cli: add commands to inspect the tree

src/cli.rs

@@ -14,6 +14,7 @@ mod run_privileged;
 pub mod screenshot;
 mod seat_test;
 mod set_log_level;
+mod tree;
 mod unlock;
 mod xwayland;
 
@@ -22,7 +23,7 @@ use {
         cli::{
             clients::ClientsArgs, color_management::ColorManagementArgs,
             damage_tracking::DamageTrackingArgs, idle::IdleCmd, input::InputArgs, randr::RandrArgs,
-            reexec::ReexecArgs, xwayland::XwaylandArgs,
+            reexec::ReexecArgs, tree::TreeArgs, xwayland::XwaylandArgs,
         },
         compositor::start_compositor,
         format::{Format, ref_formats},
@@ -89,6 +90,8 @@ pub enum Cmd {
     Reexec(ReexecArgs),
     /// Inspect/manipulate the connected clients.
     Clients(ClientsArgs),
+    /// Inspect the surface tree.
+    Tree(TreeArgs),
     #[cfg(feature = "it")]
     RunTests,
 }
@@ -248,6 +251,7 @@ pub fn main() {
         Cmd::Xwayland(a) => xwayland::main(cli.global, a),
         Cmd::ColorManagement(a) => color_management::main(cli.global, a),
         Cmd::Clients(a) => clients::main(cli.global, a),
+        Cmd::Tree(a) => tree::main(cli.global, a),
         #[cfg(feature = "it")]
         Cmd::RunTests => crate::it::run_tests(),
         Cmd::Reexec(a) => reexec::main(cli.global, a),

