).
     pub status_collapsed_len: i32,
     /// Mode-rule SSD override; pre-gated on `!mode_locked`.
     pub rule_ssd: Option<bool>,
     /// A seat is interactively moving this window.
     pub being_moved: bool,
     pub status_edge: StatusEdge,
     pub is_focused: bool,
     pub box_geom: Rect,
     /// (min_width, min_height) size hints.
     pub min_size: (i32, i32),
     pub virtual_pos: (f64, f64),
     pub active_resize: Option<(u32, u32)>,
     /// Current `wm_requested.ssd`.
     pub ssd: bool,
     /// Raw decoration measurement (`measure_decorations`), not gated on
     /// `ssd` — placement applies it only when the effective SSD is off.
     pub decorations_size: (i32, i32),
     pub was_tiled: bool,
     pub saved_floating_size: (i32, i32),
     pub saved_floating_virtual: (f64, f64),
     /// Grid-role windows only: the latched world-anchored patch the current
     /// buffer covers. `None` until the first rendered patch arrives (the
     /// window stays out of the scene until then).
     pub grid_patch: Option<crate::api::GridPatch>,
 }
 
 /// Frame-wide inputs: config knobs plus the desktop viewport.
 pub struct ArrangeParams {
     pub bar_height: i32,
     pub status_hide_mode: bool,
     pub hide_mode_preview: i32,
     /// Gap between adjacent status segments (see `StatusBarLayoutParams::spacing`).
     pub status_module_spacing: i32,
     /// Local day fraction for the traveling light_source segment (see
     /// `StatusBarLayoutParams::day_fraction`).
     pub day_fraction: Option<f64>,
     /// `status_background_blur > 0.001`.
     pub status_blur: bool,
     pub window_blur: bool,
     /// `layout.window_opacity` — unfocused windows dim when set.
     pub opacity_enabled: bool,
     /// The configured server-side decoration, applied to every placed window.
     pub decoration: DecorationSpec,
     /// Border color for the focused window (falls back to the unfocused
     /// color in config when unset).
     pub border_color_focused: crate::api::Rgba,
     pub overlay: OverlayParams,
     pub normal: NormalParams,
     pub pan_x: f64,
     pub pan_y: f64,
     pub zoom: f64,
 }
 
 /// Write instructions for one window. `None` leaves the field untouched, so
 /// the mechanism apply loop is a flat sequence of `if let Some` writes.
 #[derive(Debug, Clone, Default, PartialEq)]
 pub struct WindowPlan {
     /// Enable/disable the window's scene tree.
     pub scene_enabled: Option<bool>,
     pub hidden: Option<bool>,
     pub tiling_mode: Option<TilingMode>,
     /// `wm_requested.tiled` edge bitmask.
     pub tiled: Option<u32>,
     pub ssd: Option<bool>,
     pub scale: Option<f64>,
     /// `rendering_requested.{x,y}`.
     pub pos: Option<(i32, i32)>,
     /// `wm_requested.dimensions` and `.bounds`.
     pub size: Option<(u32, u32)>,
     /// Persistent geometry write-back.
     pub box_geom: Option<Rect>,
     pub virtual_pos: Option<(f64, f64)>,
     pub blur: Option<bool>,
     pub decoration: Option<DecorationSpec>,
     pub opacity: Option<f32>,
     pub was_tiled: Option<bool>,
     /// Tiled-enter save: (restore size, restore virtual position).
     pub saved_floating: Option<((i32, i32), (f64, f64))>,
 }
 
 pub struct ArrangePlan {
     /// Index-aligned with the input snapshots.
     pub windows: Vec<WindowPlan>,
     /// Whether each output's fallback background rect should be shown
     /// (false while a wallpaper window exists).
     pub background_rect_enabled: bool,
     /// Whether the compositor-drawn cell lattice should be shown: false
     /// while a live grid client (role Grid, mapped, with a latched patch)
     /// covers the desktop. The gap-colored backdrop stays either way.
     pub grid_cells_enabled: bool,
 }
 
 fn is_cloud_app(app_id: Option<&str>) -> bool {
     app_id.map_or(false, |id| id.starts_with("cce-cloud"))
 }
 
 /// The decoration one placed window gets: the configured spec with the
 /// focused border color swapped in, and no border at all when fullscreen.
 fn decoration_for(p: &ArrangeParams, is_focused: bool, mode: TilingMode) -> DecorationSpec {
     if mode == TilingMode::Fullscreen {
         return DecorationSpec {
             border_width: 0,
             corner_radius: 0,
             ..p.decoration
         };
     }
     DecorationSpec {
         border_color: if is_focused {
             p.border_color_focused
         } else {
             p.decoration.border_color
         },
         ..p.decoration
     }
 }
 
 /// The whole arrange pass as one pure function: classify every window, place
 /// overlays/normals/status bars per output, and return per-window write
 /// instructions.
 ///
 /// The output loop is last-wins, like the mechanism loop it replaces: every
 /// output pass re-plans every window, so with several outputs the final plan
 /// reflects the last one. State that arranging itself evolves (box geometry,
 /// virtual position, SSD overrides, the tiled save/restore machine) is
 /// tracked on a working copy of the snapshots so later sections and later
 /// output passes read what earlier ones wrote — exactly as the mutating
 /// original did.
 pub fn arrange(
     windows: &[WindowSnapshot],
     outputs: &[OutputSnapshot],
     p: &ArrangeParams,
 ) -> ArrangePlan {
     let mut state: Vec<WindowSnapshot> = windows.to_vec();
     let mut plan: Vec<WindowPlan> = vec![WindowPlan::default(); windows.len()];
 
     let has_wallpaper = state.iter().any(|w| w.role == WindowRole::Background);
     let has_grid_client = state.iter().any(|w| {
         w.role == WindowRole::Grid && !w.closing_or_init && !w.minimized && w.grid_patch.is_some()
     });
 
     for out in outputs {
         let phys = out.layout_box;
 
         let status_edges: Vec<StatusEdge> = state
             .iter()
             .filter(|w| w.role == WindowRole::StatusBar)
             .map(|w| w.status_edge)
             .collect();
         let usable = compute_usable_area(
             phys,
             out.non_exclusive,
             p.bar_height,
             p.status_hide_mode,
             &status_edges,
         );
         let ctx = PlacementCtx {
             phys,
             usable,
             pan_x: p.pan_x,
             pan_y: p.pan_y,
             zoom: p.zoom,
         };
 
         let mut overlay_windows: Vec<usize> = Vec::new();
         let mut normal_windows: Vec<usize> = Vec::new();
 
