mod.rs

//! Window layout logic.
//!
//! Niri implements scrollable tiling with dynamic workspaces. The scrollable tiling is mostly
//! orthogonal to any particular workspace system, though outputs living in separate coordinate
//! spaces suggest per-output workspaces.
//!
//! I chose a dynamic workspace system because I think it works very well. In particular, it works
//! naturally across outputs getting added and removed, since workspaces can move between outputs
//! as necessary.
//!
//! In the layout, one output (the first one to be added) is designated as *primary*. This is where
//! workspaces from disconnected outputs will move. Currently, the primary output has no other
//! distinction from other outputs.
//!
//! Where possible, niri tries to follow these principles with regards to outputs:
//!
//! 1. Disconnecting and reconnecting the same output must not change the layout.
//!    * This includes both secondary outputs and the primary output.
//! 2. Connecting an output must not change the layout for any workspaces that were never on that
//!    output.
//!
//! Therefore, we implement the following logic: every workspace keeps track of which output it
//! originated on—its *original output*. When an output disconnects, its workspaces are appended to
//! the (potentially new) primary output, but remember their original output. Then, if the original
//! output connects again, all workspaces originally from there move back to that output.
//!
//! In order to avoid surprising behavior, if the user creates or moves any new windows onto a
//! workspace, it forgets its original output, and its current output becomes its original output.
//! Imagine a scenario: the user works with a laptop and a monitor at home, then takes their laptop
//! with them, disconnecting the monitor, and keeps working as normal, using the second monitor's
//! workspace just like any other. Then they come back, reconnect the second monitor, and now we
//! don't want an unassuming workspace to end up on it.

use std::cmp::min;
use std::collections::HashMap;
use std::mem;
use std::rc::Rc;
use std::time::Duration;

use monitor::MonitorAddWindowTarget;
use niri_config::{
    CenterFocusedColumn, Config, CornerRadius, FloatOrInt, PresetSize, Struts,
    Workspace as WorkspaceConfig, WorkspaceReference,
};
use niri_ipc::{ColumnDisplay, PositionChange, SizeChange};
use scrolling::{Column, ColumnWidth, InsertHint, InsertPosition};
use smithay::backend::renderer::element::surface::WaylandSurfaceRenderElement;
use smithay::backend::renderer::element::Id;
use smithay::backend::renderer::gles::{GlesRenderer, GlesTexture};
use smithay::output::{self, Output};
use smithay::reexports::wayland_server::protocol::wl_surface::WlSurface;
use smithay::utils::{Logical, Point, Rectangle, Scale, Serial, Size, Transform};
use tile::{Tile, TileRenderElement};
use workspace::{WorkspaceAddWindowTarget, WorkspaceId};

pub use self::monitor::MonitorRenderElement;
use self::monitor::{Monitor, WorkspaceSwitch};
use self::workspace::{OutputId, Workspace};
use crate::animation::Clock;
use crate::layout::scrolling::ScrollDirection;
use crate::niri_render_elements;
use crate::render_helpers::renderer::NiriRenderer;
use crate::render_helpers::snapshot::RenderSnapshot;
use crate::render_helpers::solid_color::{SolidColorBuffer, SolidColorRenderElement};
use crate::render_helpers::texture::TextureBuffer;
use crate::render_helpers::{BakedBuffer, RenderTarget, SplitElements};
use crate::rubber_band::RubberBand;
use crate::utils::transaction::{Transaction, TransactionBlocker};
use crate::utils::{
    ensure_min_max_size_maybe_zero, output_matches_name, output_size,
    round_logical_in_physical_max1, ResizeEdge,
};
use crate::window::ResolvedWindowRules;

pub mod closing_window;
pub mod floating;
pub mod focus_ring;
pub mod insert_hint_element;
pub mod monitor;
pub mod opening_window;
pub mod scrolling;
pub mod shadow;
pub mod tab_indicator;
pub mod tile;
pub mod workspace;

#[cfg(test)]
mod tests;

/// Size changes up to this many pixels don't animate.
pub const RESIZE_ANIMATION_THRESHOLD: f64 = 10.;

/// Pointer needs to move this far to pull a window from the layout.
const INTERACTIVE_MOVE_START_THRESHOLD: f64 = 256. * 256.;

/// Size-relative units.
pub struct SizeFrac;

niri_render_elements! {
    LayoutElementRenderElement<R> => {
        Wayland = WaylandSurfaceRenderElement<R>,
        SolidColor = SolidColorRenderElement,
    }
}

pub type LayoutElementRenderSnapshot =
    RenderSnapshot<BakedBuffer<TextureBuffer<GlesTexture>>, BakedBuffer<SolidColorBuffer>>;

pub trait LayoutElement {
    /// Type that can be used as a unique ID of this element.
    type Id: PartialEq + std::fmt::Debug + Clone;

    /// Unique ID of this element.
    fn id(&self) -> &Self::Id;

    /// Visual size of the element.
    ///
    /// This is what the user would consider the size, i.e. excluding CSD shadows and whatnot.
    /// Corresponds to the Wayland window geometry size.
    fn size(&self) -> Size<i32, Logical>;

    /// Returns the location of the element's buffer relative to the element's visual geometry.
    ///
    /// I.e. if the element has CSD shadows, its buffer location will have negative coordinates.
    fn buf_loc(&self) -> Point<i32, Logical>;

    /// Checks whether a point is in the element's input region.
    ///
    /// The point is relative to the element's visual geometry.
    fn is_in_input_region(&self, point: Point<f64, Logical>) -> bool;

    /// Renders the element at the given visual location.
    ///
    /// The element should be rendered in such a way that its visual geometry ends up at the given
    /// location.
    fn render<R: NiriRenderer>(
        &self,
        renderer: &mut R,
        location: Point<f64, Logical>,
        scale: Scale<f64>,
        alpha: f32,
        target: RenderTarget,
    ) -> SplitElements<LayoutElementRenderElement<R>>;

    /// Renders the non-popup parts of the element.
    fn render_normal<R: NiriRenderer>(
        &self,
        renderer: &mut R,
        location: Point<f64, Logical>,
        scale: Scale<f64>,
        alpha: f32,
        target: RenderTarget,
    ) -> Vec<LayoutElementRenderElement<R>> {
        self.render(renderer, location, scale, alpha, target).normal
    }

    /// Renders the popups of the element.
    fn render_popups<R: NiriRenderer>(
        &self,
        renderer: &mut R,
        location: Point<f64, Logical>,
        scale: Scale<f64>,
        alpha: f32,
        target: RenderTarget,
    ) -> Vec<LayoutElementRenderElement<R>> {
        self.render(renderer, location, scale, alpha, target).popups
    }

    /// Requests the element to change its size.
    ///
    /// The size request is stored and will be continuously sent to the element on any further
    /// state changes.
    fn request_size(
        &mut self,
        size: Size<i32, Logical>,
        animate: bool,
        transaction: Option<Transaction>,
    );

    /// Requests the element to change size once, clearing the request afterwards.
    fn request_size_once(&mut self, size: Size<i32, Logical>, animate: bool) {
        self.request_size(size, animate, None);
    }

    fn request_fullscreen(&mut self, size: Size<i32, Logical>);

    fn min_size(&self) -> Size<i32, Logical>;
    fn max_size(&self) -> Size<i32, Logical>;
    fn is_wl_surface(&self, wl_surface: &WlSurface) -> bool;
    fn has_ssd(&self) -> bool;
    fn set_preferred_scale_transform(&self, scale: output::Scale, transform: Transform);
    fn output_enter(&self, output: &Output);
    fn output_leave(&self, output: &Output);
    fn set_offscreen_element_id(&self, id: Option<Id>);
    fn set_activated(&mut self, active: bool);
    fn set_active_in_column(&mut self, active: bool);
    fn set_floating(&mut self, floating: bool);
    fn set_bounds(&self, bounds: Size<i32, Logical>);
    fn is_ignoring_opacity_window_rule(&self) -> bool;

    fn configure_intent(&self) -> ConfigureIntent;
    fn send_pending_configure(&mut self);

    /// Whether the element is currently fullscreen.
    ///
    /// This will *not* switch immediately after a [`LayoutElement::request_fullscreen()`] call.
    fn is_fullscreen(&self) -> bool;

    /// Whether we're requesting the element to be fullscreen.
    ///
    /// This *will* switch immediately after a [`LayoutElement::request_fullscreen()`] call.
    fn is_pending_fullscreen(&self) -> bool;

    /// Size previously requested through [`LayoutElement::request_size()`].
    fn requested_size(&self) -> Option<Size<i32, Logical>>;

    /// Non-fullscreen size that we expect this window has or will shortly have.
    ///
    /// This can be different from [`requested_size()`](LayoutElement::requested_size()). For
    /// example, for floating windows this will generally return the current window size, rather
    /// than the last size that we requested, since we want floating windows to be able to change
    /// size freely. But not always: if we just requested a floating window to resize and it hasn't
    /// responded to it yet, this will return the newly requested size.
    ///
    /// This function should never return a 0 size component. `None` means there's no known
    /// expected size (for example, the window is fullscreen).
    ///
    /// The default impl is for testing only, it will not preserve the window's own size changes.
    fn expected_size(&self) -> Option<Size<i32, Logical>> {
        if self.is_fullscreen() {
            return None;
        }

        let mut requested = self.requested_size().unwrap_or_default();
        let current = self.size();
        if requested.w == 0 {
            requested.w = current.w;
        }
        if requested.h == 0 {
            requested.h = current.h;
        }
        Some(requested)
    }

    fn is_child_of(&self, parent: &Self) -> bool;

    fn rules(&self) -> &ResolvedWindowRules;

    /// Runs periodic clean-up tasks.
    fn refresh(&self);

    fn animation_snapshot(&self) -> Option<&LayoutElementRenderSnapshot>;
    fn take_animation_snapshot(&mut self) -> Option<LayoutElementRenderSnapshot>;

    fn set_interactive_resize(&mut self, data: Option<InteractiveResizeData>);
    fn cancel_interactive_resize(&mut self);
    fn interactive_resize_data(&self) -> Option<InteractiveResizeData>;

    fn on_commit(&mut self, serial: Serial);
}

#[derive(Debug)]
pub struct Layout<W: LayoutElement> {
    /// Monitors and workspaes in the layout.
    monitor_set: MonitorSet<W>,
    /// Whether the layout should draw as active.
    ///
    /// This normally indicates that the layout has keyboard focus, but not always. E.g. when the
    /// screenshot UI is open, it keeps the layout drawing as active.
    is_active: bool,
    /// Map from monitor name to id of its last active workspace.
    ///
    /// This data is stored upon monitor removal and is used to restore the active workspace when
    /// the monitor is reconnected.
    ///
    /// The workspace id does not necessarily point to a valid workspace. If it doesn't, then it is
    /// simply ignored.
    last_active_workspace_id: HashMap<String, WorkspaceId>,
    /// Ongoing interactive move.
    interactive_move: Option<InteractiveMoveState<W>>,
    /// Ongoing drag-and-drop operation.
    dnd: Option<DndData>,
    /// Clock for driving animations.
    clock: Clock,
    /// Time that we last updated render elements for.
    update_render_elements_time: Duration,
    /// Configurable properties of the layout.
    options: Rc<Options>,
}

#[derive(Debug)]
enum MonitorSet<W: LayoutElement> {
    /// At least one output is connected.
    Normal {
        /// Connected monitors.
        monitors: Vec<Monitor<W>>,
        /// Index of the primary monitor.
        primary_idx: usize,
        /// Index of the active monitor.
        active_monitor_idx: usize,
    },
    /// No outputs are connected, and these are the workspaces.
    NoOutputs {
        /// The workspaces.
        workspaces: Vec<Workspace<W>>,
    },
}

#[derive(Debug, Clone, PartialEq)]
pub struct Options {
    /// Padding around windows in logical pixels.
    pub gaps: f64,
    /// Extra padding around the working area in logical pixels.
    pub struts: Struts,
    pub focus_ring: niri_config::FocusRing,
    pub border: niri_config::Border,
    pub shadow: niri_config::Shadow,
    pub tab_indicator: niri_config::TabIndicator,
    pub insert_hint: niri_config::InsertHint,
    pub center_focused_column: CenterFocusedColumn,
    pub always_center_single_column: bool,
    pub empty_workspace_above_first: bool,
    pub default_column_display: ColumnDisplay,
    /// Column or window widths that `toggle_width()` switches between.
    pub preset_column_widths: Vec<PresetSize>,
    /// Initial width for new columns.
    pub default_column_width: Option<PresetSize>,
    /// Window height that `toggle_window_height()` switches between.
    pub preset_window_heights: Vec<PresetSize>,
    pub animations: niri_config::Animations,
    pub gestures: niri_config::Gestures,
    // Debug flags.
    pub disable_resize_throttling: bool,
    pub disable_transactions: bool,
}

impl Default for Options {
    fn default() -> Self {
        Self {
            gaps: 16.,
            struts: Default::default(),
            focus_ring: Default::default(),
            border: Default::default(),
            shadow: Default::default(),
            tab_indicator: Default::default(),
            insert_hint: Default::default(),
            center_focused_column: Default::default(),
            always_center_single_column: false,
            empty_workspace_above_first: false,
            default_column_display: ColumnDisplay::Normal,
            preset_column_widths: vec![
                PresetSize::Proportion(1. / 3.),
                PresetSize::Proportion(0.5),
                PresetSize::Proportion(2. / 3.),
            ],
            default_column_width: None,
            animations: Default::default(),
            gestures: Default::default(),
            disable_resize_throttling: false,
            disable_transactions: false,
            preset_window_heights: vec![
                PresetSize::Proportion(1. / 3.),
                PresetSize::Proportion(0.5),
                PresetSize::Proportion(2. / 3.),
            ],
        }
    }
}

#[derive(Debug)]
enum InteractiveMoveState<W: LayoutElement> {
    /// Initial rubberbanding; the window remains in the layout.
    Starting {
        /// The window we're moving.
        window_id: W::Id,
        /// Current pointer delta from the starting location.
        pointer_delta: Point<f64, Logical>,
        /// Pointer location within the visual window geometry as ratio from geometry size.
        ///
        /// This helps the pointer remain inside the window as it resizes.
        pointer_ratio_within_window: (f64, f64),
    },
    /// Moving; the window is no longer in the layout.
    Moving(InteractiveMoveData<W>),
}

#[derive(Debug)]
struct InteractiveMoveData<W: LayoutElement> {
    /// The window being moved.
    pub(self) tile: Tile<W>,
    /// Output where the window is currently located/rendered.
    pub(self) output: Output,
    /// Current pointer position within output.
    pub(self) pointer_pos_within_output: Point<f64, Logical>,
    /// Window column width.
    pub(self) width: ColumnWidth,
    /// Whether the window column was full-width.
    pub(self) is_full_width: bool,
    /// Whether the window targets the floating layout.
    pub(self) is_floating: bool,
    /// Pointer location within the visual window geometry as ratio from geometry size.
    ///
    /// This helps the pointer remain inside the window as it resizes.
    pub(self) pointer_ratio_within_window: (f64, f64),
}