src/cli/tree.rs

@@ -0,0 +1,419 @@
+use {
+    crate::{
+        cli::{
+            GlobalArgs,
+            clients::{Client, ClientPrinter, handle_client_query},
+        },
+        ifs::jay_tree_query::{
+            TREE_TY_CONTAINER, TREE_TY_DISPLAY, TREE_TY_FLOAT, TREE_TY_LAYER_SURFACE,
+            TREE_TY_LOCK_SURFACE, TREE_TY_OUTPUT, TREE_TY_PLACEHOLDER, TREE_TY_WORKSPACE,
+            TREE_TY_X_WINDOW, TREE_TY_XDG_POPUP, TREE_TY_XDG_TOPLEVEL,
+        },
+        rect::Rect,
+        tools::tool_client::{Handle, ToolClient, with_tool_client},
+        wire::{JayCompositorId, JayTreeQueryId, jay_client_query, jay_compositor, jay_tree_query},
+    },
+    ahash::{AHashMap, AHashSet},
+    clap::{Args, Subcommand},
+    isnt::std_1::primitive::IsntSliceExt,
+    std::{cell::RefCell, rc::Rc},
+};
+
+#[derive(Args, Debug)]
+pub struct TreeArgs {
+    #[clap(subcommand)]
+    cmd: TreeCmd,
+}
+
+#[derive(Subcommand, Debug)]
+enum TreeCmd {
+    /// Query the tree.
+    Query(QueryArgs),
+}
+
+#[derive(Args, Debug)]
+struct QueryArgs {
+    /// Whether to perform a recursive query.
+    #[arg(short, long)]
+    recursive: bool,
+    /// Whether to repeatedly print details of the same client.
+    #[arg(long)]
+    all_clients: bool,
+    #[clap(subcommand)]
+    cmd: QueryCmd,
+}
+
+#[derive(Subcommand, Debug)]
+enum QueryCmd {
+    /// Query the entire display.
+    Root,
+    /// Query a workspace by name.
+    WorkspaceName(QueryWorkspaceNameArgs),
+    /// Interactively select a workspace to query.
+    SelectWorkspace,
+    /// Interactively select a window to query.
+    SelectWindow,
+}
+
+#[derive(Args, Debug)]
+struct QueryWorkspaceNameArgs {
+    /// The name of the workspace.
+    name: String,
+}
+
+pub fn main(global: GlobalArgs, tree_args: TreeArgs) {
+    with_tool_client(global.log_level.into(), |tc| async move {
+        let comp = tc.jay_compositor().await;
+        let tree = Rc::new(Tree {
+            tc: tc.clone(),
+            comp,
+        });
+        tree.run(tree_args).await;
+    });
+}
+
+struct Tree {
+    tc: Rc<ToolClient>,
+    comp: JayCompositorId,
+}
+
+impl Tree {
+    async fn run(&self, args: TreeArgs) {
+        match &args.cmd {
+            TreeCmd::Query(a) => self.query(a).await,
+        }
+    }
+
+    async fn query(&self, args: &QueryArgs) {
+        let id = self.tc.id();
+        self.tc.send(jay_compositor::CreateTreeQuery {
+            self_id: self.comp,
+            id,
+        });
+        let mut query = Query {
+            tree: self,
+            tc: &self.tc,
+            id,
+        };
+        query.run(args).await;
+    }
+}
+
+struct Query<'a> {
+    tree: &'a Tree,
+    tc: &'a Rc<ToolClient>,
+    id: JayTreeQueryId,
+}
+
+#[derive(Debug, Default)]
+struct Queried {
+    not_found: bool,
+    roots: Vec<Node>,
+    stack: Vec<Node>,
+    client_ids: AHashSet<u64>,
+}
+
+#[derive(Debug, Default)]
+struct Node {
+    ty: u32,
+    children: Vec<Node>,
+    position: Option<Rect>,
+    toplevel_id: Option<String>,
+    client: Option<u64>,
+    title: Option<String>,
+    app_id: Option<String>,
+    tag: Option<String>,
+    x_class: Option<String>,
+    x_instance: Option<String>,
+    x_role: Option<String>,
+    workspace: Option<String>,
+    placeholder_for: Option<String>,
+    floating: bool,
+    visible: bool,
+    urgent: bool,
+    fullscreen: bool,
+    output: Option<String>,
+}
+
+impl Query<'_> {
+    async fn run(&mut self, args: &QueryArgs) {
+        match &args.cmd {
+            QueryCmd::Root => {
+                self.tc.send(SetRootDisplay { self_id: self.id });
+            }
+            QueryCmd::WorkspaceName(a) => {
+                self.tc.send(SetRootWorkspaceName {
+                    self_id: self.id,
+                    workspace: &a.name,
+                });
+            }
+            QueryCmd::SelectWorkspace => {
+                let id = self.tc.select_workspace().await;
+                if id.is_none() {
+                    fatal!("Workspace selection failed");
+                }
+                self.tc.send(SetRootWorkspace {
+                    self_id: self.id,
+                    workspace: id,
+                });
+            }
+            QueryCmd::SelectWindow => {
+                let id = self.tc.select_toplevel().await;
+                if id.is_none() {
+                    fatal!("Window selection failed");
+                }
+                self.tc.send(SetRootToplevel {
+                    self_id: self.id,
+                    toplevel: id,
+                });
+            }
+        }
+        let tl = self.tc;
+        let id = self.id;
+        let d = Rc::new(RefCell::new(Queried::default()));
+        use jay_tree_query::*;
+        macro_rules! last {
+            ($d:ident, $n:ident) => {
+                let $d = &mut *$d.borrow_mut();
+                let $n = $d.stack.last_mut().unwrap();
+            };
+        }
+        NotFound::handle(tl, id, d.clone(), |d, _event| {
+            d.borrow_mut().not_found = true;
+        });
+        End::handle(tl, id, d.clone(), |d, _event| {
+            let d = &mut *d.borrow_mut();
+            let n = d.stack.pop().unwrap();
+            if let Some(p) = d.stack.last_mut() {
+                p.children.push(n);
+            } else {
+                d.roots.push(n);
+            }
+        });
+        Position::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.position = Rect::new_sized(event.x, event.y, event.w, event.h);
+        });
+        Start::handle(tl, id, d.clone(), |d, event| {
+            let d = &mut *d.borrow_mut();
+            let node = Node {
+                ty: event.ty,
+                ..Default::default()
+            };
+            d.stack.push(node);
+        });
+        OutputName::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.output = Some(event.name.to_string());
+        });
+        WorkspaceName::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.workspace = Some(event.name.to_string());
+        });
+        ToplevelId::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.toplevel_id = Some(event.id.to_string());
+        });
+        ClientId::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.client = Some(event.id);
+            d.client_ids.insert(event.id);
+        });
+        Title::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.title = Some(event.title.to_string());