         for (i, w) in state.iter_mut().enumerate() {
             let class = classify_window(w.role, w.minimized, w.closing_or_init, w.mode, w.being_moved);
             let wp = &mut plan[i];
             match class {
                 WindowClass::Background => {
                     wp.tiling_mode = Some(TilingMode::Status);
                     wp.tiled = Some(0);
                     wp.ssd = Some(false);
                     w.ssd = false;
                     wp.scale = Some(1.0);
                     wp.scene_enabled = Some(true);
                     wp.hidden = Some(false);
                     wp.blur = Some(false);
                     wp.pos = Some((phys.x, phys.y));
                     wp.size = Some((phys.width as u32, phys.height as u32));
                 }
                 WindowClass::StatusBar => {
                     wp.tiling_mode = Some(TilingMode::Status);
                     wp.tiled = Some(0);
                     wp.ssd = Some(false);
                     w.ssd = false;
                     wp.scale = Some(1.0);
                     wp.scene_enabled = Some(true);
                     wp.hidden = Some(false);
                     wp.blur = Some(p.status_blur);
                 }
                 WindowClass::Grid => {
                     match w.grid_patch {
                         Some(patch) if patch.scale > 0.0 => {
                             wp.scene_enabled = Some(true);
                             wp.hidden = Some(false);
                             wp.tiled = Some(0);
                             wp.ssd = Some(false);
                             w.ssd = false;
                             let (sx, sy) = ctx.virtual_to_screen(patch.x, patch.y);
                             wp.pos = Some((sx, sy));
                             // The buffer holds patch.scale px per virtual
                             // unit; displaying it at zoom/patch.scale puts
                             // it in per-frame lockstep with window content.
                             wp.scale = Some(ctx.zoom / patch.scale);
                             // The content box IS the buffer: dest sizing and
                             // culling read box_geom, which nothing else
                             // maintains for a window the compositor never
                             // configures.
                             wp.box_geom = Some(Rect {
                                 x: sx,
                                 y: sy,
                                 width: (patch.w * patch.scale).round() as i32,
                                 height: (patch.h * patch.scale).round() as i32,
                             });
                             wp.blur = Some(false);
                             wp.opacity = Some(1.0);
                         }
                         _ => {
                             // No rendered patch yet: keep it out of the
                             // scene — no flash of an unanchored buffer. The
                             // xdg "you choose" size unblocks the map state
                             // machine (a window with NO planned dimensions
                             // can never leave Ready — same trick as Utility)
                             // but is planned ONLY in this pre-patch phase:
                             // once a patch is latched the client owns its
                             // size, and re-sending 0x0 per arrange bounced
                             // the surface between the settings size and the
                             // patch size — a swapchain-thrash that ate GBs.
                             wp.size = Some((0, 0));
                             wp.scene_enabled = Some(false);
                             wp.hidden = Some(true);
                         }
                     }
                 }
                 WindowClass::Hidden => {
                     wp.scene_enabled = Some(false);
                     wp.hidden = Some(true);
                 }
                 WindowClass::Overlay | WindowClass::Normal => {
                     wp.scene_enabled = Some(true);
                     wp.hidden = Some(false);
                     wp.tiling_mode = Some(w.mode);
                     if let Some(rule_ssd) = w.rule_ssd {
                         wp.ssd = Some(rule_ssd);
                         w.ssd = rule_ssd;
                     }
                     if class == WindowClass::Overlay {
                         overlay_windows.push(i);
                     } else {
                         normal_windows.push(i);
                     }
                 }
             }
         }
 
         for (sp_idx, &i) in overlay_windows.iter().enumerate() {
             if sp_idx == 0 {
                 let w = &state[i];
                 let placement = place_overlay_window(
                     &OverlaySnapshot {
                         box_geom: w.box_geom,
                         min_width: w.min_size.0,
                         is_cloud: is_cloud_app(w.app_id.as_deref()),
                         ssd: w.ssd,
                         decorations_size: w.decorations_size,
                     },
                     &p.overlay,
                     &ctx,
                 );
 
                 if let Some(bg) = placement.box_geom_write {
                     state[i].box_geom = bg;
                 }
                 state[i].virtual_pos = placement.virtual_pos;
 
                 let wp = &mut plan[i];
                 if let Some(bg) = placement.box_geom_write {
                     wp.box_geom = Some(bg);
                 }
                 wp.pos = Some(placement.pos);
                 wp.scale = Some(1.0);
                 wp.virtual_pos = Some(placement.virtual_pos);
                 wp.size = Some(placement.size);
                 wp.tiled = Some(1 | 2 | 4 | 8);
                 wp.decoration = Some(decoration_for(p, state[i].is_focused, state[i].mode));
                 wp.blur = Some(p.window_blur);
                 wp.opacity = Some(window_opacity(
                     state[i].is_focused,
                     p.opacity_enabled,
                     OVERLAY_UNFOCUSED_OPACITY,
                 ));
             } else {
                 normal_windows.push(i);
             }
         }
 
         // Manage entering/exiting Tiled state for normal windows.
         for &i in &normal_windows {
             let w = &state[i];
             let transition = tiled_transition(
                 w.mode == TilingMode::Tiled,
                 w.was_tiled,
                 (w.box_geom.width, w.box_geom.height),
                 w.min_size,
                 w.saved_floating_size,
                 w.saved_floating_virtual,
             );
             match transition {
                 Some(TiledTransition::Enter { width, height }) => {
                     let w = &mut state[i];
                     w.saved_floating_size = (width, height);
                     w.saved_floating_virtual = w.virtual_pos;
                     w.was_tiled = true;
                     let wp = &mut plan[i];
                     wp.saved_floating = Some(((width, height), w.saved_floating_virtual));
                     wp.was_tiled = Some(true);
                     log::info!("[Tiled] Saved window {:?} geometry: {}x{} at ({}, {})",
                         w.title.as_deref().unwrap_or(""),
                         width, height,
                         w.saved_floating_virtual.0, w.saved_floating_virtual.1
                     );
                 }
                 Some(TiledTransition::Exit { width, height, virtual_x, virtual_y }) => {
                     let w = &mut state[i];
                     w.box_geom.width = width;
                     w.box_geom.height = height;
                     w.virtual_pos = (virtual_x, virtual_y);
                     w.was_tiled = false;
                     let wp = &mut plan[i];
                     wp.box_geom = Some(w.box_geom);
                     wp.virtual_pos = Some((virtual_x, virtual_y));
                     wp.was_tiled = Some(false);
                     wp.size = Some((width as u32, height as u32));
                     log::info!("[Tiled] Restored window {:?} geometry: {}x{} at ({}, {})",
                         w.title.as_deref().unwrap_or(""),
                         width, height, virtual_x, virtual_y
                     );
                 }
                 None => {}
             }
         }
 
