portal: implement workspace capture

docs/features.md

@@ -72,6 +72,12 @@ You can change this GPU at runtime.
 ## Screen Sharing
 
 Jay supports screen sharing via xdg-desktop-portal.
+There are three supported modes:
+
+- Window capture
+- Output capture
+- Workspace capture which is like output capture except that only one workspace will be
+  shown.
 
 ## Screen Locking
 

release-notes.md

@@ -1,6 +1,7 @@
 # Unreleased
 
 - Screencasts now support window capture.
+- Screencasts now support workspace capture.
 - Add support for wp-alpha-modifier.
 - Add support for per-device keymaps.
 - Add support for virtual-keyboard-unstable-v1.

src/compositor.rs

@@ -472,6 +472,7 @@ fn create_dummy_output(state: &Rc<State>) {
         has_capture: Cell::new(false),
         title_texture: Cell::new(None),
         attention_requests: Default::default(),
+        render_highlight: Default::default(),
     });
     *dummy_workspace.output_link.borrow_mut() =
         Some(dummy_output.workspaces.add_last(dummy_workspace.clone()));

src/ifs.rs

@@ -17,6 +17,7 @@ pub mod jay_screencast;
 pub mod jay_screenshot;
 pub mod jay_seat_events;
 pub mod jay_select_toplevel;
+pub mod jay_select_workspace;
 pub mod jay_toplevel;
 pub mod jay_workspace;
 pub mod jay_workspace_watcher;

src/ifs/jay_compositor.rs

@@ -15,6 +15,7 @@ use {
             jay_screenshot::JayScreenshot,
             jay_seat_events::JaySeatEvents,
             jay_select_toplevel::{JaySelectToplevel, JayToplevelSelector},
+            jay_select_workspace::{JaySelectWorkspace, JayWorkspaceSelector},
             jay_workspace_watcher::JayWorkspaceWatcher,
         },
         leaks::Tracker,
@@ -85,13 +86,14 @@ pub struct Cap;
 impl Cap {
     pub const NONE: u16 = 0;
     pub const WINDOW_CAPTURE: u16 = 1;
+    pub const SELECT_WORKSPACE: u16 = 2;
 }
 
 impl JayCompositor {
     fn send_capabilities(&self) {
         self.client.event(Capabilities {
             self_id: self.id,
-            cap: &[Cap::NONE, Cap::WINDOW_CAPTURE],
+            cap: &[Cap::NONE, Cap::WINDOW_CAPTURE, Cap::SELECT_WORKSPACE],
         });
     }
 
@@ -362,6 +364,24 @@ impl JayCompositorRequestHandler for JayCompositor {
         seat.global.select_toplevel(selector);
         Ok(())
     }
+
+    fn select_workspace(&self, req: SelectWorkspace, _slf: &Rc<Self>) -> Result<(), Self::Error> {
+        let seat = self.client.lookup(req.seat)?;
+        let obj = Rc::new(JaySelectWorkspace {
+            id: req.id,
+            client: self.client.clone(),
+            tracker: Default::default(),
+            destroyed: Cell::new(false),
+        });
+        track!(self.client, obj);
+        self.client.add_client_obj(&obj)?;
+        let selector = JayWorkspaceSelector {
+            ws: Default::default(),
+            jsw: obj.clone(),
+        };
+        seat.global.select_workspace(selector);
+        Ok(())
+    }
 }
 