+        });
+        AppId::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.app_id = Some(event.app_id.to_string());
+        });
+        Floating::handle(tl, id, d.clone(), |d, _event| {
+            last!(d, n);
+            n.floating = true;
+        });
+        Visible::handle(tl, id, d.clone(), |d, _event| {
+            last!(d, n);
+            n.visible = true;
+        });
+        Urgent::handle(tl, id, d.clone(), |d, _event| {
+            last!(d, n);
+            n.urgent = true;
+        });
+        Fullscreen::handle(tl, id, d.clone(), |d, _event| {
+            last!(d, n);
+            n.fullscreen = true;
+        });
+        Tag::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.tag = Some(event.tag.to_string());
+        });
+        XClass::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.x_class = Some(event.class.to_string());
+        });
+        XInstance::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.x_instance = Some(event.instance.to_string());
+        });
+        XRole::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.x_role = Some(event.role.to_string());
+        });
+        Workspace::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.workspace = Some(event.name.to_string());
+        });
+        PlaceholderFor::handle(tl, id, d.clone(), |d, event| {
+            last!(d, n);
+            n.placeholder_for = Some(event.id.to_string());
+        });
+        if args.recursive {
+            tl.send(SetRecursive {
+                self_id: id,
+                recursive: 1,
+            });
+        }
+        tl.send(Execute { self_id: id });
+        tl.round_trip().await;
+        let clients = {
+            let id = tl.id();
+            tl.send(jay_compositor::CreateClientQuery {
+                self_id: self.tree.comp,
+                id,
+            });
+            use jay_client_query::*;
+            for &client in &d.borrow().client_ids {
+                tl.send(AddId {
+                    self_id: id,
+                    id: client,
+                });
+            }
+            tl.send(Execute { self_id: id });
+            handle_client_query(tl, id).await
+        };
+        let mut printer = Printer {
+            clients,
+            printed_clients: Default::default(),
+            verbose: args.all_clients,
+            prefix: "".to_string(),
+            output_depth: 0,
+            workspace_depth: 0,
+        };
+        for node in &d.borrow().roots {
+            printer.print(node);
+        }
+    }
+}
+
+struct Printer {
+    clients: AHashMap<u64, Client>,
+    printed_clients: AHashSet<u64>,
+    verbose: bool,
+    prefix: String,
+    output_depth: u32,
+    workspace_depth: u32,
+}
+
+impl Printer {
+    fn print(&mut self, node: &Node) {
+        let p = &self.prefix;
+        'ty: {
+            let n = match node.ty {
+                TREE_TY_DISPLAY => "display",
+                TREE_TY_OUTPUT => "output",
+                TREE_TY_WORKSPACE => "workspace",
+                TREE_TY_FLOAT => "float",
+                TREE_TY_CONTAINER => "container",
+                TREE_TY_PLACEHOLDER => "placeholder",
+                TREE_TY_XDG_TOPLEVEL => "xdg-toplevel",
+                TREE_TY_X_WINDOW => "x-window",
+                TREE_TY_XDG_POPUP => "xdg-popup",
+                TREE_TY_LAYER_SURFACE => "layer-surface",
+                TREE_TY_LOCK_SURFACE => "lock-surface",
+                _ => {
+                    println!("{p}- unknown ({}):", node.ty);
+                    break 'ty;
+                }
+            };
+            println!("{p}- {n}:");
+        }
+        macro_rules! opt {
+            ($field:ident, $pretty:expr) => {
+                if let Some(v) = &node.$field {
+                    println!("{p}    {}: {}", $pretty, v);
+                }
+            };
+        }
+        macro_rules! bol {
+            ($field:ident, $pretty:expr) => {
+                if node.$field {
+                    println!("{p}    {}", $pretty);
+                }
+            };
+        }
+        if node.ty == TREE_TY_OUTPUT {
+            opt!(output, "name");
+        }
+        if node.ty == TREE_TY_WORKSPACE {
+            opt!(workspace, "name");
+        }
+        opt!(toplevel_id, "id");
+        opt!(placeholder_for, "placeholder-for");
+        if let Some(r) = node.position {
+            println!(
+                "{p}    pos: {}x{} + {}x{}",
+                r.x1(),
+                r.y1(),
+                r.width(),
+                r.height()
+            );
+        }
+        if let Some(client_id) = node.client {
+            let client = self.clients.get(&client_id);
+            if client.is_some() && (self.printed_clients.insert(client_id) || self.verbose) {
+                println!("{p}    client:");
+                let mut prefix = format!("{}      ", p);
+                let mut cp = ClientPrinter {
+                    prefix: &mut prefix,
+                };
+                cp.print_client(client.unwrap());
+            } else {
+                println!("{p}    client: {client_id}");
+            }
+        }
+        opt!(title, "title");
+        opt!(app_id, "app-id");
+        opt!(tag, "tag");
+        opt!(x_class, "x-class");
+        opt!(x_instance, "x-instance");
+        opt!(x_role, "x-role");
+        if self.workspace_depth == 0 && node.ty != TREE_TY_WORKSPACE {
+            opt!(workspace, "workspace");
+        }
+        if self.workspace_depth == 0 && self.output_depth == 0 && node.ty != TREE_TY_OUTPUT {
+            opt!(output, "output");
+        }
+        bol!(floating, "floating");
+        bol!(visible, "visible");
+        bol!(urgent, "urgent");
+        bol!(fullscreen, "fullscreen");
+        if node.children.is_not_empty() {
+            let (od, wd) = match node.ty {
+                TREE_TY_OUTPUT => (1, 0),
+                TREE_TY_WORKSPACE => (0, 1),
+                _ => (0, 0),
+            };
+            self.output_depth += od;
+            self.workspace_depth += wd;
+            println!("{p}    children:");
+            let len = self.prefix.len();
+            self.prefix.push_str("      ");
+            for child in &node.children {
+                self.print(child);
+            }
+            self.prefix.truncate(len);
+            self.output_depth -= od;
+            self.workspace_depth -= wd;
+        }
+    }
+}