         // Arrange normal windows on the virtual surface.
         for &i in &normal_windows {
             let w = &state[i];
             let mode = w.mode;
             let placement = place_normal_window(
                 &NormalSnapshot {
                     mode: w.mode,
                     box_geom: w.box_geom,
                     min_size: w.min_size,
                     virtual_pos: w.virtual_pos,
                     active_resize: w.active_resize,
                     is_cloud: is_cloud_app(w.app_id.as_deref()),
                 },
                 &p.normal,
                 &ctx,
             );
 
             let is_focused = w.is_focused;
             if let Some(v) = placement.virtual_write {
                 state[i].virtual_pos = v;
             }
 
             let wp = &mut plan[i];
             wp.pos = Some(placement.pos);
             wp.scale = Some(placement.scale);
             if let Some(v) = placement.virtual_write {
                 wp.virtual_pos = Some(v);
             }
             if let Some(hidden) = placement.hidden {
                 wp.hidden = Some(hidden);
             }
             wp.size = Some(placement.size);
             if placement.tiled_all_edges {
                 wp.tiled = Some(1 | 2 | 4 | 8);
             }
             wp.decoration = Some(decoration_for(p, is_focused, mode));
             wp.blur = Some(p.window_blur);
             wp.opacity = Some(window_opacity(is_focused, p.opacity_enabled, NORMAL_UNFOCUSED_OPACITY));
         }
 
         // Position status bar windows on this output, excluding any being
         // interactively dragged.
         let mut status_items: Vec<StatusBarItem> = Vec::new();
         let mut status_idxs: Vec<usize> = Vec::new();
         for (i, w) in state.iter().enumerate() {
             if w.closing_or_init {
                 continue;
             }
             if let Some(app_id) = &w.app_id {
                 if app_id.starts_with("cce-status") {
                     if w.being_moved {
                         continue;
                     }
                     if arrange_debug() {
                         log::debug!("[ArrangeStatus] app_id={} status_edge={:?}", app_id, w.status_edge);
                     }
                     // Thickness = the axis perpendicular to the segment's
                     // edge; a segment thicker than the bar has grown an
                     // in-surface menu (expanded) and keeps its FROZEN
                     // collapsed slot length instead of the live box.
                     let (len, thickness) = match w.status_edge {
                         StatusEdge::Left | StatusEdge::Right => (w.box_geom.height, w.box_geom.width),
                         _ => (w.box_geom.width, w.box_geom.height),
                     };
                     let expanded = thickness > p.bar_height && w.status_collapsed_len > 0;
                     status_items.push(StatusBarItem {
                         app_id: app_id.clone(),
                         edge: w.status_edge,
                         prev_len: if expanded { w.status_collapsed_len } else { len },
                         expanded,
                     });
                     status_idxs.push(i);
                 }
             }
         }
 
         let placements = layout_status_bars(
             &status_items,
             &StatusBarLayoutParams {
                 output: phys,
                 bar_height: p.bar_height as u32,
                 hide_mode: p.status_hide_mode,
                 hide_mode_preview: p.hide_mode_preview,
                 spacing: p.status_module_spacing,
                 day_fraction: p.day_fraction,
             },
         );
 
         for (&i, placement) in status_idxs.iter().zip(placements.iter()) {
             if let Some(pl) = placement {
                 plan[i].pos = Some((pl.x, pl.y));
                 // An expanded segment keeps client-owned sizing: scheduling
                 // the slot size would fight the open menu every commit.
                 plan[i].size = pl.enforce_size.then_some((pl.width, pl.height));
             }
         }
     }
 
     ArrangePlan {
         windows: plan,
         background_rect_enabled: !has_wallpaper,
         grid_cells_enabled: !has_grid_client,
     }
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
 
     fn params() -> StatusBarLayoutParams {
         StatusBarLayoutParams {
             output: Rect { x: 0, y: 0, width: 1920, height: 1080 },
             bar_height: 30,
             hide_mode: false,
             hide_mode_preview: 5,
             spacing: DEFAULT_STATUS_MODULE_SPACING,
             day_fraction: None,
         }
     }
 
     fn item(app_id: &str, edge: StatusEdge, prev_len: i32) -> StatusBarItem {
         StatusBarItem { app_id: app_id.to_string(), edge, prev_len, expanded: false }
     }
 
     #[test]
     fn light_source_travels_the_perimeter() {
         // 1920x1080 output, bar 30, segment len 36. Noon → top center,
         // 18:00 → mid left edge, midnight → bottom center, 06:00 → mid
         // right edge; counterclockwise in between.
         let items = vec![item("cce-status-left-light_source", StatusEdge::TopLeft, 36)];
         let mut p = params();
 
         p.day_fraction = Some(0.5); // noon
         let pl = layout_status_bars(&items, &p)[0].unwrap();
         assert_eq!((pl.x, pl.y), (1920 / 2 - 18, 0));
 
         p.day_fraction = Some(0.75); // 18:00 — mid left edge
         let pl = layout_status_bars(&items, &p)[0].unwrap();
         assert_eq!((pl.x, pl.y), (0, 1080 / 2 - 15));
 
         p.day_fraction = Some(0.0); // midnight — bottom center
         let pl = layout_status_bars(&items, &p)[0].unwrap();
         assert_eq!((pl.x, pl.y), (1920 / 2 - 18, 1080 - 30));
 
         p.day_fraction = Some(0.25); // 06:00 — mid right edge
         let pl = layout_status_bars(&items, &p)[0].unwrap();
         assert_eq!((pl.x, pl.y), (1920 - 36, 1080 / 2 - 15));
 
         // Shortly after noon the segment is still on the top edge, left of
         // center (counterclockwise = leftward along the top).
         p.day_fraction = Some(0.51);
         let pl = layout_status_bars(&items, &p)[0].unwrap();
         assert_eq!(pl.y, 0);
         assert!(pl.x < 1920 / 2 - 18);
 
         // Without a day fraction it stays in its configured edge group.
         p.day_fraction = None;
         let pl = layout_status_bars(&items, &p)[0].unwrap();
         assert_eq!((pl.x, pl.y), (12, 0));
     }
 
