Presence fixes and improvements

- Allow using invisible mode on servers not supporting presence, to
  make use of the prevention of sending typing notifications and read
  marker updates

- For servers not supporting presence, display the account's presence
  orb in the left pane with half opacity

- Indicate in the presence orb tooltip when the presence we set hasn't
  yet been noticed by the server/the server doesn't support presence

- When reconnecting after being offline, if the server doesn't indicate
  we have a status message [set from another client], restore any
  previous message we had set in the current client

- Show our status message striked out when we're invisible or offline to
  indicate that it isn't being broadcasted

- Some code style cleanups

- Try to handle cases where we set a presence, but receive a new
  presence event for our account before the server takes notice of that
  new presence we want, which probably resulted in the "account keeps
  switching between online and unavailable every few sec" glitch

src/backend/matrix_client.py

@@ -306,7 +306,7 @@ class MatrixClient(nio.AsyncClient):
         )
 
         # TODO: be able to set presence before logging in
-        item.set_fields(presence=Presence.State.online, connecting=True)
+        item.set_fields(presence=Presence.State.echo_online, connecting=True)
         self._presence  = "online"
         self.start_task = asyncio.ensure_future(self._start())
 
@@ -326,6 +326,9 @@ class MatrixClient(nio.AsyncClient):
         account        = self.models["accounts"][user_id]
         self._presence = "offline" if state == "invisible" else state
 
+        if state != "offline":
+            state = f"echo_{state}"
+
         account.set_fields(
             presence=Presence.State(state), status_msg=status_msg,
         )
@@ -385,7 +388,6 @@ class MatrixClient(nio.AsyncClient):
 
         account = self.models["accounts"][self.user_id]
 
-        # Get or create presence for account
         presence = self.backend.presences.setdefault(self.user_id, Presence())
         presence.account = account
         presence.presence = Presence.State(self._presence)
@@ -518,10 +520,10 @@ class MatrixClient(nio.AsyncClient):
 
     async def pause_while_offline(self) -> None:
         """Block until our account is online."""
-        while (
-            self.models["accounts"][self.user_id].presence ==
-            Presence.State.offline
-        ):
+
+        account = self.models["accounts"][self.user_id]
+
+        while account.presence == Presence.State.offline:
             await asyncio.sleep(0.2)
 
 
@@ -1382,9 +1384,11 @@ class MatrixClient(nio.AsyncClient):
         ):
             return
 
-        presence = self.models["accounts"][self.user_id].presence
-
-        if presence not in [Presence.State.invisible, Presence.State.offline]:
+        if self.models["accounts"][self.user_id].presence not in [
+            Presence.State.echo_invisible,
+            Presence.State.invisible,
+            Presence.State.offline,
+        ]:
             await super().room_typing(room_id, typing_state, timeout)
 
 
@@ -1589,60 +1593,61 @@ class MatrixClient(nio.AsyncClient):
     ) -> None:
         """Set presence state for this account."""
 
-        account    = self.models["accounts"][self.user_id]
-        status_msg = status_msg if status_msg is not None else (
-            self.models["accounts"][self.user_id].status_msg
-        )
-        set_status_msg = True
+        account           = self.models["accounts"][self.user_id]
+        call_presence_api = True
+        new_presence      = presence
+        for_server        = "offline" if presence == "invisible" else presence
 
-        if presence == "offline":
-            # Do not do anything if account is offline and setting to offline
+        if status_msg is None:
+            status_msg = account.status_msg
+
+        # Starting/stopping client if current/new presence is offline
+
+        if new_presence == "offline":
             if account.presence == Presence.State.offline:
                 return
 
             await self._stop()
 
-            # Update manually since we may not receive the presence event back
-            # in time
+            # We stop syncing, so update the account manually
             account.set_fields(
                 presence         = Presence.State.offline,
+                status_msg       = "",
                 currently_active = False,
             )
-        elif (
-            account.presence == Presence.State.offline and
-            presence         != "offline"
-        ):
-            # In this case we will not run super().set_presence()
-            set_status_msg     = False
+        elif account.presence == Presence.State.offline:
+            # We might receive a recent status_msg set from another client on
+            # startup, so don't try to set a new one immediatly.
+            # Presence though will be sent on first sync.
+            self._presence     = for_server
+            call_presence_api  = False
             account.connecting = True
             self.start_task    = asyncio.ensure_future(self._start())
 
-            self._presence = "offline" if presence == "invisible" else presence
+        # Update our account model item's presence
 
         if (
             Presence.State(presence) != account.presence and
-            presence                 != "offline"
+            new_presence             != "offline"
         ):
-            account.presence = Presence.State("echo_" + presence)
+            account.presence = Presence.State("echo_" + new_presence)
 
-        if not account.presence_support:
-            account.presence = Presence.State(presence)
+        # Saving new details in accounts.json
 
         if save:
             account.save_presence = True
+
             await self.backend.saved_accounts.set(
-                self.user_id, presence=presence, status_msg=status_msg,
+                self.user_id, presence=new_presence, status_msg=status_msg,
             )
         else:
             account.save_presence = False
 
-        if set_status_msg:
-            account.status_msg = status_msg
+        # Update our presence/status on the server
 
-            await super().set_presence(
-                "offline" if presence == "invisible" else presence,
-                status_msg,
-            )
+        if call_presence_api:
+            account.status_msg = status_msg
+            await super().set_presence(for_server, status_msg)
 
 
     async def import_keys(self, infile: str, passphrase: str) -> None: