Implement wlr-output-management protocol

fix: wlr_output_management use WeakOutput

5 files changed, 926 insertions, 4 deletions

diff --git a/niri-ipc/src/lib.rs b/niri-ipc/src/lib.rs
index 4db883e5..572b4a83 100644
--- a/niri-ipc/src/lib.rs
+++ b/niri-ipc/src/lib.rs
@@ -433,7 +433,7 @@ pub struct Output {
 }
 
 /// Output mode.
-#[derive(Debug, Serialize, Deserialize, Clone, Copy)]
+#[derive(Debug, Serialize, Deserialize, Clone, Copy, PartialEq)]
 pub struct Mode {
     /// Width in physical pixels.
     pub width: u16,
@@ -446,7 +446,7 @@ pub struct Mode {
 }
 
 /// Logical output in the compositor's coordinate space.
-#[derive(Debug, Serialize, Deserialize, Clone, Copy)]
+#[derive(Debug, Serialize, Deserialize, Clone, Copy, PartialEq)]
 pub struct LogicalOutput {
     /// Logical X position.
     pub x: i32,
diff --git a/src/handlers/mod.rs b/src/handlers/mod.rs
index 845faf08..f288e24f 100644
--- a/src/handlers/mod.rs
+++ b/src/handlers/mod.rs
@@ -68,9 +68,13 @@ use crate::protocols::foreign_toplevel::{
     self, ForeignToplevelHandler, ForeignToplevelManagerState,
 };
 use crate::protocols::gamma_control::{GammaControlHandler, GammaControlManagerState};
+use crate::protocols::output_management::{OutputManagementHandler, OutputManagementManagerState};
 use crate::protocols::screencopy::{Screencopy, ScreencopyHandler};
 use crate::utils::{output_size, send_scale_transform};
-use crate::{delegate_foreign_toplevel, delegate_gamma_control, delegate_screencopy};
+use crate::{
+    delegate_foreign_toplevel, delegate_gamma_control, delegate_output_management,
+    delegate_screencopy,
+};
 
 impl SeatHandler for State {
     type KeyboardFocus = WlSurface;
@@ -545,3 +549,15 @@ delegate_xdg_activation!(State);
 
 impl FractionalScaleHandler for State {}
 delegate_fractional_scale!(State);
+
+impl OutputManagementHandler for State {
+    fn output_management_state(&mut self) -> &mut OutputManagementManagerState {
+        &mut self.niri.output_management_state
+    }
+
+    fn apply_output_config(&mut self, config: Vec<niri_config::Output>) {
+        self.niri.config.borrow_mut().outputs = config;
+        self.reload_output_config();
+    }
+}
+delegate_output_management!(State);
diff --git a/src/niri.rs b/src/niri.rs
index b017d90e..24a328a0 100644
--- a/src/niri.rs
+++ b/src/niri.rs
@@ -114,6 +114,7 @@ use crate::ipc::server::IpcServer;
 use crate::layout::{Layout, LayoutElement as _, MonitorRenderElement};
 use crate::protocols::foreign_toplevel::{self, ForeignToplevelManagerState};
 use crate::protocols::gamma_control::GammaControlManagerState;
+use crate::protocols::output_management::OutputManagementManagerState;
 use crate::protocols::screencopy::{Screencopy, ScreencopyManagerState};
 use crate::pw_utils::{Cast, PipeWire};
 #[cfg(feature = "xdp-gnome-screencast")]
@@ -202,6 +203,7 @@ pub struct Niri {
     pub session_lock_state: SessionLockManagerState,
     pub foreign_toplevel_state: ForeignToplevelManagerState,
     pub screencopy_state: ScreencopyManagerState,
+    pub output_management_state: OutputManagementManagerState,
     pub viewporter_state: ViewporterState,
     pub xdg_foreign_state: XdgForeignState,
     pub shm_state: ShmState,
@@ -1051,7 +1053,7 @@ impl State {
         self.niri.queue_redraw_all();
     }
 
-    fn reload_output_config(&mut self) {
+    pub fn reload_output_config(&mut self) {
         let mut resized_outputs = vec![];
         for output in self.niri.global_space.outputs() {
             let name = output.name();
@@ -1103,6 +1105,9 @@ impl State {
         if let Some(touch) = self.niri.seat.get_touch() {
             touch.cancel(self);
         }
+
+        let config = self.niri.config.borrow().outputs.clone();
+        self.niri.output_management_state.on_config_changed(config);
     }
 
     pub fn apply_transient_output_config(&mut self, name: &str, action: niri_ipc::OutputAction) {
@@ -1178,6 +1183,9 @@ impl State {
 
         #[cfg(feature = "dbus")]
         self.niri.on_ipc_outputs_changed();
+
+        let new_config = self.backend.ipc_outputs().lock().unwrap().clone();
+        self.niri.output_management_state.notify_changes(new_config);
     }
 
     #[cfg(feature = "xdp-gnome-screencast")]
@@ -1482,6 +1490,11 @@ impl Niri {
             ForeignToplevelManagerState::new::<State, _>(&display_handle, |client| {
                 !client.get_data::<ClientState>().unwrap().restricted
             });
+        let mut output_management_state =
+            OutputManagementManagerState::new::<State, _>(&display_handle, |client| {
+                !client.get_data::<ClientState>().unwrap().restricted
