Implement ext-workspace

4 files changed, 764 insertions, 2 deletions

diff --git a/src/handlers/mod.rs b/src/handlers/mod.rs
index 8353cd09..5955bcec 100644
--- a/src/handlers/mod.rs
+++ b/src/handlers/mod.rs
@@ -76,8 +76,10 @@ use smithay::{
 };
 
 pub use crate::handlers::xdg_shell::KdeDecorationsModeState;
+use crate::layout::workspace::WorkspaceId;
 use crate::layout::ActivateWindow;
 use crate::niri::{DndIcon, NewClient, State};
+use crate::protocols::ext_workspace::{self, ExtWorkspaceHandler, ExtWorkspaceManagerState};
 use crate::protocols::foreign_toplevel::{
     self, ForeignToplevelHandler, ForeignToplevelManagerState,
 };
@@ -92,8 +94,9 @@ use crate::protocols::virtual_pointer::{
 };
 use crate::utils::{output_size, send_scale_transform, with_toplevel_role};
 use crate::{
-    delegate_foreign_toplevel, delegate_gamma_control, delegate_mutter_x11_interop,
-    delegate_output_management, delegate_screencopy, delegate_virtual_pointer,
+    delegate_ext_workspace, delegate_foreign_toplevel, delegate_gamma_control,
+    delegate_mutter_x11_interop, delegate_output_management, delegate_screencopy,
+    delegate_virtual_pointer,
 };
 
 pub const XDG_ACTIVATION_TOKEN_TIMEOUT: Duration = Duration::from_secs(10);
@@ -414,6 +417,7 @@ delegate_ext_data_control!(State);
 impl OutputHandler for State {
     fn output_bound(&mut self, output: Output, wl_output: WlOutput) {
         foreign_toplevel::on_output_bound(self, &output, &wl_output);
+        ext_workspace::on_output_bound(self, &output, &wl_output);
     }
 }
 delegate_output!(State);
@@ -574,6 +578,42 @@ impl ForeignToplevelHandler for State {
 }
 delegate_foreign_toplevel!(State);
 
+impl ExtWorkspaceHandler for State {
+    fn ext_workspace_manager_state(&mut self) -> &mut ExtWorkspaceManagerState {
+        &mut self.niri.ext_workspace_state
+    }
+
+    fn activate_workspace(&mut self, id: WorkspaceId) {
+        let reference = niri_config::WorkspaceReference::Id(id.get());
+        if let Some((mut output, index)) = self.niri.find_output_and_workspace_index(reference) {
+            if let Some(active) = self.niri.layout.active_output() {
+                if output.as_ref() == Some(active) {
+                    output = None;
+                }
+            }
+
+            if let Some(output) = output {
+                self.niri.layout.focus_output(&output);
+            }
+            self.niri.layout.switch_workspace(index);
+            // No mouse warp: assuming the layer-shell bar workspaces use-case.
+
+            // FIXME: granular
+            self.niri.queue_redraw_all();
+        }
+    }
+
+    fn assign_workspace(&mut self, ws_id: WorkspaceId, output: Output) {
+        let reference = niri_config::WorkspaceReference::Id(ws_id.get());
+        if let Some((old_output, old_idx)) = self.niri.find_output_and_workspace_index(reference) {
+            self.niri
+                .layout
+                .move_workspace_to_output_by_id(old_idx, old_output, output);
+        }
+    }
+}
+delegate_ext_workspace!(State);
+
 impl ScreencopyHandler for State {
     fn frame(&mut self, manager: &ZwlrScreencopyManagerV1, screencopy: Screencopy) {
         // If with_damage then push it onto the queue for redraw of the output,
diff --git a/src/niri.rs b/src/niri.rs
index fd4112e6..05db2fd0 100644
--- a/src/niri.rs
+++ b/src/niri.rs
@@ -136,6 +136,7 @@ use crate::layout::tile::TileRenderElement;
 use crate::layout::workspace::{Workspace, WorkspaceId};
 use crate::layout::{HitType, Layout, LayoutElement as _, MonitorRenderElement};
 use crate::niri_render_elements;
+use crate::protocols::ext_workspace::{self, ExtWorkspaceManagerState};
 use crate::protocols::foreign_toplevel::{self, ForeignToplevelManagerState};
 use crate::protocols::gamma_control::GammaControlManagerState;
 use crate::protocols::mutter_x11_interop::MutterX11InteropManagerState;
@@ -259,6 +260,7 @@ pub struct Niri {
     pub layer_shell_state: WlrLayerShellState,
     pub session_lock_state: SessionLockManagerState,
     pub foreign_toplevel_state: ForeignToplevelManagerState,
+    pub ext_workspace_state: ExtWorkspaceManagerState,
     pub screencopy_state: ScreencopyManagerState,
     pub output_management_state: OutputManagementManagerState,
     pub viewporter_state: ViewporterState,
@@ -719,6 +721,7 @@ impl State {
         self.niri.refresh_idle_inhibit();
         self.refresh_pointer_contents();
         foreign_toplevel::refresh(self);
+        ext_workspace::refresh(self);
 
         #[cfg(feature = "xdp-gnome-screencast")]
         self.niri.refresh_mapped_cast_outputs();
@@ -2325,6 +2328,8 @@ impl Niri {
             VirtualPointerManagerState::new::<State, _>(&display_handle, client_is_unrestricted);
         let foreign_toplevel_state =
             ForeignToplevelManagerState::new::<State, _>(&display_handle, client_is_unrestricted);
+        let ext_workspace_state =
+            ExtWorkspaceManagerState::new::<State, _>(&display_handle, client_is_unrestricted);
         let mut output_management_state =
             OutputManagementManagerState::new::<State, _>(&display_handle, client_is_unrestricted);
         output_management_state.on_config_changed(config_.outputs.clone());
@@ -2519,6 +2524,7 @@ impl Niri {
             layer_shell_state,
             session_lock_state,
             foreign_toplevel_state,
+            ext_workspace_state,
             output_management_state,
             screencopy_state,
             viewporter_state,
diff --git a/src/protocols/ext_workspace.rs b/src/protocols/ext_workspace.rs
new file mode 100644
index 00000000..3d97cc4f
--- /dev/null
+++ b/src/protocols/ext_workspace.rs
@@ -0,0 +1,715 @@
+//! ext-workspace protocol implementation.
+//!
+//! This is how we map the protocol concepts to the niri concepts:
+//!
+//! - Workspace groups are outputs.
+//! - Workspace coordinates: X = 0, Y = workspace index. They need to be two-dimensional because 1D
+//!   coordinates are defined to be a plain list without a geometric interpretation, while we do
+//!   order workspaces in a vertical line.
+//! - Workspace id: name for named workspaces, unset for unnamed. Because ids in this protocol are
+//!   expected to be stable across sessions.
+//! - Workspace name: name for named workspaces, index for unnamed.
+
+use std::collections::hash_map::Entry;
+use std::collections::HashMap;
+use std::mem;
+
+use arrayvec::ArrayVec;
+use ext_workspace_group_handle_v1::ExtWorkspaceGroupHandleV1;
+use ext_workspace_handle_v1::ExtWorkspaceHandleV1;
+use ext_workspace_manager_v1::ExtWorkspaceManagerV1;
+use smithay::output::{Output, WeakOutput};
+use smithay::reexports::wayland_protocols::ext::workspace::v1::server::{
+    ext_workspace_group_handle_v1, ext_workspace_handle_v1, ext_workspace_manager_v1,
+};
+use smithay::reexports::wayland_server::protocol::wl_output::WlOutput;
+use smithay::reexports::wayland_server::{
+    Client, DataInit, Dispatch, DisplayHandle, GlobalDispatch, New, Resource,
+};
+use wayland_backend::server::ClientId;
+
+use crate::layout::monitor::Monitor;
+use crate::layout::workspace::{Workspace, WorkspaceId};
+use crate::niri::State;
+use crate::window::Mapped;
+
+const VERSION: u32 = 1;
+
+pub trait ExtWorkspaceHandler {
+    fn ext_workspace_manager_state(&mut self) -> &mut ExtWorkspaceManagerState;
+    fn activate_workspace(&mut self, id: WorkspaceId);
+    fn assign_workspace(&mut self, ws_id: WorkspaceId, output: Output);
+}
+
+enum Action {
+    Assign(WorkspaceId, WeakOutput),
+    Activate(WorkspaceId),
+}
+
+impl Action {
+    fn order(&self) -> u8 {
+        // First assign everything (move across outputs), then activate.
