feat: Background portal

I based my implementation on the official specs as well as code from
GNOME, KDE, Xapp (Xfce), and Pantheon (elementary). KDE's imminently
readable codebase served as this implementation's primary inspiration.

Autostart is deprecated but seemingly still used, so this implementation
will still support it for compatibility.

The Background portal depends on a working Access portal as
`xdg-desktop-portal` calls it to show the initial warning.

References:
* https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.impl.portal.Background.html
* https://gitlab.gnome.org/GNOME/xdg-desktop-portal-gnome/-/blob/main/src/background.c
* https://invent.kde.org/plasma/xdg-desktop-portal-kde/-/blob/master/src/background.cpp
* https://github.com/linuxmint/xdg-desktop-portal-xapp/blob/f1c24244f90571209c56b7f45802b70e80da4922/src/background.c
* https://github.com/elementary/portals/blob/d868cfa854c731e0f37615e225d5db07cc3f4604/src/Background/Portal.vala
* flatpak/xdg-desktop-portal#1188

Author: joshuamegnauth54

cosmic-portal-config/src/background.rs

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-3.0-only
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Copy, Default, PartialEq, Deserialize, Serialize)]
+#[serde(deny_unknown_fields)]
+pub struct Background {
+    /// Default preference for NotifyBackground's dialog
+    pub default_perm: PermissionDialog,
+}
+
+#[derive(Debug, Clone, Copy, Default, PartialEq, Eq, Deserialize, Serialize)]
+pub enum PermissionDialog {
+    /// Grant apps permission to run in the background
+    Allow,
+    /// Deny apps permission to run in the background
+    Deny,
+    /// Always ask if new apps should be granted background permissions
+    #[default]
+    Ask,
+}

cosmic-portal-config/src/lib.rs

@@ -1,10 +1,12 @@
 // SPDX-License-Identifier: GPL-3.0-only
 
+pub mod background;
 pub mod screenshot;
 
 use cosmic_config::{cosmic_config_derive::CosmicConfigEntry, CosmicConfigEntry};
 use serde::{Deserialize, Serialize};
 
+use background::Background;
 use screenshot::Screenshot;
 
 pub const APP_ID: &str = "com.system76.CosmicPortal";
@@ -17,6 +19,8 @@ pub const CONFIG_VERSION: u64 = 1;
 pub struct Config {
     /// Interactive screenshot settings
     pub screenshot: Screenshot,
+    /// Background portal settings
+    pub background: Background,
 }
 
 impl Config {

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.Background;org.freedesktop.impl.portal.FileChooser;org.freedesktop.impl.portal.Screenshot;org.freedesktop.impl.portal.Settings;org.freedesktop.impl.portal.ScreenCast
 UseIn=cosmic

examples/background.rs

@@ -0,0 +1,27 @@
+use ashpd::desktop::background::Background;
+
+#[tokio::main(flavor = "current_thread")]
+async fn main() -> ashpd::Result<()> {
+    let command = std::env::args()
+        .nth(1)
+        .unwrap_or_else(|| "FakeTestApp".into());
+
+    // Based off of the ashpd docs
+    // https://docs.rs/ashpd/latest/ashpd/desktop/background/index.html
+    let response = Background::request()
+        .reason("Testing the background portal")
+        .auto_start(false)
+        .dbus_activatable(false)
+        .command(&[command])
+        .send()
+        .await?
+        .response()?;
+
+    assert!(!response.auto_start(), "Auto start should be disabled");
+    assert!(
+        response.run_in_background(),
+        "App should have background permissions"
+    );
+
+    Ok(())
+}

i18n/en/xdg_desktop_portal_cosmic.ftl

@@ -13,3 +13,9 @@ share-screen = Share your screen
 unknown-application = Unknown Application
 output = Output
 window = Window
+
+# Background portal
+allow-once = Allow once
+deny = Deny
+bg-dialog-title = Background
+bg-dialog-body = {$appname} requests to run in the background. This will allow it to run without any open windows.

src/app.rs

@@ -1,4 +1,6 @@
-use crate::{access, config, file_chooser, fl, screencast_dialog, screenshot, subscription};
+use crate::{
+    access, background, config, file_chooser, fl, screencast_dialog, screenshot, subscription,
+};
 use cosmic::iced_core::event::wayland::OutputEvent;
 use cosmic::widget::{self, dropdown};
 use cosmic::Command;
@@ -29,6 +31,7 @@ pub struct CosmicPortal {
 
     pub config_handler: Option<cosmic_config::Config>,
     pub config: config::Config,
+    pub tx_conf: Option<tokio::sync::watch::Sender<config::Config>>,
 
     pub access_args: Option<access::AccessDialogArgs>,
     pub access_choices: Vec<(Option<usize>, Vec<String>)>,
@@ -43,6 +46,8 @@ pub struct CosmicPortal {
     pub prev_rectangle: Option<screenshot::Rect>,
     pub wayland_helper: crate::wayland::WaylandHelper,
 