 object_base! {

src/ifs/jay_select_workspace.rs

@@ -0,0 +1,105 @@
+use {
+    crate::{
+        client::{Client, ClientError},
+        ifs::{jay_workspace::JayWorkspace, wl_seat::WorkspaceSelector},
+        leaks::Tracker,
+        object::{Object, Version},
+        tree::WorkspaceNode,
+        utils::clonecell::CloneCell,
+        wire::{jay_select_workspace::*, JaySelectWorkspaceId, JayWorkspaceId},
+    },
+    std::{cell::Cell, rc::Rc},
+    thiserror::Error,
+};
+
+pub struct JaySelectWorkspace {
+    pub id: JaySelectWorkspaceId,
+    pub client: Rc<Client>,
+    pub tracker: Tracker<Self>,
+    pub destroyed: Cell<bool>,
+}
+
+pub struct JayWorkspaceSelector {
+    pub ws: CloneCell<Option<Rc<WorkspaceNode>>>,
+    pub jsw: Rc<JaySelectWorkspace>,
+}
+
+impl WorkspaceSelector for JayWorkspaceSelector {
+    fn set(&self, ws: Rc<WorkspaceNode>) {
+        self.ws.set(Some(ws));
+    }
+}
+
+impl Drop for JayWorkspaceSelector {
+    fn drop(&mut self) {
+        if self.jsw.destroyed.get() {
+            return;
+        }
+        match self.ws.take() {
+            None => {
+                self.jsw.send_cancelled();
+            }
+            Some(ws) => {
+                let id = match self.jsw.client.new_id() {
+                    Ok(id) => id,
+                    Err(e) => {
+                        self.jsw.client.error(e);
+                        return;
+                    }
+                };
+                let jw = Rc::new(JayWorkspace {
+                    id,
+                    client: self.jsw.client.clone(),
+                    workspace: CloneCell::new(Some(ws.clone())),
+                    tracker: Default::default(),
+                });
+                track!(self.jsw.client, jw);
+                self.jsw.client.add_server_obj(&jw);
+                self.jsw
+                    .send_selected(ws.output.get().global.name.raw(), id);
+                ws.jay_workspaces
+                    .set((self.jsw.client.id, jw.id), jw.clone());
+                jw.send_initial_properties(&ws);
+            }
+        };
+        let _ = self.jsw.client.remove_obj(&*self.jsw);
+    }
+}
+
+impl JaySelectWorkspace {
+    fn send_cancelled(&self) {
+        self.client.event(Cancelled { self_id: self.id });
+    }
+
+    fn send_selected(&self, output: u32, id: JayWorkspaceId) {
+        self.client.event(Selected {
+            self_id: self.id,
+            output,
+            id,
+        });
+    }
+}
+
+impl JaySelectWorkspaceRequestHandler for JaySelectWorkspace {
+    type Error = JaySelectWorkspaceError;
+}
+
+object_base! {
+    self = JaySelectWorkspace;
+    version = Version(1);
+}
+
+impl Object for JaySelectWorkspace {
+    fn break_loops(&self) {
+        self.destroyed.set(true);
+    }
+}
+
+simple_add_obj!(JaySelectWorkspace);
+
+#[derive(Debug, Error)]
+pub enum JaySelectWorkspaceError {
+    #[error(transparent)]
+    ClientError(Box<ClientError>),
+}
+efrom!(JaySelectWorkspaceError, ClientError);

src/ifs/jay_workspace.rs

@@ -19,6 +19,14 @@ pub struct JayWorkspace {
 }
 
 impl JayWorkspace {
+    pub fn send_initial_properties(&self, workspace: &WorkspaceNode) {
+        self.send_linear_id(workspace);
+        self.send_name(workspace);
+        self.send_output(&workspace.output.get());
+        self.send_visible(workspace.visible.get());
+        self.send_done();
+    }
+
     pub fn send_linear_id(&self, ws: &WorkspaceNode) {
         self.client.event(LinearId {
             self_id: self.id,

src/ifs/jay_workspace_watcher.rs

@@ -36,11 +36,7 @@ impl JayWorkspaceWatcher {
             id: jw.id,
             linear_id: workspace.id.raw(),
         });
-        jw.send_linear_id(workspace);
+        jw.send_initial_properties(workspace);
-        jw.send_name(workspace);
-        jw.send_output(&workspace.output.get());
-        jw.send_visible(workspace.visible.get());
-        jw.send_done();
         Ok(())
     }
 

src/ifs/wl_seat.rs

@@ -83,7 +83,10 @@ use {
     thiserror::Error,
     uapi::OwnedFd,
 };
-pub use {event_handling::NodeSeatState, pointer_owner::ToplevelSelector};
+pub use {
+    event_handling::NodeSeatState,
+    pointer_owner::{ToplevelSelector, WorkspaceSelector},
+};
 
 pub const POINTER: u32 = 1;
 const KEYBOARD: u32 = 2;
@@ -1153,10 +1156,13 @@ impl WlSeatGlobal {
         self.forward.set(forward);
     }
 
-    #[allow(dead_code)]
     pub fn select_toplevel(self: &Rc<Self>, selector: impl ToplevelSelector) {
         self.pointer_owner.select_toplevel(self, selector);
     }
+
+    pub fn select_workspace(self: &Rc<Self>, selector: impl WorkspaceSelector) {
+        self.pointer_owner.select_workspace(self, selector);
+    }
 }
 
 global_base!(WlSeatGlobal, WlSeat, WlSeatError);

src/ifs/wl_seat/pointer_owner.rs

@@ -14,7 +14,7 @@ use {
             xdg_toplevel_drag_v1::XdgToplevelDragV1,
         },
         state::DeviceHandlerData,
-        tree::{FindTreeUsecase, FoundNode, Node, ToplevelNode},
+        tree::{FindTreeUsecase, FoundNode, Node, ToplevelNode, WorkspaceNode},
         utils::{clonecell::CloneCell, smallmap::SmallMap},
     },
     std::{
@@ -33,6 +33,10 @@ pub trait ToplevelSelector: 'static {
     fn set(&self, toplevel: Rc<dyn ToplevelNode>);
 }
 
