portal: add a desktop portal

etc/jay.portal

@@ -0,0 +1,4 @@
+[portal]
+DBusName=org.freedesktop.impl.portal.desktop.jay
+Interfaces=org.freedesktop.impl.portal.ScreenCast;
+UseIn=jay

etc/org.freedesktop.impl.portal.desktop.jay.service

@@ -0,0 +1,4 @@
+[D-BUS Service]
+Name=org.freedesktop.impl.portal.desktop.jay
+Exec=/bin/false
+SystemdService=xdg-desktop-portal-jay.service

etc/xdg-desktop-portal-jay.service

@@ -0,0 +1,7 @@
+[Unit]
+Description=Jay Portal
+
+[Service]
+Type=dbus
+BusName=org.freedesktop.impl.portal.desktop.jay
+ExecStart=/home/julian/bin/jay portal

src/cli.rs

@@ -9,7 +9,7 @@ mod set_log_level;
 mod unlock;
 
 use {
-    crate::compositor::start_compositor,
+    crate::{compositor::start_compositor, portal},
     ::log::Level,
     clap::{ArgEnum, Args, Parser, Subcommand},
     clap_complete::Shell,
@@ -53,6 +53,8 @@ pub enum Cmd {
     RunPrivileged(RunPrivilegedArgs),
     /// Tests the events produced by a seat.
     SeatTest(SeatTestArgs),
+    /// Run the desktop portal.
+    Portal,
     #[cfg(feature = "it")]
     RunTests,
 }
@@ -214,6 +216,7 @@ pub fn main() {
         Cmd::Unlock => unlock::main(cli.global),
         Cmd::RunPrivileged(a) => run_privileged::main(cli.global, a),
         Cmd::SeatTest(a) => seat_test::main(cli.global, a),
+        Cmd::Portal => portal::run(cli.global),
         #[cfg(feature = "it")]
         Cmd::RunTests => crate::it::run_tests(),
     }

src/dbus.rs

@@ -276,10 +276,8 @@ const ALLOW_INTERACTIVE_AUTHORIZATION: u8 = 0x4;
 pub const DBUS_NAME_FLAG_ALLOW_REPLACEMENT: u32 = 0x1;
 #[allow(dead_code)]
 pub const DBUS_NAME_FLAG_REPLACE_EXISTING: u32 = 0x2;
-#[allow(dead_code)]
 pub const DBUS_NAME_FLAG_DO_NOT_QUEUE: u32 = 0x4;
 
-#[allow(dead_code)]
 pub const DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER: u32 = 1;
 #[allow(dead_code)]
 pub const DBUS_REQUEST_NAME_REPLY_IN_QUEUE: u32 = 2;
@@ -604,7 +602,6 @@ impl Drop for DbusObject {
 }
 
 impl DbusObject {
-    #[allow(dead_code)]
     pub fn add_method<T, F>(&self, handler: F)
     where
         T: MethodCall<'static>,
@@ -623,7 +620,6 @@ impl DbusObject {
         self.data.methods.set(key, rhd);
     }
 
-    #[allow(dead_code)]
     pub fn set_property<T>(&self, value: Variant<'static>)
     where
         T: Property + 'static,
@@ -649,12 +645,10 @@ impl DbusObject {
         self.data.properties.set(key, phd);
     }
 
-    #[allow(dead_code)]
     pub fn emit_signal<'a, T: Signal<'a>>(&self, signal: &T) {
         self.socket.emit_signal(&self.data.path, signal);
     }
 
-    #[allow(dead_code)]
     pub fn path(&self) -> &str {
         &self.data.path
     }

src/dbus/socket.rs

@@ -43,7 +43,6 @@ impl DbusSocket {
         }
     }
 
-    #[allow(dead_code)]
     pub fn call_noreply<'a, T: MethodCall<'a>>(&self, destination: &str, path: &str, msg: T) {
         if !self.dead.get() {
             self.send_call(path, destination, NO_REPLY_EXPECTED, &msg);
@@ -135,7 +134,6 @@ impl DbusSocket {
         }
     }
 
-    #[allow(dead_code)]
     pub fn add_object(
         self: &Rc<Self>,
         object: impl Into<Cow<'static, str>>,
@@ -158,7 +156,6 @@ impl DbusSocket {
         }
     }
 
-    #[allow(dead_code)]
     pub fn handle_signal<T, F>(
         self: &Rc<Self>,
         sender: Option<&str>,
@@ -271,7 +268,6 @@ impl DbusSocket {
         );
     }
 
-    #[allow(dead_code)]
     pub fn emit_signal<'a, T: Signal<'a>>(&self, path: &str, msg: &T) -> u32 {
         let (msg, serial) = self.format_signal(path, msg);
         self.bufio.send(msg);

src/ifs/wl_seat.rs

@@ -76,7 +76,7 @@ use {
     uapi::{c, Errno, OwnedFd},
 };
 
-const POINTER: u32 = 1;
+pub const POINTER: u32 = 1;
 const KEYBOARD: u32 = 2;
 #[allow(dead_code)]
 const TOUCH: u32 = 4;

src/ifs/wl_seat/wl_pointer.rs

@@ -17,7 +17,7 @@ use {
 const ROLE: u32 = 0;
 
 pub(super) const RELEASED: u32 = 0;
-pub(super) const PRESSED: u32 = 1;
+pub const PRESSED: u32 = 1;
 
 pub const VERTICAL_SCROLL: u32 = 0;
 pub const HORIZONTAL_SCROLL: u32 = 1;

src/it/test_backend.rs

@@ -168,7 +168,7 @@ impl TestBackend {
             return Err(TestBackendError::NoDrmNode);
         };
         let file = match uapi::open(node.as_path(), c::O_RDWR | c::O_CLOEXEC, 0) {
-            Ok(f) => f,
+            Ok(f) => Rc::new(f),
             Err(e) => {
                 return Err(TestBackendError::OpenDrmNode(
                     node.as_os_str().as_bytes().as_bstr().to_string(),

src/macros.rs

@@ -174,6 +174,40 @@ macro_rules! id {
     };
 }
 
+macro_rules! shared_ids {
+    ($id:ident) => {
+        shared_ids!($id, u32);
+    };
+    ($id:ident, $ty:ty) => {
+        #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
+        pub struct $id($ty);
+
+        impl $id {
+            #[allow(dead_code)]
+            pub fn raw(&self) -> $ty {
+                self.0
+            }
+
+            #[allow(dead_code)]
+            pub fn from_raw(id: $ty) -> Self {
+                Self(id)
+            }
+        }
+
+        impl From<$ty> for $id {
+            fn from(id: $ty) -> Self {
+                Self(id)
+            }
+        }
+
+        impl std::fmt::Display for $id {
+            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                std::fmt::Display::fmt(&self.0, f)
+            }
+        }
+    };
+}
+
 macro_rules! linear_ids {
     ($ids:ident, $id:ident) => {
         linear_ids!($ids, $id, u32);

src/main.rs

@@ -60,6 +60,7 @@ mod logind;
 mod object;
 mod pango;
 mod pipewire;
+mod portal;
 mod rect;
 mod render;
 mod screenshoter;

src/pipewire.rs

@@ -1,5 +1,3 @@
-#![allow(dead_code)]
-
 pub mod pw_con;
 pub mod pw_formatter;
 pub mod pw_ifs;

src/pipewire/pw_mem.rs

@@ -41,6 +41,7 @@ pub struct PwMemTyped<T> {
     _phantom: PhantomData<T>,
 }
 
+#[allow(dead_code)]
 pub struct PwMemSlice {
     mem: Rc<PwMemMap>,
     range: Range<usize>,
@@ -134,6 +135,7 @@ impl PwMemMap {
 }
 
 impl<T: Pod> PwMemTyped<T> {
+    #[allow(dead_code)]
     pub unsafe fn read(&self) -> &T {
         (self.mem.map.ptr.cast::<u8>().add(self.offset) as *const T).deref()
     }

src/portal.rs

@@ -0,0 +1,161 @@
+mod ptl_display;
+mod ptl_render_ctx;
+mod ptl_screencast;
+mod ptr_gui;
+
+use {
+    crate::{
+        async_engine::{AsyncEngine, SpawnedFuture},
+        cli::GlobalArgs,
+        dbus::{
+            Dbus, DbusSocket, BUS_DEST, BUS_PATH, DBUS_NAME_FLAG_DO_NOT_QUEUE,
+            DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER,
+        },
+        io_uring::IoUring,
+        logger,
+        pipewire::pw_con::{PwCon, PwConHolder, PwConOwner},
+        portal::{
+            ptl_display::{watch_displays, PortalDisplay, PortalDisplayId},
+            ptl_render_ctx::PortalRenderCtx,
+            ptl_screencast::{add_screencast_dbus_members, ScreencastSession},
+        },
+        utils::{
+            copyhashmap::CopyHashMap, errorfmt::ErrorFmt, numcell::NumCell,
+            run_toplevel::RunToplevel, xrd::xrd,
+        },
+        wheel::Wheel,
+        wire_dbus::org,
+    },
+    std::{
+        cell::Cell,
+        rc::{Rc, Weak},
+    },
+    uapi::c,
+};
+
+const PORTAL_SUCCESS: u32 = 0;
+#[allow(dead_code)]
+const PORTAL_CANCELLED: u32 = 1;
+#[allow(dead_code)]
+const PORTAL_ENDED: u32 = 2;
+
+pub fn run(global: GlobalArgs) {
+    logger::Logger::install_stderr(global.log_level.into());
+    let xrd = match xrd() {
+        Some(xrd) => xrd,
+        _ => {
+            fatal!("XDG_RUNTIME_DIR is not set");
+        }
+    };
+    let eng = AsyncEngine::new();
+    let ring = match IoUring::new(&eng, 32) {
+        Ok(r) => r,
+        Err(e) => {
+            fatal!("Could not create an IO-uring: {}", ErrorFmt(e));
+        }
+    };
+    let wheel = match Wheel::new(&eng, &ring) {
+        Ok(w) => w,
+        Err(e) => {
+            fatal!("Could not create a timer wheel: {}", ErrorFmt(e));
+        }
+    };
+    let pw_con = match PwConHolder::new(&eng, &ring) {
+        Ok(p) => p,
+        Err(e) => {
+            fatal!("Could not connect to pipewire: {}", ErrorFmt(e));
+        }
+    };
+    let (_rtl_future, rtl) = RunToplevel::install(&eng);
+    let dbus = Dbus::new(&eng, &ring, &rtl);
+    let dbus = init_dbus_session(&dbus);
+    let state = Rc::new(PortalState {
+        xrd,
+        ring,
+        eng,
+        wheel,
+        pw_con: pw_con.con.clone(),
+        displays: Default::default(),
+        watch_displays: Cell::new(None),
+        dbus,
+        screencasts: Default::default(),
+        next_id: NumCell::new(1),
+        render_ctxs: Default::default(),
+    });
+    let _root = {
+        let obj = state
+            .dbus
+            .add_object("/org/freedesktop/portal/desktop")
+            .unwrap();
+        add_screencast_dbus_members(&state, &obj);
+        obj
+    };
+    state
+        .watch_displays
+        .set(Some(state.eng.spawn(watch_displays(state.clone()))));
+    state.pw_con.owner.set(Some(state.clone()));
+    if let Err(e) = state.ring.run() {
+        fatal!("The IO-uring returned an error: {}", ErrorFmt(e));
+    }
+}
+
+const UNIQUE_NAME: &str = "org.freedesktop.impl.portal.desktop.jay";
+
+fn init_dbus_session(dbus: &Dbus) -> Rc<DbusSocket> {
+    let session = match dbus.session() {
+        Ok(s) => s,
+        Err(e) => {
+            fatal!("Could not connect to dbus session daemon: {}", ErrorFmt(e));
+        }
+    };
+    session.call(
+        BUS_DEST,
+        BUS_PATH,
+        org::freedesktop::dbus::RequestName {
+            name: UNIQUE_NAME.into(),
+            flags: DBUS_NAME_FLAG_DO_NOT_QUEUE,
+        },
+        |rv| match rv {
+            Ok(r) if r.rv == DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER => {
+                log::info!("Acquired unique name {}", UNIQUE_NAME);
+                return;
+            }
+            Ok(r) => {
+                fatal!("Could not acquire unique name {}: {}", UNIQUE_NAME, r.rv);
+            }
+            Err(e) => {
+                fatal!(
+                    "Could not communicate with the session bus: {}",
+                    ErrorFmt(e)
+                );
+            }
+        },
+    );
+    session
+}
+
+struct PortalState {
+    xrd: String,
+    ring: Rc<IoUring>,
+    eng: Rc<AsyncEngine>,
+    wheel: Rc<Wheel>,
+    pw_con: Rc<PwCon>,
+    displays: CopyHashMap<PortalDisplayId, Rc<PortalDisplay>>,
+    watch_displays: Cell<Option<SpawnedFuture<()>>>,
+    dbus: Rc<DbusSocket>,
+    screencasts: CopyHashMap<String, Rc<ScreencastSession>>,
+    next_id: NumCell<u32>,
+    render_ctxs: CopyHashMap<c::dev_t, Weak<PortalRenderCtx>>,
+}
+
+impl PortalState {
+    pub fn id<T: From<u32>>(&self) -> T {
+        T::from(self.next_id.fetch_add(1))
+    }
+}
+
+impl PwConOwner for PortalState {
+    fn killed(&self) {
+        fatal!("The pipewire connection has been closed");
+    }
+}