+        match self {
+            Action::Assign(_, _) => 0,
+            Action::Activate(_) => 1,
+        }
+    }
+}
+
+pub struct ExtWorkspaceManagerState {
+    display: DisplayHandle,
+    instances: HashMap<ExtWorkspaceManagerV1, Vec<Action>>,
+    workspace_groups: HashMap<Output, ExtWorkspaceGroupData>,
+    workspaces: HashMap<WorkspaceId, ExtWorkspaceData>,
+}
+
+struct ExtWorkspaceGroupData {
+    instances: Vec<ExtWorkspaceGroupHandleV1>,
+}
+
+struct ExtWorkspaceData {
+    // id cannot change once set.
+    id: Option<String>,
+    name: String,
+    coordinates: ArrayVec<u32, 2>,
+    state: ext_workspace_handle_v1::State,
+    instances: Vec<ExtWorkspaceHandleV1>,
+    output: Option<Output>,
+}
+
+pub struct ExtWorkspaceGlobalData {
+    filter: Box<dyn for<'c> Fn(&'c Client) -> bool + Send + Sync>,
+}
+
+pub fn refresh(state: &mut State) {
+    let _span = tracy_client::span!("ext_workspace::refresh");
+
+    let protocol_state = &mut state.niri.ext_workspace_state;
+
+    let mut changed = false;
+
+    // Remove workspaces that no longer exist (sending workspace_leave to workspace groups).
+    let mut seen_workspaces = HashMap::new();
+    for (mon, _, ws) in state.niri.layout.workspaces() {
+        let output = mon.map(|mon| mon.output());
+        seen_workspaces.insert(ws.id(), output);
+    }
+
+    protocol_state.workspaces.retain(|id, workspace| {
+        if seen_workspaces.contains_key(id) {
+            return true;
+        }
+
+        remove_workspace_instances(&protocol_state.workspace_groups, workspace);
+        changed = true;
+        false
+    });
+
+    // Remove workspace groups for outputs that no longer exist.
+    protocol_state.workspace_groups.retain(|output, data| {
+        if state.niri.sorted_outputs.contains(output) {
+            return true;
+        }
+
+        for group in &data.instances {
+            // Send workspace_leave for all workspaces in this group with matching manager.
+            let manager: &ExtWorkspaceManagerV1 = group.data().unwrap();
+            for ws in protocol_state.workspaces.values() {
+                if ws.output.as_ref() == Some(output) {
+                    for workspace in &ws.instances {
+                        if workspace.data() == Some(manager) {
+                            group.workspace_leave(workspace);
+                        }
+                    }
+                }
+            }
+
+            group.removed();
+        }
+
+        changed = true;
+        false
+    });
+
+    // Update existing workspaces and create new ones.
+    for (mon, ws_idx, ws) in state.niri.layout.workspaces() {
+        changed |= refresh_workspace(protocol_state, mon, ws_idx, ws);
+    }
+
+    // Update workspace groups and create new ones, sending workspace_enter events as needed.
+    for output in &state.niri.sorted_outputs {
+        changed |= refresh_workspace_group(protocol_state, output);
+    }
+
+    if changed {
+        for manager in protocol_state.instances.keys() {
+            manager.done();
+        }
+    }
+}
+
+pub fn on_output_bound(state: &mut State, output: &Output, wl_output: &WlOutput) {
+    let Some(client) = wl_output.client() else {
+        return;
+    };
+
+    let mut sent = false;
+
+    let protocol_state = &mut state.niri.ext_workspace_state;
+    if let Some(data) = protocol_state.workspace_groups.get_mut(output) {
+        for group in &mut data.instances {
+            if group.client().as_ref() != Some(&client) {
+                continue;
+            }
+
+            group.output_enter(wl_output);
+            sent = true;
+        }
+    }
+
+    if !sent {
+        return;
+    }
+
+    for manager in protocol_state.instances.keys() {
+        if manager.client().as_ref() == Some(&client) {
+            manager.done();
+        }
+    }
+}
+
+fn refresh_workspace_group(protocol_state: &mut ExtWorkspaceManagerState, output: &Output) -> bool {
+    if protocol_state.workspace_groups.contains_key(output) {
+        // Existing workspace group. Nothing can actually change since our workspace groups are tied
+        // to an output.