src/ifs.rs

@@ -31,6 +31,7 @@ pub mod jay_select_toplevel;
 pub mod jay_select_workspace;
 pub mod jay_toplevel;
 pub mod jay_tray_v1;
+pub mod jay_tree_query;
 pub mod jay_workspace;
 pub mod jay_workspace_watcher;
 pub mod jay_xwayland;

src/ifs/jay_compositor.rs

@@ -20,6 +20,7 @@ use {
             jay_seat_events::JaySeatEvents,
             jay_select_toplevel::{JaySelectToplevel, JayToplevelSelector},
             jay_select_workspace::{JaySelectWorkspace, JayWorkspaceSelector},
+            jay_tree_query::JayTreeQuery,
             jay_workspace_watcher::JayWorkspaceWatcher,
             jay_xwayland::JayXwayland,
         },
@@ -507,6 +508,13 @@ impl JayCompositorRequestHandler for JayCompositor {
         self.client.state.clients.kill(ClientId::from_raw(req.id));
         Ok(())
     }
+
+    fn create_tree_query(&self, req: CreateTreeQuery, _slf: &Rc<Self>) -> Result<(), Self::Error> {
+        let obj = Rc::new(JayTreeQuery::new(&self.client, req.id, self.version));
+        track!(self.client, obj);
+        self.client.add_client_obj(&obj)?;
+        Ok(())
+    }
 }
 