+pub trait WorkspaceSelector: 'static {
+    fn set(&self, ws: Rc<WorkspaceNode>);
+}
+
 impl Default for PointerOwnerHolder {
     fn default() -> Self {
         let default = Rc::new(SimplePointerOwner {
@@ -157,19 +161,32 @@ impl PointerOwnerHolder {
         seat.changes.or_assign(CHANGE_CURSOR_MOVED);
     }
 
-    pub fn select_toplevel(&self, seat: &Rc<WlSeatGlobal>, selector: impl ToplevelSelector) {
+    fn select_element(&self, seat: &Rc<WlSeatGlobal>, usecase: impl SimplePointerOwnerUsecase) {
         self.revert_to_default(seat);
-        let usecase = Rc::new(SelectToplevelUsecase {
-            seat: Rc::downgrade(seat),
-            selector,
-            latest: Default::default(),
-        });
         if let Some(node) = seat.pointer_stack.borrow().last() {
             usecase.node_focus(seat, node);
         }
         self.owner.set(Rc::new(SimplePointerOwner { usecase }));
         seat.trigger_tree_changed();
     }
+
+    pub fn select_toplevel(&self, seat: &Rc<WlSeatGlobal>, selector: impl ToplevelSelector) {
+        let usecase = Rc::new(SelectToplevelUsecase {
+            seat: Rc::downgrade(seat),
+            selector,
+            latest: Default::default(),
+        });
+        self.select_element(seat, usecase)
+    }
+
+    pub fn select_workspace(&self, seat: &Rc<WlSeatGlobal>, selector: impl WorkspaceSelector) {
+        let usecase = Rc::new(SelectWorkspaceUsecase {
+            seat: Rc::downgrade(seat),
+            selector,
+            latest: Default::default(),
+        });
+        self.select_element(seat, usecase)
+    }
 }
 
 trait PointerOwner {
@@ -221,6 +238,12 @@ struct SelectToplevelUsecase<S: ?Sized> {
     selector: S,
 }
 
+struct SelectWorkspaceUsecase<S: ?Sized> {
+    seat: Weak<WlSeatGlobal>,
+    latest: CloneCell<Option<Rc<WorkspaceNode>>>,
+    selector: S,
+}
+
 impl<T: SimplePointerOwnerUsecase> PointerOwner for SimplePointerOwner<T> {
     fn button(&self, seat: &Rc<WlSeatGlobal>, time_usec: u64, button: u32, state: KeyState) {
         if state != KeyState::Pressed {
@@ -674,8 +697,22 @@ impl SimplePointerOwnerUsecase for DefaultPointerUsecase {
     }
 }
 
-impl<S: ToplevelSelector + ?Sized> SimplePointerOwnerUsecase for Rc<SelectToplevelUsecase<S>> {
+trait NodeSelectorUsecase: Sized + 'static {
-    const FIND_TREE_USECASE: FindTreeUsecase = FindTreeUsecase::SelectToplevel;
+    const FIND_TREE_USECASE: FindTreeUsecase;
+
+    fn default_button(
+        self: &Rc<Self>,
+        spo: &SimplePointerOwner<Rc<Self>>,
+        seat: &Rc<WlSeatGlobal>,
+        button: u32,
+        pn: &Rc<dyn Node>,
+    ) -> bool;
+
+    fn node_focus(self: &Rc<Self>, seat: &Rc<WlSeatGlobal>, node: &Rc<dyn Node>);
+}
+
+impl<U: NodeSelectorUsecase + ?Sized> SimplePointerOwnerUsecase for Rc<U> {
+    const FIND_TREE_USECASE: FindTreeUsecase = <U as NodeSelectorUsecase>::FIND_TREE_USECASE;
     const IS_DEFAULT: bool = false;
 
     fn default_button(
@@ -685,17 +722,7 @@ impl<S: ToplevelSelector + ?Sized> SimplePointerOwnerUsecase for Rc<SelectToplev
         button: u32,
         pn: &Rc<dyn Node>,
     ) -> bool {
-        let Some(tl) = pn.clone().node_into_toplevel() else {
+        <U as NodeSelectorUsecase>::default_button(self, spo, seat, button, pn)
-            return false;
-        };
-        let selected_toplevel =
-            button == BTN_RIGHT || (button == BTN_LEFT && !tl.tl_admits_children());
-        if !selected_toplevel {
-            return false;
-        }
-        self.selector.set(tl);
-        spo.revert_to_default(seat);
-        true
     }
 
     fn start_drag(
@@ -721,6 +748,34 @@ impl<S: ToplevelSelector + ?Sized> SimplePointerOwnerUsecase for Rc<SelectToplev
     }
 