+            });
+        output_management_state.on_config_changed(config_.outputs.clone());
         let screencopy_state = ScreencopyManagerState::new::<State, _>(&display_handle, |client| {
             !client.get_data::<ClientState>().unwrap().restricted
         });
@@ -1626,6 +1639,7 @@ impl Niri {
             layer_shell_state,
             session_lock_state,
             foreign_toplevel_state,
+            output_management_state,
             screencopy_state,
             viewporter_state,
             xdg_foreign_state,
diff --git a/src/protocols/mod.rs b/src/protocols/mod.rs
index d1779b7e..a58b48bf 100644
--- a/src/protocols/mod.rs
+++ b/src/protocols/mod.rs
@@ -1,3 +1,4 @@
 pub mod foreign_toplevel;
 pub mod gamma_control;
+pub mod output_management;
 pub mod screencopy;
diff --git a/src/protocols/output_management.rs b/src/protocols/output_management.rs
new file mode 100644
index 00000000..2842fced
--- /dev/null
+++ b/src/protocols/output_management.rs
@@ -0,0 +1,891 @@
+use std::collections::hash_map::Entry;
+use std::collections::HashMap;
+use std::iter::zip;
+use std::mem;
+
+use niri_config::FloatOrInt;
+use niri_ipc::Transform;
+use smithay::reexports::wayland_protocols_wlr::output_management::v1::server::{
+    zwlr_output_configuration_head_v1, zwlr_output_configuration_v1, zwlr_output_head_v1,
+    zwlr_output_manager_v1, zwlr_output_mode_v1,
+};
+use smithay::reexports::wayland_server::backend::ClientId;
+use smithay::reexports::wayland_server::protocol::wl_output::Transform as WlTransform;
+use smithay::reexports::wayland_server::{
+    Client, DataInit, Dispatch, DisplayHandle, GlobalDispatch, New, Resource, WEnum,
+};
+use zwlr_output_configuration_head_v1::ZwlrOutputConfigurationHeadV1;
+use zwlr_output_configuration_v1::ZwlrOutputConfigurationV1;
+use zwlr_output_head_v1::{AdaptiveSyncState, ZwlrOutputHeadV1};
+use zwlr_output_manager_v1::ZwlrOutputManagerV1;
+use zwlr_output_mode_v1::ZwlrOutputModeV1;
+
+use crate::backend::OutputId;
+use crate::niri::State;
+use crate::utils::ipc_transform_to_smithay;
+
+const VERSION: u32 = 4;
+
+#[derive(Debug)]
+struct ClientData {
+    heads: HashMap<OutputId, (ZwlrOutputHeadV1, Vec<ZwlrOutputModeV1>)>,
+    confs: HashMap<ZwlrOutputConfigurationV1, OutputConfigurationState>,
+    manager: ZwlrOutputManagerV1,
+}
+
+pub struct OutputManagementManagerState {
+    display: DisplayHandle,
+    serial: u32,
+    clients: HashMap<ClientId, ClientData>,
+    current_state: HashMap<OutputId, niri_ipc::Output>,
+    current_config: Vec<niri_config::Output>,
+}
+
+pub struct OutputManagementManagerGlobalData {
+    filter: Box<dyn for<'c> Fn(&'c Client) -> bool + Send + Sync>,
+}
+
+pub trait OutputManagementHandler {
+    fn output_management_state(&mut self) -> &mut OutputManagementManagerState;
+    fn apply_output_config(&mut self, config: Vec<niri_config::Output>);
+}
+
+#[derive(Debug)]
+enum OutputConfigurationState {
+    Ongoing(HashMap<OutputId, niri_config::Output>),
+    Finished,
+}
+
+pub enum OutputConfigurationHeadState {
+    Cancelled,
+    Ok(OutputId, ZwlrOutputConfigurationV1),
+}
+
+impl OutputManagementManagerState {
+    pub fn new<D, F>(display: &DisplayHandle, filter: F) -> Self
+    where
+        D: GlobalDispatch<ZwlrOutputManagerV1, OutputManagementManagerGlobalData>,
+        D: Dispatch<ZwlrOutputManagerV1, ()>,
+        D: Dispatch<ZwlrOutputHeadV1, OutputId>,
+        D: Dispatch<ZwlrOutputConfigurationV1, u32>,
+        D: Dispatch<ZwlrOutputConfigurationHeadV1, OutputConfigurationHeadState>,
+        D: Dispatch<ZwlrOutputModeV1, ()>,
+        D: OutputManagementHandler,
+        D: 'static,
+        F: for<'c> Fn(&'c Client) -> bool + Send + Sync + 'static,
+    {
+        let global_data = OutputManagementManagerGlobalData {
+            filter: Box::new(filter),
+        };
+        display.create_global::<D, ZwlrOutputManagerV1, _>(VERSION, global_data);
+
+        Self {
+            display: display.clone(),
+            clients: HashMap::new(),
+            serial: 0,
+            current_state: HashMap::new(),
+            current_config: Vec::new(),
+        }
+    }
+
+    pub fn on_config_changed(&mut self, new_config: Vec<niri_config::Output>) {
+        self.current_config = new_config;
+    }
+
+    pub fn notify_changes(&mut self, new_state: HashMap<OutputId, niri_ipc::Output>) {
+        let mut changed = false; /* most likely to end up true */
+        for (output, conf) in new_state.iter() {
+            if let Some(old) = self.current_state.get(output) {
+                if old.vrr_enabled != conf.vrr_enabled {