src/portal/ptl_display.rs

@@ -0,0 +1,486 @@
+use {
+    crate::{
+        ifs::wl_seat::POINTER,
+        portal::{ptl_render_ctx::PortalRenderCtx, ptr_gui::WindowData, PortalState},
+        render::RenderContext,
+        utils::{
+            bitflags::BitflagsExt, clonecell::CloneCell, copyhashmap::CopyHashMap,
+            errorfmt::ErrorFmt, oserror::OsError,
+        },
+        video::drm::Drm,
+        wire::{
+            wl_pointer, JayCompositor, WlCompositor, WlOutput, WlSeat, WlSurfaceId,
+            WpFractionalScaleManagerV1, WpViewporter, ZwlrLayerShellV1, ZwpLinuxDmabufV1,
+        },
+        wl_usr::{
+            usr_ifs::{
+                usr_jay_compositor::UsrJayCompositor,
+                usr_jay_output::{UsrJayOutput, UsrJayOutputOwner},
+                usr_jay_pointer::UsrJayPointer,
+                usr_jay_render_ctx::UsrJayRenderCtxOwner,
+                usr_linux_dmabuf::UsrLinuxDmabuf,
+                usr_wl_compositor::UsrWlCompositor,
+                usr_wl_output::{UsrWlOutput, UsrWlOutputOwner},
+                usr_wl_pointer::{UsrWlPointer, UsrWlPointerOwner},
+                usr_wl_registry::{UsrWlRegistry, UsrWlRegistryOwner},
+                usr_wl_seat::{UsrWlSeat, UsrWlSeatOwner},
+                usr_wlr_layer_shell::UsrWlrLayerShell,
+                usr_wp_fractional_scale_manager::UsrWpFractionalScaleManager,
+                usr_wp_viewporter::UsrWpViewporter,
+            },
+            UsrCon, UsrConOwner,
+        },
+    },
+    ahash::AHashMap,
+    std::{
+        cell::{Cell, RefCell},
+        ops::Deref,
+        os::unix::ffi::OsStrExt,
+        rc::Rc,
+        str::FromStr,
+    },
+    uapi::{c, AsUstr, OwnedFd},
+};
+use crate::portal::ptl_screencast::ScreencastSession;
+
+struct PortalDisplayPrelude {
+    con: Rc<UsrCon>,
+    state: Rc<PortalState>,
+    registry: Rc<UsrWlRegistry>,
+    globals: RefCell<AHashMap<String, Vec<(u32, u32)>>>,
+}
+
+shared_ids!(PortalDisplayId);
+pub struct PortalDisplay {
+    pub id: PortalDisplayId,
+    pub con: Rc<UsrCon>,
+    pub(super) state: Rc<PortalState>,
+    registry: Rc<UsrWlRegistry>,
+    pub dmabuf: CloneCell<Option<Rc<UsrLinuxDmabuf>>>,
+
+    pub jc: Rc<UsrJayCompositor>,
+    pub ls: Rc<UsrWlrLayerShell>,
+    pub comp: Rc<UsrWlCompositor>,
+    pub fsm: Rc<UsrWpFractionalScaleManager>,
+    pub vp: Rc<UsrWpViewporter>,
+    pub render_ctx: CloneCell<Option<Rc<PortalRenderCtx>>>,
+
+    pub outputs: CopyHashMap<u32, Rc<PortalOutput>>,
+    pub seats: CopyHashMap<u32, Rc<PortalSeat>>,
+
+    pub windows: CopyHashMap<WlSurfaceId, Rc<WindowData>>,
+    pub screencasts: CopyHashMap<String, Rc<ScreencastSession>>,
+}
+
+pub struct PortalOutput {
+    pub global_id: u32,
+    pub dpy: Rc<PortalDisplay>,
+    pub wl: Rc<UsrWlOutput>,
+    pub jay: Rc<UsrJayOutput>,
+}
+
+pub struct PortalSeat {
+    pub global_id: u32,
+    pub dpy: Rc<PortalDisplay>,
+    pub wl: Rc<UsrWlSeat>,
+    pub jay_pointer: Rc<UsrJayPointer>,
+    pub pointer: CloneCell<Option<Rc<UsrWlPointer>>>,
+    pub name: RefCell<String>,
+    pub capabilities: Cell<u32>,
+    pub pointer_focus: CloneCell<Option<Rc<WindowData>>>,
+}
+
+impl UsrWlSeatOwner for PortalSeat {
+    fn name(&self, name: &str) {
+        *self.name.borrow_mut() = name.to_string();
+    }
+
+    fn capabilities(self: Rc<Self>, value: u32) {
+        let old = self.capabilities.replace(value);
+        if old.contains(POINTER) != value.contains(POINTER) {
+            if old.contains(POINTER) {
+                if let Some(pointer) = self.pointer.take() {
+                    pointer.con.remove_obj(pointer.deref());
+                }
+            } else {
+                let pointer = self.wl.get_pointer();
+                pointer.owner.set(Some(self.clone()));
+                self.pointer.set(Some(pointer));
+            }
+        }
+    }
+}
+
+impl UsrWlPointerOwner for PortalSeat {
+    fn enter(&self, ev: &wl_pointer::Enter) {
+        if let Some(window) = self.dpy.windows.get(&ev.surface) {
+            self.pointer_focus.set(Some(window.clone()));
+            window.motion(self, ev.surface_x, ev.surface_y, true);
+        }
+    }
+
+    fn leave(&self, _ev: &wl_pointer::Leave) {
+        self.pointer_focus.take();
+    }
+
+    fn motion(&self, ev: &wl_pointer::Motion) {
+        if let Some(window) = self.pointer_focus.get() {
+            window.motion(self, ev.surface_x, ev.surface_y, false);
+        }
+    }
+
+    fn button(&self, ev: &wl_pointer::Button) {
+        if let Some(window) = self.pointer_focus.get() {
+            window.button(self, ev.button, ev.state);
+        }
+    }
+}
+
+impl UsrWlRegistryOwner for PortalDisplayPrelude {
+    fn global(self: Rc<Self>, name: u32, interface: &str, version: u32) {
+        self.globals
+            .borrow_mut()
+            .entry(interface.to_string())
+            .or_default()
+            .push((name, version));
+    }
+}
+
+impl UsrJayRenderCtxOwner for PortalDisplay {
+    fn no_device(&self) {
+        self.render_ctx.take();
+    }
+
+    fn device(&self, fd: Rc<OwnedFd>) {
+        self.render_ctx.take();
+        let dev_id = match uapi::fstat(fd.raw()) {
+            Ok(s) => s.st_dev,
+            Err(e) => {
+                log::error!("Could not fstat display device: {}", ErrorFmt(e));
+                return;
+            }
+        };
+        if let Some(ctx) = self.state.render_ctxs.get(&dev_id) {
+            if let Some(ctx) = ctx.upgrade() {
+                self.render_ctx.set(Some(ctx));
+            }
+        }
+        if self.render_ctx.get().is_none() {
+            let drm = Drm::open_existing(fd);
+            let ctx = match RenderContext::from_drm_device(&drm) {
+                Ok(c) => c,
+                Err(e) => {
+                    log::error!(
+                        "Could not create render context from drm device: {}",
+                        ErrorFmt(e)
+                    );
+                    return;
+                }
+            };
+            let ctx = Rc::new(PortalRenderCtx {
+                dev_id,
+                ctx: Rc::new(ctx),
+            });
+            self.render_ctx.set(Some(ctx.clone()));
+            self.state.render_ctxs.set(dev_id, Rc::downgrade(&ctx));
+        }
+    }
+}
+
+impl UsrConOwner for PortalDisplay {
+    fn killed(&self) {
+        log::info!("Removing display {}", self.id);
+        for (_, sc) in self.screencasts.lock().drain() {
+            sc.kill();
+        }
+        self.windows.clear();
+        self.state.displays.remove(&self.id);
+    }
+}
+
+impl UsrWlRegistryOwner for PortalDisplay {
+    fn global(self: Rc<Self>, name: u32, interface: &str, version: u32) {
+        if interface == WlOutput.name() {
+            add_output(&self, name, version);
+        } else if interface == WlSeat.name() {
+            add_seat(&self, name, version);
+        } else if interface == ZwpLinuxDmabufV1.name() {
+            let ls = Rc::new(UsrLinuxDmabuf {
+                id: self.con.id(),
+                con: self.con.clone(),
+                owner: Default::default(),
+            });
+            self.con.add_object(ls.clone());
+            self.registry.request_bind(name, version, ls.deref());
+            self.dmabuf.set(Some(ls));
+        }
+    }
+}
+
+impl UsrJayOutputOwner for PortalOutput {
+    fn destroyed(&self) {
+        log::info!(
+            "Display {}: Output {} removed",
+            self.dpy.con.server_id,
+            self.global_id,
+        );
+        self.dpy.outputs.remove(&self.global_id);
+        self.dpy.con.remove_obj(self.wl.deref());
+        self.dpy.con.remove_obj(self.jay.deref());
+    }
+}
+
+impl UsrWlOutputOwner for PortalOutput {}
+
+fn maybe_add_display(state: &Rc<PortalState>, name: &str) {
+    let tail = match name.strip_prefix("wayland-") {
+        Some(t) => t,
+        _ => return,
+    };
+    let head = match tail.strip_suffix(".jay") {
+        Some(h) => h,
+        _ => return,
+    };
+    let num = match u32::from_str(head) {
+        Ok(n) => n,
+        _ => return,
+    };
+    let path = format!("{}/{}", state.xrd, name);
+    let con = match UsrCon::new(&state.ring, &state.wheel, &state.eng, &path, num) {
+        Ok(c) => c,
+        Err(e) => {
+            log::error!(
+                "Could not connect to wayland display {}: {}",
+                name,
+                ErrorFmt(e)
+            );
+            return;
+        }
+    };
+    let registry = con.get_registry();
+    let dpy = Rc::new(PortalDisplayPrelude {
+        con: con.clone(),
+        state: state.clone(),
+        registry,
+        globals: Default::default(),
+    });
+    dpy.registry.owner.set(Some(dpy.clone()));
+    con.sync(move || {
+        finish_display_connect(dpy);
+    });
+    log::info!("Connected to wayland display {num}: {name}");
+}
+
+fn finish_display_connect(dpy: Rc<PortalDisplayPrelude>) {
+    let mut jc_opt = None;
+    let mut ls_opt = None;
+    let mut fsm_opt = None;
+    let mut comp_opt = None;
+    let mut vp_opt = None;
+    let mut dmabuf_opt = None;
+    let mut outputs = vec![];
+    let mut seats = vec![];
+    for (interface, instances) in dpy.globals.borrow_mut().deref() {
+        for &(name, version) in instances {
+            if interface == JayCompositor.name() {
+                let jc = Rc::new(UsrJayCompositor {
+                    id: dpy.con.id(),
+                    con: dpy.con.clone(),
+                    owner: Default::default(),
+                });
+                dpy.con.add_object(jc.clone());
+                dpy.registry.request_bind(name, version, jc.deref());
+                jc_opt = Some(jc);
+            } else if interface == WpFractionalScaleManagerV1.name() {
+                let ls = Rc::new(UsrWpFractionalScaleManager {
+                    id: dpy.con.id(),
+                    con: dpy.con.clone(),
+                });
+                dpy.con.add_object(ls.clone());
+                dpy.registry.request_bind(name, version, ls.deref());
+                fsm_opt = Some(ls);
+            } else if interface == ZwlrLayerShellV1.name() {
+                let ls = Rc::new(UsrWlrLayerShell {
+                    id: dpy.con.id(),
+                    con: dpy.con.clone(),
+                });
+                dpy.con.add_object(ls.clone());
+                dpy.registry.request_bind(name, version, ls.deref());
+                ls_opt = Some(ls);
+            } else if interface == WpViewporter.name() {
+                let ls = Rc::new(UsrWpViewporter {
+                    id: dpy.con.id(),
+                    con: dpy.con.clone(),
+                });
+                dpy.con.add_object(ls.clone());
+                dpy.registry.request_bind(name, version, ls.deref());
+                vp_opt = Some(ls);
+            } else if interface == WlCompositor.name() {
+                let ls = Rc::new(UsrWlCompositor {
+                    id: dpy.con.id(),
+                    con: dpy.con.clone(),
+                });
+                dpy.con.add_object(ls.clone());
+                dpy.registry.request_bind(name, version, ls.deref());
+                comp_opt = Some(ls);
+            } else if interface == ZwpLinuxDmabufV1.name() {
+                let ls = Rc::new(UsrLinuxDmabuf {
+                    id: dpy.con.id(),
+                    con: dpy.con.clone(),
+                    owner: Default::default(),
+                });
+                dpy.con.add_object(ls.clone());
+                dpy.registry.request_bind(name, version, ls.deref());
+                dmabuf_opt = Some(ls);
+            } else if interface == WlOutput.name() {
+                outputs.push((name, version));
+            } else if interface == WlSeat.name() {
+                seats.push((name, version));
+            }
+        }
+    }
+    macro_rules! get {
+        ($opt:expr, $ty:expr) => {
+            match $opt {
+                Some(c) => c,
+                _ => {
+                    log::error!("Compositor did not advertise a {}", $ty.name());
+                    dpy.con.kill();
+                    return;
+                }
+            }
+        };
+    }
+    let jc = get!(jc_opt, JayCompositor);
+    let ls = get!(ls_opt, ZwlrLayerShellV1);
+    let comp = get!(comp_opt, WlCompositor);
+    let fsm = get!(fsm_opt, WpFractionalScaleManagerV1);
+    let vp = get!(vp_opt, WpViewporter);
+
+    let dpy = Rc::new(PortalDisplay {
+        id: dpy.state.id(),
+        con: dpy.con.clone(),
+        state: dpy.state.clone(),
+        registry: dpy.registry.clone(),
+        dmabuf: CloneCell::new(dmabuf_opt),
+        jc,
+        outputs: Default::default(),
+        render_ctx: Default::default(),
+        seats: Default::default(),
+        ls,
+        comp,
+        fsm,
+        vp,
+        windows: Default::default(),
+        screencasts: Default::default(),
+    });
+
+    dpy.state.displays.set(dpy.id, dpy.clone());
+    dpy.con.owner.set(Some(dpy.clone()));
+    dpy.registry.owner.set(Some(dpy.clone()));
+
+    let jrc = dpy.jc.get_render_context();
+    jrc.owner.set(Some(dpy.clone()));
+
+    for (name, version) in outputs {
+        add_output(&dpy, name, version);
+    }
+    for (name, version) in seats {
+        add_seat(&dpy, name, version);
+    }
+    log::info!("Display {} initialized", dpy.id);
+}
+
+fn add_seat(dpy: &Rc<PortalDisplay>, name: u32, version: u32) {
+    let wl = Rc::new(UsrWlSeat {
+        id: dpy.con.id(),
+        con: dpy.con.clone(),
+        owner: Default::default(),
+    });
+    dpy.con.add_object(wl.clone());
+    dpy.registry.request_bind(name, version, wl.deref());
+    let jay_pointer = dpy.jc.get_pointer(&wl);
+    let js = Rc::new(PortalSeat {
+        global_id: name,
+        dpy: dpy.clone(),
+        wl,
+        jay_pointer,
+        pointer: Default::default(),
+        name: RefCell::new("".to_string()),
+        capabilities: Cell::new(0),
+        pointer_focus: Default::default(),
+    });
+    js.wl.owner.set(Some(js.clone()));
+    dpy.seats.set(name, js);
+}
+
+fn add_output(dpy: &Rc<PortalDisplay>, name: u32, version: u32) {
+    let wl = Rc::new(UsrWlOutput {
+        id: dpy.con.id(),
+        con: dpy.con.clone(),
+        owner: Default::default(),
+    });
+    dpy.con.add_object(wl.clone());
+    dpy.registry.request_bind(name, version, wl.deref());
+    let jo = dpy.jc.get_output(&wl);
+    let po = Rc::new(PortalOutput {
+        global_id: name,
+        dpy: dpy.clone(),
+        wl: wl.clone(),
+        jay: jo.clone(),
+    });
+    po.wl.owner.set(Some(po.clone()));
+    po.jay.owner.set(Some(po.clone()));
+    dpy.outputs.set(name, po);
+}
+
+pub(super) async fn watch_displays(state: Rc<PortalState>) {
+    let inotify = Rc::new(uapi::inotify_init1(c::IN_CLOEXEC | c::IN_NONBLOCK).unwrap());
+    if let Err(e) = uapi::inotify_add_watch(inotify.raw(), state.xrd.as_str(), c::IN_CREATE) {
+        log::error!(
+            "Cannot watch directory `{}`: {}",
+            state.xrd,
+            ErrorFmt(OsError::from(e))
+        );
+        return;
+    }
+    let rd = match std::fs::read_dir(&state.xrd) {
+        Ok(rd) => rd,
+        Err(e) => {
+            log::error!("Cannot enumerate `{}`: {}", state.xrd, ErrorFmt(e));
+            return;
+        }
+    };
+    for entry in rd {
+        let entry = match entry {
+            Ok(e) => e,
+            Err(e) => {
+                log::error!("Cannot enumerate `{}`: {}", state.xrd, ErrorFmt(e));
+                return;
+            }
+        };
+        if let Ok(s) = std::str::from_utf8(entry.file_name().as_bytes()) {
+            maybe_add_display(&state, s);
+        }
+    }
+    let mut buf = vec![0u8; 4096];
+    loop {
+        if let Err(e) = state.ring.readable(&inotify).await {
+            log::error!("Cannot wait for `{}` to change: {}", state.xrd, ErrorFmt(e));
+        }
+        let events = match uapi::inotify_read(inotify.raw(), &mut buf[..]) {
+            Ok(s) => s,
+            Err(e) => {
+                log::error!("Could not read from inotify fd: {}", ErrorFmt(e));
+                return;
+            }
+        };
+        for event in events {
+            if event.mask.contains(c::IN_CREATE) {
+                if let Ok(s) = std::str::from_utf8(event.name().as_ustr().as_bytes()) {
+                    maybe_add_display(&state, s);
+                }
+            }
+        }
+    }
+}