 object_base! {

src/ifs/jay_tree_query.rs

@@ -0,0 +1,458 @@
+use {
+    crate::{
+        client::{Client, ClientError},
+        globals::GlobalBase,
+        ifs::wl_surface::{
+            ext_session_lock_surface_v1::ExtSessionLockSurfaceV1,
+            x_surface::xwindow::Xwindow,
+            xdg_surface::{xdg_popup::XdgPopup, xdg_toplevel::XdgToplevel},
+            zwlr_layer_surface_v1::ZwlrLayerSurfaceV1,
+        },
+        leaks::Tracker,
+        object::{Object, Version},
+        rect::Rect,
+        tree::{
+            self, ContainerNode, DisplayNode, FloatNode, Node, NodeVisitor, OutputNode,
+            PlaceholderNode, ToplevelData, ToplevelNodeBase, ToplevelType, WorkspaceNode,
+        },
+        utils::{opaque::OpaqueError, opt::Opt, toplevel_identifier::ToplevelIdentifier},
+        wire::{JayTreeQueryId, jay_tree_query::*},
+    },
+    isnt::std_1::primitive::IsntStrExt,
+    std::{
+        cell::{Cell, RefCell},
+        ops::Deref,
+        rc::Rc,
+        str::FromStr,
+    },
+    thiserror::Error,
+};
+
+pub const TREE_TY_DISPLAY: u32 = 1;
+pub const TREE_TY_OUTPUT: u32 = 2;
+pub const TREE_TY_WORKSPACE: u32 = 3;
+pub const TREE_TY_FLOAT: u32 = 4;
+pub const TREE_TY_CONTAINER: u32 = 5;
+pub const TREE_TY_PLACEHOLDER: u32 = 6;
+pub const TREE_TY_XDG_TOPLEVEL: u32 = 7;
+pub const TREE_TY_X_WINDOW: u32 = 8;
+pub const TREE_TY_XDG_POPUP: u32 = 9;
+pub const TREE_TY_LAYER_SURFACE: u32 = 10;
+pub const TREE_TY_LOCK_SURFACE: u32 = 11;
+
+pub struct JayTreeQuery {
+    pub id: JayTreeQueryId,
+    pub client: Rc<Client>,
+    pub tracker: Tracker<Self>,
+    pub version: Version,
+    recursive: Cell<bool>,
+    root: RefCell<Option<Root>>,
+}
+
+enum Root {
+    Display,
+    WorkspaceNode(Rc<Opt<WorkspaceNode>>),
+    WorkspaceName(String),
+    ToplevelId(ToplevelIdentifier),
+}
+
+impl JayTreeQuery {
+    pub fn new(client: &Rc<Client>, id: JayTreeQueryId, version: Version) -> Self {
+        Self {
+            id,
+            client: client.clone(),
+            tracker: Default::default(),
+            version,
+            recursive: Cell::new(false),
+            root: Default::default(),
+        }
+    }
+
+    fn send_node_position(&self, node: &dyn Node) {
+        let rect = node.node_absolute_position();
+        self.send_position(rect);
+    }
+
+    fn send_position(&self, rect: Rect) {
+        self.client.event(Position {
+            self_id: self.id,
+            x: rect.x1(),
+            y: rect.y1(),
+            w: rect.width(),
+            h: rect.height(),
+        });
+    }
+
+    fn send_not_found(&self) {
+        self.client.event(NotFound { self_id: self.id });
+    }
+
+    fn send_done(&self) {
+        self.client.event(Done { self_id: self.id });
+    }
+
+    fn send_end(&self) {
+        self.client.event(End { self_id: self.id });
+    }
+
+    fn send_start(&self, ty: u32) {
+        self.client.event(Start {
+            self_id: self.id,
+            ty,
+        });
+    }
+
+    fn send_client(&self, node: &impl Node) {
+        if let Some(id) = node.node_client_id() {
+            self.client.event(ClientId {
+                self_id: self.id,
+                id: id.raw(),
+            });
+        }
+    }
+
+    fn send_workspace_name(&self, name: &str) {
+        self.client.event(WorkspaceName {
+            self_id: self.id,
+            name,
+        });
+    }
+
+    fn send_output_name(&self, name: &str) {
+        self.client.event(OutputName {
+            self_id: self.id,
+            name,
+        });
+    }
+
+    fn send_toplevel(&self, data: &ToplevelData) {
+        self.client.event(Start {
+            self_id: self.id,
+            ty: match &data.kind {
+                ToplevelType::Container => TREE_TY_CONTAINER,
+                ToplevelType::Placeholder(_) => TREE_TY_PLACEHOLDER,
+                ToplevelType::XdgToplevel(_) => TREE_TY_XDG_TOPLEVEL,
+                ToplevelType::XWindow(_) => TREE_TY_X_WINDOW,
+            },
+        });
+        self.client.event(ToplevelId {
+            self_id: self.id,
+            id: &data.identifier.get().to_string(),
+        });
+        self.send_position(data.desired_extents.get());
+        if let Some(cl) = data.client.as_ref().map(|c| c.id.raw()) {
+            self.client.event(ClientId {
+                self_id: self.id,
+                id: cl,
+            });
+        }
+        self.client.event(Title {
+            self_id: self.id,
+            title: &data.title.borrow(),
+        });
+        if let Some(w) = data.workspace.get() {
+            self.send_workspace_name(&w.name);
+        }
+        match &data.kind {
+            ToplevelType::Container => {}
+            ToplevelType::Placeholder(id) => {
+                if let Some(id) = *id {
+                    self.client.event(PlaceholderFor {
+                        self_id: self.id,
+                        id: &id.to_string(),
+                    });
+                }
+            }
+            ToplevelType::XdgToplevel(d) => {
+                self.client.event(AppId {
+                    self_id: self.id,
+                    app_id: &data.app_id.borrow(),
+                });
+                let tag = &*d.tag.borrow();
+                if tag.is_not_empty() {
+                    self.client.event(Tag {
+                        self_id: self.id,
+                        tag,
+                    });
+                }
+            }
+            ToplevelType::XWindow(d) => {
+                if let Some(class) = &*d.info.class.borrow() {
+                    self.client.event(XClass {
+                        self_id: self.id,
+                        class,
+                    });
+                }
+                if let Some(instance) = &*d.info.instance.borrow() {
+                    self.client.event(XInstance {
+                        self_id: self.id,
+                        instance,
+                    });
+                }
+                if let Some(role) = &*d.info.role.borrow() {
+                    self.client.event(XRole {
+                        self_id: self.id,
+                        role,
+                    });
+                }
+            }
+        }
+        if data.is_floating.get() {
+            self.client.event(Floating { self_id: self.id });
+        }
+        if data.visible.get() {
+            self.client.event(Visible { self_id: self.id });
+        }
+        if data.wants_attention.get() {
+            self.client.event(Urgent { self_id: self.id });
+        }
+        for seat_id in data.seat_foci.lock().keys() {
+            for seat in data.state.globals.seats.lock().values() {
+                if seat.id() == *seat_id {
+                    self.client.event(Focused {
+                        self_id: self.id,
+                        global: seat.name().raw(),
+                    });
+                }
+            }
+        }
+        if data.is_fullscreen.get() {
+            self.client.event(Fullscreen { self_id: self.id });
+        }
+        if let Some(ws) = data.workspace.get() {
+            self.client.event(Workspace {
+                self_id: self.id,