#[derive(Debug)]
pub struct DndData {
    /// Output where the pointer is currently located.
    output: Output,
    /// Current pointer position within output.
    pointer_pos_within_output: Point<f64, Logical>,
}

#[derive(Debug, Clone, Copy)]
pub struct InteractiveResizeData {
    pub(self) edges: ResizeEdge,
}

#[derive(Debug, Clone, Copy)]
pub enum ConfigureIntent {
    /// A configure is not needed (no changes to server pending state).
    NotNeeded,
    /// A configure is throttled (due to resizing too fast for example).
    Throttled,
    /// Can send the configure if it isn't throttled externally (only size changed).
    CanSend,
    /// Should send the configure regardless of external throttling (something other than size
    /// changed).
    ShouldSend,
}

/// Tile that was just removed from the layout.
pub struct RemovedTile<W: LayoutElement> {
    tile: Tile<W>,
    /// Width of the column the tile was in.
    width: ColumnWidth,
    /// Whether the column the tile was in was full-width.
    is_full_width: bool,
    /// Whether the tile was floating.
    is_floating: bool,
}

/// Whether to activate a newly added window.
#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
pub enum ActivateWindow {
    /// Activate unconditionally.
    Yes,
    /// Activate based on heuristics.
    #[default]
    Smart,
    /// Do not activate.
    No,
}

/// Where to put a newly added window.
#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
pub enum AddWindowTarget<'a, W: LayoutElement> {
    /// No particular preference.
    #[default]
    Auto,
    /// On this output.
    Output(&'a Output),
    /// On this workspace.
    Workspace(WorkspaceId),
    /// Next to this existing window.
    NextTo(&'a W::Id),
}

/// Type of the window hit from `window_under()`.
#[derive(Debug, Clone, Copy, PartialEq)]
pub enum HitType {
    /// The hit is within a window's input region and can be used for sending events to it.
    Input {
        /// Position of the window's buffer.
        win_pos: Point<f64, Logical>,
    },
    /// The hit can activate a window, but it is not in the input region so cannot send events.
    ///
    /// For example, this could be clicking on a tile border outside the window.
    Activate {
        /// Whether the hit was on the tab indicator.
        is_tab_indicator: bool,
    },
}

impl<W: LayoutElement> InteractiveMoveState<W> {
    fn moving(&self) -> Option<&InteractiveMoveData<W>> {
        match self {
            InteractiveMoveState::Moving(move_) => Some(move_),
            _ => None,
        }
    }

    fn moving_mut(&mut self) -> Option<&mut InteractiveMoveData<W>> {
        match self {
            InteractiveMoveState::Moving(move_) => Some(move_),
            _ => None,
        }
    }
}

impl<W: LayoutElement> InteractiveMoveData<W> {
    fn tile_render_location(&self) -> Point<f64, Logical> {
        let scale = Scale::from(self.output.current_scale().fractional_scale());
        let window_size = self.tile.window_size();
        let pointer_offset_within_window = Point::from((
            window_size.w * self.pointer_ratio_within_window.0,
            window_size.h * self.pointer_ratio_within_window.1,
        ));
        let pos =
            self.pointer_pos_within_output - pointer_offset_within_window - self.tile.window_loc()
                + self.tile.render_offset();
        // Round to physical pixels.
        pos.to_physical_precise_round(scale).to_logical(scale)
    }
}

impl ActivateWindow {
    pub fn map_smart(self, f: impl FnOnce() -> bool) -> bool {
        match self {
            ActivateWindow::Yes => true,
            ActivateWindow::Smart => f(),
            ActivateWindow::No => false,
        }
    }
}

impl HitType {
    pub fn offset_win_pos(mut self, offset: Point<f64, Logical>) -> Self {
        match &mut self {
            HitType::Input { win_pos } => *win_pos += offset,
            HitType::Activate { .. } => (),
        }
        self
    }

    pub fn hit_tile<W: LayoutElement>(
        tile: &Tile<W>,
        tile_pos: Point<f64, Logical>,
        point: Point<f64, Logical>,
    ) -> Option<(&W, Self)> {
        let pos_within_tile = point - tile_pos;
        tile.hit(pos_within_tile)
            .map(|hit| (tile.window(), hit.offset_win_pos(tile_pos)))
    }
}

impl Options {
    fn from_config(config: &Config) -> Self {
        let layout = &config.layout;

        let preset_column_widths = if layout.preset_column_widths.is_empty() {
            Options::default().preset_column_widths
        } else {
            layout.preset_column_widths.clone()
        };
        let preset_window_heights = if layout.preset_window_heights.is_empty() {
            Options::default().preset_window_heights
        } else {
            layout.preset_window_heights.clone()
        };

        // Missing default_column_width maps to Some(PresetSize::Proportion(0.5)),
        // while present, but empty, maps to None.
        let default_column_width = layout
            .default_column_width
            .as_ref()
            .map(|w| w.0)
            .unwrap_or(Some(PresetSize::Proportion(0.5)));

        Self {
            gaps: layout.gaps.0,
            struts: layout.struts,
            focus_ring: layout.focus_ring,
            border: layout.border,
            shadow: layout.shadow,
            tab_indicator: layout.tab_indicator,
            insert_hint: layout.insert_hint,
            center_focused_column: layout.center_focused_column,
            always_center_single_column: layout.always_center_single_column,
            empty_workspace_above_first: layout.empty_workspace_above_first,
            default_column_display: layout.default_column_display,
            preset_column_widths,
            default_column_width,
            animations: config.animations.clone(),
            gestures: config.gestures,
            disable_resize_throttling: config.debug.disable_resize_throttling,
            disable_transactions: config.debug.disable_transactions,
            preset_window_heights,
        }
    }

    fn adjusted_for_scale(mut self, scale: f64) -> Self {
        let round = |logical: f64| round_logical_in_physical_max1(scale, logical);

        self.gaps = round(self.gaps);
        self.focus_ring.width = FloatOrInt(round(self.focus_ring.width.0));
        self.border.width = FloatOrInt(round(self.border.width.0));

        self
    }
}

impl<W: LayoutElement> Layout<W> {
    pub fn new(clock: Clock, config: &Config) -> Self {
        Self::with_options_and_workspaces(clock, config, Options::from_config(config))
    }

    pub fn with_options(clock: Clock, options: Options) -> Self {
        Self {
            monitor_set: MonitorSet::NoOutputs { workspaces: vec![] },
            is_active: true,
            last_active_workspace_id: HashMap::new(),
            interactive_move: None,
            dnd: None,
            clock,
            update_render_elements_time: Duration::ZERO,
            options: Rc::new(options),
        }
    }

    fn with_options_and_workspaces(clock: Clock, config: &Config, options: Options) -> Self {
        let opts = Rc::new(options);

        let workspaces = config
            .workspaces
            .iter()
            .map(|ws| {
                Workspace::new_with_config_no_outputs(Some(ws.clone()), clock.clone(), opts.clone())
            })
            .collect();

        Self {
            monitor_set: MonitorSet::NoOutputs { workspaces },
            is_active: true,
            last_active_workspace_id: HashMap::new(),
            interactive_move: None,
            dnd: None,
            clock,
            update_render_elements_time: Duration::ZERO,
            options: opts,
        }
    }

    pub fn add_output(&mut self, output: Output) {
        self.monitor_set = match mem::take(&mut self.monitor_set) {
            MonitorSet::Normal {
                mut monitors,
                primary_idx,
                active_monitor_idx,
            } => {
                let primary = &mut monitors[primary_idx];

                let ws_id_to_activate = self.last_active_workspace_id.remove(&output.name());
                let mut active_workspace_idx = None;

                let mut stopped_primary_ws_switch = false;

                let mut workspaces = vec![];
                for i in (0..primary.workspaces.len()).rev() {
                    if primary.workspaces[i].original_output.matches(&output) {
                        let ws = primary.workspaces.remove(i);

                        // FIXME: this can be coded in a way that the workspace switch won't be
                        // affected if the removed workspace is invisible. But this is good enough
                        // for now.
                        if primary.workspace_switch.is_some() {
                            primary.workspace_switch = None;
                            stopped_primary_ws_switch = true;
                        }

                        // The user could've closed a window while remaining on this workspace, on
                        // another monitor. However, we will add an empty workspace in the end
                        // instead.
                        if ws.has_windows_or_name() {
                            if Some(ws.id()) == ws_id_to_activate {
                                active_workspace_idx = Some(workspaces.len());
                            }

                            workspaces.push(ws);
                        }

                        if i <= primary.active_workspace_idx
                            // Generally when moving the currently active workspace, we want to
                            // fall back to the workspace above, so as not to end up on the last
                            // empty workspace. However, with empty workspace above first, when
                            // moving the workspace at index 1 (first non-empty), we want to stay
                            // at index 1, so as once again not to end up on an empty workspace.
                            //
                            // This comes into play at compositor startup when having named
                            // workspaces set up across multiple monitors. Without this check, the
                            // first monitor to connect can end up with the first empty workspace
                            // focused instead of the first named workspace.
                            && !(self.options.empty_workspace_above_first
                                && primary.active_workspace_idx == 1)
                        {
                            primary.active_workspace_idx =
                                primary.active_workspace_idx.saturating_sub(1);
                        }
                    }
                }

                // If we stopped a workspace switch, then we might need to clean up workspaces.
                // Also if empty_workspace_above_first is set and there are only 2 workspaces left,
                // both will be empty and one of them needs to be removed. clean_up_workspaces
                // takes care of this.

                if stopped_primary_ws_switch
                    || (primary.options.empty_workspace_above_first
                        && primary.workspaces.len() == 2)
                {
                    primary.clean_up_workspaces();
                }

                workspaces.reverse();

                if let Some(idx) = &mut active_workspace_idx {
                    *idx = workspaces.len() - *idx - 1;
                }
                let mut active_workspace_idx = active_workspace_idx.unwrap_or(0);

                // Make sure there's always an empty workspace.
                workspaces.push(Workspace::new(
                    output.clone(),
                    self.clock.clone(),
                    self.options.clone(),
                ));

                if self.options.empty_workspace_above_first && workspaces.len() > 1 {
                    workspaces.insert(
                        0,
                        Workspace::new(output.clone(), self.clock.clone(), self.options.clone()),
                    );
                    active_workspace_idx += 1;
                }

                for ws in &mut workspaces {
                    ws.set_output(Some(output.clone()));
                }

                let mut monitor =
                    Monitor::new(output, workspaces, self.clock.clone(), self.options.clone());
                monitor.active_workspace_idx = active_workspace_idx;
                monitors.push(monitor);

                MonitorSet::Normal {
                    monitors,
                    primary_idx,
                    active_monitor_idx,
                }
            }
            MonitorSet::NoOutputs { mut workspaces } => {
                // We know there are no empty workspaces there, so add one.
                workspaces.push(Workspace::new(
                    output.clone(),
                    self.clock.clone(),
                    self.options.clone(),
                ));

                let mut active_workspace_idx = 0;
                if self.options.empty_workspace_above_first && workspaces.len() > 1 {
                    workspaces.insert(
                        0,
                        Workspace::new(output.clone(), self.clock.clone(), self.options.clone()),
                    );
                    active_workspace_idx += 1;
                }

                let ws_id_to_activate = self.last_active_workspace_id.remove(&output.name());

                for (i, workspace) in workspaces.iter_mut().enumerate() {
                    workspace.set_output(Some(output.clone()));

                    if Some(workspace.id()) == ws_id_to_activate {
                        active_workspace_idx = i;
                    }
                }

                let mut monitor =
                    Monitor::new(output, workspaces, self.clock.clone(), self.options.clone());
                monitor.active_workspace_idx = active_workspace_idx;

                MonitorSet::Normal {
                    monitors: vec![monitor],
                    primary_idx: 0,
                    active_monitor_idx: 0,
                }
            }
        }
    }

    pub fn remove_output(&mut self, output: &Output) {
        self.monitor_set = match mem::take(&mut self.monitor_set) {
            MonitorSet::Normal {
                mut monitors,
                mut primary_idx,
                mut active_monitor_idx,
            } => {
                let idx = monitors
                    .iter()
                    .position(|mon| &mon.output == output)
                    .expect("trying to remove non-existing output");
                let monitor = monitors.remove(idx);

                self.last_active_workspace_id.insert(
                    monitor.output_name().clone(),
                    monitor.workspaces[monitor.active_workspace_idx].id(),
                );

                let mut workspaces = monitor.workspaces;

                for ws in &mut workspaces {
                    ws.set_output(None);
                }

                // Get rid of empty workspaces.
                workspaces.retain(|ws| ws.has_windows_or_name());

                if monitors.is_empty() {
                    // Removed the last monitor.
                    MonitorSet::NoOutputs { workspaces }
                } else {
                    if primary_idx >= idx {
                        // Update primary_idx to either still point at the same monitor, or at some
                        // other monitor if the primary has been removed.
                        primary_idx = primary_idx.saturating_sub(1);
                    }
                    if active_monitor_idx >= idx {
                        // Update active_monitor_idx to either still point at the same monitor, or
                        // at some other monitor if the active monitor has
                        // been removed.
                        active_monitor_idx = active_monitor_idx.saturating_sub(1);
                    }

                    let primary = &mut monitors[primary_idx];
                    for ws in &mut workspaces {
                        ws.set_output(Some(primary.output.clone()));
                    }

                    let mut stopped_primary_ws_switch = false;
                    if !workspaces.is_empty() && primary.workspace_switch.is_some() {
                        // FIXME: if we're adding workspaces to currently invisible positions
                        // (outside the workspace switch), we don't need to cancel it.
                        primary.workspace_switch = None;
                        stopped_primary_ws_switch = true;
                    }

                    let empty_was_focused =
                        primary.active_workspace_idx == primary.workspaces.len() - 1;

                    // Push the workspaces from the removed monitor in the end, right before the
                    // last, empty, workspace.
                    let empty = primary.workspaces.remove(primary.workspaces.len() - 1);
                    primary.workspaces.extend(workspaces);
                    primary.workspaces.push(empty);

                    // If empty_workspace_above_first is set and the first workspace is now no
                    // longer empty, add a new empty workspace on top.
                    if primary.options.empty_workspace_above_first
                        && primary.workspaces[0].has_windows_or_name()
                    {
                        primary.add_workspace_top();
                    }