src/portal/ptl_render_ctx.rs

@@ -0,0 +1,6 @@
+use {crate::render::RenderContext, std::rc::Rc, uapi::c};
+
+pub struct PortalRenderCtx {
+    pub dev_id: c::dev_t,
+    pub ctx: Rc<RenderContext>,
+}

src/portal/ptl_screencast.rs

@@ -0,0 +1,450 @@
+mod screencast_gui;
+
+use {
+    crate::{
+        dbus::{prelude::Variant, DbusObject, DictEntry, DynamicType, PendingReply},
+        pipewire::{
+            pw_ifs::pw_client_node::{
+                PwClientNode, PwClientNodeBufferConfig, PwClientNodeOwner, PwClientNodePort,
+                PwClientNodePortSupportedFormats, SUPPORTED_META_VIDEO_CROP,
+            },
+            pw_pod::{
+                spa_point, spa_rectangle, spa_region, PwPodRectangle, SPA_DATA_DmaBuf,
+                SPA_MEDIA_SUBTYPE_raw, SPA_MEDIA_TYPE_video, SpaChunkFlags, SPA_STATUS_HAVE_DATA,
+            },
+        },
+        portal::{
+            ptl_display::{PortalDisplay, PortalDisplayId, PortalOutput},
+            ptl_screencast::screencast_gui::SelectionGui,
+            PortalState, PORTAL_SUCCESS,
+        },
+        utils::{
+            clonecell::{CloneCell, UnsafeCellCloneSafe},
+            copyhashmap::CopyHashMap,
+        },
+        video::dmabuf::DmaBuf,
+        wire::jay_screencast::Ready,
+        wire_dbus::{
+            org,
+            org::freedesktop::impl_::portal::{
+                screen_cast::{
+                    CreateSession, CreateSessionReply, SelectSources, SelectSourcesReply, Start,
+                    StartReply,
+                },
+                session::{CloseReply as SessionCloseReply, Closed},
+            },
+        },
+        wl_usr::usr_ifs::usr_jay_screencast::{UsrJayScreencast, UsrJayScreencastOwner},
+    },
+    std::{
+        borrow::Cow,
+        cell::{Cell, RefCell},
+        ops::Deref,
+        rc::Rc,
+    },
+};
+
+shared_ids!(ScreencastSessionId);
+pub struct ScreencastSession {
+    _id: ScreencastSessionId,
+    state: Rc<PortalState>,
+    pub app: String,
+    session_obj: DbusObject,
+    pub phase: CloneCell<ScreencastPhase>,
+}
+
+#[derive(Clone)]
+pub enum ScreencastPhase {
+    Init,
+    SourcesSelected,
+    Selecting(Rc<SelectingScreencast>),
+    Starting(Rc<StartingScreencast>),
+    Started(Rc<StartedScreencast>),
+    Terminated,
+}
+
+unsafe impl UnsafeCellCloneSafe for ScreencastPhase {}
+
+pub struct SelectingScreencast {
+    pub session: Rc<ScreencastSession>,
+    pub request_obj: Rc<DbusObject>,
+    pub reply: Rc<PendingReply<StartReply<'static>>>,
+    pub guis: CopyHashMap<PortalDisplayId, Rc<SelectionGui>>,
+    pub output_selected: Cell<bool>,
+}
+
+pub struct StartingScreencast {
+    pub session: Rc<ScreencastSession>,
+    pub request_obj: Rc<DbusObject>,
+    pub reply: Rc<PendingReply<StartReply<'static>>>,
+    pub node: Rc<PwClientNode>,
+    pub dpy: Rc<PortalDisplay>,
+    pub output: Rc<PortalOutput>,
+}
+
+pub struct StartedScreencast {
+    session: Rc<ScreencastSession>,
+    node: Rc<PwClientNode>,
+    port: Rc<PwClientNodePort>,
+    buffers: RefCell<Vec<DmaBuf>>,
+    dpy: Rc<PortalDisplay>,
+    jay_screencast: Rc<UsrJayScreencast>,
+}
+
+bitflags! {
+    CursorModes: u32;
+
+    HIDDEN = 1,
+    EMBEDDED = 2,
+    METADATA = 4,
+}
+
+bitflags! {
+    SourceTypes: u32;
+
+    MONITOR = 1,
+    WINDOW = 2,
+}
+
+impl PwClientNodeOwner for StartingScreencast {
+    fn bound_id(&self, node_id: u32) {
+        {
+            let inner_type = DynamicType::DictEntry(
+                Box::new(DynamicType::String),
+                Box::new(DynamicType::Variant),
+            );
+            let kt = DynamicType::Struct(vec![
+                DynamicType::U32,
+                DynamicType::Array(Box::new(inner_type.clone())),
+            ]);
+            let variants = &[DictEntry {
+                key: "streams".into(),
+                value: Variant::Array(
+                    kt,
+                    vec![Variant::U32(node_id), Variant::Array(inner_type, vec![])],
+                ),
+            }];
+            self.reply.ok(&StartReply {
+                response: PORTAL_SUCCESS,
+                results: Cow::Borrowed(variants),
+            });
+        }
+        let port = self.node.create_port(true);
+        port.can_alloc_buffers.set(true);
+        port.supported_metas.set(SUPPORTED_META_VIDEO_CROP);
+        let jsc = self.dpy.jc.create_screencast();
+        jsc.set_output(&self.output.jay);
+        jsc.set_use_linear_buffers(true);
+        jsc.set_allow_all_workspaces(true);
+        jsc.configure();
+        let started = Rc::new(StartedScreencast {
+            session: self.session.clone(),
+            node: self.node.clone(),
+            port,
+            buffers: Default::default(),
+            dpy: self.dpy.clone(),
+            jay_screencast: jsc,
+        });
+        self.session
+            .phase
+            .set(ScreencastPhase::Started(started.clone()));
+        started.jay_screencast.owner.set(Some(started.clone()));
+        self.node.owner.set(Some(started.clone()));
+    }
+}
+
+impl PwClientNodeOwner for StartedScreencast {
+    fn port_format_changed(&self, port: &Rc<PwClientNodePort>) {
+        self.node.send_port_update(port);
+    }
+
+    fn use_buffers(&self, port: &Rc<PwClientNodePort>) {
+        self.node
+            .send_port_output_buffers(port, &self.buffers.borrow_mut());
+    }
+
+    fn start(self: Rc<Self>) {
+        self.jay_screencast.set_running(true);
+        self.jay_screencast.configure();
+    }
+
+    fn pause(self: Rc<Self>) {
+        self.jay_screencast.set_running(false);
+        self.jay_screencast.configure();
+    }
+
+    fn suspend(self: Rc<Self>) {
+        self.jay_screencast.set_running(false);
+        self.jay_screencast.configure();
+    }
+}
+
+impl ScreencastSession {
+    pub(super) fn kill(&self) {
+        self.session_obj.emit_signal(&Closed);
+        self.state.screencasts.remove(self.session_obj.path());
+        match self.phase.set(ScreencastPhase::Terminated) {
+            ScreencastPhase::Init => {}
+            ScreencastPhase::SourcesSelected => {}
+            ScreencastPhase::Terminated => {}
+            ScreencastPhase::Selecting(s) => {
+                s.reply.err("Session has been terminated");
+                for (_, gui) in s.guis.lock().drain() {
+                    gui.kill(false);
+                }
+            }
+            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());
+            }
+            ScreencastPhase::Started(s) => {
+                s.jay_screencast.con.remove_obj(s.jay_screencast.deref());
+                s.node.con.destroy_obj(s.node.deref());
+                s.dpy.screencasts.remove(self.session_obj.path());
+            }
+        }
+    }
+
+    fn dbus_select_sources(
+        self: &Rc<Self>,
+        _req: SelectSources,
+        reply: PendingReply<SelectSourcesReply<'static>>,
+    ) {
+        match self.phase.get() {
+            ScreencastPhase::Init => {}
+            _ => {
+                self.kill();
+                reply.err("Sources have already been selected");
+                return;
+            }
+        }
+        self.phase.set(ScreencastPhase::SourcesSelected);
+        reply.ok(&SelectSourcesReply {
+            response: PORTAL_SUCCESS,
+            results: Default::default(),
+        });
+    }
+
+    fn dbus_start(self: &Rc<Self>, req: Start<'_>, reply: PendingReply<StartReply<'static>>) {
+        match self.phase.get() {
+            ScreencastPhase::SourcesSelected => {}
+            _ => {
+                self.kill();
+                reply.err("Session is not in the correct phase for starting");
+                return;
+            }
+        }
+        let request_obj = match self.state.dbus.add_object(req.handle.to_string()) {
+            Ok(r) => r,
+            Err(_) => {
+                self.kill();
+                reply.err("Request handle is not unique");
+                return;
+            }
+        };
+        {
+            use org::freedesktop::impl_::portal::request::*;
+            request_obj.add_method::<Close, _>({
+                let slf = self.clone();
+                move |_, pr| {
+                    slf.kill();
+                    pr.ok(&CloseReply);
+                }
+            });
+        }
+        let guis = CopyHashMap::new();
+        for dpy in self.state.displays.lock().values() {
+            if dpy.outputs.len() > 0 {
+                guis.set(dpy.id, SelectionGui::new(self, dpy));
+            }
+        }
+        if guis.is_empty() {
+            self.kill();
+            reply.err("There are no running displays");
+            return;
+        }
+        self.phase
+            .set(ScreencastPhase::Selecting(Rc::new(SelectingScreencast {
+                session: self.clone(),
+                request_obj: Rc::new(request_obj),
+                reply: Rc::new(reply),
+                guis,
+                output_selected: Cell::new(false),
+            })));
+    }
+}
+
+impl UsrJayScreencastOwner for StartedScreencast {
+    fn buffers(&self, buffers: Vec<DmaBuf>) {
+        if buffers.len() == 0 {
+            return;
+        }
+        let buffer = &buffers[0];
+        *self.port.supported_formats.borrow_mut() = Some(PwClientNodePortSupportedFormats {
+            media_type: Some(SPA_MEDIA_TYPE_video),
+            media_sub_type: Some(SPA_MEDIA_SUBTYPE_raw),
+            video_size: Some(PwPodRectangle {
+                width: buffer.width as _,
+                height: buffer.height as _,
+            }),
+            formats: vec![buffer.format],
+            modifiers: vec![buffer.modifier],
+        });
+        let bc = PwClientNodeBufferConfig {
+            num_buffers: buffers.len(),
+            planes: buffer.planes.len(),
+            stride: Some(buffer.planes[0].stride),
+            size: Some(buffer.planes[0].stride * buffer.height as u32),
+            align: 16,
+            data_type: SPA_DATA_DmaBuf,
+        };
+        self.port.buffer_config.set(Some(bc));
+        self.node.send_port_update(&self.port);
+        self.node.send_active(true);
+        *self.buffers.borrow_mut() = buffers;
+    }
+
+    fn ready(&self, ev: &Ready) {
+        let idx = ev.idx as usize;
+        unsafe {
+            let mut used = false;
+            if let Some(io) = self.port.io_buffers.lock().values().next() {
+                let io = io.write();
+                if io.status != SPA_STATUS_HAVE_DATA {
+                    used = true;
+                    if io.buffer_id != ev.idx {
+                        if (io.buffer_id as usize) < self.buffers.borrow_mut().len() {
+                            self.jay_screencast.release_buffer(io.buffer_id as usize);
+                        }
+                    }
+                    io.buffer_id = ev.idx;
+                    io.status = SPA_STATUS_HAVE_DATA;
+                }
+            }
+            if !used {
+                self.jay_screencast.release_buffer(idx);
+            }
+            {
+                let pbuffers = self.port.buffers.borrow_mut();
+                let buffers = self.buffers.borrow_mut();
+                if let Some(pbuffer) = pbuffers.get(idx) {
+                    let buffer = &buffers[idx];
+                    for (chunk, plane) in pbuffer.chunks.iter().zip(buffer.planes.iter()) {
+                        let chunk = chunk.write();
+                        chunk.flags = SpaChunkFlags::none();
+                        chunk.offset = plane.offset;
+                        chunk.stride = plane.stride;
+                        chunk.size = plane.stride * buffer.height as u32;
+                    }
+                    if let Some(crop) = &pbuffer.meta_video_crop {
+                        crop.write().region = spa_region {
+                            position: spa_point { x: 0, y: 0 },
+                            size: spa_rectangle {
+                                width: buffer.width as _,
+                                height: buffer.height as _,
+                            },
+                        };
+                    }
+                }
+            }
+        }
+        if let Some(wfd) = self.port.node.transport_out.get() {
+            let _ = uapi::eventfd_write(wfd.raw(), 1);
+        }
+    }
+
+    fn destroyed(&self) {
+        self.session.kill();
+    }
+}
+
+pub(super) fn add_screencast_dbus_members(state_: &Rc<PortalState>, object: &DbusObject) {
+    use org::freedesktop::impl_::portal::screen_cast::*;
+    let state = state_.clone();
+    object.add_method::<CreateSession, _>(move |req, pr| {
+        dbus_create_session(&state, req, pr);
+    });
+    let state = state_.clone();
+    object.add_method::<SelectSources, _>(move |req, pr| {
+        dbus_select_sources(&state, req, pr);
+    });
+    let state = state_.clone();
+    object.add_method::<Start, _>(move |req, pr| {
+        dbus_start(&state, req, pr);
+    });
+    object.set_property::<AvailableSourceTypes>(Variant::U32(MONITOR.0));
+    object.set_property::<AvailableCursorModes>(Variant::U32(EMBEDDED.0));
+    object.set_property::<version>(Variant::U32(4));
+}
+
+fn dbus_create_session(
+    state: &Rc<PortalState>,
+    req: CreateSession,
+    reply: PendingReply<CreateSessionReply<'static>>,
+) {
+    log::info!("Create Session {:#?}", req);
+    if state.screencasts.contains(req.session_handle.0.deref()) {
+        reply.err("Session already exists");
+        return;
+    }
+    let obj = match state.dbus.add_object(req.session_handle.0.to_string()) {
+        Ok(obj) => obj,
+        Err(_) => {
+            reply.err("Session path is not unique");
+            return;
+        }
+    };
+    let session = Rc::new(ScreencastSession {
+        _id: state.id(),
+        state: state.clone(),
+        app: req.app_id.to_string(),
+        session_obj: obj,
+        phase: CloneCell::new(ScreencastPhase::Init),
+    });
+    {
+        use org::freedesktop::impl_::portal::session::*;
+        let ses = session.clone();
+        session.session_obj.add_method::<Close, _>(move |_, pr| {
+            ses.kill();
+            pr.ok(&SessionCloseReply);
+        });
+        session.session_obj.set_property::<version>(Variant::U32(4));
+    }
+    state
+        .screencasts
+        .set(req.session_handle.0.to_string(), session);
+    reply.ok(&CreateSessionReply {
+        response: PORTAL_SUCCESS,
+        results: Default::default(),
+    });
+}
+
+fn dbus_select_sources(
+    state: &Rc<PortalState>,
+    req: SelectSources,
+    reply: PendingReply<SelectSourcesReply<'static>>,
+) {
+    if let Some(s) = get_session(state, &reply, &req.session_handle.0) {
+        s.dbus_select_sources(req, reply);
+    }
+}
+
+fn dbus_start(state: &Rc<PortalState>, req: Start, reply: PendingReply<StartReply<'static>>) {
+    if let Some(s) = get_session(state, &reply, &req.session_handle.0) {
+        s.dbus_start(req, reply);
+    }
+}
+
+fn get_session<T>(
+    state: &Rc<PortalState>,
+    reply: &PendingReply<T>,
+    handle: &str,
+) -> Option<Rc<ScreencastSession>> {
+    let res = state.screencasts.get(handle);
+    if res.is_none() {
+        let msg = format!("Screencast session `{}` does not exist", handle);
+        reply.err(&msg);
+    }
+    res
+}