+    pub background_prompts: HashMap<window::Id, background::Args>,
+
     pub outputs: Vec<OutputState>,
     pub active_output: Option<WlOutput>,
 }
@@ -64,8 +69,10 @@ pub enum Msg {
     FileChooser(window::Id, file_chooser::Msg),
     Screenshot(screenshot::Msg),
     Screencast(screencast_dialog::Msg),
+    Background(background::Msg),
     Portal(subscription::Event),
     Output(OutputEvent, WlOutput),
+    ConfigNotifyWatcher,
     ConfigSetScreenshot(config::screenshot::Screenshot),
     /// Update config from external changes
     ConfigSubUpdate(config::Config),
@@ -127,6 +134,7 @@ impl cosmic::Application for CosmicPortal {
                 core,
                 config_handler,
                 config,
+                tx_conf: None,
                 access_args: Default::default(),
                 access_choices: Default::default(),
                 file_choosers: Default::default(),
@@ -135,6 +143,7 @@ impl cosmic::Application for CosmicPortal {
                 screencast_tab_model: Default::default(),
                 location_options: Vec::new(),
                 prev_rectangle: Default::default(),
+                background_prompts: Default::default(),
                 outputs: Default::default(),
                 active_output: Default::default(),
                 wayland_helper,
@@ -155,6 +164,8 @@ impl cosmic::Application for CosmicPortal {
             screencast_dialog::view(self).map(Msg::Screencast)
         } else if self.outputs.iter().any(|o| o.id == id) {
             screenshot::view(self, id).map(Msg::Screenshot)
+        } else if self.background_prompts.contains_key(&id) {
+            background::view(self, id).map(Msg::Background)
         } else {
             file_chooser::view(self, id)
         }
@@ -181,19 +192,25 @@ impl cosmic::Application for CosmicPortal {
                 subscription::Event::CancelScreencast(handle) => {
                     screencast_dialog::cancel(self, handle).map(cosmic::app::Message::App)
                 }
+                subscription::Event::Background(args) => {
+                    background::update_args(self, args).map(cosmic::app::Message::App)
+                }
                 subscription::Event::Config(config) => self.update(Msg::ConfigSubUpdate(config)),
                 subscription::Event::Accent(_)
                 | subscription::Event::IsDark(_)
-                | subscription::Event::HighContrast(_) => cosmic::iced::Command::none(),
-                subscription::Event::Init(tx) => {
+                | subscription::Event::HighContrast(_)
+                | subscription::Event::BackgroundToplevels => cosmic::iced::Command::none(),
+                subscription::Event::Init { tx, tx_conf } => {
                     self.tx = Some(tx);
-                    Command::none()
+                    self.tx_conf = Some(tx_conf);
+                    self.update(Msg::ConfigNotifyWatcher)
                 }
             },
             Msg::Screenshot(m) => screenshot::update_msg(self, m).map(cosmic::app::Message::App),
             Msg::Screencast(m) => {
                 screencast_dialog::update_msg(self, m).map(cosmic::app::Message::App)
             }
+            Msg::Background(m) => background::update_msg(self, m).map(cosmic::app::Message::App),
             Msg::Output(o_event, wl_output) => {
                 match o_event {
                     OutputEvent::Created(Some(info))
@@ -266,6 +283,12 @@ impl cosmic::Application for CosmicPortal {
 
                 cosmic::iced::Command::none()
             }
+            Msg::ConfigNotifyWatcher => {
+                if let Some(tx) = self.tx_conf.as_mut() {
+                    tx.send_replace(self.config.clone());
+                }
+                cosmic::iced::Command::none()
+            }
             Msg::ConfigSetScreenshot(screenshot) => {
                 match &mut self.config_handler {
                     Some(handler) => {
@@ -275,12 +298,11 @@ impl cosmic::Application for CosmicPortal {
                     }
                     None => log::error!("Failed to save config: No config handler"),
                 }
-
-                cosmic::iced::Command::none()
+                self.update(Msg::ConfigNotifyWatcher)
             }
             Msg::ConfigSubUpdate(config) => {
                 self.config = config;
-                cosmic::iced::Command::none()
+                self.update(Msg::ConfigNotifyWatcher)
             }
         }
     }