     #[test]
     fn top_groups_flow_from_edges() {
         let items = vec![
             item("cce-status-left-viewport", StatusEdge::TopLeft, 0),
             item("cce-status-left-window", StatusEdge::TopLeft, 0),
             item("cce-status-right-clock", StatusEdge::TopRight, 200),
         ];
         let p = layout_status_bars(&items, &params());
         // Left group flows right from the margin; fresh bars default to width 100.
         assert_eq!(p[0], Some(StatusBarPlacement { x: 12, y: 0, width: 100, height: 30, enforce_size: true }));
         assert_eq!(p[1], Some(StatusBarPlacement { x: 124, y: 0, width: 100, height: 30, enforce_size: true }));
         // Right group is placed from the right edge inward.
         assert_eq!(p[2], Some(StatusBarPlacement { x: 1908 - 200, y: 0, width: 200, height: 30, enforce_size: true }));
     }
 
     #[test]
     fn expanded_segment_keeps_slot_and_client_size() {
         // battery expanded (in-surface menu open): its slot still consumes the
         // frozen collapsed length (100), so the neighbor (memory, left of it)
         // does not shift — and its placement stops enforcing size.
         let mut battery = item("cce-status-right-battery", StatusEdge::TopRight, 100);
         battery.expanded = true;
         let items = vec![
             item("cce-status-right-clock", StatusEdge::TopRight, 200),
             battery,
             item("cce-status-right-memory", StatusEdge::TopRight, 150),
         ];
         let p = layout_status_bars(&items, &params());
         // Right-to-left: clock at the edge, battery next, memory after —
         // identical x positions to the collapsed layout.
         assert_eq!(p[0].unwrap().x, 1908 - 200);
         let bat = p[1].unwrap();
         assert_eq!(bat.x, 1908 - 200 - 12 - 100);
         assert!(!bat.enforce_size, "expanded segment is position-only");
         let mem = p[2].unwrap();
         assert_eq!(mem.x, 1908 - 200 - 12 - 100 - 12 - 150);
         assert!(mem.enforce_size);
     }
 
     #[test]
     fn right_group_sorted_by_module_order() {
         let items = vec![
             item("cce-status-right-clock", StatusEdge::TopRight, 100),
             item("cce-status-right-battery", StatusEdge::TopRight, 100),
         ];
         let p = layout_status_bars(&items, &params());
         // RIGHT_ORDER puts battery before clock left-to-right, so clock hugs the edge.
         assert_eq!(p[0].unwrap().x, 1808);
         assert_eq!(p[1].unwrap().x, 1808 - 12 - 100);
     }
 
     #[test]
     fn hide_mode_pushes_top_bars_offscreen_with_preview() {
         let mut prm = params();
         prm.hide_mode = true;
         let items = vec![item("cce-status-left-viewport", StatusEdge::Unspecified, 0)];
         let p = layout_status_bars(&items, &prm);
         // Unspecified resolves to TopLeft; y = 0 - (30 - 5).
         assert_eq!(p[0].unwrap().y, -25);
     }
 
     #[test]
     fn usable_area_reserves_bar_edges() {
         let output = Rect { x: 0, y: 0, width: 1920, height: 1080 };
         let no_excl = Rect { x: 0, y: 0, width: 0, height: 0 };
 
         // No bars, no exclusion: the full output.
         assert_eq!(compute_usable_area(output, no_excl, 30, false, &[]), output);
 
         // Top + left bars each reserve one bar-height.
         let edges = [StatusEdge::TopLeft, StatusEdge::Left];
         assert_eq!(
             compute_usable_area(output, no_excl, 30, false, &edges),
             Rect { x: 30, y: 30, width: 1890, height: 1050 }
         );
 
         // Hide mode releases the top reservation but not the others.
         assert_eq!(
             compute_usable_area(output, no_excl, 30, true, &edges),
             Rect { x: 30, y: 0, width: 1890, height: 1080 }
         );
 
         // Layer-shell non-exclusive area applies before bar reservations.
         let excl = Rect { x: 10, y: 20, width: 1900, height: 1040 };
         assert_eq!(
             compute_usable_area(output, excl, 30, false, &[StatusEdge::BottomCenter]),
             Rect { x: 10, y: 20, width: 1900, height: 1010 }
         );
     }
 
     #[test]
     fn window_roles_from_app_id() {
         assert_eq!(WindowRole::from_app_id(Some("cce-wallpaper")), WindowRole::Background);
         assert_eq!(WindowRole::from_app_id(Some("cce-status-interface-right-clock")), WindowRole::StatusBar);
         assert_eq!(WindowRole::from_app_id(Some("firefox")), WindowRole::Normal);
         assert_eq!(WindowRole::from_app_id(None), WindowRole::Normal);
     }
 
     #[test]
     fn classification_precedence() {
         // Role wins over visibility: a minimized wallpaper still arranges as background.
         assert_eq!(
             classify_window(WindowRole::Background, true, true, TilingMode::Floating, false),
             WindowClass::Background
         );
         assert_eq!(
             classify_window(WindowRole::StatusBar, false, false, TilingMode::Floating, false),
             WindowClass::StatusBar
         );
         // Minimized or closing/init normal windows are hidden.
         assert_eq!(
             classify_window(WindowRole::Normal, true, false, TilingMode::Floating, false),
             WindowClass::Hidden
         );
         // Overlay mode gets the overlay slot — unless mid-drag.
         assert_eq!(
             classify_window(WindowRole::Normal, false, false, TilingMode::Overlay, false),
             WindowClass::Overlay
         );
         assert_eq!(
             classify_window(WindowRole::Normal, false, false, TilingMode::Overlay, true),
             WindowClass::Normal
         );
         assert_eq!(
             classify_window(WindowRole::Normal, false, false, TilingMode::Tiled, false),
             WindowClass::Normal
         );
     }
 
     fn ctx() -> PlacementCtx {
         PlacementCtx {
             phys: Rect { x: 0, y: 0, width: 1920, height: 1080 },
             usable: Rect { x: 0, y: 30, width: 1920, height: 1050 },
             pan_x: 0.0,
             pan_y: 0.0,
             zoom: 1.0,
         }
     }
 
     #[test]
     fn fresh_overlay_gets_configured_slot() {
         let placement = place_overlay_window(
             &OverlaySnapshot {
                 box_geom: Rect { x: 0, y: 0, width: 0, height: 0 },
                 min_width: 0,
                 is_cloud: false,
                 ssd: true,
                 decorations_size: (0, 16),
             },
             &OverlayParams {
                 overlay_width: 400,
                 border_gap: 8,
                 border_width: 0,
                 position_right: true,
                 cloud_position_default: None,
             },
             &ctx(),
         );
         // Right slot: x = usable right edge - width - gap; height fills the
         // usable area minus the 16px decoration strip and both gaps.
         assert_eq!(placement.pos, (1512, 54));
         assert_eq!(placement.size, (400, 1018));
         assert_eq!(placement.box_geom_write, Some(Rect { x: 1512, y: 54, width: 400, height: 1018 }));
         assert_eq!(placement.virtual_pos, (1512.0, 54.0));
     }
 