                    // If the empty workspace was focused on the primary monitor, keep it focused.
                    if empty_was_focused {
                        primary.active_workspace_idx = primary.workspaces.len() - 1;
                    }

                    if stopped_primary_ws_switch {
                        primary.clean_up_workspaces();
                    }

                    MonitorSet::Normal {
                        monitors,
                        primary_idx,
                        active_monitor_idx,
                    }
                }
            }
            MonitorSet::NoOutputs { .. } => {
                panic!("tried to remove output when there were already none")
            }
        }
    }

    pub fn add_column_by_idx(
        &mut self,
        monitor_idx: usize,
        workspace_idx: usize,
        column: Column<W>,
        activate: bool,
    ) {
        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        else {
            panic!()
        };

        monitors[monitor_idx].add_column(workspace_idx, column, activate);

        if activate {
            *active_monitor_idx = monitor_idx;
        }
    }

    /// Adds a new window to the layout.
    ///
    /// Returns an output that the window was added to, if there were any outputs.
    #[allow(clippy::too_many_arguments)]
    pub fn add_window(
        &mut self,
        window: W,
        target: AddWindowTarget<W>,
        width: Option<PresetSize>,
        height: Option<PresetSize>,
        is_full_width: bool,
        is_floating: bool,
        activate: ActivateWindow,
    ) -> Option<&Output> {
        let scrolling_width = self.resolve_scrolling_width(&window, width);
        let scrolling_height = height.map(SizeChange::from);
        let id = window.id().clone();

        match &mut self.monitor_set {
            MonitorSet::Normal {
                monitors,
                active_monitor_idx,
                ..
            } => {
                let (mon_idx, target) = match target {
                    AddWindowTarget::Auto => (*active_monitor_idx, MonitorAddWindowTarget::Auto),
                    AddWindowTarget::Output(output) => {
                        let mon_idx = monitors
                            .iter()
                            .position(|mon| mon.output == *output)
                            .unwrap();

                        (mon_idx, MonitorAddWindowTarget::Auto)
                    }
                    AddWindowTarget::Workspace(ws_id) => {
                        let mon_idx = monitors
                            .iter()
                            .position(|mon| mon.workspaces.iter().any(|ws| ws.id() == ws_id))
                            .unwrap();

                        (
                            mon_idx,
                            MonitorAddWindowTarget::Workspace {
                                id: ws_id,
                                column_idx: None,
                            },
                        )
                    }
                    AddWindowTarget::NextTo(next_to) => {
                        if let Some(output) = self
                            .interactive_move
                            .as_ref()
                            .and_then(|move_| {
                                if let InteractiveMoveState::Moving(move_) = move_ {
                                    Some(move_)
                                } else {
                                    None
                                }
                            })
                            .filter(|move_| next_to == move_.tile.window().id())
                            .map(|move_| move_.output.clone())
                        {
                            // The next_to window is being interactively moved.
                            let mon_idx = monitors
                                .iter()
                                .position(|mon| mon.output == output)
                                .unwrap_or(*active_monitor_idx);

                            (mon_idx, MonitorAddWindowTarget::Auto)
                        } else {
                            let mon_idx = monitors
                                .iter()
                                .position(|mon| {
                                    mon.workspaces.iter().any(|ws| ws.has_window(next_to))
                                })
                                .unwrap();
                            (mon_idx, MonitorAddWindowTarget::NextTo(next_to))
                        }
                    }
                };
                let mon = &mut monitors[mon_idx];

                mon.add_window(
                    window,
                    target,
                    activate,
                    scrolling_width,
                    is_full_width,
                    is_floating,
                );

                if activate.map_smart(|| false) {
                    *active_monitor_idx = mon_idx;
                }

                // Set the default height for scrolling windows.
                if !is_floating {
                    if let Some(change) = scrolling_height {
                        let ws = mon
                            .workspaces
                            .iter_mut()
                            .find(|ws| ws.has_window(&id))
                            .unwrap();
                        ws.set_window_height(Some(&id), change);
                    }
                }

                Some(&mon.output)
            }
            MonitorSet::NoOutputs { workspaces } => {
                let (ws_idx, target) = match target {
                    AddWindowTarget::Auto => {
                        if workspaces.is_empty() {
                            workspaces.push(Workspace::new_no_outputs(
                                self.clock.clone(),
                                self.options.clone(),
                            ));
                        }

                        (0, WorkspaceAddWindowTarget::Auto)
                    }
                    AddWindowTarget::Output(_) => panic!(),
                    AddWindowTarget::Workspace(ws_id) => {
                        let ws_idx = workspaces.iter().position(|ws| ws.id() == ws_id).unwrap();
                        (ws_idx, WorkspaceAddWindowTarget::Auto)
                    }
                    AddWindowTarget::NextTo(next_to) => {
                        if self
                            .interactive_move
                            .as_ref()
                            .and_then(|move_| {
                                if let InteractiveMoveState::Moving(move_) = move_ {
                                    Some(move_)
                                } else {
                                    None
                                }
                            })
                            .filter(|move_| next_to == move_.tile.window().id())
                            .is_some()
                        {
                            // The next_to window is being interactively moved.
                            (0, WorkspaceAddWindowTarget::Auto)
                        } else {
                            let ws_idx = workspaces
                                .iter()
                                .position(|ws| ws.has_window(next_to))
                                .unwrap();
                            (ws_idx, WorkspaceAddWindowTarget::NextTo(next_to))
                        }
                    }
                };
                let ws = &mut workspaces[ws_idx];

                let tile = ws.make_tile(window);
                ws.add_tile(
                    tile,
                    target,
                    activate,
                    scrolling_width,
                    is_full_width,
                    is_floating,
                );

                // Set the default height for scrolling windows.
                if !is_floating {
                    if let Some(change) = scrolling_height {
                        ws.set_window_height(Some(&id), change);
                    }
                }

                None
            }
        }
    }

    pub fn remove_window(
        &mut self,
        window: &W::Id,
        transaction: Transaction,
    ) -> Option<RemovedTile<W>> {
        if let Some(state) = &self.interactive_move {
            match state {
                InteractiveMoveState::Starting { window_id, .. } => {
                    if window_id == window {
                        self.interactive_move_end(window);
                    }
                }
                InteractiveMoveState::Moving(move_) => {
                    if move_.tile.window().id() == window {
                        let Some(InteractiveMoveState::Moving(move_)) =
                            self.interactive_move.take()
                        else {
                            unreachable!()
                        };

                        // Unlock the view on the workspaces.
                        for ws in self.workspaces_mut() {
                            ws.dnd_scroll_gesture_end();
                        }

                        return Some(RemovedTile {
                            tile: move_.tile,
                            width: move_.width,
                            is_full_width: move_.is_full_width,
                            is_floating: false,
                        });
                    }
                }
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for (idx, ws) in mon.workspaces.iter_mut().enumerate() {
                        if ws.has_window(window) {
                            let removed = ws.remove_tile(window, transaction);

                            // Clean up empty workspaces that are not active and not last.
                            if !ws.has_windows_or_name()
                                && idx != mon.active_workspace_idx
                                && idx != mon.workspaces.len() - 1
                                && mon.workspace_switch.is_none()
                            {
                                mon.workspaces.remove(idx);

                                if idx < mon.active_workspace_idx {
                                    mon.active_workspace_idx -= 1;
                                }
                            }

                            // Special case handling when empty_workspace_above_first is set and all
                            // workspaces are empty.
                            if mon.options.empty_workspace_above_first
                                && mon.workspaces.len() == 2
                                && mon.workspace_switch.is_none()
                            {
                                assert!(!mon.workspaces[0].has_windows_or_name());
                                assert!(!mon.workspaces[1].has_windows_or_name());
                                mon.workspaces.remove(1);
                                mon.active_workspace_idx = 0;
                            }
                            return Some(removed);
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for (idx, ws) in workspaces.iter_mut().enumerate() {
                    if ws.has_window(window) {
                        let removed = ws.remove_tile(window, transaction);

                        // Clean up empty workspaces.
                        if !ws.has_windows_or_name() {
                            workspaces.remove(idx);
                        }

                        return Some(removed);
                    }
                }
            }
        }

        None
    }

    pub fn descendants_added(&mut self, id: &W::Id) -> bool {
        for ws in self.workspaces_mut() {
            if ws.descendants_added(id) {
                return true;
            }
        }

        false
    }

    pub fn update_window(&mut self, window: &W::Id, serial: Option<Serial>) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if move_.tile.window().id() == window {
                move_.tile.update_window();
                return;
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        if ws.has_window(window) {
                            ws.update_window(window, serial);
                            return;
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    if ws.has_window(window) {
                        ws.update_window(window, serial);
                        return;
                    }
                }
            }
        }
    }

    pub fn find_workspace_by_id(&self, id: WorkspaceId) -> Option<(usize, &Workspace<W>)> {
        match &self.monitor_set {
            MonitorSet::Normal { ref monitors, .. } => {
                for mon in monitors {
                    if let Some((index, workspace)) = mon
                        .workspaces
                        .iter()
                        .enumerate()
                        .find(|(_, w)| w.id() == id)
                    {
                        return Some((index, workspace));
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces } => {
                if let Some((index, workspace)) =
                    workspaces.iter().enumerate().find(|(_, w)| w.id() == id)
                {
                    return Some((index, workspace));
                }
            }
        }

        None
    }

    pub fn find_workspace_by_name(&self, workspace_name: &str) -> Option<(usize, &Workspace<W>)> {
        match &self.monitor_set {
            MonitorSet::Normal { ref monitors, .. } => {
                for mon in monitors {
                    if let Some((index, workspace)) =
                        mon.workspaces.iter().enumerate().find(|(_, w)| {
                            w.name
                                .as_ref()
                                .is_some_and(|name| name.eq_ignore_ascii_case(workspace_name))
                        })
                    {
                        return Some((index, workspace));
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces } => {
                if let Some((index, workspace)) = workspaces.iter().enumerate().find(|(_, w)| {
                    w.name
                        .as_ref()
                        .is_some_and(|name| name.eq_ignore_ascii_case(workspace_name))
                }) {
                    return Some((index, workspace));
                }
            }
        }

        None
    }

    pub fn find_workspace_by_ref(
        &mut self,
        reference: WorkspaceReference,
    ) -> Option<&mut Workspace<W>> {
        if let WorkspaceReference::Index(index) = reference {
            self.active_monitor().and_then(|m| {
                let index = index.saturating_sub(1) as usize;
                m.workspaces.get_mut(index)
            })
        } else {
            self.workspaces_mut().find(|ws| match &reference {
                WorkspaceReference::Name(ref_name) => ws
                    .name
                    .as_ref()
                    .is_some_and(|name| name.eq_ignore_ascii_case(ref_name)),
                WorkspaceReference::Id(id) => ws.id().get() == *id,
                WorkspaceReference::Index(_) => unreachable!(),
            })
        }
    }

    pub fn unname_workspace(&mut self, workspace_name: &str) {
        self.unname_workspace_by_ref(WorkspaceReference::Name(workspace_name.into()));
    }

    pub fn unname_workspace_by_ref(&mut self, reference: WorkspaceReference) {
        let id = self.find_workspace_by_ref(reference).map(|ws| ws.id());
        if let Some(id) = id {
            self.unname_workspace_by_id(id);
        }
    }

    pub fn unname_workspace_by_id(&mut self, id: WorkspaceId) {
        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    if mon.unname_workspace(id) {
                        if mon.workspace_switch.is_none() {
                            mon.clean_up_workspaces();
                        }
                        return;
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces } => {
                for (idx, ws) in workspaces.iter_mut().enumerate() {
                    if ws.id() == id {
                        ws.unname();

                        // Clean up empty workspaces.
                        if !ws.has_windows() {
                            workspaces.remove(idx);
                        }

                        return;
                    }
                }
            }
        }
    }

    pub fn find_window_and_output(&self, wl_surface: &WlSurface) -> Option<(&W, Option<&Output>)> {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if move_.tile.window().is_wl_surface(wl_surface) {
                return Some((move_.tile.window(), Some(&move_.output)));
            }
        }

        match &self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mon.workspaces {
                        if let Some(window) = ws.find_wl_surface(wl_surface) {
                            return Some((window, Some(&mon.output)));
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces } => {
                for ws in workspaces {
                    if let Some(window) = ws.find_wl_surface(wl_surface) {
                        return Some((window, None));
                    }
                }
            }
        }

        None
    }

    pub fn find_window_and_output_mut(
        &mut self,
        wl_surface: &WlSurface,
    ) -> Option<(&mut W, Option<&Output>)> {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if move_.tile.window().is_wl_surface(wl_surface) {
                return Some((move_.tile.window_mut(), Some(&move_.output)));
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        if let Some(window) = ws.find_wl_surface_mut(wl_surface) {
                            return Some((window, Some(&mon.output)));
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces } => {
                for ws in workspaces {
                    if let Some(window) = ws.find_wl_surface_mut(wl_surface) {
                        return Some((window, None));
                    }
                }
            }
        }

        None
    }

    /// Computes the window-geometry-relative target rect for popup unconstraining.
    ///
    /// We will try to fit popups inside this rect.
    pub fn popup_target_rect(&self, window: &W::Id) -> Rectangle<f64, Logical> {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if move_.tile.window().id() == window {
                // Follow the scrolling layout logic and fit the popup horizontally within the
                // window geometry.
                let width = move_.tile.window_size().w;
                let height = output_size(&move_.output).h;
                let mut target = Rectangle::from_size(Size::from((width, height)));
                // FIXME: ideally this shouldn't include the tile render offset, but the code
                // duplication would be a bit annoying for this edge case.
                target.loc.y -= move_.tile_render_location().y;
                target.loc.y -= move_.tile.window_loc().y;
                return target;
            }
        }

        self.workspaces()
            .find_map(|(_, _, ws)| ws.popup_target_rect(window))
            .unwrap()
    }

    pub fn update_output_size(&mut self, output: &Output) {
        let _span = tracy_client::span!("Layout::update_output_size");

        let MonitorSet::Normal { monitors, .. } = &mut self.monitor_set else {
            panic!()
        };

        for mon in monitors {
            if &mon.output == output {
                for ws in &mut mon.workspaces {
                    ws.update_output_size();
                }

                break;
            }
        }
    }

    pub fn scroll_amount_to_activate(&self, window: &W::Id) -> f64 {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if move_.tile.window().id() == window {
                return 0.;
            }
        }

        let MonitorSet::Normal { monitors, .. } = &self.monitor_set else {
            return 0.;
        };

        for mon in monitors {
            for ws in &mon.workspaces {
                if ws.has_window(window) {
                    return ws.scroll_amount_to_activate(window);
                }
            }
        }