+                    changed = true;
+                    for client in self.clients.values() {
+                        if let Some((head, _)) = client.heads.get(output) {
+                            if head.version() >= zwlr_output_head_v1::EVT_ADAPTIVE_SYNC_SINCE {
+                                head.adaptive_sync(match conf.vrr_enabled {
+                                    true => AdaptiveSyncState::Enabled,
+                                    false => AdaptiveSyncState::Disabled,
+                                });
+                            }
+                        }
+                    }
+                }
+
+                // TTY outputs can't change modes I think, however, winit and virtual outputs can.
+                let modes_changed = old.modes != conf.modes;
+                if modes_changed {
+                    changed = true;
+                    if old.modes.len() != conf.modes.len() {
+                        error!("output's old mode count doesn't match new modes");
+                    } else {
+                        for client in self.clients.values() {
+                            if let Some((_, modes)) = client.heads.get(output) {
+                                for (wl_mode, mode) in zip(modes, &conf.modes) {
+                                    wl_mode.size(i32::from(mode.width), i32::from(mode.height));
+                                    if let Ok(refresh_rate) = mode.refresh_rate.try_into() {
+                                        wl_mode.refresh(refresh_rate);
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+
+                match (old.current_mode, conf.current_mode) {
+                    (Some(old_index), Some(new_index)) => {
+                        if old.modes.len() == conf.modes.len()
+                            && (modes_changed || old_index != new_index)
+                        {
+                            changed = true;
+                            for client in self.clients.values() {
+                                if let Some((head, modes)) = client.heads.get(output) {
+                                    if let Some(new_mode) = modes.get(new_index) {
+                                        head.current_mode(new_mode);
+                                    } else {
+                                        error!(
+                                            "output new mode doesnt exist for the client's output"
+                                        );
+                                    }
+                                }
+                            }
+                        }
+                    }
+                    (Some(_), None) => {
+                        changed = true;
+                        for client in self.clients.values() {
+                            if let Some((head, _)) = client.heads.get(output) {
+                                head.enabled(0);
+                            }
+                        }
+                    }
+                    (None, Some(new_index)) => {
+                        if old.modes.len() == conf.modes.len() {
+                            changed = true;
+                            for client in self.clients.values() {
+                                if let Some((head, modes)) = client.heads.get(output) {
+                                    head.enabled(1);
+                                    if let Some(mode) = modes.get(new_index) {
+                                        head.current_mode(mode);
+                                    } else {
+                                        error!(
+                                            "output new mode doesnt exist for the client's output"
+                                        );
+                                    }
+                                }
+                            }
+                        }
+                    }
+                    (None, None) => {}
+                }
+                match (old.logical, conf.logical) {
+                    (Some(old_logical), Some(new_logical)) => {
+                        if old_logical != new_logical {
+                            changed = true;
+                            for client in self.clients.values() {
+                                if let Some((head, _)) = client.heads.get(output) {
+                                    if old_logical.x != new_logical.x
+                                        || old_logical.y != new_logical.y
+                                    {
+                                        head.position(new_logical.x, new_logical.y);