src/portal/ptl_screencast/screencast_gui.rs

@@ -0,0 +1,182 @@
+use {
+    crate::{
+        ifs::wl_seat::{wl_pointer::PRESSED, BTN_LEFT},
+        portal::{
+            ptl_display::{PortalDisplay, PortalOutput},
+            ptl_screencast::{ScreencastPhase, ScreencastSession, StartingScreencast},
+            ptr_gui::{
+                Align, Button, ButtonOwner, Flow, GuiElement, Label, Orientation, OverlayWindow,
+                OverlayWindowOwner,
+            },
+        },
+        theme::Color,
+        utils::copyhashmap::CopyHashMap,
+    },
+    std::rc::Rc,
+};
+
+const H_MARGIN: f32 = 30.0;
+const V_MARGIN: f32 = 20.0;
+
+pub struct SelectionGui {
+    screencast_session: Rc<ScreencastSession>,
+    dpy: Rc<PortalDisplay>,
+    surfaces: CopyHashMap<u32, Rc<SelectionGuiSurface>>,
+}
+
+pub struct SelectionGuiSurface {
+    gui: Rc<SelectionGui>,
+    output: Rc<PortalOutput>,
+    overlay: Rc<OverlayWindow>,
+}
+
+struct StaticButton {
+    surface: Rc<SelectionGuiSurface>,
+    role: ButtonRole,
+}
+
+#[derive(Copy, Clone, Eq, PartialEq)]
+enum ButtonRole {
+    Accept,
+    Reject,
+}
+
+impl SelectionGui {
+    pub fn kill(&self, upwards: bool) {
+        for (_, surface) in self.surfaces.lock().drain() {
+            surface.overlay.data.kill(false);
+        }
+        if let ScreencastPhase::Selecting(s) = self.screencast_session.phase.get() {
+            s.guis.remove(&self.dpy.id);
+            if upwards && s.guis.is_empty() {
+                self.screencast_session.kill();
+            }
+        }
+    }
+}
+
+fn create_accept_gui(surface: &Rc<SelectionGuiSurface>) -> Rc<dyn GuiElement> {
+    let app = &surface.gui.screencast_session.app;
+    let text = if app.is_empty() {
+        format!("An application wants to capture the screen")
+    } else {
+        format!("`{}` wants to capture the screen", app)
+    };
+    let label = Rc::new(Label::default());
+    *label.text.borrow_mut() = text;
+    let accept_button = static_button(surface, ButtonRole::Accept, "Share This Output");
+    let reject_button = static_button(surface, ButtonRole::Reject, "Reject");
+    let buttons = [&accept_button, &reject_button];
+    for button in buttons {
+        button.border_color.set(Color::from_gray(100));
+        button.border.set(2.0);
+        button.padding.set(5.0);
+    }
+    accept_button.bg_color.set(Color::from_rgb(170, 200, 170));
+    accept_button
+        .bg_hover_color
+        .set(Color::from_rgb(170, 255, 170));
+    reject_button.bg_color.set(Color::from_rgb(200, 170, 170));
+    reject_button
+        .bg_hover_color
+        .set(Color::from_rgb(255, 170, 170));
+    let flow = Rc::new(Flow::default());
+    flow.orientation.set(Orientation::Vertical);
+    flow.cross_align.set(Align::Center);
+    flow.in_margin.set(V_MARGIN);
+    flow.cross_margin.set(H_MARGIN);
+    *flow.elements.borrow_mut() = vec![label, accept_button, reject_button];
+    flow
+}
+
+impl OverlayWindowOwner for SelectionGuiSurface {
+    fn kill(&self, upwards: bool) {
+        self.gui.dpy.windows.remove(&self.overlay.data.surface.id);
+        self.gui.surfaces.remove(&self.output.global_id);
+        if upwards && self.gui.surfaces.is_empty() {
+            self.gui.kill(true);
+        }
+    }
+}
+
+impl SelectionGui {
+    pub fn new(ss: &Rc<ScreencastSession>, dpy: &Rc<PortalDisplay>) -> Rc<Self> {
+        let gui = Rc::new(SelectionGui {
+            screencast_session: ss.clone(),
+            dpy: dpy.clone(),
+            surfaces: Default::default(),
+        });
+        for output in dpy.outputs.lock().values() {
+            let sgs = Rc::new(SelectionGuiSurface {
+                gui: gui.clone(),
+                output: output.clone(),
+                overlay: OverlayWindow::new(output),
+            });
+            let element = create_accept_gui(&sgs);
+            sgs.overlay.data.content.set(Some(element));
+            gui.dpy
+                .windows
+                .set(sgs.overlay.data.surface.id, sgs.overlay.data.clone());
+            gui.surfaces.set(output.global_id, sgs);
+        }
+        gui
+    }
+}
+
+impl ButtonOwner for StaticButton {
+    fn button(&self, button: u32, state: u32) {
+        if button != BTN_LEFT || state != PRESSED {
+            return;
+        }
+        match self.role {
+            ButtonRole::Accept => {
+                log::info!("User has accepted the request");
+                let selecting = match self.surface.gui.screencast_session.phase.get() {
+                    ScreencastPhase::Selecting(selecting) => selecting,
+                    _ => return,
+                };
+                for (_, gui) in selecting.guis.lock().drain() {
+                    gui.kill(false);
+                }
+                let node = self.surface.gui.dpy.state.pw_con.create_client_node(&[
+                    ("media.class".to_string(), "Video/Source".to_string()),
+                    ("node.name".to_string(), "jay-desktop-portal".to_string()),
+                    ("node.driver".to_string(), "true".to_string()),
+                ]);
+                let starting = Rc::new(StartingScreencast {
+                    session: self.surface.gui.screencast_session.clone(),
+                    request_obj: selecting.request_obj.clone(),
+                    reply: selecting.reply.clone(),
+                    node,
+                    dpy: self.surface.gui.dpy.clone(),
+                    output: self.surface.output.clone(),
+                });
+                self.surface
+                    .gui
+                    .screencast_session
+                    .phase
+                    .set(ScreencastPhase::Starting(starting.clone()));
+                starting.node.owner.set(Some(starting.clone()));
+                self.surface.gui.dpy.screencasts.set(
+                    self.surface.gui.screencast_session.session_obj.path().to_owned(),
+                    self.surface.gui.screencast_session.clone(),
+                );
+            }
+            ButtonRole::Reject => {
+                log::info!("User has rejected the screencast request");
+                self.surface.gui.screencast_session.kill();
+            }
+        }
+    }
+}
+
+fn static_button(surface: &Rc<SelectionGuiSurface>, role: ButtonRole, text: &str) -> Rc<Button> {
+    let button = Rc::new(Button::default());
+    let slf = Rc::new(StaticButton {
+        surface: surface.clone(),
+        role,
+    });
+    button.owner.set(Some(slf));
+    *button.text.borrow_mut() = text.to_string();
+    button
+}