        0.
    }

    pub fn should_trigger_focus_follows_mouse_on(&self, window: &W::Id) -> bool {
        // During an animation, it's easy to trigger focus-follows-mouse on the previous workspace,
        // especially when clicking to switch workspace on a bar of some kind. This cancels the
        // workspace switch, which is annoying and not intended.
        //
        // This function allows focus-follows-mouse to trigger only on the animation target
        // workspace.
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if move_.tile.window().id() == window {
                return true;
            }
        }

        let MonitorSet::Normal { monitors, .. } = &self.monitor_set else {
            return true;
        };

        let (mon, ws_idx) = monitors
            .iter()
            .find_map(|mon| {
                mon.workspaces
                    .iter()
                    .position(|ws| ws.has_window(window))
                    .map(|ws_idx| (mon, ws_idx))
            })
            .unwrap();

        // During a gesture, focus-follows-mouse does not cause any unintended workspace switches.
        if let Some(WorkspaceSwitch::Gesture(_)) = mon.workspace_switch {
            return true;
        }

        ws_idx == mon.active_workspace_idx
    }

    pub fn activate_window(&mut self, window: &W::Id) {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if move_.tile.window().id() == window {
                return;
            }
        }

        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        else {
            return;
        };

        for (monitor_idx, mon) in monitors.iter_mut().enumerate() {
            for (workspace_idx, ws) in mon.workspaces.iter_mut().enumerate() {
                if ws.activate_window(window) {
                    *active_monitor_idx = monitor_idx;

                    // If currently in the middle of a vertical swipe between the target workspace
                    // and some other, don't switch the workspace.
                    match &mon.workspace_switch {
                        Some(WorkspaceSwitch::Gesture(gesture))
                            if gesture.current_idx.floor() == workspace_idx as f64
                                || gesture.current_idx.ceil() == workspace_idx as f64 => {}
                        _ => mon.switch_workspace(workspace_idx),
                    }

                    return;
                }
            }
        }
    }

    pub fn activate_window_without_raising(&mut self, window: &W::Id) {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if move_.tile.window().id() == window {
                return;
            }
        }

        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        else {
            return;
        };

        for (monitor_idx, mon) in monitors.iter_mut().enumerate() {
            for (workspace_idx, ws) in mon.workspaces.iter_mut().enumerate() {
                if ws.activate_window_without_raising(window) {
                    *active_monitor_idx = monitor_idx;

                    // If currently in the middle of a vertical swipe between the target workspace
                    // and some other, don't switch the workspace.
                    match &mon.workspace_switch {
                        Some(WorkspaceSwitch::Gesture(gesture))
                            if gesture.current_idx.floor() == workspace_idx as f64
                                || gesture.current_idx.ceil() == workspace_idx as f64 => {}
                        _ => mon.switch_workspace(workspace_idx),
                    }

                    return;
                }
            }
        }
    }

    pub fn activate_output(&mut self, output: &Output) {
        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        else {
            return;
        };

        let idx = monitors
            .iter()
            .position(|mon| &mon.output == output)
            .unwrap();
        *active_monitor_idx = idx;
    }

    pub fn active_output(&self) -> Option<&Output> {
        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &self.monitor_set
        else {
            return None;
        };

        Some(&monitors[*active_monitor_idx].output)
    }

    pub fn active_workspace(&self) -> Option<&Workspace<W>> {
        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &self.monitor_set
        else {
            return None;
        };

        let mon = &monitors[*active_monitor_idx];
        Some(&mon.workspaces[mon.active_workspace_idx])
    }

    pub fn active_workspace_mut(&mut self) -> Option<&mut Workspace<W>> {
        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        else {
            return None;
        };

        let mon = &mut monitors[*active_monitor_idx];
        Some(&mut mon.workspaces[mon.active_workspace_idx])
    }

    pub fn windows_for_output(&self, output: &Output) -> impl Iterator<Item = &W> + '_ {
        let MonitorSet::Normal { monitors, .. } = &self.monitor_set else {
            panic!()
        };

        let moving_window = self
            .interactive_move
            .as_ref()
            .and_then(|x| x.moving())
            .filter(|move_| move_.output == *output)
            .map(|move_| move_.tile.window())
            .into_iter();

        let mon = monitors.iter().find(|mon| &mon.output == output).unwrap();
        let mon_windows = mon.workspaces.iter().flat_map(|ws| ws.windows());

        moving_window.chain(mon_windows)
    }

    pub fn windows_for_output_mut(&mut self, output: &Output) -> impl Iterator<Item = &mut W> + '_ {
        let MonitorSet::Normal { monitors, .. } = &mut self.monitor_set else {
            panic!()
        };

        let moving_window = self
            .interactive_move
            .as_mut()
            .and_then(|x| x.moving_mut())
            .filter(|move_| move_.output == *output)
            .map(|move_| move_.tile.window_mut())
            .into_iter();

        let mon = monitors
            .iter_mut()
            .find(|mon| &mon.output == output)
            .unwrap();
        let mon_windows = mon.workspaces.iter_mut().flat_map(|ws| ws.windows_mut());

        moving_window.chain(mon_windows)
    }

    pub fn with_windows(&self, mut f: impl FnMut(&W, Option<&Output>, Option<WorkspaceId>)) {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            f(move_.tile.window(), Some(&move_.output), None);
        }

        match &self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mon.workspaces {
                        for win in ws.windows() {
                            f(win, Some(&mon.output), Some(ws.id()));
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces } => {
                for ws in workspaces {
                    for win in ws.windows() {
                        f(win, None, Some(ws.id()));
                    }
                }
            }
        }
    }

    pub fn with_windows_mut(&mut self, mut f: impl FnMut(&mut W, Option<&Output>)) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            f(move_.tile.window_mut(), Some(&move_.output));
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        for win in ws.windows_mut() {
                            f(win, Some(&mon.output));
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces } => {
                for ws in workspaces {
                    for win in ws.windows_mut() {
                        f(win, None);
                    }
                }
            }
        }
    }

    fn active_monitor(&mut self) -> Option<&mut Monitor<W>> {
        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        else {
            return None;
        };

        Some(&mut monitors[*active_monitor_idx])
    }

    pub fn active_monitor_ref(&self) -> Option<&Monitor<W>> {
        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &self.monitor_set
        else {
            return None;
        };

        Some(&monitors[*active_monitor_idx])
    }

    pub fn monitor_for_output(&self, output: &Output) -> Option<&Monitor<W>> {
        let MonitorSet::Normal { monitors, .. } = &self.monitor_set else {
            return None;
        };

        monitors.iter().find(|mon| &mon.output == output)
    }

    pub fn monitor_for_output_mut(&mut self, output: &Output) -> Option<&mut Monitor<W>> {
        let MonitorSet::Normal { monitors, .. } = &mut self.monitor_set else {
            return None;
        };

        monitors.iter_mut().find(|mon| &mon.output == output)
    }

    pub fn monitor_for_workspace(&self, workspace_name: &str) -> Option<&Monitor<W>> {
        let MonitorSet::Normal { monitors, .. } = &self.monitor_set else {
            return None;
        };

        monitors.iter().find(|monitor| {
            monitor.workspaces.iter().any(|ws| {
                ws.name
                    .as_ref()
                    .is_some_and(|name| name.eq_ignore_ascii_case(workspace_name))
            })
        })
    }

    pub fn outputs(&self) -> impl Iterator<Item = &Output> + '_ {
        let monitors = if let MonitorSet::Normal { monitors, .. } = &self.monitor_set {
            &monitors[..]
        } else {
            &[][..]
        };

        monitors.iter().map(|mon| &mon.output)
    }

    pub fn move_left(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_left();
    }

    pub fn move_right(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_right();
    }

    pub fn move_column_to_first(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_column_to_first();
    }

    pub fn move_column_to_last(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_column_to_last();
    }

    pub fn move_column_left_or_to_output(&mut self, output: &Output) -> bool {
        if let Some(monitor) = self.active_monitor() {
            if monitor.move_left() {
                return false;
            }
        }

        self.move_column_to_output(output);
        true
    }

    pub fn move_column_right_or_to_output(&mut self, output: &Output) -> bool {
        if let Some(monitor) = self.active_monitor() {
            if monitor.move_right() {
                return false;
            }
        }

        self.move_column_to_output(output);
        true
    }

    pub fn move_down(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_down();
    }

    pub fn move_up(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_up();
    }

    pub fn move_down_or_to_workspace_down(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_down_or_to_workspace_down();
    }

    pub fn move_up_or_to_workspace_up(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_up_or_to_workspace_up();
    }

    pub fn consume_or_expel_window_left(&mut self, window: Option<&W::Id>) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if window.is_none() || window == Some(move_.tile.window().id()) {
                return;
            }
        }

        let workspace = if let Some(window) = window {
            Some(
                self.workspaces_mut()
                    .find(|ws| ws.has_window(window))
                    .unwrap(),
            )
        } else {
            self.active_workspace_mut()
        };

        let Some(workspace) = workspace else {
            return;
        };
        workspace.consume_or_expel_window_left(window);
    }

    pub fn consume_or_expel_window_right(&mut self, window: Option<&W::Id>) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if window.is_none() || window == Some(move_.tile.window().id()) {
                return;
            }
        }

        let workspace = if let Some(window) = window {
            Some(
                self.workspaces_mut()
                    .find(|ws| ws.has_window(window))
                    .unwrap(),
            )
        } else {
            self.active_workspace_mut()
        };

        let Some(workspace) = workspace else {
            return;
        };
        workspace.consume_or_expel_window_right(window);
    }

    pub fn focus_left(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_left();
    }

    pub fn focus_right(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_right();
    }

    pub fn focus_column_first(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_column_first();
    }

    pub fn focus_column_last(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_column_last();
    }

    pub fn focus_column_right_or_first(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_column_right_or_first();
    }

    pub fn focus_column_left_or_last(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_column_left_or_last();
    }

    pub fn focus_window_up_or_output(&mut self, output: &Output) -> bool {
        if let Some(monitor) = self.active_monitor() {
            if monitor.focus_up() {
                return false;
            }
        }

        self.focus_output(output);
        true
    }

    pub fn focus_window_down_or_output(&mut self, output: &Output) -> bool {
        if let Some(monitor) = self.active_monitor() {
            if monitor.focus_down() {
                return false;
            }
        }

        self.focus_output(output);
        true
    }

    pub fn focus_column_left_or_output(&mut self, output: &Output) -> bool {
        if let Some(monitor) = self.active_monitor() {
            if monitor.focus_left() {
                return false;
            }
        }

        self.focus_output(output);
        true
    }

    pub fn focus_column_right_or_output(&mut self, output: &Output) -> bool {
        if let Some(monitor) = self.active_monitor() {
            if monitor.focus_right() {
                return false;
            }
        }

        self.focus_output(output);
        true
    }

    pub fn focus_window_in_column(&mut self, index: u8) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_window_in_column(index);
    }

    pub fn focus_down(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_down();
    }

    pub fn focus_up(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_up();
    }

    pub fn focus_down_or_left(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_down_or_left();
    }

    pub fn focus_down_or_right(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_down_or_right();
    }

    pub fn focus_up_or_left(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_up_or_left();
    }

    pub fn focus_up_or_right(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_up_or_right();
    }

    pub fn focus_window_or_workspace_down(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_window_or_workspace_down();
    }

    pub fn focus_window_or_workspace_up(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_window_or_workspace_up();
    }

    pub fn focus_window_top(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_window_top();
    }

    pub fn focus_window_bottom(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_window_bottom();
    }

    pub fn focus_window_down_or_top(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_window_down_or_top();
    }

    pub fn focus_window_up_or_bottom(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.focus_window_up_or_bottom();
    }

    pub fn move_to_workspace_up(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_to_workspace_up();
    }

    pub fn move_to_workspace_down(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_to_workspace_down();
    }

    pub fn move_to_workspace(&mut self, window: Option<&W::Id>, idx: usize) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if window.is_none() || window == Some(move_.tile.window().id()) {
                return;
            }
        }

        let monitor = if let Some(window) = window {
            match &mut self.monitor_set {
                MonitorSet::Normal { monitors, .. } => monitors
                    .iter_mut()
                    .find(|mon| mon.has_window(window))
                    .unwrap(),
                MonitorSet::NoOutputs { .. } => {
                    return;
                }
            }
        } else {
            let Some(monitor) = self.active_monitor() else {
                return;
            };
            monitor
        };
        monitor.move_to_workspace(window, idx);
    }

    pub fn move_column_to_workspace_up(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_column_to_workspace_up();
    }

    pub fn move_column_to_workspace_down(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_column_to_workspace_down();
    }

    pub fn move_column_to_workspace(&mut self, idx: usize) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_column_to_workspace(idx);
    }

    pub fn move_column_to_workspace_on_output(&mut self, output: &Output, idx: usize) {
        self.move_column_to_output(output);
        self.focus_output(output);
        self.move_column_to_workspace(idx);
    }

    pub fn switch_workspace_up(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.switch_workspace_up();
    }

    pub fn switch_workspace_down(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.switch_workspace_down();
    }

    pub fn switch_workspace(&mut self, idx: usize) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.switch_workspace(idx);
    }

    pub fn switch_workspace_auto_back_and_forth(&mut self, idx: usize) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.switch_workspace_auto_back_and_forth(idx);
    }

    pub fn switch_workspace_previous(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.switch_workspace_previous();
    }

    pub fn consume_into_column(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.consume_into_column();
    }

    pub fn expel_from_column(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.expel_from_column();
    }

    pub fn swap_window_in_direction(&mut self, direction: ScrollDirection) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.swap_window_in_direction(direction);
    }

    pub fn toggle_column_tabbed_display(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.toggle_column_tabbed_display();
    }

    pub fn set_column_display(&mut self, display: ColumnDisplay) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.set_column_display(display);
    }

    pub fn center_column(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.center_column();
    }

    pub fn center_window(&mut self, id: Option<&W::Id>) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if id.is_none() || id == Some(move_.tile.window().id()) {
                return;
            }
        }

        let workspace = if let Some(id) = id {
            Some(self.workspaces_mut().find(|ws| ws.has_window(id)).unwrap())
        } else {
            self.active_workspace_mut()
        };

        let Some(workspace) = workspace else {
            return;
        };
        workspace.center_window(id);
    }

    pub fn focus(&self) -> Option<&W> {
        self.focus_with_output().map(|(win, _out)| win)
    }

    pub fn focus_with_output(&self) -> Option<(&W, &Output)> {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            return Some((move_.tile.window(), &move_.output));
        }

        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &self.monitor_set
        else {
            return None;
        };

        let mon = &monitors[*active_monitor_idx];
        mon.active_window().map(|win| (win, &mon.output))
    }

    /// Returns the window under the cursor and the hit type.
    pub fn window_under(
        &self,
        output: &Output,
        pos_within_output: Point<f64, Logical>,
    ) -> Option<(&W, HitType)> {
        let MonitorSet::Normal { monitors, .. } = &self.monitor_set else {
            return None;
        };