+                name: &ws.name,
+            });
+        }
+    }
+}
+
+impl JayTreeQueryRequestHandler for JayTreeQuery {
+    type Error = JayTreeQueryError;
+
+    fn destroy(&self, _req: Destroy, _slf: &Rc<Self>) -> Result<(), Self::Error> {
+        self.client.remove_obj(self)?;
+        Ok(())
+    }
+
+    fn execute(&self, _req: Execute, _slf: &Rc<Self>) -> Result<(), Self::Error> {
+        let Some(root) = &*self.root.borrow() else {
+            return Err(JayTreeQueryError::NoRootSet);
+        };
+        match root {
+            Root::Display => Visitor(self).visit_display(&self.client.state.root),
+            Root::WorkspaceNode(n) => match n.get() {
+                Some(n) => Visitor(self).visit_workspace(&n),
+                None => self.send_not_found(),
+            },
+            Root::WorkspaceName(n) => match self.client.state.workspaces.get(n) {
+                Some(n) => Visitor(self).visit_workspace(&n),
+                None => self.send_not_found(),
+            },
+            Root::ToplevelId(id) => match self
+                .client
+                .state
+                .toplevels
+                .get(id)
+                .and_then(|t| t.upgrade())
+            {
+                Some(t) => t.node_visit(&mut Visitor(self)),
+                None => self.send_not_found(),
+            },
+        }
+        self.send_done();
+        Ok(())
+    }
+
+    fn set_root_display(&self, _req: SetRootDisplay, _slf: &Rc<Self>) -> Result<(), Self::Error> {
+        *self.root.borrow_mut() = Some(Root::Display);
+        Ok(())
+    }
+
+    fn set_recursive(&self, req: SetRecursive, _slf: &Rc<Self>) -> Result<(), Self::Error> {
+        self.recursive.set(req.recursive != 0);
+        Ok(())
+    }
+
+    fn set_root_workspace(
+        &self,
+        req: SetRootWorkspace,
+        _slf: &Rc<Self>,
+    ) -> Result<(), Self::Error> {
+        let ws = self.client.lookup(req.workspace)?;
+        let opt = match ws.workspace.get() {
+            Some(ws) => ws.opt.clone(),
+            _ => Default::default(),
+        };
+        let root = &mut *self.root.borrow_mut();
+        *root = Some(Root::WorkspaceNode(opt));
+        Ok(())
+    }
+
+    fn set_root_workspace_name(
+        &self,
+        req: SetRootWorkspaceName,
+        _slf: &Rc<Self>,
+    ) -> Result<(), Self::Error> {
+        let root = &mut *self.root.borrow_mut();
+        *root = Some(Root::WorkspaceName(req.workspace.to_owned()));
+        Ok(())
+    }
+
+    fn set_root_toplevel(&self, req: SetRootToplevel, _slf: &Rc<Self>) -> Result<(), Self::Error> {
+        let tl = self.client.lookup(req.toplevel)?;
+        let root = &mut *self.root.borrow_mut();
+        *root = Some(Root::ToplevelId(tl.toplevel.tl_data().identifier.get()));
+        Ok(())
+    }
+
+    fn set_root_window_id(
+        &self,
+        req: SetRootWindowId<'_>,
+        _slf: &Rc<Self>,
+    ) -> Result<(), Self::Error> {
+        let id =
+            ToplevelIdentifier::from_str(req.id).map_err(JayTreeQueryError::InvalidToplevelId)?;
+        let root = &mut *self.root.borrow_mut();
+        *root = Some(Root::ToplevelId(id));
+        Ok(())
+    }
+}
+
+struct Visitor<'a>(&'a JayTreeQuery);
+
+impl tree::NodeVisitorBase for Visitor<'_> {
+    fn visit_container(&mut self, node: &Rc<ContainerNode>) {
+        let s = self.0;
+        s.send_toplevel(node.tl_data());
+        if s.recursive.get() {
+            node.node_visit_children(self);
+        }
+        s.send_end();
+    }
+
+    fn visit_toplevel(&mut self, node: &Rc<XdgToplevel>) {
+        let s = self.0;
+        s.send_toplevel(node.tl_data());
+        node.xdg.for_each_popup(|popup| {
+            NodeVisitor::visit_popup(self, popup);
+        });
+        s.send_end();
+    }
+
+    fn visit_popup(&mut self, node: &Rc<XdgPopup>) {
+        let s = self.0;
+        s.send_start(TREE_TY_XDG_POPUP);
+        s.send_node_position(&**node);
+        s.send_end();
+    }
+
+    fn visit_display(&mut self, node: &Rc<DisplayNode>) {
+        let s = self.0;
+        s.send_start(TREE_TY_DISPLAY);
+        s.send_node_position(&**node);
+        if s.recursive.get() {
+            for output in node.outputs.lock().values() {
+                NodeVisitor::visit_output(self, output);
+            }
+            for stacked in node.stacked.iter() {
+                if stacked.stacked_has_workspace_link() {
+                    continue;
+                }
+                stacked.deref().clone().node_visit(self);
+            }
+        }
+        s.send_end();
+    }
+
+    fn visit_output(&mut self, node: &Rc<OutputNode>) {
+        let s = self.0;
+        s.send_start(TREE_TY_OUTPUT);
+        s.send_node_position(&**node);
+        s.send_output_name(&node.global.connector.name);
+        if s.recursive.get() {
+            node.node_visit_children(self);
+        }
+        s.send_end();
+    }
+
+    fn visit_float(&mut self, node: &Rc<FloatNode>) {
+        let s = self.0;
+        s.send_start(TREE_TY_FLOAT);
+        s.send_node_position(&**node);
+        if s.recursive.get() {
+            node.node_visit_children(self);
+        }
+        s.send_end();
+    }
+
+    fn visit_workspace(&mut self, node: &Rc<WorkspaceNode>) {
+        let s = self.0;
+        s.send_start(TREE_TY_WORKSPACE);
+        s.send_node_position(&**node);
+        s.send_workspace_name(&node.name);
+        s.send_output_name(&node.output.get().global.connector.name);
+        for stacked in node.stacked.iter() {
+            if stacked.stacked_is_xdg_popup() {
+                continue;
+            }
+            stacked.deref().clone().node_visit(self);
+        }
+        if s.recursive.get() {
+            node.node_visit_children(self);
+        }
+        s.send_end();
+    }
+
+    fn visit_layer_surface(&mut self, node: &Rc<ZwlrLayerSurfaceV1>) {
+        let s = self.0;
+        s.send_start(TREE_TY_LAYER_SURFACE);
+        s.send_client(&**node);
+        s.send_node_position(&**node);
+        node.for_each_popup(|popup| {
+            NodeVisitor::visit_popup(self, popup);
+        });
+        s.send_end();
+    }
+
+    fn visit_xwindow(&mut self, node: &Rc<Xwindow>) {
+        let s = self.0;
+        s.send_toplevel(node.tl_data());
+        s.send_end();
+    }
+
+    fn visit_placeholder(&mut self, node: &Rc<PlaceholderNode>) {
+        let s = self.0;
+        s.send_toplevel(node.tl_data());
+        s.send_end();
+    }
+
+    fn visit_lock_surface(&mut self, node: &Rc<ExtSessionLockSurfaceV1>) {
+        let s = self.0;
+        s.send_start(TREE_TY_LOCK_SURFACE);
+        s.send_client(&**node);
+        s.send_node_position(&**node);
+        s.send_end();
+    }
+}
+
+object_base! {
+    self = JayTreeQuery;
+    version = self.version;
+}
+
+impl Object for JayTreeQuery {}
+
+simple_add_obj!(JayTreeQuery);
+
+#[derive(Debug, Error)]
+pub enum JayTreeQueryError {
+    #[error(transparent)]
+    ClientError(Box<ClientError>),
+    #[error("Toplevel id is ill-formed")]
+    InvalidToplevelId(OpaqueError),
+    #[error("No root node was set")]
+    NoRootSet,
+}
+efrom!(JayTreeQueryError, ClientError);