src/portal/ptr_gui.rs

@@ -0,0 +1,876 @@
+use {
+    crate::{
+        async_engine::{Phase, SpawnedFuture},
+        cursor::KnownCursor,
+        fixed::Fixed,
+        format::ARGB8888,
+        ifs::zwlr_layer_shell_v1::OVERLAY,
+        portal::ptl_display::{PortalDisplay, PortalOutput, PortalSeat},
+        render::{Framebuffer, RenderContext, RendererBase, Texture},
+        text::{self, TextMeasurement},
+        theme::Color,
+        utils::{
+            asyncevent::AsyncEvent, clonecell::CloneCell, copyhashmap::CopyHashMap,
+            errorfmt::ErrorFmt, rc_eq::rc_eq,
+        },
+        video::{gbm::GBM_BO_USE_RENDERING, ModifiedFormat, INVALID_MODIFIER},
+        wire::{
+            wp_fractional_scale_v1::PreferredScale, zwlr_layer_surface_v1::Configure,
+            ZwpLinuxBufferParamsV1Id,
+        },
+        wl_usr::usr_ifs::{
+            usr_linux_buffer_params::{UsrLinuxBufferParams, UsrLinuxBufferParamsOwner},
+            usr_wl_buffer::{UsrWlBuffer, UsrWlBufferOwner},
+            usr_wl_surface::UsrWlSurface,
+            usr_wlr_layer_surface::{UsrWlrLayerSurface, UsrWlrLayerSurfaceOwner},
+            usr_wp_fractional_scale::{UsrWpFractionalScale, UsrWpFractionalScaleOwner},
+            usr_wp_viewport::UsrWpViewport,
+        },
+    },
+    ahash::AHashSet,
+    std::{
+        borrow::Cow,
+        cell::{Cell, RefCell},
+        ops::Deref,
+        rc::Rc,
+    },
+};
+
+#[derive(Default)]
+pub struct GuiElementData {
+    pub x: Cell<f32>,
+    pub y: Cell<f32>,
+    pub width: Cell<f32>,
+    pub height: Cell<f32>,
+}
+
+pub trait GuiElement {
+    fn data(&self) -> &GuiElementData;
+    fn layout(
+        &self,
+        ctx: &Rc<RenderContext>,
+        scale: f32,
+        max_width: f32,
+        max_height: f32,
+    ) -> (f32, f32);
+    fn render_at(&self, r: &mut RendererBase, x: f32, y: f32);
+    fn child_at(&self, x: f32, y: f32) -> Option<Rc<dyn GuiElement>>;
+
+    fn hover_cursor(&self) -> KnownCursor {
+        KnownCursor::Default
+    }
+
+    fn button(&self, seat: &PortalSeat, button: u32, state: u32) {
+        let _ = seat;
+        let _ = button;
+        let _ = state;
+    }
+
+    fn hover(&self, seat: &PortalSeat, hover: bool) -> bool {
+        let _ = seat;
+        let _ = hover;
+        false
+    }
+
+    fn destroy(&self) {}
+}
+
+#[derive(Copy, Clone, Debug, Default)]
+pub struct ButtonExtents {
+    pub width: f32,
+    pub height: f32,
+    pub tex_off_x: f32,
+    pub tex_off_y: f32,
+}
+
+pub fn button_extents(
+    msmt: &TextMeasurement,
+    scale: f32,
+    padding: f32,
+    border: f32,
+) -> ButtonExtents {
+    let above_baseline_height =
+        (msmt.baseline - msmt.ink_rect.y1().max(msmt.logical_rect.y1())) as f32 / scale;
+    let height = above_baseline_height + 2.0 * (padding + border);
+    let width = msmt.ink_rect.width() as f32 / scale + 2.0 * (padding + border);
+    let tex_off_x = padding + border;
+    // let tex_off_y = ((msmt.ink_rect.y1() - msmt.logical_rect.y1()) as f64 / scale).round() as i32 + padding + border;
+    let tex_off_y = padding + border;
+    ButtonExtents {
+        width,
+        height,
+        tex_off_x,
+        tex_off_y,
+    }
+}
+
+pub struct Button {
+    pub data: GuiElementData,
+    pub tex_off_x: Cell<f32>,
+    pub tex_off_y: Cell<f32>,
+    pub hover: RefCell<AHashSet<u32>>,
+    pub padding: Cell<f32>,
+    pub border: Cell<f32>,
+    pub border_color: Cell<Color>,
+    pub bg_color: Cell<Color>,
+    pub bg_hover_color: Cell<Color>,
+    pub text: RefCell<String>,
+    pub font: RefCell<Cow<'static, str>>,
+    pub tex: CloneCell<Option<Rc<Texture>>>,
+    pub owner: CloneCell<Option<Rc<dyn ButtonOwner>>>,
+}
+
+pub trait ButtonOwner {
+    fn button(&self, button: u32, state: u32);
+}
+
+impl Default for Button {
+    fn default() -> Self {
+        Self {
+            data: Default::default(),
+            tex_off_x: Cell::new(0.0),
+            tex_off_y: Cell::new(0.0),
+            hover: Default::default(),
+            padding: Default::default(),
+            border: Default::default(),
+            border_color: Cell::new(Color::from_gray(0)),
+            bg_color: Cell::new(Color::from_gray(255)),
+            bg_hover_color: Cell::new(Color::from_gray(255)),
+            text: Default::default(),
+            font: RefCell::new(DEFAULT_FONT.into()),
+            tex: Default::default(),
+            owner: Default::default(),
+        }
+    }
+}
+
+impl GuiElement for Button {
+    fn hover_cursor(&self) -> KnownCursor {
+        KnownCursor::Pointer
+    }
+
+    fn data(&self) -> &GuiElementData {
+        &self.data
+    }
+
+    fn layout(
+        &self,
+        ctx: &Rc<RenderContext>,
+        scale: f32,
+        _max_width: f32,
+        _max_height: f32,
+    ) -> (f32, f32) {
+        let font = self.font.borrow_mut();
+        let text = self.text.borrow_mut();
+        let tex = text::render_fitting2(
+            ctx,
+            None,
+            &font,
+            &text,
+            Color::from_gray(0),
+            false,
+            Some(scale as _),
+            true,
+        )
+        .ok();
+        let (tex, msmt) = match tex {
+            Some((a, b)) => (Some(a), Some(b)),
+            _ => (None, None),
+        };
+        let extents = match msmt {
+            Some(m) => button_extents(&m, scale, self.padding.get(), self.border.get()),
+            _ => Default::default(),
+        };
+        self.tex.set(tex);
+        self.tex_off_x.set(extents.tex_off_x);
+        self.tex_off_y.set(extents.tex_off_y);
+        (extents.width, extents.height)
+    }
+
+    fn render_at(&self, r: &mut RendererBase, x1: f32, y1: f32) {
+        let x2 = x1 + self.data.width.get();
+        let y2 = y1 + self.data.height.get();
+        let border = self.border.get();
+        {
+            let rects = [
+                (x1, y1, x2, y1 + border),
+                (x1, y2 - border, x2, y2),
+                (x1, y1 + border, x1 + border, y2 - border),
+                (x2 - border, y1 + border, x2, y2 - border),
+            ];
+            r.fill_boxes_f(&rects, &self.border_color.get());
+        }
+        {
+            let rects = [(x1 + border, y1 + border, x2 - border, y2 - border)];
+            let color = match self.hover.borrow_mut().is_empty() {
+                true => self.bg_color.get(),
+                false => self.bg_hover_color.get(),
+            };
+            r.fill_boxes_f(&rects, &color);
+        }
+        if let Some(tex) = self.tex.get() {
+            let (tx, ty) =
+                r.scale_point_f(x1 + self.tex_off_x.get(), y1 as f32 + self.tex_off_y.get());
+            r.render_texture(
+                &tex,
+                tx.round() as _,
+                ty.round() as _,
+                ARGB8888,
+                None,
+                None,
+                r.scale(),
+            );
+        }
+    }
+
+    fn child_at(&self, _x: f32, _y: f32) -> Option<Rc<dyn GuiElement>> {
+        None
+    }
+
+    fn hover(&self, seat: &PortalSeat, hover: bool) -> bool {
+        let ret;
+        let mut set = self.hover.borrow_mut();
+        if hover {
+            ret = set.is_empty();
+            set.insert(seat.global_id);
+        } else {
+            set.remove(&seat.global_id);
+            ret = set.is_empty();
+        }
+        ret
+    }
+
+    fn destroy(&self) {
+        self.owner.take();
+    }
+
+    fn button(&self, _seat: &PortalSeat, button: u32, state: u32) {
+        if let Some(owner) = self.owner.get() {
+            owner.button(button, state);
+        }
+    }
+}
+
+const DEFAULT_FONT: &str = "sans-serif 16";
+
+pub struct Label {
+    pub data: GuiElementData,
+    pub font: RefCell<Cow<'static, str>>,
+    pub text: RefCell<String>,
+    pub tex: CloneCell<Option<Rc<Texture>>>,
+}
+
+impl Default for Label {
+    fn default() -> Self {
+        Self {
+            data: Default::default(),
+            font: RefCell::new(DEFAULT_FONT.into()),
+            text: RefCell::new("".to_string()),
+            tex: Default::default(),
+        }
+    }
+}
+
+impl GuiElement for Label {
+    fn data(&self) -> &GuiElementData {
+        &self.data
+    }
+
+    fn layout(
+        &self,
+        ctx: &Rc<RenderContext>,
+        scale: f32,
+        _max_width: f32,
+        _max_height: f32,
+    ) -> (f32, f32) {
+        let text = self.text.borrow_mut();
+        let font = self.font.borrow_mut();
+        let tex = text::render_fitting2(
+            ctx,
+            None,
+            &font,
+            &text,
+            Color::from_gray(255),
+            false,
+            Some(scale as _),
+            false,
+        )
+        .ok();
+        let (tex, width, height) = match tex {
+            Some((t, _)) => (Some(t.clone()), t.width(), t.height()),
+            _ => (None, 0, 0),
+        };
+        self.tex.set(tex);
+        (width as f32 / scale, height as f32 / scale)
+    }
+
+    fn render_at(&self, r: &mut RendererBase, x: f32, y: f32) {
+        if let Some(tex) = self.tex.get() {
+            let (tx, ty) = r.scale_point_f(x, y);
+            r.render_texture(
+                &tex,
+                tx.round() as _,
+                ty.round() as _,
+                ARGB8888,
+                None,
+                None,
+                r.scale(),
+            );
+        }
+    }
+
+    fn child_at(&self, _x: f32, _y: f32) -> Option<Rc<dyn GuiElement>> {
+        None
+    }
+}
+
+#[derive(Copy, Clone, Eq, PartialEq, Default)]
+pub enum Align {
+    #[allow(dead_code)]
+    Left,
+    #[default]
+    Center,
+    #[allow(dead_code)]
+    Right,
+}
+
+#[derive(Copy, Clone, Eq, PartialEq, Default)]
+pub enum Orientation {
+    #[default]
+    Horizontal,
+    #[allow(dead_code)]
+    Vertical,
+}
+
+#[derive(Default)]
+pub struct Flow {
+    pub data: GuiElementData,
+    pub in_margin: Cell<f32>,
+    pub cross_margin: Cell<f32>,
+    pub orientation: Cell<Orientation>,
+    pub cross_align: Cell<Align>,
+    pub elements: RefCell<Vec<Rc<dyn GuiElement>>>,
+}
+
+impl GuiElement for Flow {
+    fn data(&self) -> &GuiElementData {
+        &self.data
+    }
+
+    fn layout(
+        &self,
+        ctx: &Rc<RenderContext>,
+        scale: f32,
+        max_width: f32,
+        max_height: f32,
+    ) -> (f32, f32) {
+        let elements = self.elements.borrow_mut();
+        let orientation = self.orientation.get();
+        let (max_in_size, _max_cross_size) = match orientation {
+            Orientation::Horizontal => (max_width, max_height),
+            Orientation::Vertical => (max_height, max_width),
+        };
+        let mut runs = vec![];
+        let mut run = vec![];
+        let cross_margin = self.cross_margin.get();
+        let in_margin = self.in_margin.get();
+        {
+            let mut run_cross_size: f32 = 0.0;
+            let mut in_pos = in_margin;
+            for element in elements.deref() {
+                let (w, h) = element.layout(ctx, scale, max_width, max_height);
+                let (cur_in_size, cur_cross_size) = match orientation {
+                    Orientation::Horizontal => (w, h),
+                    Orientation::Vertical => (h, w),
+                };
+                if in_pos + cur_in_size > max_in_size && run.len() > 0 {
+                    runs.push((run, run_cross_size));
+                    run = vec![];
+                    in_pos = in_margin;
+                    run_cross_size = 0.0;
+                }
+                run_cross_size = run_cross_size.max(cur_cross_size);
+                run.push((element, cur_in_size, cur_cross_size));
+                in_pos += cur_in_size + in_margin;
+            }
+            if run.len() > 0 {
+                runs.push((run, run_cross_size));
+            }
+        }
+        let mut max_in_pos: f32 = 0.0;
+        let mut cross_pos = cross_margin;
+        for (run, run_cross_size) in runs {
+            let mut in_pos = in_margin;
+            for (element, cur_in_size, cur_cross_size) in run {
+                let cur_cross_pos = cross_pos
+                    + match self.cross_align.get() {
+                        Align::Left => 0.0,
+                        Align::Center => (run_cross_size - cur_cross_size) / 2.0,
+                        Align::Right => run_cross_size - cur_cross_size,
+                    };
+                let (x, y, w, h) = match orientation {
+                    Orientation::Horizontal => (in_pos, cur_cross_pos, cur_in_size, cur_cross_size),
+                    Orientation::Vertical => (cur_cross_pos, in_pos, cur_cross_size, cur_in_size),
+                };
+                element.data().x.set(x);
+                element.data().y.set(y);
+                element.data().width.set(w);
+                element.data().height.set(h);
+                in_pos += in_margin + cur_in_size;
+            }
+            max_in_pos = max_in_pos.max(in_pos);
+            cross_pos += cross_margin + run_cross_size;
+        }
+        let (w, h) = match orientation {
+            Orientation::Horizontal => (max_in_pos, cross_pos),
+            Orientation::Vertical => (cross_pos, max_in_pos),
+        };
+        (w.min(max_width), h.min(max_height))
+    }
+
+    fn render_at(&self, r: &mut RendererBase, x: f32, y: f32) {
+        for element in self.elements.borrow_mut().deref() {
+            element.render_at(r, x + element.data().x.get(), y + element.data().y.get());
+        }
+    }
+
+    fn child_at(&self, x: f32, y: f32) -> Option<Rc<dyn GuiElement>> {