        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            let tile_pos = move_.tile_render_location();
            return HitType::hit_tile(&move_.tile, tile_pos, pos_within_output);
        };

        let mon = monitors.iter().find(|mon| &mon.output == output)?;
        mon.window_under(pos_within_output)
    }

    pub fn resize_edges_under(
        &self,
        output: &Output,
        pos_within_output: Point<f64, Logical>,
    ) -> Option<ResizeEdge> {
        let MonitorSet::Normal { monitors, .. } = &self.monitor_set else {
            return None;
        };

        let mon = monitors.iter().find(|mon| &mon.output == output)?;
        mon.resize_edges_under(pos_within_output)
    }

    #[cfg(test)]
    fn verify_invariants(&self) {
        use std::collections::HashSet;

        use approx::assert_abs_diff_eq;

        use crate::layout::monitor::WorkspaceSwitch;

        let mut move_win_id = None;
        if let Some(state) = &self.interactive_move {
            match state {
                InteractiveMoveState::Starting {
                    window_id,
                    pointer_delta: _,
                    pointer_ratio_within_window: _,
                } => {
                    assert!(
                        self.has_window(window_id),
                        "interactive move must be on an existing window"
                    );
                    move_win_id = Some(window_id.clone());
                }
                InteractiveMoveState::Moving(move_) => {
                    assert_eq!(self.clock, move_.tile.clock);

                    let scale = move_.output.current_scale().fractional_scale();
                    let options = Options::clone(&self.options).adjusted_for_scale(scale);
                    assert_eq!(
                        &*move_.tile.options, &options,
                        "interactive moved tile options must be \
                         base options adjusted for output scale"
                    );

                    let tile_pos = move_.tile_render_location();
                    let rounded_pos = tile_pos.to_physical_precise_round(scale).to_logical(scale);

                    // Tile position must be rounded to physical pixels.
                    assert_abs_diff_eq!(tile_pos.x, rounded_pos.x, epsilon = 1e-5);
                    assert_abs_diff_eq!(tile_pos.y, rounded_pos.y, epsilon = 1e-5);
                }
            }
        }

        let mut seen_workspace_id = HashSet::new();
        let mut seen_workspace_name = Vec::<String>::new();

        let (monitors, &primary_idx, &active_monitor_idx) = match &self.monitor_set {
            MonitorSet::Normal {
                monitors,
                primary_idx,
                active_monitor_idx,
            } => (monitors, primary_idx, active_monitor_idx),
            MonitorSet::NoOutputs { workspaces } => {
                for workspace in workspaces {
                    assert!(
                        workspace.has_windows_or_name(),
                        "with no outputs there cannot be empty unnamed workspaces"
                    );

                    assert_eq!(self.clock, workspace.clock);

                    assert_eq!(
                        workspace.base_options, self.options,
                        "workspace base options must be synchronized with layout"
                    );

                    let options = Options::clone(&workspace.base_options)
                        .adjusted_for_scale(workspace.scale().fractional_scale());
                    assert_eq!(
                        &*workspace.options, &options,
                        "workspace options must be base options adjusted for workspace scale"
                    );

                    assert!(
                        seen_workspace_id.insert(workspace.id()),
                        "workspace id must be unique"
                    );

                    if let Some(name) = &workspace.name {
                        assert!(
                            !seen_workspace_name
                                .iter()
                                .any(|n| n.eq_ignore_ascii_case(name)),
                            "workspace name must be unique"
                        );
                        seen_workspace_name.push(name.clone());
                    }

                    workspace.verify_invariants(move_win_id.as_ref());
                }

                return;
            }
        };

        assert!(primary_idx < monitors.len());
        assert!(active_monitor_idx < monitors.len());

        let mut saw_view_offset_gesture = false;

        for (idx, monitor) in monitors.iter().enumerate() {
            assert!(
                !monitor.workspaces.is_empty(),
                "monitor must have at least one workspace"
            );
            assert!(monitor.active_workspace_idx < monitor.workspaces.len());

            assert_eq!(self.clock, monitor.clock);
            assert_eq!(
                monitor.options, self.options,
                "monitor options must be synchronized with layout"
            );

            if let Some(WorkspaceSwitch::Animation(anim)) = &monitor.workspace_switch {
                let before_idx = anim.from() as usize;
                let after_idx = anim.to() as usize;

                assert!(before_idx < monitor.workspaces.len());
                assert!(after_idx < monitor.workspaces.len());
            }

            if idx == primary_idx {
                for ws in &monitor.workspaces {
                    if ws.original_output.matches(&monitor.output) {
                        // This is the primary monitor's own workspace.
                        continue;
                    }

                    let own_monitor_exists = monitors
                        .iter()
                        .any(|m| ws.original_output.matches(&m.output));
                    assert!(
                        !own_monitor_exists,
                        "primary monitor cannot have workspaces for which their own monitor exists"
                    );
                }
            } else {
                assert!(
                    monitor
                        .workspaces
                        .iter()
                        .any(|workspace| workspace.original_output.matches(&monitor.output)),
                    "secondary monitor must not have any non-own workspaces"
                );
            }

            assert!(
                !monitor.workspaces.last().unwrap().has_windows(),
                "monitor must have an empty workspace in the end"
            );
            if monitor.options.empty_workspace_above_first {
                assert!(
                    !monitor.workspaces.first().unwrap().has_windows(),
                    "first workspace must be empty when empty_workspace_above_first is set"
                )
            }

            assert!(
                monitor.workspaces.last().unwrap().name.is_none(),
                "monitor must have an unnamed workspace in the end"
            );
            if monitor.options.empty_workspace_above_first {
                assert!(
                    monitor.workspaces.first().unwrap().name.is_none(),
                    "first workspace must be unnamed when empty_workspace_above_first is set"
                )
            }

            if monitor.options.empty_workspace_above_first {
                assert!(
                    monitor.workspaces.len() != 2,
                    "if empty_workspace_above_first is set there must be just 1 or 3+ workspaces"
                )
            }

            // If there's no workspace switch in progress, there can't be any non-last non-active
            // empty workspaces. If empty_workspace_above_first is set then the first workspace
            // will be empty too.
            let pre_skip = if monitor.options.empty_workspace_above_first {
                1
            } else {
                0
            };
            if monitor.workspace_switch.is_none() {
                for (idx, ws) in monitor
                    .workspaces
                    .iter()
                    .enumerate()
                    .skip(pre_skip)
                    .rev()
                    // skip last
                    .skip(1)
                {
                    if idx != monitor.active_workspace_idx {
                        assert!(
                            ws.has_windows_or_name(),
                            "non-active workspace can't be empty and unnamed except the last one"
                        );
                    }
                }
            }

            // FIXME: verify that primary doesn't have any workspaces for which their own monitor
            // exists.

            for workspace in &monitor.workspaces {
                assert_eq!(self.clock, workspace.clock);

                assert_eq!(
                    workspace.base_options, self.options,
                    "workspace options must be synchronized with layout"
                );

                let options = Options::clone(&workspace.base_options)
                    .adjusted_for_scale(workspace.scale().fractional_scale());
                assert_eq!(
                    &*workspace.options, &options,
                    "workspace options must be base options adjusted for workspace scale"
                );

                assert!(
                    seen_workspace_id.insert(workspace.id()),
                    "workspace id must be unique"
                );

                if let Some(name) = &workspace.name {
                    assert!(
                        !seen_workspace_name
                            .iter()
                            .any(|n| n.eq_ignore_ascii_case(name)),
                        "workspace name must be unique"
                    );
                    seen_workspace_name.push(name.clone());
                }

                workspace.verify_invariants(move_win_id.as_ref());

                let has_view_offset_gesture = workspace.scrolling().view_offset().is_gesture();
                if self.dnd.is_some() || self.interactive_move.is_some() {
                    // We'd like to check that all workspaces have the gesture here, furthermore we
                    // want to check that they have the gesture only if the interactive move
                    // targets the scrolling layout. However, we cannot do that because we start
                    // and stop the gesture lazily. Otherwise the gesture code would pollute a lot
                    // of places like adding new workspaces, implicitly moving windows between
                    // floating and tiling on fullscreen, etc.
                    //
                    // assert!(
                    //     has_view_offset_gesture,
                    //     "during an interactive move in the scrolling layout, \
                    //      all workspaces should be in a view offset gesture"
                    // );
                } else if saw_view_offset_gesture {
                    assert!(
                        !has_view_offset_gesture,
                        "only one workspace can have an ongoing view offset gesture"
                    );
                }
                saw_view_offset_gesture = has_view_offset_gesture;
            }
        }
    }

    pub fn advance_animations(&mut self) {
        let _span = tracy_client::span!("Layout::advance_animations");

        let mut dnd_scroll = None;
        if let Some(dnd) = &self.dnd {
            dnd_scroll = Some((dnd.output.clone(), dnd.pointer_pos_within_output));
        }

        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            move_.tile.advance_animations();

            if !move_.is_floating && dnd_scroll.is_none() {
                dnd_scroll = Some((move_.output.clone(), move_.pointer_pos_within_output));
            }
        }

        // Scroll the view if needed.
        if let Some((output, pos_within_output)) = dnd_scroll {
            if let Some(mon) = self.monitor_for_output_mut(&output) {
                if let Some((ws, offset)) = mon.workspace_under(pos_within_output) {
                    let ws_id = ws.id();
                    let ws = mon
                        .workspaces
                        .iter_mut()
                        .find(|ws| ws.id() == ws_id)
                        .unwrap();
                    ws.dnd_scroll_gesture_scroll(pos_within_output - offset);
                }
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    mon.advance_animations();
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    ws.advance_animations();
                }
            }
        }
    }

    pub fn are_animations_ongoing(&self, output: Option<&Output>) -> bool {
        // Keep advancing animations if we might need to scroll the view.
        if let Some(dnd) = &self.dnd {
            if output.map_or(true, |output| *output == dnd.output) {
                return true;
            }
        }

        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if output.map_or(true, |output| *output == move_.output) {
                if move_.tile.are_animations_ongoing() {
                    return true;
                }

                // Keep advancing animations if we might need to scroll the view.
                if !move_.is_floating {
                    return true;
                }
            }
        }

        let MonitorSet::Normal { monitors, .. } = &self.monitor_set else {
            return false;
        };

        for mon in monitors {
            if output.is_some_and(|output| mon.output != *output) {
                continue;
            }

            if mon.are_animations_ongoing() {
                return true;
            }
        }

        false
    }

    pub fn update_render_elements(&mut self, output: Option<&Output>) {
        let _span = tracy_client::span!("Layout::update_render_elements");

        self.update_render_elements_time = self.clock.now();

        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if output.map_or(true, |output| move_.output == *output) {
                let pos_within_output = move_.tile_render_location();
                let view_rect =
                    Rectangle::new(pos_within_output.upscale(-1.), output_size(&move_.output));
                move_.tile.update_render_elements(true, view_rect);
            }
        }

        self.update_insert_hint(output);

        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        else {
            error!("update_render_elements called with no monitors");
            return;
        };

        for (idx, mon) in monitors.iter_mut().enumerate() {
            if output.map_or(true, |output| mon.output == *output) {
                let is_active = self.is_active
                    && idx == *active_monitor_idx
                    && !matches!(self.interactive_move, Some(InteractiveMoveState::Moving(_)));
                mon.update_render_elements(is_active);
            }
        }
    }

    pub fn update_shaders(&mut self) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            move_.tile.update_shaders();
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        ws.update_shaders();
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    ws.update_shaders();
                }
            }
        }
    }

    fn update_insert_hint(&mut self, output: Option<&Output>) {
        let _span = tracy_client::span!("Layout::update_insert_hint");

        let _span = tracy_client::span!("Layout::update_insert_hint::clear");
        for ws in self.workspaces_mut() {
            ws.clear_insert_hint();
        }

        if !matches!(self.interactive_move, Some(InteractiveMoveState::Moving(_))) {
            return;
        }
        let Some(InteractiveMoveState::Moving(move_)) = self.interactive_move.take() else {
            unreachable!()
        };
        if output.is_some_and(|out| &move_.output != out) {
            self.interactive_move = Some(InteractiveMoveState::Moving(move_));
            return;
        }

        // No insert hint when targeting floating.
        if move_.is_floating {
            self.interactive_move = Some(InteractiveMoveState::Moving(move_));
            return;
        }

        let _span = tracy_client::span!("Layout::update_insert_hint::update");

        if let Some(mon) = self.monitor_for_output_mut(&move_.output) {
            if let Some((ws, offset)) = mon.workspace_under(move_.pointer_pos_within_output) {
                let ws_id = ws.id();
                let ws = mon
                    .workspaces
                    .iter_mut()
                    .find(|ws| ws.id() == ws_id)
                    .unwrap();

                let position = ws.get_insert_position(move_.pointer_pos_within_output - offset);

                let rules = move_.tile.window().rules();
                let border_width = move_.tile.effective_border_width().unwrap_or(0.);
                let corner_radius = rules
                    .geometry_corner_radius
                    .map_or(CornerRadius::default(), |radius| {
                        radius.expanded_by(border_width as f32)
                    });

                ws.set_insert_hint(InsertHint {
                    position,
                    width: move_.width,
                    is_full_width: move_.is_full_width,
                    corner_radius,
                });
            }
        }

        self.interactive_move = Some(InteractiveMoveState::Moving(move_));
    }

    pub fn ensure_named_workspace(&mut self, ws_config: &WorkspaceConfig) {
        if self.find_workspace_by_name(&ws_config.name.0).is_some() {
            return;
        }

        let clock = self.clock.clone();
        let options = self.options.clone();

        match &mut self.monitor_set {
            MonitorSet::Normal {
                monitors,
                primary_idx,
                active_monitor_idx,
            } => {
                let mon_idx = ws_config
                    .open_on_output
                    .as_deref()
                    .map(|name| {
                        monitors
                            .iter_mut()
                            .position(|monitor| output_matches_name(&monitor.output, name))
                            .unwrap_or(*primary_idx)
                    })
                    .unwrap_or(*active_monitor_idx);
                let mon = &mut monitors[mon_idx];

                let mut insert_idx = 0;
                if mon.options.empty_workspace_above_first {
                    // need to insert new empty workspace on top
                    mon.add_workspace_top();
                    insert_idx += 1;
                }

                let ws = Workspace::new_with_config(
                    mon.output.clone(),
                    Some(ws_config.clone()),
                    clock,
                    options,
                );
                mon.workspaces.insert(insert_idx, ws);
                mon.active_workspace_idx += 1;

                mon.workspace_switch = None;
                mon.clean_up_workspaces();
            }
            MonitorSet::NoOutputs { workspaces } => {
                let ws =
                    Workspace::new_with_config_no_outputs(Some(ws_config.clone()), clock, options);
                workspaces.insert(0, ws);
            }
        }
    }

    pub fn update_config(&mut self, config: &Config) {
        self.update_options(Options::from_config(config));
    }

    fn update_options(&mut self, options: Options) {
        let options = Rc::new(options);

        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            let view_size = output_size(&move_.output);
            let scale = move_.output.current_scale().fractional_scale();
            move_.tile.update_config(
                view_size,
                scale,
                Rc::new(Options::clone(&options).adjusted_for_scale(scale)),
            );
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    mon.update_config(options.clone());
                }
            }
            MonitorSet::NoOutputs { workspaces } => {
                for ws in workspaces {
                    ws.update_config(options.clone());
                }
            }
        }

        self.options = options;
    }

    pub fn toggle_width(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.toggle_width();
    }

    pub fn toggle_window_width(&mut self, window: Option<&W::Id>) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if window.is_none() || window == Some(move_.tile.window().id()) {
                return;
            }
        }

        let workspace = if let Some(window) = window {
            Some(
                self.workspaces_mut()
                    .find(|ws| ws.has_window(window))
                    .unwrap(),
            )
        } else {
            self.active_workspace_mut()
        };

        let Some(workspace) = workspace else {
            return;
        };
        workspace.toggle_window_width(window);
    }

    pub fn toggle_window_height(&mut self, window: Option<&W::Id>) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if window.is_none() || window == Some(move_.tile.window().id()) {
                return;
            }
        }

        let workspace = if let Some(window) = window {
            Some(
                self.workspaces_mut()
                    .find(|ws| ws.has_window(window))
                    .unwrap(),
            )
        } else {
            self.active_workspace_mut()
        };

        let Some(workspace) = workspace else {
            return;
        };
        workspace.toggle_window_height(window);
    }

    pub fn toggle_full_width(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.toggle_full_width();
    }

    pub fn set_column_width(&mut self, change: SizeChange) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.set_column_width(change);
    }

    pub fn set_window_width(&mut self, window: Option<&W::Id>, change: SizeChange) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if window.is_none() || window == Some(move_.tile.window().id()) {
                return;
            }
        }

        let workspace = if let Some(window) = window {
            Some(
                self.workspaces_mut()
                    .find(|ws| ws.has_window(window))
                    .unwrap(),
            )
        } else {
            self.active_workspace_mut()
        };

        let Some(workspace) = workspace else {
            return;
        };
        workspace.set_window_width(window, change);
    }

    pub fn set_window_height(&mut self, window: Option<&W::Id>, change: SizeChange) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if window.is_none() || window == Some(move_.tile.window().id()) {
                return;
            }
        }

        let workspace = if let Some(window) = window {
            Some(
                self.workspaces_mut()
                    .find(|ws| ws.has_window(window))
                    .unwrap(),
            )
        } else {
            self.active_workspace_mut()
        };

        let Some(workspace) = workspace else {
            return;
        };
        workspace.set_window_height(window, change);
    }

    pub fn reset_window_height(&mut self, window: Option<&W::Id>) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if window.is_none() || window == Some(move_.tile.window().id()) {
                return;
            }
        }

        let workspace = if let Some(window) = window {
            Some(
                self.workspaces_mut()
                    .find(|ws| ws.has_window(window))
                    .unwrap(),
            )
        } else {
            self.active_workspace_mut()
        };

        let Some(workspace) = workspace else {
            return;
        };
        workspace.reset_window_height(window);
    }

    pub fn expand_column_to_available_width(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.expand_column_to_available_width();
    }

    pub fn toggle_window_floating(&mut self, window: Option<&W::Id>) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if window.is_none() || window == Some(move_.tile.window().id()) {
                move_.is_floating = !move_.is_floating;

                // When going to floating, restore the floating window size.
                if move_.is_floating {
                    let floating_size = move_.tile.floating_window_size;
                    let win = move_.tile.window_mut();
                    let mut size =
                        floating_size.unwrap_or_else(|| win.expected_size().unwrap_or_default());

                    // Apply min/max size window rules. If requesting a concrete size, apply
                    // completely; if requesting (0, 0), apply only when min/max results in a fixed
                    // size.
                    let min_size = win.min_size();
                    let max_size = win.max_size();
                    size.w = ensure_min_max_size_maybe_zero(size.w, min_size.w, max_size.w);
                    size.h = ensure_min_max_size_maybe_zero(size.h, min_size.h, max_size.h);

                    win.request_size_once(size, true);
                }

                return;
            }
        }

        let workspace = if let Some(window) = window {
            Some(
                self.workspaces_mut()
                    .find(|ws| ws.has_window(window))
                    .unwrap(),
            )
        } else {
            self.active_workspace_mut()
        };

        let Some(workspace) = workspace else {
            return;
        };
        workspace.toggle_window_floating(window);
    }

    pub fn set_window_floating(&mut self, window: Option<&W::Id>, floating: bool) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if window.is_none() || window == Some(move_.tile.window().id()) {
                if move_.is_floating != floating {
                    self.toggle_window_floating(window);
                }
                return;
            }
        }

        let workspace = if let Some(window) = window {
            Some(
                self.workspaces_mut()
                    .find(|ws| ws.has_window(window))
                    .unwrap(),
            )
        } else {
            self.active_workspace_mut()
        };

        let Some(workspace) = workspace else {
            return;
        };
        workspace.set_window_floating(window, floating);
    }

    pub fn focus_floating(&mut self) {
        let Some(workspace) = self.active_workspace_mut() else {
            return;
        };
        workspace.focus_floating();
    }

    pub fn focus_tiling(&mut self) {
        let Some(workspace) = self.active_workspace_mut() else {
            return;
        };
        workspace.focus_tiling();
    }

    pub fn switch_focus_floating_tiling(&mut self) {
        let Some(workspace) = self.active_workspace_mut() else {
            return;
        };
        workspace.switch_focus_floating_tiling();
    }

    pub fn move_floating_window(
        &mut self,
        id: Option<&W::Id>,
        x: PositionChange,
        y: PositionChange,
        animate: bool,
    ) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if id.is_none() || id == Some(move_.tile.window().id()) {
                return;
            }
        }

        let workspace = if let Some(id) = id {
            Some(self.workspaces_mut().find(|ws| ws.has_window(id)).unwrap())
        } else {
            self.active_workspace_mut()
        };

        let Some(workspace) = workspace else {
            return;
        };
        workspace.move_floating_window(id, x, y, animate);
    }

    pub fn focus_output(&mut self, output: &Output) {
        if let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        {
            for (idx, mon) in monitors.iter().enumerate() {
                if &mon.output == output {
                    *active_monitor_idx = idx;
                    return;
                }
            }
        }
    }

    pub fn move_to_output(
        &mut self,
        window: Option<&W::Id>,
        output: &Output,
        target_ws_idx: Option<usize>,
    ) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if window.is_none() || window == Some(move_.tile.window().id()) {
                return;
            }
        }

        if let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        {
            let new_idx = monitors
                .iter()
                .position(|mon| &mon.output == output)
                .unwrap();

            let (mon_idx, ws_idx) = if let Some(window) = window {
                monitors
                    .iter()
                    .enumerate()
                    .find_map(|(mon_idx, mon)| {
                        mon.workspaces
                            .iter()
                            .position(|ws| ws.has_window(window))
                            .map(|ws_idx| (mon_idx, ws_idx))
                    })
                    .unwrap()
            } else {
                let mon_idx = *active_monitor_idx;
                let mon = &monitors[mon_idx];
                (mon_idx, mon.active_workspace_idx)
            };

            let workspace_idx = target_ws_idx.unwrap_or(monitors[new_idx].active_workspace_idx);
            if mon_idx == new_idx && ws_idx == workspace_idx {
                return;
            }
            let ws_id = monitors[new_idx].workspaces[workspace_idx].id();

            let mon = &mut monitors[mon_idx];
            let activate = window.map_or(true, |win| {
                mon_idx == *active_monitor_idx
                    && mon.active_window().map(|win| win.id()) == Some(win)
            });
            let activate = if activate {
                ActivateWindow::Yes
            } else {
                ActivateWindow::No
            };

            let ws = &mut mon.workspaces[ws_idx];
            let transaction = Transaction::new();
            let mut removed = if let Some(window) = window {
                ws.remove_tile(window, transaction)
            } else if let Some(removed) = ws.remove_active_tile(transaction) {
                removed
            } else {
                return;
            };

            removed.tile.stop_move_animations();

            let mon = &mut monitors[new_idx];
            mon.add_tile(
                removed.tile,
                MonitorAddWindowTarget::Workspace {
                    id: ws_id,
                    column_idx: None,
                },
                activate,
                removed.width,
                removed.is_full_width,
                removed.is_floating,
            );
            if activate.map_smart(|| false) {
                *active_monitor_idx = new_idx;
            }

            let mon = &mut monitors[mon_idx];
            if mon.workspace_switch.is_none() {
                monitors[mon_idx].clean_up_workspaces();
            }
        }
    }

    pub fn move_column_to_output(&mut self, output: &Output) {
        if let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        {
            let new_idx = monitors
                .iter()
                .position(|mon| &mon.output == output)
                .unwrap();

            let current = &mut monitors[*active_monitor_idx];
            let ws = current.active_workspace();

            if ws.floating_is_active() {
                self.move_to_output(None, output, None);
                return;
            }

            let Some(column) = ws.remove_active_column() else {
                return;
            };

            let workspace_idx = monitors[new_idx].active_workspace_idx;
            self.add_column_by_idx(new_idx, workspace_idx, column, true);
        }
    }

    pub fn move_workspace_to_output(&mut self, output: &Output) -> bool {
        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        else {
            return false;
        };

        let current = &mut monitors[*active_monitor_idx];

        // Do not do anything if the output is already correct
        if &current.output == output {
            // Just update the original output since this is an explicit movement action.
            current.active_workspace().original_output = OutputId::new(output);

            return false;
        }

        if current.active_workspace_idx == current.workspaces.len() - 1 {
            // Insert a new empty workspace.
            current.add_workspace_bottom();
        }
        if current.options.empty_workspace_above_first && current.active_workspace_idx == 0 {
            current.add_workspace_top();
        }

        let mut ws = current.workspaces.remove(current.active_workspace_idx);
        current.active_workspace_idx = current.active_workspace_idx.saturating_sub(1);
        current.workspace_switch = None;
        current.clean_up_workspaces();

        ws.set_output(Some(output.clone()));
        ws.original_output = OutputId::new(output);

        let target_idx = monitors
            .iter()
            .position(|mon| &mon.output == output)
            .unwrap();
        let target = &mut monitors[target_idx];

        target.previous_workspace_id = Some(target.workspaces[target.active_workspace_idx].id());

        if target.options.empty_workspace_above_first && target.workspaces.len() == 1 {
            // Insert a new empty workspace on top to prepare for insertion of new workspace.
            target.add_workspace_top();
        }
        // Insert the workspace after the currently active one. Unless the currently active one is
        // the last empty workspace, then insert before.
        let target_ws_idx = min(target.active_workspace_idx + 1, target.workspaces.len() - 1);
        target.workspaces.insert(target_ws_idx, ws);
        target.active_workspace_idx = target_ws_idx;
        target.workspace_switch = None;
        target.clean_up_workspaces();

        *active_monitor_idx = target_idx;

        true
    }

    // FIXME: accept workspace by id and deduplicate logic with move_workspace_to_output()
    pub fn move_workspace_to_output_by_id(
        &mut self,
        old_idx: usize,
        old_output: Option<Output>,
        new_output: Output,
    ) -> bool {
        let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        else {
            return false;
        };

        let current_idx = if let Some(old_output) = old_output {
            monitors
                .iter()
                .position(|mon| mon.output == old_output)
                .unwrap()
        } else {
            *active_monitor_idx
        };
        let target_idx = monitors
            .iter()
            .position(|mon| mon.output == new_output)
            .unwrap();

        let current = &mut monitors[current_idx];

        // Do not do anything if the output is already correct
        if current_idx == target_idx {
            // Just update the original output since this is an explicit movement action.
            current.workspaces[old_idx].original_output = OutputId::new(&current.output);

            return false;
        }

        let current_active_ws_idx = current.active_workspace_idx;

        if old_idx == current.workspaces.len() - 1 {
            // Insert a new empty workspace.
            current.add_workspace_bottom();
        }

        let mut ws = current.workspaces.remove(old_idx);

        if current.options.empty_workspace_above_first && old_idx == 0 {
            current.add_workspace_top();
        }

        if old_idx < current.active_workspace_idx {
            current.active_workspace_idx -= 1;
        }
        current.workspace_switch = None;
        current.clean_up_workspaces();

        ws.set_output(Some(new_output.clone()));
        ws.original_output = OutputId::new(&new_output);

        let target = &mut monitors[target_idx];

        target.previous_workspace_id = Some(target.workspaces[target.active_workspace_idx].id());

        if target.options.empty_workspace_above_first && target.workspaces.len() == 1 {
            // Insert a new empty workspace on top to prepare for insertion of new workspace.
            target.add_workspace_top();
        }
        // Insert the workspace after the currently active one. Unless the currently active one is
        // the last empty workspace, then insert before.
        let target_ws_idx = min(target.active_workspace_idx + 1, target.workspaces.len() - 1);
        target.workspaces.insert(target_ws_idx, ws);

        // Only switch active monitor if the workspace moved was the currently focused one on the
        // current monitor
        let res = if current_idx == *active_monitor_idx && old_idx == current_active_ws_idx {
            *active_monitor_idx = target_idx;
            target.active_workspace_idx = target_ws_idx;
            true
        } else {
            if target_ws_idx <= target.active_workspace_idx {
                target.active_workspace_idx += 1;
            }
            false
        };

        target.workspace_switch = None;
        target.clean_up_workspaces();

        res
    }

    pub fn set_fullscreen(&mut self, window: &W::Id, is_fullscreen: bool) {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if move_.tile.window().id() == window {
                return;
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        if ws.has_window(window) {
                            ws.set_fullscreen(window, is_fullscreen);
                            return;
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    if ws.has_window(window) {
                        ws.set_fullscreen(window, is_fullscreen);
                        return;
                    }
                }
            }
        }
    }

    pub fn toggle_fullscreen(&mut self, window: &W::Id) {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if move_.tile.window().id() == window {
                return;
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        if ws.has_window(window) {
                            ws.toggle_fullscreen(window);
                            return;
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    if ws.has_window(window) {
                        ws.toggle_fullscreen(window);
                        return;
                    }
                }
            }
        }
    }

    pub fn workspace_switch_gesture_begin(&mut self, output: &Output, is_touchpad: bool) {
        let monitors = match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => monitors,
            MonitorSet::NoOutputs { .. } => unreachable!(),
        };

        for monitor in monitors {
            // Cancel the gesture on other outputs.
            if &monitor.output != output {
                monitor.workspace_switch_gesture_end(true, None);
                continue;
            }

            monitor.workspace_switch_gesture_begin(is_touchpad);
        }
    }

    pub fn workspace_switch_gesture_update(
        &mut self,
        delta_y: f64,
        timestamp: Duration,
        is_touchpad: bool,
    ) -> Option<Option<Output>> {
        let monitors = match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => monitors,
            MonitorSet::NoOutputs { .. } => return None,
        };

        for monitor in monitors {
            if let Some(refresh) =
                monitor.workspace_switch_gesture_update(delta_y, timestamp, is_touchpad)
            {
                if refresh {
                    return Some(Some(monitor.output.clone()));
                } else {
                    return Some(None);
                }
            }
        }