     fn node_focus(&self, seat: &Rc<WlSeatGlobal>, node: &Rc<dyn Node>) {
+        <U as NodeSelectorUsecase>::node_focus(self, seat, node)
+    }
+}
+
+impl<S: ToplevelSelector> NodeSelectorUsecase for SelectToplevelUsecase<S> {
+    const FIND_TREE_USECASE: FindTreeUsecase = FindTreeUsecase::SelectToplevel;
+
+    fn default_button(
+        self: &Rc<Self>,
+        spo: &SimplePointerOwner<Rc<Self>>,
+        seat: &Rc<WlSeatGlobal>,
+        button: u32,
+        pn: &Rc<dyn Node>,
+    ) -> bool {
+        let Some(tl) = pn.clone().node_into_toplevel() else {
+            return false;
+        };
+        let selected_toplevel =
+            button == BTN_RIGHT || (button == BTN_LEFT && !tl.tl_admits_children());
+        if !selected_toplevel {
+            return false;
+        }
+        self.selector.set(tl);
+        spo.revert_to_default(seat);
+        true
+    }
+
+    fn node_focus(self: &Rc<Self>, seat: &Rc<WlSeatGlobal>, node: &Rc<dyn Node>) {
         let mut damage = false;
         let tl = node.clone().node_into_toplevel();
         if let Some(tl) = &tl {
@@ -750,3 +805,50 @@ impl<S: ?Sized> Drop for SelectToplevelUsecase<S> {
         }
     }
 }
+
+impl<S: WorkspaceSelector> NodeSelectorUsecase for SelectWorkspaceUsecase<S> {
+    const FIND_TREE_USECASE: FindTreeUsecase = FindTreeUsecase::SelectWorkspace;
+
+    fn default_button(
+        self: &Rc<Self>,
+        spo: &SimplePointerOwner<Rc<Self>>,
+        seat: &Rc<WlSeatGlobal>,
+        _button: u32,
+        pn: &Rc<dyn Node>,
+    ) -> bool {
+        let Some(ws) = pn.clone().node_into_workspace() else {
+            return false;
+        };
+        self.selector.set(ws);
+        spo.revert_to_default(seat);
+        true
+    }
+
+    fn node_focus(self: &Rc<Self>, seat: &Rc<WlSeatGlobal>, node: &Rc<dyn Node>) {
+        let mut damage = false;
+        let ws = node.clone().node_into_workspace();
+        if let Some(ws) = &ws {
+            ws.render_highlight.fetch_add(1);
+            seat.set_known_cursor(KnownCursor::Pointer);
+            damage = true;
+        }
+        if let Some(prev) = self.latest.set(ws) {
+            prev.render_highlight.fetch_sub(1);
+            damage = true;
+        }
+        if damage {
+            seat.state.damage();
+        }
+    }
+}
+
+impl<S: ?Sized> Drop for SelectWorkspaceUsecase<S> {
+    fn drop(&mut self) {
+        if let Some(prev) = self.latest.take() {
+            prev.render_highlight.fetch_sub(1);
+            if let Some(seat) = self.seat.upgrade() {
+                seat.state.damage();
+            }
+        }
+    }
+}

src/portal/ptl_display.rs

@@ -297,7 +297,7 @@ fn finish_display_connect(dpy: Rc<PortalDisplayPrelude>) {
                     id: dpy.con.id(),
                     con: dpy.con.clone(),
                     owner: Default::default(),
-                    window_capture: Cell::new(false),
+                    caps: Default::default(),
                 });
                 dpy.con.add_object(jc.clone());
                 dpy.registry.request_bind(name, version, jc.deref());

src/portal/ptl_screencast.rs

@@ -37,7 +37,9 @@ use {
         wl_usr::usr_ifs::{
             usr_jay_screencast::{UsrJayScreencast, UsrJayScreencastOwner},
             usr_jay_select_toplevel::UsrJaySelectToplevel,
+            usr_jay_select_workspace::UsrJaySelectWorkspace,
             usr_jay_toplevel::UsrJayToplevel,
+            usr_jay_workspace::UsrJayWorkspace,
         },
     },
     std::{
@@ -64,6 +66,7 @@ pub enum ScreencastPhase {
     SourcesSelected,
     Selecting(Rc<SelectingScreencast>),
     SelectingWindow(Rc<SelectingWindowScreencast>),
+    SelectingWorkspace(Rc<SelectingWorkspaceScreencast>),
     Starting(Rc<StartingScreencast>),
     Started(Rc<StartedScreencast>),
     Terminated,
@@ -89,6 +92,12 @@ pub struct SelectingWindowScreencast {
     pub selector: Rc<UsrJaySelectToplevel>,
 }
 
+pub struct SelectingWorkspaceScreencast {
+    pub core: SelectingScreencastCore,
+    pub dpy: Rc<PortalDisplay>,
+    pub selector: Rc<UsrJaySelectWorkspace>,
+}
+
 pub struct StartingScreencast {
     pub session: Rc<ScreencastSession>,
     pub request_obj: Rc<DbusObject>,
@@ -100,6 +109,7 @@ pub struct StartingScreencast {
 
 pub enum ScreencastTarget {
     Output(Rc<PortalOutput>),
+    Workspace(Rc<PortalOutput>, Rc<UsrJayWorkspace>),
     Toplevel(Rc<UsrJayToplevel>),
 }
 