+        return false;
+    }
+
+    // New workspace group, start tracking it.
+    let mut data = ExtWorkspaceGroupData {
+        instances: Vec::new(),
+    };
+
+    // Create workspace group handle for each manager instance.
+    for manager in protocol_state.instances.keys() {
+        if let Some(client) = manager.client() {
+            data.add_instance::<State>(&protocol_state.display, &client, manager, output);
+        }
+    }
+
+    // Send workspace_enter for all existing workspaces on this output.
+    for group in &data.instances {
+        let manager: &ExtWorkspaceManagerV1 = group.data().unwrap();
+        for (_, ws) in protocol_state.workspaces.iter() {
+            if ws.output.as_ref() != Some(output) {
+                continue;
+            }
+            for workspace in &ws.instances {
+                if workspace.data() == Some(manager) {
+                    group.workspace_enter(workspace);
+                }
+            }
+        }
+    }
+
+    protocol_state.workspace_groups.insert(output.clone(), data);
+    true
+}
+
+fn send_workspace_enter_leave(
+    workspace_groups: &HashMap<Output, ExtWorkspaceGroupData>,
+    data: &ExtWorkspaceData,
+    enter: bool,
+) {
+    if let Some(output) = &data.output {
+        if let Some(group_data) = workspace_groups.get(output) {
+            for group in &group_data.instances {
+                let manager: &ExtWorkspaceManagerV1 = group.data().unwrap();
+                for workspace in &data.instances {
+                    if workspace.data() == Some(manager) {
+                        if enter {
+                            group.workspace_enter(workspace);
+                        } else {
+                            group.workspace_leave(workspace);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+fn remove_workspace_instances(
+    workspace_groups: &HashMap<Output, ExtWorkspaceGroupData>,
+    data: &ExtWorkspaceData,
+) {
+    send_workspace_enter_leave(workspace_groups, data, false);
+
+    for workspace in &data.instances {
+        workspace.removed();
+    }
+}
+
+fn build_name(ws: &Workspace<Mapped>, ws_idx: usize) -> String {
+    ws.name().cloned().unwrap_or_else(|| {
+        // Add 1 since this is a human-readable name, and our action indexing is 1-based.
+        (ws_idx + 1).to_string()
+    })
+}
+
+fn refresh_workspace(
+    protocol_state: &mut ExtWorkspaceManagerState,
+    mon: Option<&Monitor<Mapped>>,
+    ws_idx: usize,
+    ws: &Workspace<Mapped>,
+) -> bool {
+    let mut state = ext_workspace_handle_v1::State::empty();
+    if mon.is_some_and(|mon| mon.active_workspace_idx() == ws_idx) {
+        state |= ext_workspace_handle_v1::State::Active;
+    }
+    if ws.is_urgent() {
+        state |= ext_workspace_handle_v1::State::Urgent;
+    }
+
+    let output = mon.map(|mon| mon.output());
+
+    match protocol_state.workspaces.entry(ws.id()) {
+        Entry::Occupied(entry) => {
+            // Existing workspace, check if anything changed.
+            let data = entry.into_mut();
+
+            let mut id_set = false;
+            let mut recreate = false;
+            let id = ws.name();
+            if data.id.as_ref() != id {
+                if data.id.is_some() {
+                    recreate = true;
+                } else {
+                    id_set = true;
+                }
+                data.id = id.cloned();
+            }
+
+            let mut coordinates_changed = false;
+            if data.coordinates[1] != ws_idx as u32 {
+                data.coordinates[1] = ws_idx as u32;
+                coordinates_changed = true;
+            }
+
+            let mut state_changed = false;
+            if data.state != state {
+                data.state = state;
+                state_changed = true;
+            }
+
+            // Recreate means name got changed or unset (meaning data.name is back to ws_idx).
