matrix_sdk_base: room: add direct_target field

Rooms marked as "direct" are associated a user_id in "m.direct" events.
Clients could want to handle these separately

matrix_sdk_base/src/client.rs

@@ -27,7 +27,7 @@ use matrix_sdk_common::locks::Mutex;
 use matrix_sdk_common::{
     api::r0 as api,
     events::{
-        ignored_user_list::IgnoredUserListEvent, push_rules::PushRulesEvent,
+        direct::DirectEvent, ignored_user_list::IgnoredUserListEvent, push_rules::PushRulesEvent,
         room::member::MemberEventContent, AnyBasicEvent, AnyStrippedStateEvent,
         AnySyncEphemeralRoomEvent, AnySyncMessageEvent, AnySyncRoomEvent, AnySyncStateEvent,
     },
@@ -695,6 +695,24 @@ impl BaseClient {
         // }
     }
 
+    /// Handle a m.direct event, updating rooms states if necessary.
+    ///
+    /// Returns true if any room changed, false otherwise.
+    pub(crate) async fn handle_direct(&self, event: &DirectEvent) -> bool {
+        let mut update = false;
+        for (user_id, rooms) in event.content.iter() {
+            for room_id in rooms.iter() {
+                if let Some(room) = self.get_joined_room(room_id).await {
+                    let mut room = room.write().await;
+                    if room.handle_direct(user_id) {
+                        update = true;
+                    }
+                }
+            }
+        }
+        update
+    }
+
     /// Receive a timeline event for a joined room and update the client state.
     ///
     /// Returns a bool, true when the `Room` state has been updated.
@@ -888,6 +906,7 @@ impl BaseClient {
         match event {
             AnyBasicEvent::IgnoredUserList(event) => self.handle_ignored_users(event).await,
             AnyBasicEvent::PushRules(event) => self.handle_push_rules(event).await,
+            AnyBasicEvent::Direct(event) => self.handle_direct(event).await,
             _ => false,
         }
     }

matrix_sdk_base/src/models/message.rs

@@ -206,6 +206,7 @@ mod test {
                     },
                     "own_user_id": "@example:example.com",
                     "creator": null,
+                    "direct_target": null,
                     "joined_members": {},
                     "invited_members": {},
                     "messages": [ msg ],
@@ -253,6 +254,7 @@ mod test {
                 },
                 "own_user_id": "@example:example.com",
                 "creator": null,
+                "direct_target": null,
                 "joined_members": {},
                 "invited_members": {},
                 "messages": [ msg ],

matrix_sdk_base/src/models/room.rs

@@ -190,6 +190,8 @@ pub struct Room {
     pub own_user_id: UserId,
     /// The mxid of the room creator.
     pub creator: Option<UserId>,
+    /// The mxid of the "direct" target if any
+    pub direct_target: Option<UserId>,
     // TODO: Track banned members, e.g. for /unban support?
     /// The map of invited room members.
     pub invited_members: HashMap<UserId, RoomMember>,
@@ -312,6 +314,7 @@ impl Room {
             room_name: RoomName::default(),
             own_user_id: own_user_id.clone(),
             creator: None,
+            direct_target: None,
             invited_members: HashMap::new(),
             joined_members: HashMap::new(),
             #[cfg(feature = "messages")]
@@ -799,6 +802,20 @@ impl Room {
         true
     }
 
+    /// Handle setting direct attribute as part of a m.direct event,
+    /// updating the room if necessary
+    ///
+    /// Returns true if the direct_target changed, false otherwise.
+    pub fn handle_direct(&mut self, user_id: &UserId) -> bool {
+        if let Some(old_target) = &self.direct_target {
+            if old_target == user_id {
+                return false;
+            }
+        }
+        self.direct_target = Some(user_id.clone());
+        true
+    }
+
     fn handle_encryption_event(&mut self, event: &SyncStateEvent<EncryptionEventContent>) -> bool {
         self.encrypted = Some(event.into());
         true

matrix_sdk_base/src/state/mod.rs

@@ -160,6 +160,7 @@ mod test {
                     },
                     "own_user_id": "@example:example.com",
                     "creator": null,
+                    "direct_target": null,
                     "joined_members": {},
                     "invited_members": {},
                     "typing_users": [],
@@ -188,6 +189,7 @@ mod test {
                     },
                     "own_user_id": "@example:example.com",
                     "creator": null,
+                    "direct_target": null,
                     "joined_members": {},
                     "invited_members": {},
                     "messages": [],