Make offline presence to stop sync

Setting the presence of an account to offline
will make the client to end sync task and will
prevent messages from being sent.

Setting it to online again or any other presence
will start sync task again.

Left:
- Local echo to presence change
- UI Control to affect all members presence
- Block more requests to be sent (e.g. member
  actions)

src/backend/models/items.py

@@ -56,27 +56,33 @@ class Presence():
     last_active_ago:  int      = -1
     status_msg:       str      = ""
 
-    members: Dict[Tuple[str, str], Union["Member", "Account"]] = \
-        field(default_factory=dict)
+    members: Dict[Tuple[str, str], "Member"] = field(default_factory=dict)
+    account: Optional["Account"]             = None
 
-    def update_members(self):
+    def update_members(self) -> None:
         for member in self.members.values():
-            # Do not update if member is changing to invisible
-            # Because when setting invisible presence will give us presence
-            # event telling us we are offline, we do not want to set member
-            # presence to offline.
-            if (
-                member.presence == self.State.invisible
-            ) and (
-                self.presence   == self.State.offline
-            ):
-                continue
-
             member.presence         = self.presence
             member.status_msg       = self.status_msg
             member.last_active_ago  = self.last_active_ago
             member.currently_active = self.currently_active
 
+    def update_account(self) -> None:
+        # Do not update if account is changing to invisible.
+        # When setting presence to invisible, the server will give us a
+        # presence event telling us we are offline, but we do not want to set
+        # account presence to offline.
+        if (
+            not self.account or
+            self.account.presence == self.State.invisible and
+            self.presence         == self.State.offline
+        ):
+            return
+
+        self.account.presence         = self.presence
+        self.account.status_msg       = self.status_msg
+        self.account.last_active_ago  = self.last_active_ago
+        self.account.currently_active = self.currently_active
+
 
 @dataclass
 class Account(ModelItem):
@@ -88,7 +94,7 @@ class Account(ModelItem):
     avatar_url:       str      = ""
     max_upload_size:  int      = 0
     profile_updated:  datetime = ZeroDate
-    first_sync_done:  bool     = False
+    connecting:       bool     = False
     total_unread:     int      = 0
     total_highlights: int      = 0
     local_unreads:    bool     = False
@@ -96,11 +102,11 @@ class Account(ModelItem):
 
     # For some reason, Account cannot inherit Presence, because QML keeps
     # complaining type error on unknown file
-    presence_support: bool             = False
-    presence:         Presence.State   = Presence.State.offline
-    currently_active: bool             = False
-    last_active_ago:  int              = -1
-    status_msg:       str              = ""
+    presence_support: bool           = False
+    presence:         Presence.State = Presence.State.offline
+    currently_active: bool           = False
+    last_active_ago:  int            = -1
+    status_msg:       str            = ""
 
     def __lt__(self, other: "Account") -> bool:
         """Sort by order, then by user ID."""
@@ -220,7 +226,7 @@ class AccountOrRoom(Account, Room):
 
 
 @dataclass
-class Member(Presence, ModelItem):
+class Member(ModelItem):
     """A member in a matrix room."""
 
     id:              str      = field()
@@ -234,6 +240,11 @@ class Member(Presence, ModelItem):
     last_read_event: str      = ""
     last_read_at:    datetime = ZeroDate
 
+    presence:         Presence.State = Presence.State.offline
+    currently_active: bool           = False
+    last_active_ago:  int            = -1
+    status_msg:       str            = ""
+
     def __lt__(self, other: "Member") -> bool:
         """Sort by presence, power level, then by display name/user ID."""