        None
    }

    pub fn workspace_switch_gesture_end(
        &mut self,
        cancelled: bool,
        is_touchpad: Option<bool>,
    ) -> Option<Output> {
        let monitors = match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => monitors,
            MonitorSet::NoOutputs { .. } => return None,
        };

        for monitor in monitors {
            if monitor.workspace_switch_gesture_end(cancelled, is_touchpad) {
                return Some(monitor.output.clone());
            }
        }

        None
    }

    pub fn view_offset_gesture_begin(&mut self, output: &Output, is_touchpad: bool) {
        let monitors = match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => monitors,
            MonitorSet::NoOutputs { .. } => unreachable!(),
        };

        for monitor in monitors {
            for (idx, ws) in monitor.workspaces.iter_mut().enumerate() {
                // Cancel the gesture on other workspaces.
                if &monitor.output != output || idx != monitor.active_workspace_idx {
                    ws.view_offset_gesture_end(true, None);
                    continue;
                }

                ws.view_offset_gesture_begin(is_touchpad);
            }
        }
    }

    pub fn view_offset_gesture_update(
        &mut self,
        delta_x: f64,
        timestamp: Duration,
        is_touchpad: bool,
    ) -> Option<Option<Output>> {
        let monitors = match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => monitors,
            MonitorSet::NoOutputs { .. } => return None,
        };

        for monitor in monitors {
            for ws in &mut monitor.workspaces {
                if let Some(refresh) =
                    ws.view_offset_gesture_update(delta_x, timestamp, is_touchpad)
                {
                    if refresh {
                        return Some(Some(monitor.output.clone()));
                    } else {
                        return Some(None);
                    }
                }
            }
        }

        None
    }

    pub fn view_offset_gesture_end(
        &mut self,
        cancelled: bool,
        is_touchpad: Option<bool>,
    ) -> Option<Output> {
        let monitors = match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => monitors,
            MonitorSet::NoOutputs { .. } => return None,
        };

        for monitor in monitors {
            for ws in &mut monitor.workspaces {
                if ws.view_offset_gesture_end(cancelled, is_touchpad) {
                    return Some(monitor.output.clone());
                }
            }
        }

        None
    }

    pub fn interactive_move_begin(
        &mut self,
        window_id: W::Id,
        output: &Output,
        start_pos_within_output: Point<f64, Logical>,
    ) -> bool {
        if self.interactive_move.is_some() {
            return false;
        }

        let MonitorSet::Normal { monitors, .. } = &mut self.monitor_set else {
            return false;
        };

        let Some((mon, (ws, ws_offset))) = monitors.iter().find_map(|mon| {
            mon.workspaces_with_render_positions()
                .find(|(ws, _)| ws.has_window(&window_id))
                .map(|rv| (mon, rv))
        }) else {
            return false;
        };

        if mon.output() != output {
            return false;
        }

        let is_floating = ws.is_floating(&window_id);
        let (tile, tile_offset, _visible) = ws
            .tiles_with_render_positions()
            .find(|(tile, _, _)| tile.window().id() == &window_id)
            .unwrap();
        let window_offset = tile.window_loc();

        let tile_pos = ws_offset + tile_offset;

        let pointer_offset_within_window = start_pos_within_output - tile_pos - window_offset;
        let window_size = tile.window_size();
        let pointer_ratio_within_window = (
            f64::clamp(pointer_offset_within_window.x / window_size.w, 0., 1.),
            f64::clamp(pointer_offset_within_window.y / window_size.h, 0., 1.),
        );

        self.interactive_move = Some(InteractiveMoveState::Starting {
            window_id,
            pointer_delta: Point::from((0., 0.)),
            pointer_ratio_within_window,
        });

        // Lock the view for scrolling interactive move.
        if !is_floating {
            for ws in self.workspaces_mut() {
                ws.dnd_scroll_gesture_begin();
            }
        }

        true
    }

    pub fn interactive_move_update(
        &mut self,
        window: &W::Id,
        delta: Point<f64, Logical>,
        output: Output,
        pointer_pos_within_output: Point<f64, Logical>,
    ) -> bool {
        let Some(state) = self.interactive_move.take() else {
            return false;
        };

        match state {
            InteractiveMoveState::Starting {
                window_id,
                mut pointer_delta,
                pointer_ratio_within_window,
            } => {
                if window_id != *window {
                    self.interactive_move = Some(InteractiveMoveState::Starting {
                        window_id,
                        pointer_delta,
                        pointer_ratio_within_window,
                    });
                    return false;
                }

                pointer_delta += delta;

                let (cx, cy) = (pointer_delta.x, pointer_delta.y);
                let sq_dist = cx * cx + cy * cy;

                let factor = RubberBand {
                    stiffness: 1.0,
                    limit: 0.5,
                }
                .band(sq_dist / INTERACTIVE_MOVE_START_THRESHOLD);

                let (is_floating, tile) = self
                    .workspaces_mut()
                    .find(|ws| ws.has_window(&window_id))
                    .map(|ws| {
                        (
                            ws.is_floating(&window_id),
                            ws.tiles_mut()
                                .find(|tile| *tile.window().id() == window_id)
                                .unwrap(),
                        )
                    })
                    .unwrap();
                tile.interactive_move_offset = pointer_delta.upscale(factor);

                // Put it back to be able to easily return.
                self.interactive_move = Some(InteractiveMoveState::Starting {
                    window_id: window_id.clone(),
                    pointer_delta,
                    pointer_ratio_within_window,
                });

                if !is_floating && sq_dist < INTERACTIVE_MOVE_START_THRESHOLD {
                    return true;
                }

                // If the pointer is currently on the window's own output, then we can animate the
                // window movement from its current (rubberbanded and possibly moved away) position
                // to the pointer. Otherwise, we just teleport it as the layout code is not aware
                // of monitor positions.
                //
                // FIXME: when and if the layout code knows about monitor positions, this will be
                // potentially animatable.
                let mut tile_pos = None;
                if let MonitorSet::Normal { monitors, .. } = &self.monitor_set {
                    if let Some((mon, (ws, ws_offset))) = monitors.iter().find_map(|mon| {
                        mon.workspaces_with_render_positions()
                            .find(|(ws, _)| ws.has_window(window))
                            .map(|rv| (mon, rv))
                    }) {
                        if mon.output() == &output {
                            let (_, tile_offset, _) = ws
                                .tiles_with_render_positions()
                                .find(|(tile, _, _)| tile.window().id() == window)
                                .unwrap();

                            tile_pos = Some(ws_offset + tile_offset);
                        }
                    }
                }

                let RemovedTile {
                    mut tile,
                    width,
                    is_full_width,
                    mut is_floating,
                } = self.remove_window(window, Transaction::new()).unwrap();

                tile.stop_move_animations();
                tile.interactive_move_offset = Point::from((0., 0.));
                tile.window().output_enter(&output);
                tile.window().set_preferred_scale_transform(
                    output.current_scale(),
                    output.current_transform(),
                );

                let view_size = output_size(&output);
                let scale = output.current_scale().fractional_scale();
                tile.update_config(
                    view_size,
                    scale,
                    Rc::new(Options::clone(&self.options).adjusted_for_scale(scale)),
                );

                // Unfullscreen.
                let floating_size = tile.floating_window_size;
                let unfullscreen_to_floating = tile.unfullscreen_to_floating;
                let win = tile.window_mut();
                if win.is_pending_fullscreen() {
                    // If we're unfullscreening to floating, use the stored floating size,
                    // otherwise use (0, 0).
                    let mut size = if unfullscreen_to_floating {
                        floating_size.unwrap_or_default()
                    } else {
                        Size::from((0, 0))
                    };

                    // Apply min/max size window rules. If requesting a concrete size, apply
                    // completely; if requesting (0, 0), apply only when min/max results in a fixed
                    // size.
                    let min_size = win.min_size();
                    let max_size = win.max_size();
                    size.w = ensure_min_max_size_maybe_zero(size.w, min_size.w, max_size.w);
                    size.h = ensure_min_max_size_maybe_zero(size.h, min_size.h, max_size.h);

                    win.request_size_once(size, true);

                    // If we're unfullscreening to floating, default to the floating layout.
                    is_floating = unfullscreen_to_floating;
                }

                let mut data = InteractiveMoveData {
                    tile,
                    output,
                    pointer_pos_within_output,
                    width,
                    is_full_width,
                    is_floating,
                    pointer_ratio_within_window,
                };

                if let Some(tile_pos) = tile_pos {
                    let new_tile_pos = data.tile_render_location();
                    data.tile.animate_move_from(tile_pos - new_tile_pos);
                }

                self.interactive_move = Some(InteractiveMoveState::Moving(data));
            }
            InteractiveMoveState::Moving(mut move_) => {
                if window != move_.tile.window().id() {
                    self.interactive_move = Some(InteractiveMoveState::Moving(move_));
                    return false;
                }

                if output != move_.output {
                    move_.tile.window().output_leave(&move_.output);
                    move_.tile.window().output_enter(&output);
                    move_.tile.window().set_preferred_scale_transform(
                        output.current_scale(),
                        output.current_transform(),
                    );
                    let view_size = output_size(&output);
                    let scale = output.current_scale().fractional_scale();
                    move_.tile.update_config(
                        view_size,
                        scale,
                        Rc::new(Options::clone(&self.options).adjusted_for_scale(scale)),
                    );
                    move_.output = output.clone();
                    self.focus_output(&output);
                }

                move_.pointer_pos_within_output = pointer_pos_within_output;

                self.interactive_move = Some(InteractiveMoveState::Moving(move_));
            }
        }

        true
    }

    pub fn interactive_move_end(&mut self, window: &W::Id) {
        let Some(move_) = &self.interactive_move else {
            return;
        };

        let move_ = match move_ {
            InteractiveMoveState::Starting { window_id, .. } => {
                if window_id != window {
                    return;
                }

                let Some(InteractiveMoveState::Starting { window_id, .. }) =
                    self.interactive_move.take()
                else {
                    unreachable!()
                };

                for ws in self.workspaces_mut() {
                    if let Some(tile) = ws.tiles_mut().find(|tile| *tile.window().id() == window_id)
                    {
                        let offset = tile.interactive_move_offset;
                        tile.interactive_move_offset = Point::from((0., 0.));
                        tile.animate_move_from(offset);
                    }

                    // Unlock the view on the workspaces, but if the moved window was active,
                    // preserve that.
                    let moved_tile_was_active =
                        ws.active_window().is_some_and(|win| *win.id() == window_id);

                    ws.dnd_scroll_gesture_end();

                    if moved_tile_was_active {
                        ws.activate_window(&window_id);
                    }
                }

                return;
            }
            InteractiveMoveState::Moving(move_) => move_,
        };

        if window != move_.tile.window().id() {
            return;
        }

        let Some(InteractiveMoveState::Moving(move_)) = self.interactive_move.take() else {
            unreachable!()
        };

        // Unlock the view on the workspaces.
        if !move_.is_floating {
            for ws in self.workspaces_mut() {
                ws.dnd_scroll_gesture_end();
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal {
                monitors,
                active_monitor_idx,
                ..
            } => {
                let (mon, ws_idx, position, offset) = if let Some(mon) =
                    monitors.iter_mut().find(|mon| mon.output == move_.output)
                {
                    let (ws, offset) = mon
                        .workspace_under(move_.pointer_pos_within_output)
                        // If the pointer is somehow outside the move output and a workspace switch
                        // is in progress, this won't necessarily do the expected thing, but also
                        // that is not really supposed to happen so eh?
                        .unwrap_or_else(|| mon.workspaces_with_render_positions().next().unwrap());

                    let ws_id = ws.id();
                    let ws_idx = mon
                        .workspaces
                        .iter_mut()
                        .position(|ws| ws.id() == ws_id)
                        .unwrap();

                    let position = if move_.is_floating {
                        InsertPosition::Floating
                    } else {
                        let ws = &mut mon.workspaces[ws_idx];
                        ws.get_insert_position(move_.pointer_pos_within_output - offset)
                    };

                    (mon, ws_idx, position, offset)
                } else {
                    let mon = &mut monitors[*active_monitor_idx];
                    // No point in trying to use the pointer position on the wrong output.
                    let (ws, offset) = mon.workspaces_with_render_positions().next().unwrap();

                    let position = if move_.is_floating {
                        InsertPosition::Floating
                    } else {
                        ws.get_insert_position(Point::from((0., 0.)))
                    };

                    let ws_id = ws.id();
                    let ws_idx = mon
                        .workspaces
                        .iter_mut()
                        .position(|ws| ws.id() == ws_id)
                        .unwrap();
                    (mon, ws_idx, position, offset)
                };

                let win_id = move_.tile.window().id().clone();
                let window_render_loc = move_.tile_render_location() + move_.tile.window_loc();

                match position {
                    InsertPosition::NewColumn(column_idx) => {
                        let ws_id = mon.workspaces[ws_idx].id();
                        mon.add_tile(
                            move_.tile,
                            MonitorAddWindowTarget::Workspace {
                                id: ws_id,
                                column_idx: Some(column_idx),
                            },
                            ActivateWindow::Yes,
                            move_.width,
                            move_.is_full_width,
                            false,
                        );
                    }
                    InsertPosition::InColumn(column_idx, tile_idx) => {
                        mon.add_tile_to_column(
                            ws_idx,
                            column_idx,
                            Some(tile_idx),
                            move_.tile,
                            true,
                        );
                    }
                    InsertPosition::Floating => {
                        let pos = move_.tile_render_location() - offset;

                        let mut tile = move_.tile;
                        let pos = mon.workspaces[ws_idx].floating_logical_to_size_frac(pos);
                        tile.floating_pos = Some(pos);

                        // Set the floating size so it takes into account any window resizing that
                        // took place during the move.
                        if let Some(size) = tile.window().expected_size() {
                            tile.floating_window_size = Some(size);
                        }

                        let ws_id = mon.workspaces[ws_idx].id();
                        mon.add_tile(
                            tile,
                            MonitorAddWindowTarget::Workspace {
                                id: ws_id,
                                column_idx: None,
                            },
                            ActivateWindow::Yes,
                            move_.width,
                            move_.is_full_width,
                            true,
                        );
                    }
                }

                // needed because empty_workspace_above_first could have modified the idx
                let ws_idx = mon.active_workspace_idx();
                let ws = &mut mon.workspaces[ws_idx];
                let (tile, tile_render_loc) = ws
                    .tiles_with_render_positions_mut(false)
                    .find(|(tile, _)| tile.window().id() == &win_id)
                    .unwrap();
                let new_window_render_loc = offset + tile_render_loc + tile.window_loc();

                tile.animate_move_from(window_render_loc - new_window_render_loc);
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                if workspaces.is_empty() {
                    workspaces.push(Workspace::new_no_outputs(
                        self.clock.clone(),
                        self.options.clone(),
                    ));
                }
                let ws = &mut workspaces[0];

                // No point in trying to use the pointer position without outputs.
                ws.add_tile(
                    move_.tile,
                    WorkspaceAddWindowTarget::Auto,
                    ActivateWindow::Yes,
                    move_.width,
                    move_.is_full_width,
                    move_.is_floating,
                );
            }
        }
    }

    pub fn interactive_move_is_moving_above_output(&self, output: &Output) -> bool {
        let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move else {
            return false;
        };

        move_.output == *output
    }

    pub fn dnd_update(&mut self, output: Output, pointer_pos_within_output: Point<f64, Logical>) {
        let begin_gesture = self.dnd.is_none();

        self.dnd = Some(DndData {
            output,
            pointer_pos_within_output,
        });

        if begin_gesture {
            for ws in self.workspaces_mut() {
                ws.dnd_scroll_gesture_begin();
            }
        }
    }

    pub fn dnd_end(&mut self) {
        if self.dnd.is_none() {
            return;
        }

        self.dnd = None;

        for ws in self.workspaces_mut() {
            ws.dnd_scroll_gesture_end();
        }
    }

    pub fn interactive_resize_begin(&mut self, window: W::Id, edges: ResizeEdge) -> bool {
        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        if ws.has_window(&window) {
                            return ws.interactive_resize_begin(window, edges);
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    if ws.has_window(&window) {
                        return ws.interactive_resize_begin(window, edges);
                    }
                }
            }
        }

        false
    }

    pub fn interactive_resize_update(
        &mut self,
        window: &W::Id,
        delta: Point<f64, Logical>,
    ) -> bool {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if move_.tile.window().id() == window {
                return false;
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        if ws.has_window(window) {
                            return ws.interactive_resize_update(window, delta);
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    if ws.has_window(window) {
                        return ws.interactive_resize_update(window, delta);
                    }
                }
            }
        }

        false
    }

    pub fn interactive_resize_end(&mut self, window: &W::Id) {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if move_.tile.window().id() == window {
                return;
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        if ws.has_window(window) {
                            ws.interactive_resize_end(Some(window));
                            return;
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    if ws.has_window(window) {
                        ws.interactive_resize_end(Some(window));
                        return;
                    }
                }
            }
        }
    }

    pub fn move_workspace_down(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_workspace_down();
    }

    pub fn move_workspace_up(&mut self) {
        let Some(monitor) = self.active_monitor() else {
            return;
        };
        monitor.move_workspace_up();
    }

    pub fn move_workspace_to_idx(
        &mut self,
        reference: Option<(Option<Output>, usize)>,
        new_idx: usize,
    ) {
        let (monitor, old_idx) = if let Some((output, old_idx)) = reference {
            let monitor = if let Some(output) = output {
                let Some(monitor) = self.monitor_for_output_mut(&output) else {
                    return;
                };
                monitor
            } else {
                // In case a numbered workspace reference is used, assume the active monitor
                let Some(monitor) = self.active_monitor() else {
                    return;
                };
                monitor
            };

            (monitor, old_idx)
        } else {
            let Some(monitor) = self.active_monitor() else {
                return;
            };
            let index = monitor.active_workspace_idx;
            (monitor, index)
        };

        monitor.move_workspace_to_idx(old_idx, new_idx);
    }

    pub fn set_workspace_name(&mut self, name: String, reference: Option<WorkspaceReference>) {
        // ignore the request if the name is already used by another workspace
        if self.find_workspace_by_name(&name).is_some() {
            return;
        }

        let ws = if let Some(reference) = reference {
            self.find_workspace_by_ref(reference)
        } else {
            self.active_workspace_mut()
        };
        let Some(ws) = ws else {
            return;
        };

        ws.name.replace(name);

        let wsid = ws.id();

        // if `empty_workspace_above_first` is set and `ws` is the first
        // worskpace on a monitor, another empty workspace needs to
        // be added before.
        // Conversely, if `ws` was the last workspace on a monitor, an
        // empty workspace needs to be added after.

        if let MonitorSet::Normal {
            monitors,
            active_monitor_idx,
            ..
        } = &mut self.monitor_set
        {
            let monitor = &mut monitors[*active_monitor_idx];
            if self.options.empty_workspace_above_first
                && monitor
                    .workspaces
                    .first()
                    .is_some_and(|first| first.id() == wsid)
            {
                monitor.add_workspace_top();
            }
            if monitor
                .workspaces
                .last()
                .is_some_and(|last| last.id() == wsid)
            {
                monitor.add_workspace_bottom();
            }
        }
    }

    pub fn unset_workspace_name(&mut self, reference: Option<WorkspaceReference>) {
        let ws = if let Some(reference) = reference {
            self.find_workspace_by_ref(reference)
        } else {
            self.active_workspace_mut()
        };
        let Some(ws) = ws else {
            return;
        };
        let id = ws.id();

        self.unname_workspace_by_id(id);
    }

    pub fn start_open_animation_for_window(&mut self, window: &W::Id) {
        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if move_.tile.window().id() == window {
                return;
            }
        }

        for ws in self.workspaces_mut() {
            if ws.start_open_animation(window) {
                return;
            }
        }
    }

    pub fn store_unmap_snapshot(&mut self, renderer: &mut GlesRenderer, window: &W::Id) {
        let _span = tracy_client::span!("Layout::store_unmap_snapshot");

        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if move_.tile.window().id() == window {
                let scale = Scale::from(move_.output.current_scale().fractional_scale());
                move_.tile.store_unmap_snapshot_if_empty(renderer, scale);
                return;
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        if ws.has_window(window) {
                            ws.store_unmap_snapshot_if_empty(renderer, window);
                            return;
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    if ws.has_window(window) {
                        ws.store_unmap_snapshot_if_empty(renderer, window);
                        return;
                    }
                }
            }
        }
    }

    pub fn clear_unmap_snapshot(&mut self, window: &W::Id) {
        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if move_.tile.window().id() == window {
                let _ = move_.tile.take_unmap_snapshot();
                return;
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        if ws.has_window(window) {
                            ws.clear_unmap_snapshot(window);
                            return;
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    if ws.has_window(window) {
                        ws.clear_unmap_snapshot(window);
                        return;
                    }
                }
            }
        }
    }

    pub fn start_close_animation_for_window(
        &mut self,
        renderer: &mut GlesRenderer,
        window: &W::Id,
        blocker: TransactionBlocker,
    ) {
        let _span = tracy_client::span!("Layout::start_close_animation_for_window");

        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            if move_.tile.window().id() == window {
                let Some(snapshot) = move_.tile.take_unmap_snapshot() else {
                    return;
                };
                let tile_pos = move_.tile_render_location();
                let tile_size = move_.tile.tile_size();

                let output = move_.output.clone();
                let pointer_pos_within_output = move_.pointer_pos_within_output;
                let Some(mon) = self.monitor_for_output_mut(&output) else {
                    return;
                };
                let Some((ws, offset)) = mon.workspace_under(pointer_pos_within_output) else {
                    return;
                };
                let ws_id = ws.id();
                let ws = mon
                    .workspaces
                    .iter_mut()
                    .find(|ws| ws.id() == ws_id)
                    .unwrap();

                let tile_pos = tile_pos - offset;
                ws.start_close_animation_for_tile(renderer, snapshot, tile_size, tile_pos, blocker);
                return;
            }
        }

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                for mon in monitors {
                    for ws in &mut mon.workspaces {
                        if ws.has_window(window) {
                            ws.start_close_animation_for_window(renderer, window, blocker);
                            return;
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    if ws.has_window(window) {
                        ws.start_close_animation_for_window(renderer, window, blocker);
                        return;
                    }
                }
            }
        }
    }

    pub fn render_floating_for_output<'a, R: NiriRenderer + 'a>(
        &'a self,
        renderer: &mut R,
        output: &Output,
        target: RenderTarget,
    ) -> impl Iterator<Item = TileRenderElement<R>> + 'a {
        if self.update_render_elements_time != self.clock.now() {
            error!("clock moved between updating render elements and rendering");
        }

        let mut rv = None;

        if let Some(InteractiveMoveState::Moving(move_)) = &self.interactive_move {
            if &move_.output == output {
                let scale = Scale::from(move_.output.current_scale().fractional_scale());
                let location = move_.tile_render_location();
                rv = Some(move_.tile.render(renderer, location, scale, true, target));
            }
        }

        rv.into_iter().flatten()
    }

    pub fn refresh(&mut self, is_active: bool) {
        let _span = tracy_client::span!("Layout::refresh");

        self.is_active = is_active;

        let mut ongoing_scrolling_dnd = self.dnd.is_some().then_some(true);

        if let Some(InteractiveMoveState::Moving(move_)) = &mut self.interactive_move {
            let win = move_.tile.window_mut();

            win.set_active_in_column(true);
            win.set_floating(move_.is_floating);
            win.set_activated(true);

            win.set_interactive_resize(None);

            win.set_bounds(output_size(&move_.output).to_i32_round());

            win.send_pending_configure();
            win.refresh();

            ongoing_scrolling_dnd.get_or_insert(!move_.is_floating);
        } else if let Some(InteractiveMoveState::Starting { window_id, .. }) =
            &self.interactive_move
        {
            ongoing_scrolling_dnd.get_or_insert_with(|| {
                let (_, _, ws) = self
                    .workspaces()
                    .find(|(_, _, ws)| ws.has_window(window_id))
                    .unwrap();
                !ws.is_floating(window_id)
            });
        }

        match &mut self.monitor_set {
            MonitorSet::Normal {
                monitors,
                active_monitor_idx,
                ..
            } => {
                for (idx, mon) in monitors.iter_mut().enumerate() {
                    let is_active = self.is_active
                        && idx == *active_monitor_idx
                        && !matches!(self.interactive_move, Some(InteractiveMoveState::Moving(_)));
                    for (ws_idx, ws) in mon.workspaces.iter_mut().enumerate() {
                        ws.refresh(is_active);

                        if let Some(is_scrolling) = ongoing_scrolling_dnd {
                            // Lock or unlock the view for scrolling interactive move.
                            if is_scrolling {
                                ws.dnd_scroll_gesture_begin();
                            } else {
                                ws.dnd_scroll_gesture_end();
                            }
                        } else {
                            // Cancel the view offset gesture after workspace switches, moves, etc.
                            if ws_idx != mon.active_workspace_idx {
                                ws.view_offset_gesture_end(false, None);
                            }
                        }
                    }
                }
            }
            MonitorSet::NoOutputs { workspaces, .. } => {
                for ws in workspaces {
                    ws.refresh(false);
                    ws.view_offset_gesture_end(false, None);
                }
            }
        }
    }

    pub fn workspaces(
        &self,
    ) -> impl Iterator<Item = (Option<&Monitor<W>>, usize, &Workspace<W>)> + '_ {
        let iter_normal;
        let iter_no_outputs;

        match &self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                let it = monitors.iter().flat_map(|mon| {
                    mon.workspaces
                        .iter()
                        .enumerate()
                        .map(move |(idx, ws)| (Some(mon), idx, ws))
                });

                iter_normal = Some(it);
                iter_no_outputs = None;
            }
            MonitorSet::NoOutputs { workspaces } => {
                let it = workspaces
                    .iter()
                    .enumerate()
                    .map(|(idx, ws)| (None, idx, ws));

                iter_normal = None;
                iter_no_outputs = Some(it);
            }
        }

        let iter_normal = iter_normal.into_iter().flatten();
        let iter_no_outputs = iter_no_outputs.into_iter().flatten();
        iter_normal.chain(iter_no_outputs)
    }

    pub fn workspaces_mut(&mut self) -> impl Iterator<Item = &mut Workspace<W>> + '_ {
        let iter_normal;
        let iter_no_outputs;

        match &mut self.monitor_set {
            MonitorSet::Normal { monitors, .. } => {
                let it = monitors
                    .iter_mut()
                    .flat_map(|mon| mon.workspaces.iter_mut());

                iter_normal = Some(it);
                iter_no_outputs = None;
            }
            MonitorSet::NoOutputs { workspaces } => {
                let it = workspaces.iter_mut();

                iter_normal = None;
                iter_no_outputs = Some(it);
            }
        }

        let iter_normal = iter_normal.into_iter().flatten();
        let iter_no_outputs = iter_no_outputs.into_iter().flatten();
        iter_normal.chain(iter_no_outputs)
    }

    pub fn windows(&self) -> impl Iterator<Item = (Option<&Monitor<W>>, &W)> {
        let moving_window = self
            .interactive_move
            .as_ref()
            .and_then(|x| x.moving())
            .map(|move_| (self.monitor_for_output(&move_.output), move_.tile.window()))
            .into_iter();

        let rest = self
            .workspaces()
            .flat_map(|(mon, _, ws)| ws.windows().map(move |win| (mon, win)));

        moving_window.chain(rest)
    }

    pub fn has_window(&self, window: &W::Id) -> bool {
        self.windows().any(|(_, win)| win.id() == window)
    }

    fn resolve_scrolling_width(&self, window: &W, width: Option<PresetSize>) -> ColumnWidth {
        let width = width.unwrap_or_else(|| PresetSize::Fixed(window.size().w));
        match width {
            PresetSize::Fixed(fixed) => {
                let mut fixed = f64::from(fixed);

                // Add border width since ColumnWidth includes borders.
                let rules = window.rules();
                let border = rules.border.resolve_against(self.options.border);
                if !border.off {
                    fixed += border.width.0 * 2.;
                }

                ColumnWidth::Fixed(fixed)
            }
            PresetSize::Proportion(prop) => ColumnWidth::Proportion(prop),
        }
    }
}

impl<W: LayoutElement> Default for MonitorSet<W> {
    fn default() -> Self {
        Self::NoOutputs { workspaces: vec![] }
    }
}