     #[test]
     fn fresh_overlay_slot_ignores_border_width() {
         let placement = place_overlay_window(
             &OverlaySnapshot {
                 box_geom: Rect { x: 0, y: 0, width: 0, height: 0 },
                 min_width: 0,
                 is_cloud: false,
                 ssd: true,
                 decorations_size: (0, 16),
             },
             &OverlayParams {
                 overlay_width: 400,
                 border_gap: 8,
                 border_width: 4,
                 position_right: true,
                 cloud_position_default: None,
             },
             &ctx(),
         );
         // Placement no longer insets by the border: the content box lands on
         // the gaps exactly as it does with no border, and the border overhangs
         // outward. (bw 4 < OVERLAY_DEC_H 16, so the decoration strip is
         // unaffected too.)
         assert_eq!(placement.pos, (1512, 54));
         assert_eq!(placement.size, (400, 1018));
     }
 
     #[test]
     fn overlay_without_ssd_shrinks_by_decorations() {
         let placement = place_overlay_window(
             &OverlaySnapshot {
                 box_geom: Rect { x: 100, y: 100, width: 400, height: 500 },
                 min_width: 0,
                 is_cloud: false,
                 ssd: false,
                 decorations_size: (2, 18),
             },
             &OverlayParams { overlay_width: 400, border_gap: 8, border_width: 0, position_right: false, cloud_position_default: None },
             &ctx(),
         );
         // Existing geometry is kept; the client is sized minus decorations.
         assert_eq!(placement.pos, (100, 100));
         assert_eq!(placement.size, (398, 482));
         assert_eq!(placement.box_geom_write, None);
     }
 
     #[test]
     fn tiled_transitions() {
         // Entering with no usable geometry falls back to 800x600.
         assert_eq!(
             tiled_transition(true, false, (0, 0), (0, 0), (0, 0), (0.0, 0.0)),
             Some(TiledTransition::Enter { width: 800, height: 600 })
         );
         // Entering keeps real geometry.
         assert_eq!(
             tiled_transition(true, false, (640, 480), (0, 0), (0, 0), (0.0, 0.0)),
             Some(TiledTransition::Enter { width: 640, height: 480 })
         );
         // Steady states do nothing.
         assert_eq!(tiled_transition(true, true, (640, 480), (0, 0), (640, 480), (0.0, 0.0)), None);
         assert_eq!(tiled_transition(false, false, (640, 480), (0, 0), (0, 0), (0.0, 0.0)), None);
         // Exit restores the saved geometry; invalid saved size is a no-op.
         assert_eq!(
             tiled_transition(false, true, (0, 0), (0, 0), (640, 480), (10.0, 20.0)),
             Some(TiledTransition::Exit { width: 640, height: 480, virtual_x: 10.0, virtual_y: 20.0 })
         );
         assert_eq!(tiled_transition(false, true, (0, 0), (0, 0), (0, 480), (10.0, 20.0)), None);
     }
 
     #[test]
     fn tiled_snaps_to_grid_cells() {
         let snap = NormalSnapshot {
             mode: TilingMode::Tiled,
             box_geom: Rect { x: 0, y: 0, width: 100, height: 50 },
             min_size: (0, 0),
             virtual_pos: (150.0, 120.0),
             active_resize: None,
             is_cloud: false,
         };
         let p = NormalParams { gap_right: 10, gap_top: 6, cloud_position_default: None, desktop_cell_w: 100.0, desktop_cell_h: 100.0, desktop_gap_width: 0.0, desktop_cell_inset: 0.0 };
         let placement = place_normal_window(&snap, &p, &ctx());
         // Current geometry spans grid columns 1-2 and row 1 → snapped to
         // (100,100) with size 200x100.
         assert_eq!(placement.virtual_write, Some((100.0, 100.0)));
         assert_eq!(placement.pos, (100, 100));
         assert_eq!(placement.size, (200, 100));
         assert_eq!(placement.hidden, Some(false));
         assert_eq!(placement.scale, 1.0);
     }
 
     #[test]
     fn tiled_ignores_border_width() {
         let snap = NormalSnapshot {
             mode: TilingMode::Tiled,
             box_geom: Rect { x: 0, y: 0, width: 100, height: 50 },
             min_size: (0, 0),
             virtual_pos: (150.0, 120.0),
             active_resize: None,
             is_cloud: false,
         };
         let p = NormalParams { gap_right: 10, gap_top: 6, cloud_position_default: None, desktop_cell_w: 100.0, desktop_cell_h: 100.0, desktop_gap_width: 0.0, desktop_cell_inset: 0.0 };
         let placement = place_normal_window(&snap, &p, &ctx());
         // The content fills the covered cells (100,100)+200x100 exactly; the
         // border draws outside that and overhangs into the grid gap.
         assert_eq!(placement.virtual_write, Some((100.0, 100.0)));
         assert_eq!(placement.pos, (100, 100));
         assert_eq!(placement.size, (200, 100));
     }
 
     #[test]
     fn tiled_snaps_to_visible_cell_edges() {
         let snap = NormalSnapshot {
             mode: TilingMode::Tiled,
             box_geom: Rect { x: 0, y: 0, width: 100, height: 50 },
             min_size: (0, 0),
             virtual_pos: (150.0, 120.0),
             active_resize: None,
             is_cloud: false,
         };
         // period 110 (gap 10), inset 5: cells x 1-2 visibly span [115, 315],
         // row y 1 spans [115, 205]; the content fills them edge to edge.
         let p = NormalParams {
             gap_right: 10,
             gap_top: 6,
             cloud_position_default: None,
             desktop_cell_w: 100.0,
             desktop_cell_h: 100.0,
             desktop_gap_width: 10.0,
             desktop_cell_inset: 5.0,
         };
         let placement = place_normal_window(&snap, &p, &ctx());
         assert_eq!(placement.virtual_write, Some((115.0, 115.0)));
         assert_eq!(placement.pos, (115, 115));
         assert_eq!(placement.size, (200, 90));
     }
 
