Add local echoing of messages

As per
https://matrix.org/docs/spec/client_server/latest.html#local-echo

TODO.md

@@ -36,3 +36,6 @@
 - nio: org.matrix.room.preview\_urls, m.room.aliases
 
 - Markdown: don't turn #things into title (space), disable __ syntax
+- ![A picture](https://picsum.photos/256/256) not clickable?
+
+- On sync, check messages API, if a limited sync timeline was received

harmonyqml/backend/client.py

@@ -46,6 +46,7 @@ class Client(QObject):
     roomPastPrevBatchTokenReceived = pyqtSignal(str, str)
     roomEventReceived              = pyqtSignal(str, str, dict)
     roomTypingUsersUpdated         = pyqtSignal(str, list)
+    messageAboutToBeSent           = pyqtSignal(str, dict)
 
 
     def __init__(self,
@@ -171,7 +172,6 @@ class Client(QObject):
             return
         self._loading = True
 
-        print("load", limit)
         self._on_past_events(
             room_id,
             self.net.talk(
@@ -201,4 +201,11 @@ class Client(QObject):
             "format": "org.matrix.custom.html",
             "msgtype": "m.text",
         }
-        self.net.talk(self.nio.room_send, room_id, "m.room.message", content)
+        self.messageAboutToBeSent.emit(room_id, content)
+
+        self.net.talk(
+            self.nio.room_send,
+            room_id      = room_id,
+            message_type = "m.room.message",
+            content      = content,
+        )

harmonyqml/backend/model/items.py

@@ -24,3 +24,4 @@ class RoomEvent(NamedTuple):
     type:          str
     date_time:     QDateTime
     dict:          Dict[str, str]
+    is_local_echo: bool = False

harmonyqml/backend/signal_manager.py

@@ -6,19 +6,22 @@ from typing import Any, Deque, Dict, List, Optional
 
 from PyQt5.QtCore import QDateTime, QObject, pyqtBoundSignal
 
+import nio
+
 from .backend import Backend
 from .client import Client
 from .model.items import Room, RoomEvent, User
 
 
 class SignalManager(QObject):
-    _duplicate_check_lock: Lock = Lock()
+    _event_handling_lock: Lock = Lock()
 
     def __init__(self, backend: Backend) -> None:
         super().__init__(parent=backend)
         self.backend = backend
 
         self.last_room_events: Deque[str] = Deque(maxlen=1000)
+        self._events_in_transfer:     int        = 0
 
         cm = self.backend.clientManager
         cm.clientAdded.connect(self.onClientAdded)
@@ -103,28 +106,53 @@ class SignalManager(QObject):
             self, _: Client, room_id: str, etype: str, edict: Dict[str, Any]
         ) -> None:
 
+        with self._event_handling_lock:
             # Prevent duplicate events in models due to multiple accounts
-        with self._duplicate_check_lock:
             if edict["event_id"] in self.last_room_events:
                 return
 
             self.last_room_events.appendleft(edict["event_id"])
 
             model     = self.backend.models.roomEvents[room_id]
-        date_time = QDateTime.fromMSecsSinceEpoch(edict["server_timestamp"])
+            date_time = QDateTime\
+                        .fromMSecsSinceEpoch(edict["server_timestamp"])
             new_event = RoomEvent(type=etype, date_time=date_time, dict=edict)
 
-        # Model is sorted from newest to oldest message
+            if self._events_in_transfer:
-        insert_at = None
+                local_echoes_met: int           = 0
+                replace_at:       Optional[int] = None
+
+                # Find if any locally echoed event corresponds to new_event
                 for i, event in enumerate(model):
-            if new_event.date_time > event.date_time:
+                    if not event.is_local_echo:
-                insert_at = i
+                        continue
+
+                    sb     = (event.dict["sender"], event.dict["body"])
+                    new_sb = (new_event.dict["sender"], new_event.dict["body"])
+
+                    if sb == new_sb:
+                        # The oldest matching local echo shall be replaced
+                        replace_at = max(replace_at or 0, i)
+
+                    local_echoes_met += 1
+                    if local_echoes_met >= self._events_in_transfer:
                         break
 
-        if insert_at is None:
+                if replace_at is not None:
+                    model[replace_at] = new_event
+                    self._events_in_transfer -= 1
+                    return
+
+            for i, event in enumerate(model):
+                if event.is_local_echo:
+                    continue
+
+                # Model is sorted from newest to oldest message
+                if new_event.date_time > event.date_time:
+                    model.insert(i, new_event)
+                    return
+
             model.append(new_event)
-        else:
-            model.insert(insert_at, new_event)
 
 
     def onRoomTypingUsersUpdated(
@@ -133,3 +161,25 @@ class SignalManager(QObject):
 
         rooms = self.backend.models.rooms[client.userID]
         rooms[rooms.indexWhere("room_id", room_id)].typing_users = users
+
+
+    def onMessageAboutToBeSent(
+            self, client: Client, room_id: str, content: Dict[str, str]
+        ) -> None:
+        with self._event_handling_lock:
+            timestamp = QDateTime.currentMSecsSinceEpoch()
+            model     = self.backend.models.roomEvents[room_id]
+            nio_event = nio.events.RoomMessage.parse_event({
+                "event_id":         "",
+                "sender":           client.userID,
+                "origin_server_ts": timestamp,
+                "content":          content,
+            })
+            event = RoomEvent(
+                type          = type(nio_event).__name__,
+                date_time     = QDateTime.fromMSecsSinceEpoch(timestamp),
+                dict          = nio_event.__dict__,
+                is_local_echo = True,
+            )
+            model.insert(0, event)
+            self._events_in_transfer += 1

harmonyqml/components/chat/MessageContent.qml

@@ -37,13 +37,15 @@ Row {
                   //Qt.formatDateTime(date_time, "hh:mm:ss") +
                   //"</font>" +
             //      (isOwn ? "&nbsp;&nbsp;" + content : "")
-
+            //
             text: (dict.formatted_body ?
                    Backend.htmlFilter.filter(dict.formatted_body) :
                    dict.body) +
                   "&nbsp;&nbsp;<font size=" + smallSize + "px color=gray>" +
                   Qt.formatDateTime(date_time, "hh:mm:ss") +
-                  "</font>"
+                  "</font>" +
+                  (is_local_echo ?
+                   "&nbsp;<font size=" + smallSize + "px>⏳</font>" : "")
             textFormat: Text.RichText
             background: Rectangle {color: "#DDD"}
             wrapMode: Text.Wrap