+                                    }
+                                    if old_logical.scale != new_logical.scale {
+                                        head.scale(new_logical.scale);
+                                    }
+                                    if old_logical.transform != new_logical.transform {
+                                        head.transform(
+                                            ipc_transform_to_smithay(new_logical.transform).into(),
+                                        );
+                                    }
+                                }
+                            }
+                        }
+                    }
+                    (None, Some(new_logical)) => {
+                        changed = true;
+                        for client in self.clients.values() {
+                            if let Some((head, _)) = client.heads.get(output) {
+                                // head enable in the mode diff check
+                                head.position(new_logical.x, new_logical.y);
+                                head.transform(
+                                    ipc_transform_to_smithay(new_logical.transform).into(),
+                                );
+                                head.scale(new_logical.scale);
+                            }
+                        }
+                    }
+                    (Some(_), None) => {
+                        // heads disabled in the mode diff check
+                    }
+                    (None, None) => {}
+                }
+            } else {
+                changed = true;
+                notify_new_head(self, output, conf);
+            }
+        }
+        for (old, _) in self.current_state.iter() {
+            if !new_state.contains_key(old) {
+                changed = true;
+                notify_removed_head(&mut self.clients, old);
+            }
+        }
+        if changed {
+            self.current_state = new_state;
+            self.serial += 1;
+            for data in self.clients.values() {
+                data.manager.done(self.serial);
+                for conf in data.confs.keys() {
+                    conf.cancelled();
+                }
+            }
+        }
+    }
+}
+
+impl<D> GlobalDispatch<ZwlrOutputManagerV1, OutputManagementManagerGlobalData, D>
+    for OutputManagementManagerState
+where
+    D: GlobalDispatch<ZwlrOutputManagerV1, OutputManagementManagerGlobalData>,
+    D: Dispatch<ZwlrOutputManagerV1, ()>,
+    D: Dispatch<ZwlrOutputHeadV1, OutputId>,
+    D: Dispatch<ZwlrOutputConfigurationV1, u32>,
+    D: Dispatch<ZwlrOutputConfigurationHeadV1, OutputConfigurationHeadState>,
+    D: Dispatch<ZwlrOutputModeV1, ()>,
+    D: OutputManagementHandler,
+    D: 'static,
+{
+    fn bind(
+        state: &mut D,
+        display: &DisplayHandle,
+        client: &Client,
+        manager: New<ZwlrOutputManagerV1>,
+        _manager_state: &OutputManagementManagerGlobalData,
+        data_init: &mut DataInit<'_, D>,
+    ) {
+        let manager = data_init.init(manager, ());
+        let g_state = state.output_management_state();
+        let mut client_data = ClientData {
+            heads: HashMap::new(),
+            confs: HashMap::new(),
+            manager: manager.clone(),
+        };
+        for (output, conf) in &g_state.current_state {
+            send_new_head::<D>(display, client, &mut client_data, *output, conf);
+        }
+        g_state.clients.insert(client.id(), client_data);
+        manager.done(g_state.serial);
+    }
+
+    fn can_view(client: Client, global_data: &OutputManagementManagerGlobalData) -> bool {
+        (global_data.filter)(&client)
+    }
+}
+
+impl<D> Dispatch<ZwlrOutputManagerV1, (), D> for OutputManagementManagerState
+where
+    D: GlobalDispatch<ZwlrOutputManagerV1, OutputManagementManagerGlobalData>,
+    D: Dispatch<ZwlrOutputManagerV1, ()>,
+    D: Dispatch<ZwlrOutputHeadV1, OutputId>,
+    D: Dispatch<ZwlrOutputConfigurationV1, u32>,
+    D: Dispatch<ZwlrOutputConfigurationHeadV1, OutputConfigurationHeadState>,
+    D: Dispatch<ZwlrOutputModeV1, ()>,
+    D: OutputManagementHandler,
+    D: 'static,
+{
+    fn request(
+        state: &mut D,
+        client: &Client,
+        _manager: &ZwlrOutputManagerV1,
+        request: zwlr_output_manager_v1::Request,
+        _data: &(),
+        _display: &DisplayHandle,
+        data_init: &mut DataInit<'_, D>,
+    ) {
+        match request {
+            zwlr_output_manager_v1::Request::CreateConfiguration { id, serial } => {
+                let g_state = state.output_management_state();
+                let conf = data_init.init(id, serial);
+                if let Some(client_data) = g_state.clients.get_mut(&client.id()) {
+                    if serial != g_state.serial {
+                        conf.cancelled();
+                    }
+                    let state = OutputConfigurationState::Ongoing(HashMap::new());
+                    client_data.confs.insert(conf, state);
+                } else {
+                    error!("CreateConfiguration: missing client data");
+                }
+            }
+            zwlr_output_manager_v1::Request::Stop => {
+                if let Some(c) = state.output_management_state().clients.remove(&client.id()) {
+                    c.manager.finished()
+                }
+            }
+            _ => unreachable!(),
+        }
+    }
+    fn destroyed(state: &mut D, client: ClientId, _resource: &ZwlrOutputManagerV1, _data: &()) {
+        state.output_management_state().clients.remove(&client);
+    }
+}
+
+impl<D> Dispatch<ZwlrOutputConfigurationV1, u32, D> for OutputManagementManagerState
+where
+    D: GlobalDispatch<ZwlrOutputManagerV1, OutputManagementManagerGlobalData>,
+    D: Dispatch<ZwlrOutputManagerV1, ()>,
+    D: Dispatch<ZwlrOutputHeadV1, OutputId>,
+    D: Dispatch<ZwlrOutputConfigurationV1, u32>,
+    D: Dispatch<ZwlrOutputConfigurationHeadV1, OutputConfigurationHeadState>,
+    D: Dispatch<ZwlrOutputModeV1, ()>,
+    D: OutputManagementHandler,
+    D: 'static,
+{
+    fn request(
+        state: &mut D,
+        client: &Client,
+        conf: &ZwlrOutputConfigurationV1,
+        request: zwlr_output_configuration_v1::Request,
+        serial: &u32,
+        _display: &DisplayHandle,
+        data_init: &mut DataInit<'_, D>,
+    ) {
+        let g_state = state.output_management_state();
+        let outdated = *serial != g_state.serial;
+        if outdated {
+            debug!("OutputConfiguration: request from an outdated configuration");
+        }
+
+        let new_config = g_state
+            .clients
+            .get_mut(&client.id())
+            .and_then(|data| data.confs.get_mut(conf));
+        if new_config.is_none() {
+            error!("OutputConfiguration: request from unknown configuration object");
+        }
+
+        match request {
+            zwlr_output_configuration_v1::Request::EnableHead { id, head } => {
+                let Some(output) = head.data::<OutputId>() else {
+                    error!("EnableHead: Missing attached output");
+                    let _fail = data_init.init(id, OutputConfigurationHeadState::Cancelled);
+                    return;
+                };
+                if outdated {
+                    let _fail = data_init.init(id, OutputConfigurationHeadState::Cancelled);
+                    return;
+                }
+
+                let Some(new_config) = new_config else {
+                    let _fail = data_init.init(id, OutputConfigurationHeadState::Cancelled);
+                    return;
+                };
+
+                let OutputConfigurationState::Ongoing(new_config) = new_config else {
+                    let _fail = data_init.init(id, OutputConfigurationHeadState::Cancelled);
+                    conf.post_error(
+                        zwlr_output_configuration_v1::Error::AlreadyUsed,
+                        "configuration had already been used",
+                    );
+                    return;
+                };
+
+                let Some(current_config) = g_state.current_state.get(output) else {
+                    error!("EnableHead: output missing from current config");
+                    let _fail = data_init.init(id, OutputConfigurationHeadState::Cancelled);
+                    return;
+                };
+
+                match new_config.entry(*output) {
+                    Entry::Occupied(_) => {
+                        let _fail = data_init.init(id, OutputConfigurationHeadState::Cancelled);
+                        conf.post_error(
+                            zwlr_output_configuration_v1::Error::AlreadyConfiguredHead,
+                            "head has been already configured",
+                        );
+                        return;
+                    }
+                    Entry::Vacant(entry) => {
+                        let mut config = g_state
+                            .current_config
+                            .iter()
+                            .find(|o| o.name.eq_ignore_ascii_case(&current_config.name))
+                            .cloned()
+                            .unwrap_or_else(|| niri_config::Output {
+                                name: current_config.name.clone(),
+                                ..Default::default()
+                            });
+                        config.off = false;
+                        entry.insert(config);
+                    }
+                };
+
+                data_init.init(id, OutputConfigurationHeadState::Ok(*output, conf.clone()));
+            }
+            zwlr_output_configuration_v1::Request::DisableHead { head } => {
+                if outdated {
+                    return;
+                }
+                let Some(output) = head.data::<OutputId>() else {
+                    error!("DisableHead: missing attached output head name");
+                    return;
+                };
+
+                let Some(new_config) = new_config else {
+                    return;
+                };
+
+                let OutputConfigurationState::Ongoing(new_config) = new_config else {
+                    conf.post_error(
+                        zwlr_output_configuration_v1::Error::AlreadyUsed,
+                        "configuration had already been used",
+                    );
+                    return;
+                };
+
+                let Some(current_config) = g_state.current_state.get(output) else {
+                    error!("EnableHead: output missing from current config");
+                    return;
+                };
+
+                match new_config.entry(*output) {
+                    Entry::Occupied(_) => {
+                        conf.post_error(
+                            zwlr_output_configuration_v1::Error::AlreadyConfiguredHead,
+                            "head has been already configured",
+                        );
+                    }
+                    Entry::Vacant(entry) => {
+                        let mut config = g_state
+                            .current_config
+                            .iter()
+                            .find(|o| o.name.eq_ignore_ascii_case(&current_config.name))
+                            .cloned()
+                            .unwrap_or_else(|| niri_config::Output {
+                                name: current_config.name.clone(),
+                                ..Default::default()
+                            });
+                        config.off = true;
+                        entry.insert(config);
+                    }
+                };
+            }
+            zwlr_output_configuration_v1::Request::Apply => {
+                if outdated {
+                    conf.cancelled();
+                    return;
+                }
+
+                let Some(new_config) = new_config else {
+                    return;
+                };
+
+                let OutputConfigurationState::Ongoing(new_config) =
+                    mem::replace(new_config, OutputConfigurationState::Finished)
+                else {
+                    conf.post_error(
+                        zwlr_output_configuration_v1::Error::AlreadyUsed,
+                        "configuration had already been used",
+                    );
+                    return;
+                };
+
+                let any_enabled = new_config.values().any(|c| !c.off);
+                if !any_enabled {
+                    conf.failed();
+                    return;
+                }
+
+                state.apply_output_config(new_config.into_values().collect());
+                // FIXME: verify that it had been applied successfully (which may be difficult).
+                conf.succeeded();
+            }
+            zwlr_output_configuration_v1::Request::Test => {
+                if outdated {
+                    conf.cancelled();
+                    return;
+                }
+
+                let Some(new_config) = new_config else {
+                    return;
+                };
+
+                let OutputConfigurationState::Ongoing(new_config) =
+                    mem::replace(new_config, OutputConfigurationState::Finished)
+                else {
+                    conf.post_error(
+                        zwlr_output_configuration_v1::Error::AlreadyUsed,
+                        "configuration had already been used",
+                    );
+                    return;
+                };
+
+                let any_enabled = new_config.values().any(|c| !c.off);
+                if !any_enabled {
+                    conf.failed();
+                    return;
+                }
+
+                // FIXME: actually test the configuration with TTY.