     #[test]
     fn popup_docks_top_right_of_usable_area() {
         let snap = NormalSnapshot {
             mode: TilingMode::Popup,
             box_geom: Rect { x: 0, y: 0, width: 0, height: 0 },
             min_size: (0, 0),
             virtual_pos: (0.0, 0.0),
             active_resize: None,
             is_cloud: false,
         };
         let p = NormalParams { gap_right: 10, gap_top: 6, cloud_position_default: None, desktop_cell_w: 100.0, desktop_cell_h: 100.0, desktop_gap_width: 0.0, desktop_cell_inset: 0.0 };
         let placement = place_normal_window(&snap, &p, &ctx());
         // Defaults to 360x100, docked inside the usable area (below the bar).
         assert_eq!(placement.pos, (1920 - 360 - 10, 30 + 6));
         assert_eq!(placement.size, (360, 100));
         assert_eq!(placement.hidden, None);
     }
 
     #[test]
     fn fresh_floating_window_gets_client_chosen_size() {
         // No established box, no resize in flight: the placement is the xdg
         // "you choose" 0x0, NOT the min-size hint — a self-sizing client
         // obeys any nonzero configure, so a min-size guess would become the
         // box forever.
         let snap = NormalSnapshot {
             mode: TilingMode::Floating,
             box_geom: Rect { x: 0, y: 0, width: 0, height: 0 },
             min_size: (320, 240),
             virtual_pos: (100.0, 200.0),
             active_resize: None,
             is_cloud: false,
         };
         let p = NormalParams { gap_right: 10, gap_top: 6, cloud_position_default: None, desktop_cell_w: 100.0, desktop_cell_h: 100.0, desktop_gap_width: 0.0, desktop_cell_inset: 0.0 };
         let placement = place_normal_window(&snap, &p, &ctx());
         assert_eq!(placement.size, (0, 0));
         assert_eq!(placement.hidden, None);
 
         // Once the box is established (the acked commit adopted the client's
         // geometry), the placement keeps it.
         let established = NormalSnapshot {
             box_geom: Rect { x: 0, y: 0, width: 900, height: 700 },
             ..snap
         };
         let placement = place_normal_window(&established, &p, &ctx());
         assert_eq!(placement.size, (900, 700));
 
         // Non-floating modes keep the min-size fallback: their sizes are
         // dictated by tiling, not chosen by the client.
         let other = NormalSnapshot { mode: TilingMode::Overlay, ..established };
         let other = NormalSnapshot { box_geom: Rect { x: 0, y: 0, width: 0, height: 0 }, ..other };
         let placement = place_normal_window(&other, &p, &ctx());
         assert_eq!(placement.size, (320, 240));
     }
 
     #[test]
     fn utility_window_size_is_always_client_chosen() {
         // A Utility window restates the "you choose" 0x0 on EVERY pass — even
         // with an established box — so the compositor can never dictate a
         // size to it (a restored size, an output change). The established box
         // still drives the offscreen cull.
         let p = NormalParams { gap_right: 10, gap_top: 6, cloud_position_default: None, desktop_cell_w: 100.0, desktop_cell_h: 100.0, desktop_gap_width: 0.0, desktop_cell_inset: 0.0 };
         let fresh = NormalSnapshot {
             mode: TilingMode::Utility,
             box_geom: Rect { x: 0, y: 0, width: 0, height: 0 },
             min_size: (320, 240),
             virtual_pos: (100.0, 200.0),
             active_resize: None,
             is_cloud: false,
         };
         let placement = place_normal_window(&fresh, &p, &ctx());
         assert_eq!(placement.size, (0, 0));
         assert_eq!(placement.hidden, None);
 
         let established = NormalSnapshot {
             box_geom: Rect { x: 0, y: 0, width: 520, height: 896 },
             ..fresh
         };
         let placement = place_normal_window(&established, &p, &ctx());
         assert_eq!(placement.size, (0, 0));
         // The cull is computed (from the real box), unlike the unmapped case.
         assert!(placement.hidden.is_some());
     }
 
     #[test]
     fn pannable_window_follows_viewport() {
         let snap = NormalSnapshot {
             mode: TilingMode::Overlay,
             box_geom: Rect { x: 0, y: 0, width: 640, height: 480 },
             min_size: (0, 0),
             virtual_pos: (100.0, 200.0),
             active_resize: None,
             is_cloud: false,
         };
         let p = NormalParams { gap_right: 10, gap_top: 6, cloud_position_default: None, desktop_cell_w: 100.0, desktop_cell_h: 100.0, desktop_gap_width: 0.0, desktop_cell_inset: 0.0 };
         let mut c = ctx();
         c.pan_x = 50.0;
         c.pan_y = 100.0;
         c.zoom = 2.0;
         let placement = place_normal_window(&snap, &p, &c);
         assert_eq!(placement.pos, (100, 200));
         assert_eq!(placement.scale, 2.0);
         assert_eq!(placement.size, (640, 480));
         assert_eq!(placement.hidden, Some(false));
 
         // Pan far enough away and the window is culled.
         c.pan_x = 5000.0;
         let placement = place_normal_window(&snap, &p, &c);
         assert_eq!(placement.hidden, Some(true));
 
         // Interactive resize dimensions override stored geometry.
         let resizing = NormalSnapshot { active_resize: Some((800, 600)), ..snap };
         c.pan_x = 50.0;
         let placement = place_normal_window(&resizing, &p, &c);
         assert_eq!(placement.size, (800, 600));
     }
 
     #[test]
     fn opacity_policy() {
         // Focused, or dimming disabled: always fully opaque.
         assert_eq!(window_opacity(true, true, 0.5), 1.0);
         assert_eq!(window_opacity(false, false, 0.5), 1.0);
         // Unfocused with dimming enabled: the given level passes through.
         assert_eq!(window_opacity(false, true, 0.5), 0.5);
         // The DE levels: an unfocused window looks exactly like a focused one.
         assert_eq!(window_opacity(false, true, OVERLAY_UNFOCUSED_OPACITY), 1.0);
         assert_eq!(window_opacity(false, true, NORMAL_UNFOCUSED_OPACITY), 1.0);
     }
 
     fn snap(app_id: &str) -> WindowSnapshot {
         WindowSnapshot {
             app_id: Some(app_id.to_string()),
             title: None,
             role: WindowRole::from_app_id(Some(app_id)),
             minimized: false,
             closing_or_init: false,
             mode: TilingMode::Floating,
             status_collapsed_len: 0,
             rule_ssd: None,
             being_moved: false,
             status_edge: StatusEdge::Unspecified,
             is_focused: false,
             box_geom: Rect { x: 0, y: 0, width: 640, height: 480 },
             min_size: (0, 0),
             virtual_pos: (100.0, 200.0),
             active_resize: None,
             ssd: true,
             decorations_size: (0, 16),
             was_tiled: false,
             saved_floating_size: (0, 0),
             saved_floating_virtual: (0.0, 0.0),
             grid_patch: None,
         }
     }
 