@@ -156,14 +166,26 @@ impl PwClientNodeOwner for StartingScreencast {
         port.supported_metas.set(SUPPORTED_META_VIDEO_CROP);
         let jsc = self.dpy.jc.create_screencast();
         match &self.target {
-            ScreencastTarget::Output(o) => jsc.set_output(&o.jay),
+            ScreencastTarget::Output(o) => {
+                jsc.set_output(&o.jay);
+                jsc.set_allow_all_workspaces(true);
+            }
+            ScreencastTarget::Workspace(o, ws) => {
+                jsc.set_output(&o.jay);
+                jsc.allow_workspace(ws);
+            }
             ScreencastTarget::Toplevel(t) => jsc.set_toplevel(t),
         }
         jsc.set_use_linear_buffers(true);
-        jsc.set_allow_all_workspaces(true);
         jsc.configure();
-        if let ScreencastTarget::Toplevel(t) = &self.target {
+        match &self.target {
-            self.dpy.con.remove_obj(&**t);
+            ScreencastTarget::Output(_) => {}
+            ScreencastTarget::Workspace(_, w) => {
+                self.dpy.con.remove_obj(&**w);
+            }
+            ScreencastTarget::Toplevel(t) => {
+                self.dpy.con.remove_obj(&**t);
+            }
         }
         let started = Rc::new(StartedScreencast {
             session: self.session.clone(),
@@ -253,12 +275,22 @@ impl ScreencastSession {
                 s.dpy.con.remove_obj(&*s.selector);
                 s.core.reply.err("Session has been terminated");
             }
+            ScreencastPhase::SelectingWorkspace(s) => {
+                s.dpy.con.remove_obj(&*s.selector);
+                s.core.reply.err("Session has been terminated");
+            }
             ScreencastPhase::Starting(s) => {
                 s.reply.err("Session has been terminated");
                 s.node.con.destroy_obj(s.node.deref());
                 s.dpy.screencasts.remove(self.session_obj.path());
-                if let ScreencastTarget::Toplevel(t) = &s.target {
+                match &s.target {
-                    s.dpy.con.remove_obj(&**t);
+                    ScreencastTarget::Output(_) => {}
+                    ScreencastTarget::Workspace(_, w) => {
+                        s.dpy.con.remove_obj(&**w);
+                    }
+                    ScreencastTarget::Toplevel(t) => {
+                        s.dpy.con.remove_obj(&**t);
+                    }
                 }
             }
             ScreencastPhase::Started(s) => {

src/portal/ptl_screencast/screencast_gui.rs

@@ -5,6 +5,7 @@ use {
             ptl_display::{PortalDisplay, PortalOutput, PortalSeat},
             ptl_screencast::{
                 ScreencastPhase, ScreencastSession, ScreencastTarget, SelectingWindowScreencast,
+                SelectingWorkspaceScreencast,
             },
             ptr_gui::{
                 Align, Button, ButtonOwner, Flow, GuiElement, Label, Orientation, OverlayWindow,
@@ -14,7 +15,9 @@ use {
         theme::Color,
         utils::copyhashmap::CopyHashMap,
         wl_usr::usr_ifs::{
-            usr_jay_select_toplevel::UsrJaySelectToplevelOwner, usr_jay_toplevel::UsrJayToplevel,
+            usr_jay_select_toplevel::UsrJaySelectToplevelOwner,
+            usr_jay_select_workspace::UsrJaySelectWorkspaceOwner, usr_jay_toplevel::UsrJayToplevel,
+            usr_jay_workspace::UsrJayWorkspace,
         },
     },
     std::rc::Rc,
@@ -43,7 +46,8 @@ struct StaticButton {
 #[derive(Copy, Clone, Eq, PartialEq)]
 enum ButtonRole {
     Accept,
-    Window,
+    SelectWorkspace,
+    SelectWindow,
     Reject,
 }
 
