Fix dict changing size problem in retry_decrypt_..

Also add a copy() method to models, and make them able
to not have a sync_id (in which case they won't send pyotherside
events).

src/backend/matrix_client.py

@@ -981,7 +981,7 @@ class MatrixClient(nio.AsyncClient):
 
             _, room_id, _ = sync_id
 
-            for ev in model.values():
+            for ev in model.copy().values():
                 room = self.all_rooms[room_id]
 
                 if isinstance(ev.source, nio.MegolmEvent):

src/backend/models/model.py

@@ -2,7 +2,9 @@
 
 from bisect import bisect
 from threading import RLock
-from typing import TYPE_CHECKING, Any, Dict, Iterator, List, MutableMapping
+from typing import (
+    TYPE_CHECKING, Any, Dict, Iterator, List, MutableMapping, Optional,
+)
 
 from blist import blist
 
@@ -29,8 +31,8 @@ class Model(MutableMapping):
     Items in the model are kept sorted using the `ModelItem` subclass `__lt__`.
     """
 
-    def __init__(self, sync_id: SyncId) -> None:
-        self.sync_id:      SyncId                 = sync_id
+    def __init__(self, sync_id: Optional[SyncId]) -> None:
+        self.sync_id:      Optional[SyncId]       = sync_id
         self._data:        Dict[Any, "ModelItem"] = {}
         self._sorted_data: List["ModelItem"]      = blist()
         self._write_lock:  RLock                  = RLock()
@@ -86,6 +88,7 @@ class Model(MutableMapping):
             index           = bisect(self._sorted_data, new)
             self._sorted_data.insert(index, new)
 
+            if self.sync_id:
                 ModelItemInserted(self.sync_id, index, new)
 
 
@@ -98,6 +101,7 @@ class Model(MutableMapping):
             index = self._sorted_data.index(item)
             del self._sorted_data[index]
 
+            if self.sync_id:
                 ModelItemDeleted(self.sync_id, index)
 
 
@@ -116,4 +120,11 @@ class Model(MutableMapping):
 
     def clear(self) -> None:
         super().clear()
+        if self.sync_id:
             ModelCleared(self.sync_id)
+
+
+    def copy(self, sync_id: Optional[SyncId] = None) -> "Model":
+        new = type(self)(sync_id=sync_id)
+        new.update(self)
+        return new

src/backend/models/model_item.py

@@ -42,6 +42,7 @@ class ModelItem:
             self.parent_model._sorted_data.sort()
             new_index = self.parent_model._sorted_data.index(self)
 
+            if self.parent_model.sync_id:
                 ModelItemFieldChanged(
                     self.parent_model.sync_id,
                     old_index,

src/gui/PythonBridge/Privates/EventHandlers.qml

@@ -60,13 +60,13 @@ QtObject {
 
 
     function onModelItemInserted(syncId, index, item) {
-        // print("insert", syncId, index, item)
+        print("insert", syncId, index, item)
         ModelStore.get(syncId).insert(index, item)
     }
 
 
     function onModelItemFieldChanged(syncId, oldIndex, newIndex, field, value){
-        // print("change", syncId, oldIndex, newIndex, field, value)
+        print("change", syncId, oldIndex, newIndex, field, value)
         const model = ModelStore.get(syncId)
         model.setProperty(oldIndex, field, value)