src/ifs/wl_surface/xdg_surface.rs

@@ -328,6 +328,12 @@ impl XdgSurface {
             popup.popup.xdg.set_popup_stack(stack);
         }
     }
+
+    pub fn for_each_popup(&self, mut f: impl FnMut(&Rc<XdgPopup>)) {
+        for popup in self.popups.lock().values() {
+            f(&popup.popup);
+        }
+    }
 }
 
 impl XdgSurfaceRequestHandler for XdgSurface {

src/ifs/wl_surface/xdg_surface/xdg_popup.rs

@@ -382,6 +382,10 @@ impl StackedNode for XdgPopup {
     fn stacked_absolute_position_constrains_input(&self) -> bool {
         false
     }
+
+    fn stacked_is_xdg_popup(&self) -> bool {
+        true
+    }
 }
 
 impl XdgSurfaceExt for XdgPopup {

src/ifs/wl_surface/zwlr_layer_surface_v1.rs

@@ -210,6 +210,12 @@ impl ZwlrLayerSurfaceV1 {
             m.layer_surface.get_or_insert_default_ext()
         })
     }
+
+    pub fn for_each_popup(&self, mut f: impl FnMut(&Rc<XdgPopup>)) {
+        for popup in self.popups.lock().values() {
+            f(&popup.popup);
+        }
+    }
 }
 
 impl ZwlrLayerSurfaceV1RequestHandler for ZwlrLayerSurfaceV1 {

src/tools/tool_client.rs

@@ -23,9 +23,10 @@ use {
         },
         wheel::{Wheel, WheelError},
         wire::{
-            JayCompositor, JayCompositorId, JayDamageTracking, JayDamageTrackingId, WlCallbackId,
-            WlRegistryId, WlSeatId, jay_compositor, jay_select_toplevel, jay_toplevel, wl_callback,
-            wl_display, wl_registry,
+            JayCompositor, JayCompositorId, JayDamageTracking, JayDamageTrackingId, JayToplevelId,
+            JayWorkspaceId, WlCallbackId, WlRegistryId, WlSeatId, jay_compositor,
+            jay_select_toplevel, jay_select_workspace, jay_toplevel, wl_callback, wl_display,
+            wl_registry,
         },
     },
     ahash::AHashMap,
@@ -362,6 +363,53 @@ impl ToolClient {
         Some(id)
     }
 