@@ -71,14 +75,20 @@ fn create_accept_gui(surface: &Rc<SelectionGuiSurface>) -> Rc<dyn GuiElement> {
     let label = Rc::new(Label::default());
     *label.text.borrow_mut() = text;
     let accept_button = static_button(surface, ButtonRole::Accept, "Share This Output");
-    let window_button = static_button(surface, ButtonRole::Window, "Share A Window");
+    let workspace_button = static_button(surface, ButtonRole::SelectWorkspace, "Share A Workspcae");
+    let window_button = static_button(surface, ButtonRole::SelectWindow, "Share A Window");
     let reject_button = static_button(surface, ButtonRole::Reject, "Reject");
-    for button in [&accept_button, &window_button, &reject_button] {
+    for button in [
+        &accept_button,
+        &workspace_button,
+        &window_button,
+        &reject_button,
+    ] {
         button.border_color.set(Color::from_gray(100));
         button.border.set(2.0);
         button.padding.set(5.0);
     }
-    for button in [&accept_button, &window_button] {
+    for button in [&accept_button, &workspace_button, &window_button] {
         button.bg_color.set(Color::from_rgb(170, 200, 170));
         button.bg_hover_color.set(Color::from_rgb(170, 255, 170));
     }
@@ -92,7 +102,10 @@ fn create_accept_gui(surface: &Rc<SelectionGuiSurface>) -> Rc<dyn GuiElement> {
     flow.in_margin.set(V_MARGIN);
     flow.cross_margin.set(H_MARGIN);
     let mut elements: Vec<Rc<dyn GuiElement>> = vec![label, accept_button];
-    if surface.gui.dpy.jc.window_capture.get() {
+    if surface.gui.dpy.jc.caps.select_workspace.get() {
+        elements.push(workspace_button);
+    }
+    if surface.gui.dpy.jc.caps.window_capture.get() {
         elements.push(window_button);
     }
     elements.push(reject_button);
@@ -140,7 +153,7 @@ impl ButtonOwner for StaticButton {
             return;
         }
         match self.role {
-            ButtonRole::Accept | ButtonRole::Window => {
+            ButtonRole::Accept | ButtonRole::SelectWorkspace | ButtonRole::SelectWindow => {
                 log::info!("User has accepted the request");
                 let selecting = match self.surface.gui.screencast_session.phase.get() {
                     ScreencastPhase::Selecting(selecting) => selecting,
@@ -154,6 +167,19 @@ impl ButtonOwner for StaticButton {
                     selecting
                         .core
                         .starting(dpy, ScreencastTarget::Output(self.surface.output.clone()));
+                } else if self.role == ButtonRole::SelectWorkspace {
+                    let selector = dpy.jc.select_workspace(&seat.wl);
+                    let selecting = Rc::new(SelectingWorkspaceScreencast {
+                        core: selecting.core.clone(),
+                        dpy: dpy.clone(),
+                        selector: selector.clone(),
+                    });
+                    selector.owner.set(Some(selecting.clone()));
+                    self.surface
+                        .gui
+                        .screencast_session
+                        .phase
+                        .set(ScreencastPhase::SelectingWorkspace(selecting));
                 } else {
                     let selector = dpy.jc.select_toplevel(&seat.wl);
                     let selecting = Rc::new(SelectingWindowScreencast {
@@ -199,6 +225,37 @@ impl UsrJaySelectToplevelOwner for SelectingWindowScreencast {
     }
 }
 
+impl UsrJaySelectWorkspaceOwner for SelectingWorkspaceScreencast {
+    fn done(&self, output: u32, ws: Option<Rc<UsrJayWorkspace>>) {
+        let Some(ws) = ws else {
+            log::info!("User has aborted the selection");
+            self.core.session.kill();
+            return;
+        };
+        match self.core.session.phase.get() {
+            ScreencastPhase::SelectingWorkspace(s) => {
+                self.dpy.con.remove_obj(&*s.selector);
+            }
+            _ => {
+                self.dpy.con.remove_obj(&*ws);
+                return;
+            }
+        }
+        log::info!("User has selected a workspace");
+        let output = match self.dpy.outputs.get(&output) {
+            Some(o) => o,
+            _ => {
+                log::warn!("Workspace does not belong to any known output");
+                self.dpy.con.remove_obj(&*ws);
+                self.core.session.kill();
+                return;
+            }
+        };
+        self.core
+            .starting(&self.dpy, ScreencastTarget::Workspace(output, ws));
+    }
+}
+
 fn static_button(surface: &Rc<SelectionGuiSurface>, role: ButtonRole, text: &str) -> Rc<Button> {
     let button = Rc::new(Button::default());
     let slf = Rc::new(StaticButton {

src/renderer.rs

@@ -117,13 +117,13 @@ impl Renderer<'_> {
         if let Some(ws) = output.workspace.get() {
             fullscreen = ws.fullscreen.get();
         }
+        let theme = &self.state.theme;
+        let th = theme.sizes.title_height.get();
         if let Some(fs) = fullscreen {
             fs.tl_as_node().node_render(self, x, y, None);
         } else {
             render_layer!(output.layers[0]);
             render_layer!(output.layers[1]);
-            let theme = &self.state.theme;
-            let th = theme.sizes.title_height.get();
             {
                 let c = theme.colors.bar_background.get();
                 self.base.fill_boxes2(
@@ -201,6 +201,13 @@ impl Renderer<'_> {
         }
         render_layer!(output.layers[2]);
         render_layer!(output.layers[3]);
+        if let Some(ws) = output.workspace.get() {
+            if ws.render_highlight.get() > 0 {
+                let color = self.state.theme.colors.highlight.get();
+                let bounds = ws.position.get().at_point(x, y + th + 1);
+                self.base.fill_boxes(&[bounds], &color);
+            }
+        }
     }
 