+        for child in self.elements.borrow_mut().deref() {
+            let data = child.data();
+            let x1 = data.x.get();
+            let y1 = data.y.get();
+            if x >= x1 && x - x1 < data.width.get() && y >= y1 && y - y1 < data.height.get() {
+                return Some(child.clone());
+            }
+        }
+        None
+    }
+
+    fn destroy(&self) {
+        for element in self.elements.borrow_mut().drain(..) {
+            element.destroy();
+        }
+    }
+}
+
+pub struct OverlayWindow {
+    pub layer_surface: Rc<UsrWlrLayerSurface>,
+    pub data: Rc<WindowData>,
+    pub owner: CloneCell<Option<Rc<dyn OverlayWindowOwner>>>,
+}
+
+pub trait OverlayWindowOwner {
+    fn kill(&self, upwards: bool);
+}
+
+pub struct WindowData {
+    pub frame_missed: Cell<bool>,
+    pub first_scale: Cell<bool>,
+    pub have_frame: Cell<bool>,
+    pub scale: Cell<Fixed>,
+    pub render_trigger: AsyncEvent,
+    pub render_task: Cell<Option<SpawnedFuture<()>>>,
+    pub dpy: Rc<PortalDisplay>,
+    pub content: CloneCell<Option<Rc<dyn GuiElement>>>,
+    pub surface: Rc<UsrWlSurface>,
+    pub viewport: Rc<UsrWpViewport>,
+    pub fractional_scale: Rc<UsrWpFractionalScale>,
+    pub bufs: RefCell<Vec<Rc<GuiBuffer>>>,
+    pending_bufs: CopyHashMap<ZwpLinuxBufferParamsV1Id, Rc<GuiBufferPending>>,
+    pub width: Cell<i32>,
+    pub height: Cell<i32>,
+    pub owner: CloneCell<Option<Rc<dyn WindowDataOwner>>>,
+    pub seats: CopyHashMap<u32, Rc<GuiWindowSeatState>>,
+}
+
+#[derive(Default)]
+pub struct GuiWindowSeatState {
+    pub x: Cell<f32>,
+    pub y: Cell<f32>,
+    pub tree: RefCell<Vec<Rc<dyn GuiElement>>>,
+    pub cursor: Cell<Option<KnownCursor>>,
+}
+
+pub trait WindowDataOwner {
+    fn post_layout(&self);
+    fn kill(&self, upwards: bool);
+}
+
+impl WindowDataOwner for OverlayWindow {
+    fn post_layout(&self) {
+        self.layer_surface
+            .set_size(self.data.width.get(), self.data.height.get());
+        self.data.surface.commit();
+    }
+
+    fn kill(&self, upwards: bool) {
+        if let Some(owner) = self.owner.take() {
+            owner.kill(upwards);
+        }
+        self.layer_surface
+            .con
+            .remove_obj(self.layer_surface.deref());
+    }
+}
+
+const NUM_BUFFERS: usize = 2;
+
+impl OverlayWindow {
+    pub fn new(output: &Rc<PortalOutput>) -> Rc<Self> {
+        let data = WindowData::new(&output.dpy);
+        let layer_surface = output
+            .dpy
+            .ls
+            .get_layer_surface(&data.surface, &output.wl, OVERLAY);
+        layer_surface.set_size(1, 1);
+        let slf = Rc::new(Self {
+            layer_surface,
+            data,
+            owner: Default::default(),
+        });
+        slf.data.owner.set(Some(slf.clone()));
+        slf.layer_surface.owner.set(Some(slf.clone()));
+        slf.data.surface.commit();
+        slf
+    }
+}
+
+impl WindowData {
+    pub fn schedule_render(&self) {
+        self.render_trigger.trigger();
+    }
+
+    pub fn new(dpy: &Rc<PortalDisplay>) -> Rc<Self> {
+        let surface = dpy.comp.create_surface();
+        let viewport = dpy.vp.get_viewport(&surface);
+        let fractional_scale = dpy.fsm.get_fractional_scale(&surface);
+        viewport.set_destination(1, 1);
+        let data = Rc::new(WindowData {
+            frame_missed: Cell::new(false),
+            first_scale: Cell::new(true),
+            have_frame: Cell::new(true),
+            bufs: Default::default(),
+            pending_bufs: Default::default(),
+            width: Cell::new(0),
+            height: Cell::new(0),
+            owner: Default::default(),
+            render_trigger: Default::default(),
+            render_task: Cell::new(None),
+            dpy: dpy.clone(),
+            content: Default::default(),
+            surface,
+            viewport,
+            scale: Cell::new(Fixed::from_int(1)),
+            fractional_scale,
+            seats: Default::default(),
+        });
+        data.render_task.set(Some(
+            dpy.state
+                .eng
+                .spawn2(Phase::Present, data.clone().render_task()),
+        ));
+        data.fractional_scale.owner.set(Some(data.clone()));
+        data
+    }
+
+    pub fn layout(&self) {
+        let ctx = match self.dpy.render_ctx.get() {
+            Some(ctx) => ctx,
+            _ => return,
+        };
+        let scale = self.scale.get().to_f64() as f32;
+        let content = match self.content.get() {
+            Some(c) => c,
+            _ => return,
+        };
+        let (mut width, mut height) = content.layout(&ctx.ctx, scale, f32::INFINITY, f32::INFINITY);
+        content.data().width.set(width);
+        content.data().height.set(height);
+        width = width.max(1.0);
+        height = height.max(1.0);
+        self.width.set(width.round() as _);
+        self.height.set(height.round() as _);
+        self.viewport
+            .set_destination(width.round() as _, height.round() as _);
+        if let Some(owner) = self.owner.get() {
+            owner.post_layout();
+        }
+    }
+
+    async fn render_task(self: Rc<Self>) {
+        loop {
+            self.render_trigger.triggered().await;
+            self.render();
+        }
+    }
+
+    fn render(self: &Rc<Self>) {
+        self.frame_missed.set(true);
+        if !self.have_frame.get() {
+            return;
+        }
+        let bufs = self.bufs.borrow_mut();
+        let buf = 'get_buf: {
+            for buf in bufs.deref() {
+                if buf.free.get() {
+                    break 'get_buf buf;
+                }
+            }
+            return;
+        };
+        self.frame_missed.set(false);
+
+        self.surface.frame({
+            let slf = self.clone();
+            move || {
+                slf.have_frame.set(true);
+                if slf.frame_missed.get() {
+                    slf.schedule_render();
+                }
+            }
+        });
+
+        self.have_frame.set(false);
+        buf.free.set(false);
+
+        buf.fb.render_custom(self.scale.get(), |r| {
+            r.clear(&Color::from_gray(0));
+            if let Some(content) = self.content.get() {
+                content.render_at(r, 0.0, 0.0)
+            }
+        });
+
+        self.surface.attach(&buf.wl);
+        self.surface.commit();
+    }
+
+    pub fn kill(&self, upwards: bool) {
+        if let Some(owner) = self.owner.take() {
+            owner.kill(upwards);
+        }
+        self.render_task.take();
+        for (_, pb) in self.pending_bufs.lock().drain() {
+            pb.params.con.remove_obj(pb.params.deref());
+        }
+        for buf in self.bufs.borrow_mut().drain(..) {
+            buf.wl.con.remove_obj(buf.wl.deref());
+        }
+        self.fractional_scale
+            .con
+            .remove_obj(self.fractional_scale.deref());
+        self.viewport.con.remove_obj(self.viewport.deref());
+        self.surface.con.remove_obj(self.surface.deref());
+        if let Some(content) = self.content.take() {
+            content.destroy();
+        }
+    }
+
+    pub fn allocate_buffers(self: &Rc<Self>) {
+        {
+            for (_, buf) in self.pending_bufs.lock().drain() {
+                buf.params.con.remove_obj(buf.params.deref());
+            }
+        }
+        {
+            let mut bufs = self.bufs.borrow_mut();
+            for buf in bufs.drain(..) {
+                buf.wl.con.remove_obj(buf.wl.deref());
+            }
+        }
+        let ctx = match self.dpy.render_ctx.get() {
+            Some(ctx) => ctx,
+            _ => return,
+        };
+        let dmabuf = match self.dpy.dmabuf.get() {
+            Some(dmabuf) => dmabuf,
+            _ => return,
+        };
+        self.frame_missed.set(true);
+        let width = (self.width.get() as f64 * self.scale.get().to_f64()).round() as i32;
+        let height = (self.height.get() as f64 * self.scale.get().to_f64()).round() as i32;
+        for _ in 0..NUM_BUFFERS {
+            let format = ModifiedFormat {
+                format: ARGB8888,
+                modifier: INVALID_MODIFIER,
+            };
+            let bo = match ctx
+                .ctx
+                .gbm
+                .create_bo(width, height, &format, GBM_BO_USE_RENDERING)
+            {
+                Ok(b) => b,
+                Err(e) => {
+                    log::error!("Could not allocate dmabuf: {}", ErrorFmt(e));
+                    return;
+                }
+            };
+            let img = match ctx.ctx.dmabuf_img(bo.dmabuf()) {
+                Ok(b) => b,
+                Err(e) => {
+                    log::error!("Could not import dmabuf into EGL: {}", ErrorFmt(e));
+                    return;
+                }
+            };
+            let fb = match img.to_framebuffer() {
+                Ok(b) => b,
+                Err(e) => {
+                    log::error!(
+                        "Could not turns EGL image into framebuffer: {}",
+                        ErrorFmt(e)
+                    );
+                    return;
+                }
+            };
+            let params = dmabuf.create_params();
+            params.create(bo.dmabuf());
+            let pending = Rc::new(GuiBufferPending {
+                window: self.clone(),
+                fb,
+                params,
+                size: (width, height),
+            });
+            pending.params.owner.set(Some(pending.clone()));
+            self.pending_bufs.set(pending.params.id, pending.clone());
+        }
+    }
+
+    fn tree_at(&self, tree: &mut Vec<Rc<dyn GuiElement>>, mut x: f32, mut y: f32) {
+        let mut element = match self.content.get() {
+            Some(e) => e,
+            _ => return,
+        };
+        tree.push(element.clone());
+        while let Some(c) = element.child_at(x, y) {
+            tree.push(c.clone());
+            x -= c.data().x.get();
+            y -= c.data().y.get();
+            element = c;
+        }
+    }
+
+    pub fn motion(&self, pseat: &PortalSeat, x: Fixed, y: Fixed, _enter: bool) {
+        let x = x.to_f64() as f32;
+        let y = y.to_f64() as f32;
+        let seat = self
+            .seats
+            .lock()
+            .entry(pseat.global_id)
+            .or_default()
+            .clone();
+        seat.x.set(x);
+        seat.y.set(y);
+
+        let mut tree = seat.tree.borrow_mut();
+        let old_element = tree.last().cloned();
+        self.tree_at(&mut tree, x, y);
+        let new_element = tree.last().cloned();
+
+        let element_changed = match (&old_element, &new_element) {
+            (Some(old), Some(new)) => !rc_eq(old, new),
+            (None, None) => false,
+            _ => true,
+        };
+
+        if element_changed {
+            if let Some(o) = &old_element {
+                o.hover(pseat, false);
+            }
+            if let Some(o) = &new_element {
+                o.hover(pseat, true);
+            }
+        }
+
+        if element_changed {
+            self.schedule_render();
+        }
+
+        let cursor = match &new_element {
+            Some(e) => e.hover_cursor(),
+            _ => KnownCursor::Default,
+        };
+
+        if seat.cursor.replace(Some(cursor)) != Some(cursor) {
+            pseat.jay_pointer.set_known_cursor(cursor);
+        }
+    }
+
+    pub fn button(&self, pseat: &PortalSeat, button: u32, state: u32) {
+        let seat = match self.seats.get(&pseat.global_id) {
+            Some(s) => s,
+            _ => return,
+        };
+        let element = seat.tree.borrow_mut().last().cloned();
+        if let Some(e) = element {
+            e.button(pseat, button, state);
+        }
+    }
+}
+
+pub struct GuiBuffer {
+    pub wl: Rc<UsrWlBuffer>,
+    pub window: Rc<WindowData>,
+    pub fb: Rc<Framebuffer>,
+    pub free: Cell<bool>,
+    pub size: (i32, i32),
+}
+
+struct GuiBufferPending {
+    pub window: Rc<WindowData>,
+    pub fb: Rc<Framebuffer>,
+    pub params: Rc<UsrLinuxBufferParams>,
+    pub size: (i32, i32),
+}
+
+impl UsrWlBufferOwner for GuiBuffer {
+    fn release(&self) {
+        self.free.set(true);
+        if self.window.frame_missed.get() {
+            self.window.schedule_render();
+        }
+    }
+}
+
+impl UsrWpFractionalScaleOwner for WindowData {
+    fn preferred_scale(self: Rc<Self>, ev: &PreferredScale) {
+        let mut layout = self.first_scale.replace(false);
+        layout |= self.scale.replace(ev.scale) != ev.scale;
+        if layout {
+            self.layout();
+            self.allocate_buffers();
+        }
+    }
+}
+
+impl UsrWlrLayerSurfaceOwner for OverlayWindow {
+    fn configure(&self, _ev: &Configure) {
+        self.data.schedule_render();
+    }
+
+    fn closed(&self) {
+        self.data.kill(true);
+    }
+}
+
+impl UsrLinuxBufferParamsOwner for GuiBufferPending {
+    fn created(&self, buffer: Rc<UsrWlBuffer>) {
+        buffer.con.add_object(buffer.clone());
+        let buf = Rc::new(GuiBuffer {
+            wl: buffer,
+            window: self.window.clone(),
+            fb: self.fb.clone(),
+            free: Cell::new(true),
+            size: self.size,
+        });
+        buf.wl.owner.set(Some(buf.clone()));
+        self.window.bufs.borrow_mut().push(buf);
+        self.params.con.remove_obj(self.params.deref());
+        self.window.pending_bufs.remove(&self.params.id);
+        if self.window.frame_missed.get() {
+            self.window.schedule_render();
+        }
+    }
+
+    fn failed(&self) {
+        self.window.kill(true);
+    }
+}