+            let check = recreate
+                || if data.id.is_some() {
+                    // True means workspace got named, going from ws_idx to name.
+                    id_set
+                } else {
+                    // The workspace is unnamed, check if ws_idx changed.
+                    coordinates_changed
+                };
+            let mut name_changed = false;
+            if check {
+                let new_name = build_name(ws, ws_idx);
+                // This will likely be true, except if the workspace got named its index.
+                if data.name != new_name {
+                    data.name = new_name;
+                    name_changed = true;
+                }
+            }
+
+            let mut output_changed = false;
+            if data.output.as_ref() != output {
+                send_workspace_enter_leave(&protocol_state.workspace_groups, data, false);
+                data.output = output.cloned();
+                output_changed = true;
+            }
+
+            if recreate {
+                remove_workspace_instances(&protocol_state.workspace_groups, data);
+                data.instances.clear();
+
+                for manager in protocol_state.instances.keys() {
+                    if let Some(client) = manager.client() {
+                        data.add_instance::<State>(&protocol_state.display, &client, manager);
+                    }
+                }
+
+                send_workspace_enter_leave(&protocol_state.workspace_groups, data, true);
+                return true;
+            }
+
+            if output_changed {
+                // Send workspace_enter to the new output's group. If the group doesn't exist yet
+                // (new groups are created after refreshing workspaces), then workspace_enter() will
+                // be sent when the group is created.
+                send_workspace_enter_leave(&protocol_state.workspace_groups, data, true);
+            }
+
+            let something_changed = id_set || name_changed || coordinates_changed || state_changed;
+            if something_changed {
+                for instance in &data.instances {
+                    if id_set {
+                        instance.id(data.id.clone().unwrap());
+                    }
+                    if name_changed {
+                        instance.name(data.name.clone());
+                    }
+                    if coordinates_changed {
+                        instance.coordinates(
+                            data.coordinates
+                                .iter()
+                                .flat_map(|x| x.to_ne_bytes())
+                                .collect(),
+                        );
+                    }
+                    if state_changed {
+                        instance.state(data.state);
+                    }
+                }
+            }
+
+            output_changed || something_changed
+        }
+        Entry::Vacant(entry) => {
+            // New workspace, start tracking it.
+            let mut data = ExtWorkspaceData {
+                id: ws.name().cloned(),
+                name: build_name(ws, ws_idx),
+                coordinates: ArrayVec::from([0, ws_idx as u32]),
+                state,
+                instances: Vec::new(),
+                output: output.cloned(),
+            };
+
+            for manager in protocol_state.instances.keys() {
+                if let Some(client) = manager.client() {
+                    data.add_instance::<State>(&protocol_state.display, &client, manager);
+                }
+            }
+
+            send_workspace_enter_leave(&protocol_state.workspace_groups, &data, true);
+            entry.insert(data);
+            true
+        }
+    }
+}
+
+impl ExtWorkspaceGroupData {
+    fn add_instance<D>(
+        &mut self,
+        handle: &DisplayHandle,
+        client: &Client,