     pub fn render_workspace(&mut self, workspace: &WorkspaceNode, x: i32, y: i32) {

src/tree.rs

@@ -104,6 +104,7 @@ impl FindTreeResult {
 pub enum FindTreeUsecase {
     None,
     SelectToplevel,
+    SelectWorkspace,
 }
 
 pub trait Node: 'static {

src/tree/output.rs

@@ -448,6 +448,7 @@ impl OutputNode {
             has_capture: Cell::new(false),
             title_texture: Default::default(),
             attention_requests: Default::default(),
+            render_highlight: Default::default(),
         });
         ws.update_has_captures();
         *ws.output_link.borrow_mut() = Some(self.workspaces.add_last(ws.clone()));
@@ -743,6 +744,20 @@ impl Node for OutputNode {
             }
             return FindTreeResult::AcceptsInput;
         }
+        let bar_height = self.state.theme.sizes.title_height.get() + 1;
+        if usecase == FindTreeUsecase::SelectWorkspace {
+            if y >= bar_height {
+                y -= bar_height;
+                if let Some(ws) = self.workspace.get() {
+                    tree.push(FoundNode {
+                        node: ws.clone(),
+                        x,
+                        y,
+                    });
+                    return FindTreeResult::AcceptsInput;
+                }
+            }
+        }
         {
             let res = self.find_layer_surface_at(x, y, &[OVERLAY, TOP], tree, usecase);
             if res.accepts_input() {
@@ -791,7 +806,6 @@ impl Node for OutputNode {
             });
             fs.tl_as_node().node_find_tree_at(x, y, tree, usecase)
         } else {
-            let bar_height = self.state.theme.sizes.title_height.get() + 1;
             if y >= bar_height {
                 y -= bar_height;
                 let len = tree.len();

src/tree/workspace.rs

@@ -20,6 +20,7 @@ use {
             clonecell::CloneCell,
             copyhashmap::CopyHashMap,
             linkedlist::{LinkedList, LinkedNode, NodeRef},
+            numcell::NumCell,
             threshold_counter::ThresholdCounter,
         },
         wire::JayWorkspaceId,
@@ -53,6 +54,7 @@ pub struct WorkspaceNode {
     pub has_capture: Cell<bool>,
     pub title_texture: Cell<Option<TextTexture>>,
     pub attention_requests: ThresholdCounter,
+    pub render_highlight: NumCell<u32>,
 }
 
 impl WorkspaceNode {

src/wl_usr/usr_ifs.rs

@@ -4,6 +4,7 @@ pub mod usr_jay_pointer;
 pub mod usr_jay_render_ctx;
 pub mod usr_jay_screencast;
 pub mod usr_jay_select_toplevel;
+pub mod usr_jay_select_workspace;
 pub mod usr_jay_toplevel;
 pub mod usr_jay_workspace;
 pub mod usr_jay_workspace_watcher;

src/wl_usr/usr_ifs/usr_jay_compositor.rs

@@ -11,6 +11,7 @@ use {
                 usr_jay_output::UsrJayOutput, usr_jay_pointer::UsrJayPointer,
                 usr_jay_render_ctx::UsrJayRenderCtx, usr_jay_screencast::UsrJayScreencast,
                 usr_jay_select_toplevel::UsrJaySelectToplevel,
+                usr_jay_select_workspace::UsrJaySelectWorkspace,
                 usr_jay_workspace_watcher::UsrJayWorkspaceWatcher, usr_wl_output::UsrWlOutput,
                 usr_wl_seat::UsrWlSeat,
             },
@@ -25,7 +26,13 @@ pub struct UsrJayCompositor {
     pub id: JayCompositorId,
     pub con: Rc<UsrCon>,
     pub owner: CloneCell<Option<Rc<dyn UsrJayCompositorOwner>>>,
+    pub caps: UsrJayCompositorCaps,
+}
+
+#[derive(Default)]
+pub struct UsrJayCompositorCaps {
     pub window_capture: Cell<bool>,
+    pub select_workspace: Cell<bool>,
 }
 
 pub trait UsrJayCompositorOwner {
@@ -129,6 +136,21 @@ impl UsrJayCompositor {
         sc
     }
 