+                conf.succeeded()
+            }
+            zwlr_output_configuration_v1::Request::Destroy => {
+                g_state
+                    .clients
+                    .get_mut(&client.id())
+                    .map(|d| d.confs.remove(conf));
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+
+impl<D> Dispatch<ZwlrOutputConfigurationHeadV1, OutputConfigurationHeadState, D>
+    for OutputManagementManagerState
+where
+    D: GlobalDispatch<ZwlrOutputManagerV1, OutputManagementManagerGlobalData>,
+    D: Dispatch<ZwlrOutputManagerV1, ()>,
+    D: Dispatch<ZwlrOutputHeadV1, OutputId>,
+    D: Dispatch<ZwlrOutputConfigurationV1, u32>,
+    D: Dispatch<ZwlrOutputConfigurationHeadV1, OutputConfigurationHeadState>,
+    D: Dispatch<ZwlrOutputModeV1, ()>,
+    D: OutputManagementHandler,
+    D: 'static,
+{
+    fn request(
+        state: &mut D,
+        client: &Client,
+        conf_head: &ZwlrOutputConfigurationHeadV1,
+        request: zwlr_output_configuration_head_v1::Request,
+        data: &OutputConfigurationHeadState,
+        _display: &DisplayHandle,
+        _data_init: &mut DataInit<'_, D>,
+    ) {
+        let g_state = state.output_management_state();
+        let Some(client_data) = g_state.clients.get_mut(&client.id()) else {
+            error!("ConfigurationHead: missing client data");
+            return;
+        };
+        let OutputConfigurationHeadState::Ok(output_id, conf) = data else {
+            warn!("ConfigurationHead: request sent to a cancelled head");
+            return;
+        };
+        let Some(serial) = conf.data::<u32>() else {
+            error!("ConfigurationHead: missing serial");
+            return;
+        };
+        if *serial != g_state.serial {
+            warn!("ConfigurationHead: request sent to an outdated");
+            return;
+        }
+        let Some(new_config) = client_data.confs.get_mut(conf) else {
+            error!("ConfigurationHead: unknown configuration");
+            return;
+        };
+        let OutputConfigurationState::Ongoing(new_config) = new_config else {
+            conf.post_error(
+                zwlr_output_configuration_v1::Error::AlreadyUsed,
+                "configuration had already been used",
+            );
+            return;
+        };
+        let Some(new_config) = new_config.get_mut(output_id) else {
+            error!("ConfigurationHead: config missing from enabled heads");
+            return;
+        };
+
+        match request {
+            zwlr_output_configuration_head_v1::Request::SetMode { mode } => {
+                let index = match client_data
+                    .heads
+                    .get(output_id)
+                    .map(|(_, mods)| mods.iter().position(|m| m.id() == mode.id()))
+                {
+                    Some(Some(index)) => index,
+                    _ => {
+                        warn!("SetMode: failed to find requested mode");
+                        conf_head.post_error(
+                            zwlr_output_configuration_head_v1::Error::InvalidMode,
+                            "failed to find requested mode",
+                        );
+                        return;
+                    }
+                };
+
+                let Some(current_config) = g_state.current_state.get(output_id) else {
+                    warn!("SetMode: output missing from the current config");
+                    return;
+                };
+
+                let Some(mode) = current_config.modes.get(index) else {
+                    error!("SetMode: requested mode is out of range");
+                    return;
+                };
+
+                new_config.mode = Some(niri_ipc::ConfiguredMode {
+                    width: mode.width,
+                    height: mode.height,
+                    refresh: Some(mode.refresh_rate as f64 / 1000.),
+                });
+            }
+            zwlr_output_configuration_head_v1::Request::SetCustomMode {
+                width,
+                height,
+                refresh,
+            } => {
+                // FIXME: Support custom mode
+                let (width, height, refresh): (u16, u16, u32) =
+                    match (width.try_into(), height.try_into(), refresh.try_into()) {
+                        (Ok(width), Ok(height), Ok(refresh)) => (width, height, refresh),
+                        _ => {
+                            warn!("SetCustomMode: invalid input data");