+    pub async fn select_workspace(self: &Rc<Self>) -> JayWorkspaceId {
+        let id = self.id();
+        self.send(jay_compositor::SelectWorkspace {
+            self_id: self.jay_compositor().await,
+            id,
+            seat: WlSeatId::NONE,
+        });
+        let ae = Rc::new(AsyncEvent::default());
+        let ws = Rc::new(Cell::new(JayWorkspaceId::NONE));
+        jay_select_workspace::Cancelled::handle(self, id, ae.clone(), |ae, _event| {
+            ae.trigger();
+        });
+        jay_select_workspace::Selected::handle(
+            self,
+            id,
+            (ae.clone(), ws.clone()),
+            |(ae, ws), event| {
+                ws.set(event.id);
+                ae.trigger();
+            },
+        );
+        ae.triggered().await;
+        ws.get()
+    }
+
+    pub async fn select_toplevel(self: &Rc<Self>) -> JayToplevelId {
+        let id = self.id();
+        self.send(jay_compositor::SelectToplevel {
+            self_id: self.jay_compositor().await,
+            id,
+            seat: WlSeatId::NONE,
+        });
+        let ae = Rc::new(AsyncEvent::default());
+        let toplevel = Rc::new(Cell::new(JayToplevelId::NONE));
+        jay_select_toplevel::Done::handle(
+            self,
+            id,
+            (ae.clone(), toplevel.clone()),
+            |(ae, toplevel), event| {
+                toplevel.set(event.id);
+                ae.trigger();
+            },
+        );
+        ae.triggered().await;
+        toplevel.get()
+    }
+
     pub async fn select_toplevel_client(self: &Rc<Self>) -> u64 {
         let id = self.id();
         self.send(jay_compositor::SelectToplevel {

src/tree/placeholder.rs

@@ -56,7 +56,7 @@ impl PlaceholderNode {
                 state,
                 node.tl_data().title.borrow().clone(),
                 node.node_client(),
-                ToplevelType::Placeholder,
+                ToplevelType::Placeholder(Some(node.tl_data().identifier.get())),
                 id,
                 slf,
             ),
@@ -75,7 +75,7 @@ impl PlaceholderNode {
                 state,
                 String::new(),
                 None,
-                ToplevelType::Placeholder,
+                ToplevelType::Placeholder(None),
                 id,
                 slf,
             ),

src/tree/stacked.rs

@@ -16,6 +16,10 @@ pub trait StackedNode: Node {
     fn stacked_absolute_position_constrains_input(&self) -> bool {
         true
     }
+
+    fn stacked_is_xdg_popup(&self) -> bool {
+        false
+    }
 }
 
 pub trait PinnedNode: StackedNode {

src/tree/toplevel.rs

@@ -279,7 +279,7 @@ impl ToplevelOpt {
 
 pub enum ToplevelType {
     Container,
-    Placeholder,
+    Placeholder(Option<ToplevelIdentifier>),
     XdgToplevel(Rc<XdgToplevelToplevelData>),
     XWindow(Rc<XwindowData>),
 }
@@ -288,7 +288,7 @@ impl ToplevelType {
     pub fn to_window_type(&self) -> WindowType {
         match self {
             ToplevelType::Container => window::CONTAINER,
-            ToplevelType::Placeholder => window::PLACEHOLDER,
+            ToplevelType::Placeholder { .. } => window::PLACEHOLDER,
             ToplevelType::XdgToplevel { .. } => window::XDG_TOPLEVEL,
             ToplevelType::XWindow { .. } => window::X_WINDOW,
         }

wire/jay_compositor.txt

@@ -117,6 +117,10 @@ request kill_client (since = 18) {
     id: pod(u64),
 }
 
+request create_tree_query (since = 18) {
+    id: id(jay_tree_query),
+}
+
 # events
 
 event client_id {

wire/jay_tree_query.txt

@@ -0,0 +1,102 @@
+request destroy { }
+
+request execute { }
+
+request set_root_display { }
+
+request set_recursive {
+    recursive: u32,
+}
+
+request set_root_workspace {
+    workspace: id(jay_workspace),
+}
+
+request set_root_workspace_name {
+    workspace: str,
+}
+
+request set_root_toplevel {
+    toplevel: id(jay_toplevel),
+}
+
+request set_root_window_id {
+    id: str,
+}
+
+event done { }
+
+event not_found { }
+
+event start {
+    ty: u32,
+}
+
+event end { }
+
+event position {
+    x: i32,
+    y: i32,
+    w: i32,
+    h: i32,
+}
+
+event workspace_name {
+    name: str,
+}
+
+event output_name {
+    name: str,
+}
+
+event toplevel_id {
+    id: str,
+}
+
+event client_id {
+    id: pod(u64),
+}
+
+event title {
+    title: str,
+}
+
+event app_id {
+    app_id: str,
+}
+
+event floating { }
+
+event visible { }
+
+event urgent { }
+
+event focused {
+    global: u32,
+}
+
+event fullscreen { }
+
+event tag {
+    tag: str,
+}
+
+event x_class {
+    class: str,
+}
+
+event x_instance {
+    instance: str,
+}
+
+event x_role {
+    role: str,
+}
+
+event workspace {
+    name: str,
+}
+
+event placeholder_for {
+    id: str,
+}