     fn arrange_params() -> ArrangeParams {
         ArrangeParams {
             bar_height: 30,
             status_hide_mode: false,
             hide_mode_preview: 5,
             status_module_spacing: DEFAULT_STATUS_MODULE_SPACING,
             day_fraction: None,
             status_blur: true,
             window_blur: true,
             opacity_enabled: true,
             decoration: DecorationSpec {
                 border_width: 0,
                 border_color: crate::api::Rgba([0.1, 0.2, 0.3, 0.4]),
                 corner_radius: 0,
             },
             border_color_focused: crate::api::Rgba([0.9, 0.1, 0.1, 1.0]),
             overlay: OverlayParams {
                 overlay_width: 400,
                 border_gap: 8,
                 border_width: 0,
                 position_right: true,
                 cloud_position_default: None,
             },
             normal: NormalParams {
                 gap_right: 10,
                 gap_top: 6,
                 cloud_position_default: None,
                 desktop_cell_w: 100.0,
             desktop_cell_h: 100.0,
                 desktop_gap_width: 0.0,
                 desktop_cell_inset: 0.0,
             },
             pan_x: 0.0,
             pan_y: 0.0,
             zoom: 1.0,
         }
     }
 
     fn one_output() -> Vec<OutputSnapshot> {
         vec![OutputSnapshot {
             layout_box: Rect { x: 0, y: 0, width: 1920, height: 1080 },
             non_exclusive: Rect { x: 0, y: 0, width: 0, height: 0 },
         }]
     }
 
     #[test]
     fn arrange_background_covers_output_and_disables_fallback_rect() {
         let windows = vec![snap("cce-wallpaper"), snap("firefox")];
         let plan = arrange(&windows, &one_output(), &arrange_params());
 
         assert!(!plan.background_rect_enabled);
         let wp = &plan.windows[0];
         assert_eq!(wp.tiling_mode, Some(TilingMode::Status));
         assert_eq!(wp.tiled, Some(0));
         assert_eq!(wp.ssd, Some(false));
         assert_eq!(wp.scene_enabled, Some(true));
         assert_eq!(wp.hidden, Some(false));
         assert_eq!(wp.blur, Some(false));
         assert_eq!(wp.pos, Some((0, 0)));
         assert_eq!(wp.size, Some((1920, 1080)));
 
         // Without a wallpaper window, the fallback rect stays on.
         let plan = arrange(&windows[1..], &one_output(), &arrange_params());
         assert!(plan.background_rect_enabled);
     }
 
     #[test]
     fn arrange_normal_window_pans_with_border_blur_opacity() {
         let mut w = snap("firefox");
         w.is_focused = false;
         let plan = arrange(&[w], &one_output(), &arrange_params());
 
         let wp = &plan.windows[0];
         assert_eq!(wp.scene_enabled, Some(true));
         assert_eq!(wp.tiling_mode, Some(TilingMode::Floating));
         assert_eq!(wp.pos, Some((100, 200)));
         assert_eq!(wp.scale, Some(1.0));
         assert_eq!(wp.size, Some((640, 480)));
         assert_eq!(wp.hidden, Some(false));
         assert_eq!(wp.tiled, None);
         assert_eq!(wp.decoration, Some(arrange_params().decoration));
         assert_eq!(wp.blur, Some(true));
         assert_eq!(wp.opacity, Some(NORMAL_UNFOCUSED_OPACITY));
     }
 
     #[test]
     fn arrange_focused_window_gets_focused_border_color() {
         let mut focused = snap("firefox");
         focused.is_focused = true;
         let unfocused = snap("terminal");
         let p = arrange_params();
         let plan = arrange(&[focused, unfocused], &one_output(), &p);
 
         assert_eq!(plan.windows[0].decoration.unwrap().border_color, p.border_color_focused);
         assert_eq!(plan.windows[1].decoration.unwrap().border_color, p.decoration.border_color);
     }
 
     #[test]
     fn arrange_fullscreen_window_gets_no_border() {
         let mut w = snap("mpv");
         w.mode = TilingMode::Fullscreen;
         let mut p = arrange_params();
         p.decoration.border_width = 4;
         p.decoration.corner_radius = 12;
         let plan = arrange(&[w], &one_output(), &p);
 
         let dec = plan.windows[0].decoration.unwrap();
         assert_eq!(dec.border_width, 0);
         assert_eq!(dec.corner_radius, 0);
     }
 
     #[test]
     fn arrange_hidden_window_disabled_in_scene() {
         let mut w = snap("firefox");
         w.minimized = true;
         let plan = arrange(&[w], &one_output(), &arrange_params());
 
         let wp = &plan.windows[0];
         assert_eq!(wp.scene_enabled, Some(false));
         assert_eq!(wp.hidden, Some(true));
         assert_eq!(wp.pos, None);
         assert_eq!(wp.size, None);
     }
 
     #[test]
     fn arrange_first_overlay_gets_slot_second_demotes_to_normal() {
         let mut first = snap("scratchpad");
         first.mode = TilingMode::Overlay;
         first.box_geom = Rect { x: 0, y: 0, width: 0, height: 0 };
         let mut second = snap("other-overlay");
         second.mode = TilingMode::Overlay;
 
         let plan = arrange(&[first, second], &one_output(), &arrange_params());
 
         // Fresh overlay: right slot (no bars, so the full output is usable),
         // box_geom written back.
         let wp = &plan.windows[0];
         assert_eq!(wp.pos, Some((1512, 24)));
         assert_eq!(wp.size, Some((400, 1048)));
         assert_eq!(wp.box_geom, Some(Rect { x: 1512, y: 24, width: 400, height: 1048 }));
         assert_eq!(wp.tiled, Some(15));
         assert_eq!(wp.opacity, Some(OVERLAY_UNFOCUSED_OPACITY));
 
         // Second overlay arranges as a pannable normal window.
         let wp = &plan.windows[1];
         assert_eq!(wp.tiling_mode, Some(TilingMode::Overlay));
         assert_eq!(wp.pos, Some((100, 200)));
         assert_eq!(wp.size, Some((640, 480)));
         assert_eq!(wp.opacity, Some(NORMAL_UNFOCUSED_OPACITY));
     }
 
     #[test]
     fn arrange_rule_ssd_reaches_overlay_sizing() {
         let mut w = snap("scratchpad");
         w.mode = TilingMode::Overlay;
         w.ssd = true;
         w.rule_ssd = Some(false);
         w.decorations_size = (2, 18);
 
         let plan = arrange(&[w], &one_output(), &arrange_params());
         let wp = &plan.windows[0];
         // The rule override is planned and the client size shrinks by the
         // decorations, proving the override was visible to placement.
         assert_eq!(wp.ssd, Some(false));
         assert_eq!(wp.size, Some((638, 462)));
     }
 