+                            return;
+                        }
+                    };
+
+                let Some(current_config) = g_state.current_state.get(output_id) else {
+                    warn!("SetMode: output missing from the current config");
+                    return;
+                };
+
+                let Some(mode) = current_config.modes.iter().find(|m| {
+                    m.width == width
+                        && m.height == height
+                        && (refresh == 0 || m.refresh_rate == refresh)
+                }) else {
+                    warn!("SetCustomMode: no matching mode");
+                    return;
+                };
+
+                new_config.mode = Some(niri_ipc::ConfiguredMode {
+                    width: mode.width,
+                    height: mode.height,
+                    refresh: Some(mode.refresh_rate as f64 / 1000.),
+                });
+            }
+            zwlr_output_configuration_head_v1::Request::SetPosition { x, y } => {
+                new_config.position = Some(niri_config::Position { x, y });
+            }
+            zwlr_output_configuration_head_v1::Request::SetTransform { transform } => {
+                let transform = match transform {
+                    WEnum::Value(WlTransform::Normal) => Transform::Normal,
+                    WEnum::Value(WlTransform::_90) => Transform::_90,
+                    WEnum::Value(WlTransform::_180) => Transform::_180,
+                    WEnum::Value(WlTransform::_270) => Transform::_270,
+                    WEnum::Value(WlTransform::Flipped) => Transform::Flipped,
+                    WEnum::Value(WlTransform::Flipped90) => Transform::Flipped90,
+                    WEnum::Value(WlTransform::Flipped180) => Transform::Flipped180,
+                    WEnum::Value(WlTransform::Flipped270) => Transform::Flipped270,
+                    _ => {
+                        warn!("SetTransform: unknown requested transform");
+                        conf_head.post_error(
+                            zwlr_output_configuration_head_v1::Error::InvalidTransform,
+                            "unknown transform value",
+                        );
+                        return;
+                    }
+                };
+                new_config.transform = transform;
+            }
+            zwlr_output_configuration_head_v1::Request::SetScale { scale } => {
+                if scale <= 0. {
+                    conf_head.post_error(
+                        zwlr_output_configuration_head_v1::Error::InvalidScale,
+                        "scale is negative or zero",
+                    );
+                    return;
+                }
+                new_config.scale = Some(FloatOrInt(scale));
+            }
+            zwlr_output_configuration_head_v1::Request::SetAdaptiveSync { state } => {
+                let enabled = match state {
+                    WEnum::Value(AdaptiveSyncState::Enabled) => true,
+                    WEnum::Value(AdaptiveSyncState::Disabled) => false,
+                    _ => {
+                        warn!("SetAdaptativeSync: unknown requested adaptative sync");
+                        conf_head.post_error(
+                            zwlr_output_configuration_head_v1::Error::InvalidAdaptiveSyncState,
+                            "unknown adaptive sync value",
+                        );
+                        return;
+                    }
+                };
+                new_config.variable_refresh_rate = enabled;
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+
+impl<D> Dispatch<ZwlrOutputHeadV1, OutputId, D> for OutputManagementManagerState
+where
+    D: GlobalDispatch<ZwlrOutputManagerV1, OutputManagementManagerGlobalData>,
+    D: Dispatch<ZwlrOutputManagerV1, ()>,
+    D: Dispatch<ZwlrOutputHeadV1, OutputId>,
+    D: Dispatch<ZwlrOutputConfigurationV1, u32>,
+    D: Dispatch<ZwlrOutputConfigurationHeadV1, OutputConfigurationHeadState>,
+    D: Dispatch<ZwlrOutputModeV1, ()>,
+    D: OutputManagementHandler,
+    D: 'static,
+{
+    fn request(
+        _state: &mut D,
+        _client: &Client,
+        _output_head: &ZwlrOutputHeadV1,
+        request: zwlr_output_head_v1::Request,
+        _data: &OutputId,
+        _display: &DisplayHandle,
+        _data_init: &mut DataInit<'_, D>,
+    ) {
+        match request {
+            zwlr_output_head_v1::Request::Release => {}
+            _ => unreachable!(),
+        }
+    }
+    fn destroyed(state: &a