Initial code for supporting notifications

DBus daemon code; needs testing, and connection to UI.

src/main.rs

@@ -3,6 +3,7 @@ use gtk4::{gdk, glib, prelude::*};
 mod deref_cell;
 mod mpris;
 mod mpris_player;
+mod notifications;
 mod status_area;
 mod status_menu;
 mod status_notifier_watcher;
@@ -39,6 +40,7 @@ fn main() {
     });
 
     status_notifier_watcher::start();
+    let _notificiations = notifications::Notifications::new();
 
     glib::MainLoop::new(None, false).run();
 }

src/notifications.rs

@@ -0,0 +1,166 @@
+use gtk4::{
+    gio,
+    glib::{self, clone},
+    prelude::*,
+};
+use std::{
+    collections::HashMap,
+    num::NonZeroU32,
+    sync::{Arc, Mutex},
+};
+
+static NOTIFICATIONS_XML: &str = "
+<node name='/org/freedesktop/Notifications'>
+  <interface name='org.freedesktop.Notifications'>
+    <method name='Notify'>
+      <arg type='s' name='app_name' direction='in'/>
+      <arg type='u' name='replaces_id' direction='in'/>
+      <arg type='s' name='app_icon' direction='in'/>
+      <arg type='s' name='summary' direction='in'/>
+      <arg type='s' name='body' direction='in'/>
+      <arg type='as' name='actions' direction='in'/>
+      <arg type='a{sv}' name='hints' direction='in'/>
+      <arg type='i' name='expire_timeout' direction='in'/>
+      <arg type='u' name='id' direction='out'/>
+    </method>
+
+    <method name='CloseNotification'>
+      <arg type='u' name='id' direction='in'/>
+    </method>
+
+    <method name='GetCapabilities'>
+      <arg type='as' direction='out'/>
+    </method>
+
+    <method name='GetServerInformation'>
+      <arg type='s' name='name' direction='out'/>
+      <arg type='s' name='vendor' direction='out'/>
+      <arg type='s' name='version' direction='out'/>
+      <arg type='s' name='spec_version' direction='out'/>
+    </method>
+
+    <signal name='NotificationClosed'>
+      <arg type='u' name='id'/>
+      <arg type='u' name='reason'/>
+    </signal>
+
+    <signal name='ActionInvoked'>
+      <arg type='u' name='id'/>
+      <arg type='s' name='action_key'/>
+    </signal>
+  </interface>
+</node>
+";
+
+pub struct Notifications {
+    next_id: Mutex<NonZeroU32>,
+}
+
+impl Notifications {
+    pub fn new() -> Arc<Self> {
+        let notifications = Arc::new(Notifications {
+            next_id: Mutex::new(NonZeroU32::new(1).unwrap()),
+        });
+
+        gio::bus_own_name(
+            gio::BusType::Session,
+            "org.freedesktop.Notifications",
+            gio::BusNameOwnerFlags::NONE,
+            clone!(@strong notifications => move |connection, name| notifications.bus_acquired(connection, name)),
+            clone!(@strong notifications => move |connection, name| notifications.name_acquired(connection, name)),
+            clone!(@strong notifications => move |connection, name| notifications.name_lost(connection, name)),
+        );
+
+        notifications
+    }
+
+    fn notify(
+        &self,
+        _app_name: String,
+        replaces_id: Option<NonZeroU32>,
+        _app_icon: String,
+        _summary: String,
+        _body: String,
+        _actions: Vec<String>,
+        _hints: HashMap<String, glib::Variant>,
+        _expire_timeout: i32,
+    ) -> NonZeroU32 {
+        let id = replaces_id.unwrap_or_else(|| {
+            let mut next_id = self.next_id.lock().unwrap();
+            let id = *next_id;
+            *next_id = NonZeroU32::new(u32::from(*next_id).wrapping_add(1))
+                .unwrap_or(NonZeroU32::new(1).unwrap());
+            id
+        });
+
+        // TODO
+
+        id
+    }
+
+    fn close_notification(&self, _id: u32) {}
+
+    fn bus_acquired(self: &Arc<Self>, _connection: gio::DBusConnection, _name: &str) {}
+
+    fn name_acquired(self: &Arc<Self>, connection: gio::DBusConnection, _name: &str) {
+        let introspection_data = gio::DBusNodeInfo::for_xml(NOTIFICATIONS_XML).unwrap();
+        let interface_info = introspection_data
+            .lookup_interface("org.freedesktop.Notifications")
+            .unwrap();
+        let method_call = clone!(@strong self as self_ => move |_connection: gio::DBusConnection,
+                           _sender: &str,
+                           _path: &str,
+                           _interface: &str,
+                           method: &str,
+                           args: glib::Variant,
+                           invocation: gio::DBusMethodInvocation| {
+            match method {
+                "Notify" => {
+                    let (app_name, replaces_id, app_icon, summary, body, actions, hints, expire_timeout) = args.get().unwrap();
+                    let replaces_id = NonZeroU32::new(replaces_id);
+                    let res = self_.notify(app_name, replaces_id, app_icon, summary, body, actions, hints, expire_timeout);
+                    invocation.return_value(Some(&(u32::from(res),).to_variant()));
+                    // TODO error?
+                }
+                "CloseNotification" => {
+                    let (id,) = args.get::<(u32,)>().unwrap();
+                    self_.close_notification(id);
+                    invocation.return_value(None);
+                    // TODO error?
+                }
+                "GetCapabilities" => {
+                    // TODO: body-markup, sound
+                    let capabilities = vec!["actions", "body", "icon-static", "persistence"];
+                    invocation.return_value(Some(&(capabilities,).to_variant()));
+                }
+                "GetServerInformation" => {
+                    let information = ("cosmic-panel", "system76", env!("CARGO_PKG_VERSION"), "1.2");
+                    invocation.return_value(Some(&information.to_variant()));
+                }
+                _ => unreachable!()
+            }
+        });
+        let get_property = |_: gio::DBusConnection,
+                            _sender: &str,
+                            _path: &str,
+                            _interface: &str,
+                            _prop: &str| { unreachable!() };
+        let set_property = |_: gio::DBusConnection,
+                            _sender: &str,
+                            _path: &str,
+                            _interface: &str,
+                            _prop: &str,
+                            _value: glib::Variant| { unreachable!() };
+        if let Err(err) = connection.register_object(
+            "/org/freedesktop/Notifications",
+            &interface_info,
+            method_call,
+            get_property,
+            set_property,
+        ) {
+            eprintln!("Failed to register object: {}", err);
+        }
+    }
+
+    fn name_lost(self: &Arc<Self>, _connection: Option<gio::DBusConnection>, _name: &str) {}
+}

src/status_notifier_watcher.rs

@@ -102,4 +102,5 @@ fn name_acquired(connection: gio::DBusConnection, _name: &str) {
         eprintln!("Failed to register object: {}", err);
     }
 }
+
 fn name_lost(_connection: Option<gio::DBusConnection>, _name: &str) {}