src/render/renderer.rs

@@ -1,4 +1,4 @@
-pub use {context::*, framebuffer::*, image::*, renderer::*, texture::*};
+pub use {context::*, framebuffer::*, image::*, renderer::*, renderer_base::*, texture::*};
 
 mod context;
 mod framebuffer;

src/render/renderer/framebuffer.rs

@@ -114,6 +114,28 @@ impl Framebuffer {
         });
     }
 
+    pub fn render_custom(&self, scale: Fixed, f: impl FnOnce(&mut RendererBase)) {
+        let _ = self.ctx.ctx.with_current(|| {
+            unsafe {
+                glBindFramebuffer(GL_FRAMEBUFFER, self.gl.fbo);
+                glViewport(0, 0, self.gl.width, self.gl.height);
+                glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+            }
+            let mut renderer = RendererBase {
+                ctx: &self.ctx,
+                fb: &self.gl,
+                scaled: scale != 1,
+                scale,
+                scalef: scale.to_f64(),
+            };
+            f(&mut renderer);
+            unsafe {
+                glFlush();
+            }
+            Ok(())
+        });
+    }
+
     pub fn render(
         &self,
         node: &dyn Node,

src/render/renderer/renderer_base.rs

@@ -15,7 +15,7 @@ use {
                 texture::image_target,
             },
             renderer::context::RenderContext,
-            sys::{glDisable, glEnable, GL_BLEND},
+            sys::{glClear, glClearColor, glDisable, glEnable, GL_BLEND, GL_COLOR_BUFFER_BIT},
             Texture,
         },
         theme::Color,
@@ -33,6 +33,10 @@ pub struct RendererBase<'a> {
 }
 
 impl RendererBase<'_> {
+    pub fn scale(&self) -> Fixed {
+        self.scale
+    }
+
     pub fn physical_extents(&self) -> Rect {
         Rect::new_sized(0, 0, self.fb.width, self.fb.height).unwrap()
     }
@@ -45,6 +49,14 @@ impl RendererBase<'_> {
         (x, y)
     }
 