     #[test]
     fn arrange_tiled_enter_saves_geometry() {
         let mut w = snap("firefox");
         w.mode = TilingMode::Tiled;
         w.box_geom = Rect { x: 0, y: 0, width: 150, height: 50 };
         w.virtual_pos = (150.0, 120.0);
 
         let plan = arrange(&[w], &one_output(), &arrange_params());
         let wp = &plan.windows[0];
         assert_eq!(wp.was_tiled, Some(true));
         assert_eq!(wp.saved_floating, Some(((150, 50), (150.0, 120.0))));
         // Grid snap: spans columns 1-2, row 1 of the 100px grid.
         assert_eq!(wp.virtual_pos, Some((100.0, 100.0)));
         assert_eq!(wp.pos, Some((100, 100)));
         assert_eq!(wp.size, Some((200, 100)));
     }
 
     #[test]
     fn arrange_tiled_exit_restores_saved_geometry() {
         let mut w = snap("firefox");
         w.mode = TilingMode::Floating;
         w.was_tiled = true;
         w.saved_floating_size = (500, 400);
         w.saved_floating_virtual = (10.0, 20.0);
 
         let plan = arrange(&[w], &one_output(), &arrange_params());
         let wp = &plan.windows[0];
         assert_eq!(wp.was_tiled, Some(false));
         assert_eq!(wp.box_geom, Some(Rect { x: 0, y: 0, width: 500, height: 400 }));
         // The restored geometry flows into the pannable placement.
         assert_eq!(wp.virtual_pos, Some((10.0, 20.0)));
         assert_eq!(wp.pos, Some((10, 20)));
         assert_eq!(wp.size, Some((500, 400)));
     }
 
     #[test]
     fn arrange_grid_client_world_anchored() {
         let mut g = snap("cce-grid");
         assert_eq!(g.role, WindowRole::Grid);
         // No patch yet: hidden, and the compositor cells stay on.
         let plan = arrange(&[g.clone()], &one_output(), &arrange_params());
         assert_eq!(plan.windows[0].scene_enabled, Some(false));
         assert!(plan.grid_cells_enabled);
 
         // With a latched patch: placed at the patch's virtual origin, scaled
         // by zoom/patch.scale, and the compositor cells yield.
         g.grid_patch = Some(crate::api::GridPatch {
             x: -1000.0,
             y: 500.0,
             w: 4000.0,
             h: 3000.0,
             scale: 0.5,
         });
         let mut p = arrange_params();
         p.pan_x = -1500.0;
         p.pan_y = 0.0;
         p.zoom = 1.0;
         let plan = arrange(&[g.clone()], &one_output(), &p);
         let wp = &plan.windows[0];
         assert_eq!(wp.scene_enabled, Some(true));
         // Screen pos = (virtual - pan) * zoom: (-1000 - -1500, 500 - 0).
         assert_eq!(wp.pos, Some((500, 500)));
         // Buffer at 0.5 px per unit shown at zoom 1 → display scale 2.
         assert_eq!(wp.scale, Some(2.0));
         assert_eq!(wp.tiled, Some(0));
         assert!(!plan.grid_cells_enabled);
 
         // A minimized or closing grid client gives the cells back.
         g.minimized = true;
         let plan = arrange(&[g], &one_output(), &p);
         assert!(plan.grid_cells_enabled);
     }
 
     #[test]
     fn arrange_status_bar_placed_unless_dragged() {
         let mut bar = snap("cce-status-left-viewport");
         bar.status_edge = StatusEdge::TopLeft;
         bar.box_geom = Rect { x: 0, y: 0, width: 200, height: 30 };
 
         let plan = arrange(&[bar.clone()], &one_output(), &arrange_params());
         let wp = &plan.windows[0];
         assert_eq!(wp.tiling_mode, Some(TilingMode::Status));
         assert_eq!(wp.blur, Some(true));
         assert_eq!(wp.pos, Some((12, 0)));
         assert_eq!(wp.size, Some((200, 30)));
 
         // A dragged bar keeps whatever geometry it has: no placement writes.
         bar.being_moved = true;
         let plan = arrange(&[bar], &one_output(), &arrange_params());
         let wp = &plan.windows[0];
         assert_eq!(wp.pos, None);
         assert_eq!(wp.size, None);
     }
 
     #[test]
     fn arrange_multi_output_is_last_wins() {
         let outputs = vec![
             OutputSnapshot {
                 layout_box: Rect { x: 0, y: 0, width: 1920, height: 1080 },
                 non_exclusive: Rect { x: 0, y: 0, width: 0, height: 0 },
             },
             OutputSnapshot {
                 layout_box: Rect { x: 1920, y: 0, width: 1280, height: 720 },
                 non_exclusive: Rect { x: 0, y: 0, width: 0, height: 0 },
             },
         ];
         let windows = vec![snap("cce-wallpaper"), snap("firefox")];
         let plan = arrange(&windows, &outputs, &arrange_params());
 
         // The background covers the second output — the last pass wins.
         assert_eq!(plan.windows[0].pos, Some((1920, 0)));
         assert_eq!(plan.windows[0].size, Some((1280, 720)));
 
         // Tiled state machine only fires once across passes: entering on
         // pass one must not re-enter (and re-save) on pass two.
         let mut w = snap("firefox");
         w.mode = TilingMode::Tiled;
         w.box_geom = Rect { x: 0, y: 0, width: 150, height: 50 };
         w.virtual_pos = (150.0, 120.0);
         let plan = arrange(&[w], &outputs, &arrange_params());
         // Saved from the original geometry, not the pass-one grid snap.
         assert_eq!(plan.windows[0].saved_floating, Some(((150, 50), (150.0, 120.0))));
     }
 
     #[test]
     fn side_stacks_center_vertically() {
         let items = vec![
             item("cce-status-a", StatusEdge::Left, 200),
             item("cce-status-b", StatusEdge::Left, 100),
         ];
         let p = layout_status_bars(&items, &params());
         // Total stack: 200 + 12 + 100 = 312, centered in 1080 → starts at 384.
         assert_eq!(p[0], Some(StatusBarPlacement { x: 0, y: 384, width: 30, height: 200, enforce_size: true }));
         assert_eq!(p[1], Some(StatusBarPlacement { x: 0, y: 596, width: 30, height: 100, enforce_size: true }));
     }
 }