+        manager: &ExtWorkspaceManagerV1,
+        output: &Output,
+    ) -> &ExtWorkspaceGroupHandleV1
+    where
+        D: Dispatch<ExtWorkspaceGroupHandleV1, ExtWorkspaceManagerV1>,
+        D: 'static,
+    {
+        let group = client
+            .create_resource::<ExtWorkspaceGroupHandleV1, _, D>(
+                handle,
+                manager.version(),
+                manager.clone(),
+            )
+            .unwrap();
+        manager.workspace_group(&group);
+
+        group.capabilities(ext_workspace_group_handle_v1::GroupCapabilities::empty());
+
+        for wl_output in output.client_outputs(client) {
+            group.output_enter(&wl_output);
+        }
+
+        self.instances.push(group);
+        self.instances.last().unwrap()
+    }
+}
+
+impl ExtWorkspaceData {
+    fn add_instance<D>(
+        &mut self,
+        handle: &DisplayHandle,
+        client: &Client,
+        manager: &ExtWorkspaceManagerV1,
+    ) -> &ExtWorkspaceHandleV1
+    where
+        D: Dispatch<ExtWorkspaceHandleV1, ExtWorkspaceManagerV1>,
+        D: 'static,
+    {
+        let workspace = client
+            .create_resource::<ExtWorkspaceHandleV1, _, D>(
+                handle,
+                manager.version(),
+                manager.clone(),
+            )
+            .unwrap();
+        manager.workspace(&workspace);
+
+        if let Some(id) = self.id.clone() {
+            workspace.id(id);
+        }
+
+        workspace.name(self.name.clone());
+        workspace.coordinates(
+            self.coordinates
+                .iter()
+                .flat_map(|x| x.to_ne_bytes())
+                .collect(),
+        );
+        workspace.state(self.state);
+        workspace.capabilities(
+            ext_workspace_handle_v1::WorkspaceCapabilities::Activate
+                | ext_workspace_handle_v1::WorkspaceCapabilities::Assign,
+        );
+
+        self.instances.push(workspace);
+        self.instances.last().unwrap()
+    }
+}
+
+impl ExtWorkspaceManagerState {
+    pub fn new<D, F>(display: &DisplayHandle, filter: F) -> Self
+    where
+        D: GlobalDispatch<ExtWorkspaceManagerV1, ExtWorkspaceGlobalData>,
+        D: Dispatch<ExtWorkspaceManagerV1, ()>,
+        D: 'static,
+        F: for<'c> Fn(&'c Client) -> bool + Send + Sync + 'static,
+    {
+        let global_data = ExtWorkspaceGlobalData {
+            filter: Box::new(filter),
+        };
+        display.create_global::<D, ExtWorkspaceManagerV1, _>(VERSION, global_data);
+        Self {
+            display: display.clone(),
+            instances: HashMap::new(),
+            workspace_groups: HashMap::new(),
+            workspaces: HashMap::new(),
+        }
+    }
+}
+
+impl<D> GlobalDispatch<ExtWorkspaceManagerV1, ExtWorkspaceGlobalData, D>
+    for ExtWorkspaceManagerState
+where
+    D: GlobalDispatch<ExtWorkspaceManagerV1, ExtWorkspaceGlobalData>,
+    D: Dispatch<ExtWorkspaceManagerV1, ()>,
+    D: Dispatch<ExtWorkspaceHandleV1, ExtWorkspaceManagerV1>,
+    D: ExtWorkspaceHandler,
+{
+    fn bind(
+        state: &mut D,
+        handle: &DisplayHandle,
+        client: &Client,
+        resource: New<ExtWorkspaceManagerV1>,
+        _global_data: &ExtWorkspaceGlobalData,
+        data_init: &mut DataInit<'_, D>,
+    ) {
+        let manager = data_init.init(resource, ());
+
+        let state = state.ext_workspace_manager_state();
+
+        // Send existing workspaces to the new client.
+        let mut new_workspaces: HashMap<_, Vec<_>> = HashMap::new();
+        for data in state.workspaces.values_mut() {
+            let output = data.output.clone();
+            let workspace = data.add_instance::<State>(handle, client, &manager);
+
+            if let Some(output) = output {
+                new_workspaces.entry(output).or_default().push(workspace);
+            }
+        }
+
+        // Create workspace groups for all outputs.