+    pub fn scale_point_f(&self, mut x: f32, mut y: f32) -> (f32, f32) {
+        if self.scaled {
+            x = (x as f64 * self.scalef) as _;
+            y = (y as f64 * self.scalef) as _;
+        }
+        (x, y)
+    }
+
     pub fn scale_rect(&self, mut rect: Rect) -> Rect {
         if self.scaled {
             let x1 = (rect.x1() as f64 * self.scalef).round() as _;
@@ -56,6 +68,25 @@ impl RendererBase<'_> {
         rect
     }
 
+    pub fn scale_rect_f(&self, mut rect: (f32, f32, f32, f32)) -> (f32, f32, f32, f32) {
+        if self.scaled {
+            let x1 = (rect.0 as f64 * self.scalef).round() as _;
+            let y1 = (rect.1 as f64 * self.scalef).round() as _;
+            let x2 = (rect.2 as f64 * self.scalef).round() as _;
+            let y2 = (rect.3 as f64 * self.scalef).round() as _;
+            rect = (x1, y1, x2, y2)
+        }
+        rect
+    }
+
+    fn xf_to_f(&self, x: f32) -> f32 {
+        2.0 * (x / self.fb.width as f32) - 1.0
+    }
+
+    fn yf_to_f(&self, y: f32) -> f32 {
+        2.0 * (y / self.fb.height as f32) - 1.0
+    }
+
     fn x_to_f(&self, x: i32) -> f32 {
         2.0 * (x as f32 / self.fb.width as f32) - 1.0
     }
@@ -64,6 +95,13 @@ impl RendererBase<'_> {
         2.0 * (y as f32 / self.fb.height as f32) - 1.0
     }
 
+    pub fn clear(&self, c: &Color) {
+        unsafe {
+            glClearColor(c.r, c.g, c.b, c.a);
+            glClear(GL_COLOR_BUFFER_BIT);
+        }
+    }
+
     pub fn fill_boxes(&self, boxes: &[Rect], color: &Color) {
         self.fill_boxes2(boxes, color, 0, 0);
     }
@@ -94,6 +132,36 @@ impl RendererBase<'_> {
         self.fill_boxes3(&pos, color)
     }
 
+    pub fn fill_boxes_f(&self, boxes: &[(f32, f32, f32, f32)], color: &Color) {
+        self.fill_boxes2_f(boxes, color, 0.0, 0.0);
+    }
+
+    pub fn fill_boxes2_f(&self, boxes: &[(f32, f32, f32, f32)], color: &Color, dx: f32, dy: f32) {
+        if boxes.is_empty() {
+            return;
+        }
+        let (dx, dy) = self.scale_point_f(dx, dy);
+        let mut pos = Vec::with_capacity(boxes.len() * 12);
+        for bx in boxes {
+            let (x1, y1, x2, y2) = self.scale_rect_f(*bx);
+            let x1 = self.xf_to_f(x1 + dx);
+            let y1 = self.yf_to_f(y1 + dy);
+            let x2 = self.xf_to_f(x2 + dx);
+            let y2 = self.yf_to_f(y2 + dy);
+            pos.extend_from_slice(&[
+                // triangle 1
+                x2, y1, // top right
+                x1, y1, // top left
+                x1, y2, // bottom left
+                // triangle 2
+                x2, y1, // top right
+                x1, y2, // bottom left
+                x2, y2, // bottom right
+            ]);
+        }
+        self.fill_boxes3(&pos, color)
+    }
+
     fn fill_boxes3(&self, boxes: &[f32], color: &Color) {
         unsafe {
             glUseProgram(self.ctx.fill_prog.prog);

src/theme.rs

@@ -17,6 +17,10 @@ fn to_u8(c: f32) -> u8 {
 }
 
 impl Color {
+    pub fn from_gray(g: u8) -> Self {
+        Self::from_rgb(g, g, g)
+    }
+
     pub fn from_rgb(r: u8, g: u8, b: u8) -> Self {
         Self {
             r: to_f32(r),

src/utils/copyhashmap.rs

@@ -50,7 +50,11 @@ impl<K: Eq + Hash, V> CopyHashMap<K, V> {
         unsafe { self.map.get().deref().get(k).cloned() }
     }
 
-    pub fn remove(&self, k: &K) -> Option<V> {
+    pub fn remove<Q: ?Sized>(&self, k: &Q) -> Option<V>
+    where
+        Q: Hash + Eq,
+        K: Borrow<Q>,
+    {
         unsafe { self.map.get().deref_mut().remove(k) }
     }
 

src/video/drm.rs

@@ -140,8 +140,8 @@ pub struct Drm {
 
 impl Drm {
     #[cfg_attr(not(feature = "it"), allow(dead_code))]
-    pub fn open_existing(fd: OwnedFd) -> Self {
+    pub fn open_existing(fd: Rc<OwnedFd>) -> Self {
-        Self { fd: Rc::new(fd) }
+        Self { fd }
     }
 
     pub fn reopen(fd: c::c_int, need_primary: bool) -> Result<Self, DrmError> {

src/wire_dbus.rs

@@ -1,3 +1,3 @@
-#![allow(unused_imports)]
+#![allow(unused_imports, non_camel_case_types)]
 
 include!(concat!(env!("OUT_DIR"), "/wire_dbus.rs"));

src/wl_usr.rs

@@ -1,5 +1,3 @@
-#![allow(dead_code)]
-
 pub mod usr_ifs;
 pub mod usr_object;
 
@@ -78,6 +76,7 @@ pub struct UsrCon {
     incoming: Cell<Option<SpawnedFuture<()>>>,
     outgoing: Cell<Option<SpawnedFuture<()>>>,
     pub owner: CloneCell<Option<Rc<dyn UsrConOwner>>>,
+    dead: Cell<bool>,
 }
 
 pub trait UsrConOwner {
@@ -126,6 +125,7 @@ impl UsrCon {
             incoming: Default::default(),
             outgoing: Default::default(),
             owner: Default::default(),
+            dead: Cell::new(false),
         });
         slf.objects.set(
             WL_DISPLAY_ID.into(),
@@ -158,6 +158,7 @@ impl UsrCon {
     }
 
     pub fn kill(&self) {
+        self.dead.set(true);
         for (_, obj) in self.objects.lock().drain() {
             if let Some(obj) = obj {
                 obj.break_loops();
@@ -186,7 +187,9 @@ impl UsrCon {
     }
 
     pub fn add_object(&self, obj: Rc<dyn UsrObject>) {
-        self.objects.set(obj.id(), Some(obj));
+        if !self.dead.get() {
+            self.objects.set(obj.id(), Some(obj));
+        }
     }
 
     pub fn get_registry(self: &Rc<Self>) -> Rc<UsrWlRegistry> {
@@ -199,7 +202,7 @@ impl UsrCon {
             self_id: WL_DISPLAY_ID,
             registry: registry.id,
         });
-        self.objects.set(registry.id.into(), Some(registry.clone()));
+        self.add_object(registry.clone());
         registry
     }
 
@@ -212,7 +215,7 @@ impl UsrCon {
             self_id: WL_DISPLAY_ID,
             callback: callback.id,
         });
-        self.objects.set(callback.id.into(), Some(callback));
+        self.add_object(callback);
     }
 
     pub fn parse<'a, R: RequestParser<'a>>(
@@ -233,6 +236,9 @@ impl UsrCon {
     }
 
     pub fn request<T: EventFormatter>(self: &Rc<Self>, event: T) {
+        if self.dead.get() {
+            return;
+        }
         if log::log_enabled!(log::Level::Trace) {
             log::trace!(
                 "Server {} <= {}@{}.{:?}",

src/wl_usr/usr_ifs/usr_jay_compositor.rs

@@ -82,6 +82,7 @@ impl UsrJayCompositor {
         jo
     }
 
+    #[allow(dead_code)]
     pub fn watch_workspaces(&self) -> Rc<UsrJayWorkspaceWatcher> {
         let ww = Rc::new(UsrJayWorkspaceWatcher {
             id: self.con.id(),

src/wl_usr/usr_ifs/usr_jay_screencast.rs

@@ -67,6 +67,7 @@ impl UsrJayScreencast {
         });
     }
 
+    #[allow(dead_code)]
     pub fn allow_workspace(&self, ws: &JayWorkspace) {
         self.con.request(AllowWorkspace {
             self_id: self.id,
@@ -74,6 +75,7 @@ impl UsrJayScreencast {
         });
     }
 
+    #[allow(dead_code)]
     pub fn touch_allowed_workspaces(&self) {
         self.con
             .request(TouchAllowedWorkspaces { self_id: self.id });

src/wl_usr/usr_ifs/usr_wl_pointer.rs

@@ -42,6 +42,7 @@ pub trait UsrWlPointerOwner {
 }
 
 impl UsrWlPointer {
+    #[allow(dead_code)]
     pub fn set_cursor(&self, serial: u32, cursor: &UsrWlSurface, hot_x: i32, hot_y: i32) {
         self.con.request(SetCursor {
             self_id: self.id,

src/wl_usr/usr_ifs/usr_wl_shm.rs

@@ -19,6 +19,7 @@ pub struct UsrWlShm {
 }
 
 impl UsrWlShm {
+    #[allow(dead_code)]
     pub fn create_pool(&self, fd: &Rc<OwnedFd>, size: i32) -> Rc<UsrWlShmPool> {
         let pool = Rc::new(UsrWlShmPool {
             id: self.con.id(),

src/wl_usr/usr_ifs/usr_wlr_layer_surface.rs

@@ -33,6 +33,7 @@ impl UsrWlrLayerSurface {
         });
     }
 
+    #[allow(dead_code)]
     pub fn set_keyboard_interactivity(&self, ki: u32) {
         self.con.request(SetKeyboardInteractivity {
             self_id: self.id,
@@ -40,6 +41,7 @@ impl UsrWlrLayerSurface {
         });
     }
 
+    #[allow(dead_code)]
     pub fn set_layer(&self, layer: u32) {
         self.con.request(SetLayer {
             self_id: self.id,

src/wl_usr/usr_ifs/usr_wp_viewport.rs

@@ -13,6 +13,7 @@ pub struct UsrWpViewport {
 }
 
 impl UsrWpViewport {
+    #[allow(dead_code)]
     pub fn set_source(&self, x: Fixed, y: Fixed, width: Fixed, height: Fixed) {
         self.con.request(SetSource {
             self_id: self.id,

src/wl_usr/usr_ifs/usr_zwlr_screencopy_frame.rs

@@ -43,6 +43,7 @@ pub trait UsrZwlrScreencopyFrameOwner {
 }
 
 impl UsrZwlrScreencopyFrame {
+    #[allow(dead_code)]
     pub fn copy(&self, buffer: &UsrWlBuffer) {
         self.con.request(Copy {
             self_id: self.id,

src/wl_usr/usr_ifs/usr_zwlr_screencopy_manager.rs

@@ -17,6 +17,7 @@ pub struct UsrZwlrScreencopyManager {
 }
 
 impl UsrZwlrScreencopyManager {
+    #[allow(dead_code)]
     pub fn capture_output(&self, output: &UsrWlOutput) -> Rc<UsrZwlrScreencopyFrame> {
         let frame = Rc::new(UsrZwlrScreencopyFrame {
             id: self.con.id(),

wire-dbus/org.freedesktop.impl.portal.Request.txt

@@ -0,0 +1 @@
+fn Close() { }

wire-dbus/org.freedesktop.impl.portal.ScreenCast.txt

@@ -0,0 +1,34 @@
+fn CreateSession(
+    handle: object_path,
+    session_handle: object_path,
+    app_id: string,
+    options: array(dict(string, variant)),
+) {
+    response: u32,
+    results: array(dict(string, variant)),
+}
+
+fn SelectSources(
+    handle: object_path,
+    session_handle: object_path,
+    app_id: string,
+    options: array(dict(string, variant)),
+) {
+    response: u32,
+    results: array(dict(string, variant)),
+}
+
+fn Start(
+    handle: object_path,
+    session_handle: object_path,
+    app_id: string,
+    parent_window: string,
+    options: array(dict(string, variant)),
+) {
+    response: u32,
+    results: array(dict(string, variant)),
+}
+
+prop AvailableSourceTypes = u32
+prop AvailableCursorModes = u32
+prop version = u32

wire-dbus/org.freedesktop.impl.portal.Session.txt

@@ -0,0 +1,9 @@
+fn Close() {
+
+}
+
+sig Closed {
+
+}
+
+prop version = u32