+    pub fn select_workspace(&self, seat: &UsrWlSeat) -> Rc<UsrJaySelectWorkspace> {
+        let sc = Rc::new(UsrJaySelectWorkspace {
+            id: self.con.id(),
+            con: self.con.clone(),
+            owner: Default::default(),
+        });
+        self.con.request(SelectWorkspace {
+            self_id: self.id,
+            id: sc.id,
+            seat: seat.id,
+        });
+        self.con.add_object(sc.clone());
+        sc
+    }
+
     fn client_id(&self, parser: MsgParser<'_, '_>) -> Result<(), MsgParserError> {
         let ev: ClientId = self.con.parse(self, parser)?;
         if let Some(owner) = self.owner.get() {
@@ -150,7 +172,8 @@ impl UsrJayCompositor {
         for &cap in ev.cap {
             match cap {
                 Cap::NONE => {}
-                Cap::WINDOW_CAPTURE => self.window_capture.set(true),
+                Cap::WINDOW_CAPTURE => self.caps.window_capture.set(true),
+                Cap::SELECT_WORKSPACE => self.caps.select_workspace.set(true),
                 _ => {}
             }
         }

src/wl_usr/usr_ifs/usr_jay_screencast.rs

@@ -1,7 +1,6 @@
 use {
     crate::{
         format::formats,
-        ifs::jay_workspace::JayWorkspace,
         utils::{
             buffd::{MsgParser, MsgParserError},
             clonecell::CloneCell,
@@ -9,7 +8,10 @@ use {
         video::dmabuf::{DmaBuf, DmaBufPlane, PlaneVec},
         wire::{jay_screencast::*, JayScreencastId},
         wl_usr::{
-            usr_ifs::{usr_jay_output::UsrJayOutput, usr_jay_toplevel::UsrJayToplevel},
+            usr_ifs::{
+                usr_jay_output::UsrJayOutput, usr_jay_toplevel::UsrJayToplevel,
+                usr_jay_workspace::UsrJayWorkspace,
+            },
             usr_object::UsrObject,
             UsrCon,
         },
@@ -78,8 +80,7 @@ impl UsrJayScreencast {
         });
     }
 
-    #[allow(dead_code)]
+    pub fn allow_workspace(&self, ws: &UsrJayWorkspace) {
-    pub fn allow_workspace(&self, ws: &JayWorkspace) {
         self.con.request(AllowWorkspace {
             self_id: self.id,
             workspace: ws.id,

src/wl_usr/usr_ifs/usr_jay_select_workspace.rs

@@ -0,0 +1,72 @@
+use {
+    crate::{
+        utils::{
+            buffd::{MsgParser, MsgParserError},
+            clonecell::CloneCell,
+        },
+        wire::{jay_select_workspace::*, JaySelectWorkspaceId},
+        wl_usr::{usr_ifs::usr_jay_workspace::UsrJayWorkspace, usr_object::UsrObject, UsrCon},
+    },
+    std::rc::Rc,
+    thiserror::Error,
+};
+
+pub struct UsrJaySelectWorkspace {
+    pub id: JaySelectWorkspaceId,
+    pub con: Rc<UsrCon>,
+    pub owner: CloneCell<Option<Rc<dyn UsrJaySelectWorkspaceOwner>>>,
+}
+
+pub trait UsrJaySelectWorkspaceOwner {
+    fn done(&self, output: u32, ws: Option<Rc<UsrJayWorkspace>>);
+}
+
+impl UsrJaySelectWorkspace {
+    fn cancelled(&self, parser: MsgParser<'_, '_>) -> Result<(), UsrJaySelectWorkspaceError> {
+        let _ev: Cancelled = self.con.parse(self, parser)?;
+        if let Some(owner) = self.owner.get() {
+            owner.done(0, None);
+        }
+        self.con.remove_obj(self);
+        Ok(())
+    }
+
+    fn selected(&self, parser: MsgParser<'_, '_>) -> Result<(), UsrJaySelectWorkspaceError> {
+        let ev: Selected = self.con.parse(self, parser)?;
+        let tl = Rc::new(UsrJayWorkspace {
+            id: ev.id,
+            con: self.con.clone(),
+            owner: Default::default(),
+        });
+        self.con.add_object(tl.clone());
+        match self.owner.get() {
+            Some(owner) => owner.done(ev.output, Some(tl)),
+            _ => self.con.remove_obj(&*tl),
+        }
+        self.con.remove_obj(self);
+        Ok(())
+    }
+}
+
+usr_object_base! {
+    UsrJaySelectWorkspace, JaySelectWorkspace;
+
+    CANCELLED => cancelled,
+    SELECTED => selected,
+}
+
+impl UsrObject for UsrJaySelectWorkspace {
+    fn destroy(&self) {
+        // nothing
+    }
+
+    fn break_loops(&self) {
+        self.owner.take();
+    }
+}
+
+#[derive(Debug, Error)]
+pub enum UsrJaySelectWorkspaceError {
+    #[error("Parsing failed")]
+    MsgParserError(#[from] MsgParserError),
+}

wire/jay_compositor.txt

@@ -83,6 +83,11 @@ request select_toplevel {
     seat: id(wl_seat),
 }
 
+request select_workspace {
+    id: id(jay_select_workspace),
+    seat: id(wl_seat),
+}
+
 # events
 
 event client_id {

wire/jay_select_workspace.txt

@@ -0,0 +1,7 @@
+event cancelled {
+}
+
+event selected {
+    output: u32,
+    id: id(jay_workspace),
+}