Prevent suspension during file operations

Closes: #1408
Partially a port of: pop-os/cosmic-player#185

Author: joshuamegnauth54

Cargo.lock

@@ -8,6 +8,7 @@ rust-version = "1.85"
 
 [dependencies]
 anyhow = "1"
+ashpd = { version = "0.12", optional = true }
 chrono = { version = "0.4", features = ["unstable-locales"] }
 icu = { version = "2.1.1", features = ["compiled_data"] }
 cctk = { git = "https://github.com/pop-os/cosmic-protocols", package = "cosmic-client-toolkit", rev = "d0e95be", optional = true }
@@ -103,6 +104,7 @@ default = [
     "notify",
     "wgpu",
     "wayland",
+    "xdg-portal",
 ]
 dbus-config = ["libcosmic/dbus-config"]
 desktop = ["libcosmic/desktop", "dep:cosmic-mime-apps", "dep:xdg"]
@@ -114,6 +116,7 @@ jemalloc = ["dep:tikv-jemallocator"]
 notify = ["dep:notify-rust"]
 wayland = ["libcosmic/wayland", "dep:cctk", "dep:wayland-client"]
 wgpu = ["libcosmic/wgpu"]
+xdg-portal = ["dep:ashpd"]
 
 [profile.dev]
 opt-level = 1

Cargo.toml

@@ -731,6 +731,8 @@ pub struct App {
     tab_drag_id: DragId,
     auto_scroll_speed: Option<i16>,
     file_dialog_opt: Option<Dialog<Message>>,
+    #[cfg(feature = "xdg-portal")]
+    pub inhibit: tokio::sync::watch::Sender<bool>,
 }
 
 impl App {
@@ -2072,6 +2074,20 @@ impl App {
 
         false
     }
+
+    /// Allow user to suspend or log out.
+    ///
+    /// Basically, undo [`Self::inhibit_suspension`].
+    fn allow_suspend(&self) {
+        #[cfg(feature = "xdg-portal")]
+        let _ = self.inhibit.send(false);
+    }
+
+    /// Prevent suspending during active file operations.
+    fn inhibit_suspend(&self) {
+        #[cfg(feature = "xdg-portal")]
+        let _ = self.inhibit.send(true);
+    }
 }
 
 /// Implement [`Application`] to integrate with COSMIC.
@@ -2153,6 +2169,15 @@ impl Application for App {
                 ),
             ]);
 
+        // The inhibit task must be created here since we need a runtime and libcosmic spawns
+        // the runtime - not main!
+        #[cfg(feature = "xdg-portal")]
+        let inhibit = {
+            let (tx, rx) = tokio::sync::watch::channel(false);
+            std::mem::drop(tokio::spawn(crate::xdg_portals::inhibit(rx)));
+            tx
+        };
+
         let mut app = Self {
             core,
             about,
@@ -2204,6 +2229,8 @@ impl Application for App {
             file_dialog_opt: None,
             #[cfg(all(feature = "wayland", feature = "desktop-applet"))]
             layer_sizes: FxHashMap::default(),
+            #[cfg(feature = "xdg-portal")]
+            inhibit,
         };
 
         let mut commands = vec![app.update_config()];
@@ -6126,7 +6153,7 @@ impl Application for App {
         }));
 
         if !self.pending_operations.is_empty() {
-            //TODO: inhibit suspend/shutdown?
+            self.inhibit_suspend();
 
             if self.core.main_window_id().is_some() {
                 // Force refresh the UI every 100ms while an operation is active.
@@ -6179,6 +6206,8 @@ impl Application for App {
                     ));
                 }
             }
+        } else {
+            self.allow_suspend();
         }
 
         let mut selected_preview = None;

src/app.rs

@@ -1,14 +1,9 @@
 // Copyright 2023 System76 <info@system76.com>
 // SPDX-License-Identifier: GPL-3.0-only
 
-use cosmic::{app::Settings, iced::Limits};
-use std::{env, fs, path::PathBuf, process};
-
-use app::{App, Flags};
 pub mod app;
 mod archive;
 pub mod clipboard;
-use config::Config;
 pub mod config;
 pub mod dialog;
 mod key_bind;
@@ -21,13 +16,22 @@ mod mounter;
 mod mouse_area;
 pub mod operation;
 mod spawn_detached;
-use tab::Location;
-mod zoom;
-
-use crate::config::State;
 pub mod tab;
 mod thumbnail_cacher;
 mod thumbnailer;
+mod zoom;
+
+#[cfg(feature = "xdg-portal")]
+pub mod xdg_portals;
+
+use cosmic::{app::Settings, iced::Limits};
+use std::{env, fs, path::PathBuf, process};
+
+use crate::{
+    app::{App, Flags},
+    config::{Config, State},
+    tab::Location,
+};
 
 pub(crate) type FxOrderMap<K, V> = ordermap::OrderMap<K, V, rustc_hash::FxBuildHasher>;
 
@@ -96,7 +100,7 @@ pub fn desktop() -> Result<(), Box<dyn std::error::Error>> {
         state,
         mode: app::Mode::Desktop,
         locations,
-        uris: Vec::new()
+        uris: Vec::new(),
     };
     cosmic::app::run::<App>(settings, flags)?;
 

src/lib.rs

@@ -0,0 +1,53 @@
+// Copyright 2023 System76 <info@system76.com>
+// SPDX-License-Identifier: GPL-3.0-only
+
+//! Integrations with XDG portals.
+
+use ashpd::{
+    desktop::inhibit::{InhibitFlags, InhibitProxy, SessionState},
+    enumflags2::{BitFlags, make_bitflags},
+};
+use futures::StreamExt;
+use log::warn;
+use tokio::sync::watch::Receiver;
+
+const INHIBIT_FLAGS: BitFlags<InhibitFlags> =
+    make_bitflags!(InhibitFlags::{Logout | UserSwitch | Suspend});
+
+/// Inhibit suspension and shutdown while file operations are in progress.
+///
+/// # Usage
+/// Enable the inhibitor by setting the watcher to `true`. Disable the inhibitor by sending a
+/// `false`. Sending multiple consecutive trues/falses is safe and guarded internally.
+///
+/// Portal:
+/// https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Inhibit.html
+pub async fn inhibit(mut signal: Receiver<bool>) -> ashpd::Result<()> {
+    let proxy = InhibitProxy::new().await?;
+    let session = proxy.create_monitor(None).await?;
+    // Mark the watcher's value as unseen so we don't need a temporary bool and branch for the
+    // initial state.
+    signal.mark_changed();
+
+    let mut states = proxy.receive_state_changed().await?;
+    while let Some(SessionState::QueryEnd) = states.next().await.map(|state| state.session_state())
+    {
+        // Copying the bool is important or else we would needlessly hold the lock below.
+        let should_inhibit = *signal.borrow_and_update();
+
+        if should_inhibit {
+            // XXX: Better message (if the message even matters).
+            let _ = proxy
+                .inhibit(None, INHIBIT_FLAGS, "File operations in progress")
+                .await
+                .inspect_err(|e| warn!("Failed to call inhibit endpoint: {e}"));
+        }
+
+        let _ = proxy
+            .query_end_response(&session)
+            .await
+            .inspect_err(|e| warn!("Error sending QueryEnd to the XDG portal: {e}"));
+    }
+
+    Ok(())
+}