+        for (output, group_data) in &mut state.workspace_groups {
+            let group = group_data.add_instance::<State>(handle, client, &manager, output);
+
+            for workspace in new_workspaces.get(output).into_iter().flatten() {
+                group.workspace_enter(workspace);
+            }
+        }
+
+        manager.done();
+        state.instances.insert(manager, Vec::new());
+    }
+
+    fn can_view(client: Client, global_data: &ExtWorkspaceGlobalData) -> bool {
+        (global_data.filter)(&client)
+    }
+}
+
+impl<D> Dispatch<ExtWorkspaceManagerV1, (), D> for ExtWorkspaceManagerState
+where
+    D: Dispatch<ExtWorkspaceManagerV1, ()>,
+    D: ExtWorkspaceHandler,
+{
+    fn request(
+        state: &mut D,
+        _client: &Client,
+        resource: &ExtWorkspaceManagerV1,
+        request: <ExtWorkspaceManagerV1 as Resource>::Request,
+        _data: &(),
+        _dhandle: &DisplayHandle,
+        _data_init: &mut DataInit<'_, D>,
+    ) {
+        match request {
+            ext_workspace_manager_v1::Request::Commit => {
+                let protocol_state = state.ext_workspace_manager_state();
+                let actions = protocol_state.instances.get_mut(resource).unwrap();
+                let mut actions = mem::take(actions);
+
+                actions.sort_by_key(Action::order);
+
+                for action in actions {
+                    match action {
+                        Action::Assign(ws_id, output) => {
+                            if let Some(output) = output.upgrade() {
+                                state.assign_workspace(ws_id, output);
+                            }
+                        }
+                        Action::Activate(id) => state.activate_workspace(id),
+                    }
+                }
+            }
+            ext_workspace_manager_v1::Request::Stop => {
+                resource.finished();
+
+                let state = state.ext_workspace_manager_state();
+                state.instances.retain(|x, _| x != resource);
+
+                for data in state.workspace_groups.values_mut() {
+                    data.instances
+                        .retain(|instance| instance.data() != Some(resource));
+                }
+
+                for data in state.workspaces.values_mut() {
+                    data.instances
+                        .retain(|instance| instance.data() != Some(resource));
+                }
+            }
+            _ => unreachable!(),
+        }
+    }
+
+    fn destroyed(state: &mut D, _client: ClientId, resource: &ExtWorkspaceManagerV1, _data: &()) {
+        let state = state.ext_workspace_manager_state();
+        state.instances.retain(|x, _| x != resource);
+    }
+}
+
+impl<D> Dispatch<ExtWorkspaceHandleV1, ExtWorkspaceManagerV1, D> for ExtWorkspaceManagerState
+where
+    D: Dispatch<ExtWorkspaceHandleV1, ExtWorkspaceManagerV1>,
+    D: ExtWorkspaceHandler,
+{
+    fn request(
+        state: &mut D,
+        _client: &Client,
+        resource: &ExtWorkspaceHandleV1,
+        request: <ExtWorkspaceHandleV1 as Resource>::Request,
+        data: &ExtWorkspaceManagerV1,
+        _dhandle: &DisplayHandle,
+        _data_init: &mut DataInit<'_, D>,
+    ) {
+        let protocol_state = state.ext_workspace_manager_state();
+
+        let Some((workspace, _)) = protocol_state
+            .workspaces
+            .iter()
+            .find(|(_, data)| data.instances.contains(resource))
+        else {
+            return;
+        };
+        let workspace = *workspace;
+
+        match request {
+            ext_workspace_handle_v1::Request::Activate => {
+                let actions = protocol_state.instances.get_mut(data).unwrap();
+                actions.push(Action::Activate(workspace));
+            }
+            ext_workspace_handle_v1::Request::Deactivate => (),
+            ext_workspace_handle_v1::Request::Assign { workspace_group } => {
+                if let Some(output) = protocol_state
+                    .workspace_groups
