feat: add RemoteDesktop portal with EIS input injection and consent dialog

Implements org.freedesktop.impl.portal.RemoteDesktop, enabling remote
keyboard, mouse, and touchscreen input injection via the EIS protocol.

The portal provides:
- CreateSession/SelectDevices/SelectSources/Start/ConnectToEIS methods
- A consent dialog with device type chips and screen/window selection
- EIS socket pair creation forwarded to the compositor via D-Bus
- Session lifecycle management with proper cleanup
- Reuse of existing ScreenCast infrastructure for video streams

Security model:
- Consent dialog is always shown (never skipped via restore data)
- Device types are masked to valid bits only
- Per-session UNIX socket isolation
- Portal's own D-Bus connection used for compositor calls

Requires compositor support for AcceptEisSocket D-Bus method
(com.system76.CosmicComp.RemoteDesktop).

Closes #23

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: olafkfreund

Cargo.toml

@@ -29,6 +29,7 @@ memmap2 = "0.9.8"
 pipewire = { git = "https://gitlab.freedesktop.org/pipewire/pipewire-rs", features = [
     "v0_3_33",
 ] }
+reis = { version = "0.5", features = ["tokio"] }
 png = "0.18"
 rustix = { version = "1.1", features = ["fs"] }
 # spa_sys = { package = "libspa-sys", git = "https://github.com/pop-os/pipewire-rs" }

data/cosmic.portal

@@ -1,4 +1,4 @@
 [portal]
 DBusName=org.freedesktop.impl.portal.desktop.cosmic
-Interfaces=org.freedesktop.impl.portal.Access;org.freedesktop.impl.portal.FileChooser;org.freedesktop.impl.portal.Screenshot;org.freedesktop.impl.portal.Settings;org.freedesktop.impl.portal.ScreenCast
+Interfaces=org.freedesktop.impl.portal.Access;org.freedesktop.impl.portal.FileChooser;org.freedesktop.impl.portal.RemoteDesktop;org.freedesktop.impl.portal.Screenshot;org.freedesktop.impl.portal.Settings;org.freedesktop.impl.portal.ScreenCast
 UseIn=COSMIC

i18n/en/xdg_desktop_portal_cosmic.ftl

@@ -13,3 +13,9 @@ share-screen = Share your screen
 unknown-application = Unknown Application
 output = Output
 window = Window
+
+remote-desktop-access = Remote Desktop Access
+    .description = "{$app_name}" is requesting remote control of your desktop. The following inputs will be shared:
+remote-desktop-keyboard = keyboard
+remote-desktop-pointer = pointer
+remote-desktop-touchscreen = touchscreen

src/app.rs

@@ -1,4 +1,7 @@
-use crate::{access, config, file_chooser, screencast_dialog, screenshot, subscription};
+use crate::{
+    access, config, file_chooser, remote_desktop_dialog, screencast_dialog, screenshot,
+    subscription,
+};
 use cosmic::Task;
 use cosmic::iced_core::event::wayland::OutputEvent;
 use cosmic::widget;
@@ -38,6 +41,9 @@ pub struct CosmicPortal {
     pub screencast_args: Option<screencast_dialog::Args>,
     pub screencast_tab_model:
         widget::segmented_button::Model<widget::segmented_button::SingleSelect>,
+    pub remotedesktop_args: Option<remote_desktop_dialog::Args>,
+    pub remotedesktop_tab_model:
+        widget::segmented_button::Model<widget::segmented_button::SingleSelect>,
     pub location_options: Vec<String>,
     pub prev_rectangle: Option<screenshot::Rect>,
     pub wayland_helper: crate::wayland::WaylandHelper,
@@ -63,6 +69,7 @@ pub enum Msg {
     FileChooser(window::Id, file_chooser::Msg),
     Screenshot(screenshot::Msg),
     Screencast(screencast_dialog::Msg),
+    RemoteDesktop(remote_desktop_dialog::Msg),
     Portal(subscription::Event),
     Output(OutputEvent, WlOutput),
     ConfigSetScreenshot(config::screenshot::Screenshot),
@@ -112,6 +119,8 @@ impl cosmic::Application for CosmicPortal {
                 screenshot_args: Default::default(),
                 screencast_args: Default::default(),
                 screencast_tab_model: Default::default(),
+                remotedesktop_args: Default::default(),
+                remotedesktop_tab_model: Default::default(),
                 location_options: Vec::new(),
                 prev_rectangle: Default::default(),
                 outputs: Default::default(),
@@ -132,6 +141,8 @@ impl cosmic::Application for CosmicPortal {
             access::view(self).map(Msg::Access)
         } else if id == *screencast_dialog::SCREENCAST_ID {
             screencast_dialog::view(self).map(Msg::Screencast)
+        } else if id == *remote_desktop_dialog::REMOTEDESKTOP_ID {
+            remote_desktop_dialog::view(self).map(Msg::RemoteDesktop)
         } else if self.outputs.iter().any(|o| o.id == id) {
             screenshot::view(self, id).map(Msg::Screenshot)
         } else {
@@ -160,6 +171,12 @@ impl cosmic::Application for CosmicPortal {
                 subscription::Event::CancelScreencast(handle) => {
                     screencast_dialog::cancel(self, handle).map(cosmic::Action::App)
                 }
+                subscription::Event::RemoteDesktop(args) => {
+                    remote_desktop_dialog::update_args(self, args).map(cosmic::Action::App)
+                }
+                subscription::Event::CancelRemoteDesktop(handle) => {
+                    remote_desktop_dialog::cancel(self, handle).map(cosmic::Action::App)
+                }
                 subscription::Event::Config(config) => self.update(Msg::ConfigSubUpdate(config)),
                 subscription::Event::Accent(_)
                 | subscription::Event::IsDark(_)
@@ -175,6 +192,9 @@ impl cosmic::Application for CosmicPortal {
             },
             Msg::Screenshot(m) => screenshot::update_msg(self, m).map(cosmic::Action::App),
             Msg::Screencast(m) => screencast_dialog::update_msg(self, m).map(cosmic::Action::App),
+            Msg::RemoteDesktop(m) => {
+                remote_desktop_dialog::update_msg(self, m).map(cosmic::Action::App)
+            }
             Msg::Output(o_event, wl_output) => {
                 match o_event {
                     OutputEvent::Created(Some(info))

src/main.rs

@@ -14,6 +14,8 @@ mod buffer;
 mod documents;
 mod file_chooser;
 mod localize;
+mod remote_desktop;
+mod remote_desktop_dialog;
 mod screencast;
 mod screencast_dialog;
 mod screencast_thread;