+                    .iter()
+                    .find(|(_, data)| data.instances.contains(&workspace_group))
+                    .map(|(output, _)| output.clone())
+                {
+                    let actions = protocol_state.instances.get_mut(data).unwrap();
+                    actions.push(Action::Assign(workspace, output.downgrade()));
+                }
+            }
+            ext_workspace_handle_v1::Request::Remove => (),
+            ext_workspace_handle_v1::Request::Destroy => (),
+            _ => unreachable!(),
+        }
+    }
+
+    fn destroyed(
+        state: &mut D,
+        _client: ClientId,
+        resource: &ExtWorkspaceHandleV1,
+        _data: &ExtWorkspaceManagerV1,
+    ) {
+        let state = state.ext_workspace_manager_state();
+        for data in state.workspaces.values_mut() {
+            data.instances.retain(|instance| instance != resource);
+        }
+    }
+}
+
+impl<D> Dispatch<ExtWorkspaceGroupHandleV1, ExtWorkspaceManagerV1, D> for ExtWorkspaceManagerState
+where
+    D: Dispatch<ExtWorkspaceGroupHandleV1, ExtWorkspaceManagerV1>,
+    D: ExtWorkspaceHandler,
+{
+    fn request(
+        _state: &mut D,
+        _client: &Client,
+        _resource: &ExtWorkspaceGroupHandleV1,
+        request: <ExtWorkspaceGroupHandleV1 as Resource>::Request,
+        _data: &ExtWorkspaceManagerV1,
+        _dhandle: &DisplayHandle,
+        _data_init: &mut DataInit<'_, D>,
+    ) {
+        match request {
+            ext_workspace_group_handle_v1::Request::CreateWorkspace { .. } => (),
+            ext_workspace_group_handle_v1::Request::Destroy => (),
+            _ => unreachable!(),
+        }
+    }
+
+    fn destroyed(
+        state: &mut D,
+        _client: ClientId,
+        resource: &ExtWorkspaceGroupHandleV1,
+        _data: &ExtWorkspaceManagerV1,
+    ) {
+        let state = state.ext_workspace_manager_state();
+        for data in state.workspace_groups.values_mut() {
+            data.instances.retain(|instance| instance != resource);
+        }
+    }
+}
+
+#[macro_export]
+macro_rules! delegate_ext_workspace {
+    ($(@<$( $lt:tt $( : $clt:tt $(+ $dlt:tt )* )? ),+>)? $ty: ty) => {
+        smithay::reexports::wayland_server::delegate_global_dispatch!($(@< $( $lt $( : $clt $(+ $dlt )* )? ),+ >)? $ty: [
+            smithay::reexports::wayland_protocols::ext::workspace::v1::server::ext_workspace_manager_v1::ExtWorkspaceManagerV1: $crate::protocols::ext_workspace::ExtWorkspaceGlobalData
+        ] => $crate::protocols::ext_workspace::ExtWorkspaceManagerState);
+        smithay::reexports::wayland_server::delegate_dispatch!($(@< $( $lt $( : $clt $(+ $dlt )* )? ),+ >)? $ty: [
+            smithay::reexports::wayland_protocols::ext::workspace::v1::server::ext_workspace_manager_v1::ExtWorkspaceManagerV1: ()
+        ] => $crate::protocols::ext_workspace::ExtWorkspaceManagerState);
+        smithay::reexports::wayland_server::delegate_dispatch!($(@< $( $lt $( : $clt $(+ $dlt )* )? ),+ >)? $ty: [
+            smithay::reexports::wayland_protocols::ext::workspace::v1::server::ext_workspace_handle_v1::ExtWorkspaceHandleV1: smithay::reexports::wayland_protocols::ext::workspace::v1::server::ext_workspace_manager_v1::ExtWorkspaceManagerV1
+        ] => $crate::protocols::ext_workspace::ExtWorkspaceManagerState);
+        smithay::reexports::wayland_server::delegate_dispatch!($(@< $( $lt $( : $clt $(+ $dlt )* )? ),+ >)? $ty: [
+            smithay::reexports::wayland_protocols::ext::workspace::v1::server::ext_workspace_group_handle_v1::ExtWorkspaceGroupHandleV1: smithay::reexports::wayland_protocols::ext::workspace::v1::server::ext_workspace_manager_v1::ExtWorkspaceManagerV1
+        ] => $crate::protocols::ext_workspace::ExtWorkspaceManagerState);
+    };
+}
diff --git a/src/protocols/mod.rs b/src/protocols/mod.rs
index 476f24eb..b150cb7f 100644
--- a/src/protocols/mod.rs
+++ b/src/protocols/mod.rs
@@ -1,3 +1,4 @@
+pub mod ext_workspace;
 pub mod foreign_toplevel;
 pub mod gamma_control;
 pub mod mutter_x11_interop;