Improved ListModel and ListItem

- New ListItem implemented using a metaclass, which makes defining new
  ListItem subclasses much cleaner and shorter

- ListModel functions taking an index now accept either an int
  (list index) or str (value of a main key)

- getWhere() gone, simply use get(a_main_key_value) now

- updateOrAppendWhere replaced by update()/upsert()

harmonyqml/backend/model/items.py

@@ -1,92 +1,38 @@
-from typing import Any, Callable, Optional, Sequence, Tuple, Union
+from typing import Any, Dict, List, Optional
 
-from PyQt5.QtCore import QObject, pyqtProperty, pyqtSignal
+from PyQt5.QtCore import QDateTime
 
-
-class ListItem(QObject):
-    roles: Tuple[str, ...] = ()
-
-    def __init__(self, *args, no_update: Sequence[str] = (), **kwargs):
-        super().__init__()
-        self.no_update = no_update
-
-        for role, value in zip(self.roles, args):
-            setattr(self, role, value)
-
-        for role, value in kwargs.items():
-            setattr(self, role, value)
-
-
-    def __repr__(self) -> str:
-        return "%s(no_update=%s, %s)" % (
-            type(self).__name__,
-            self.no_update,
-            ", ".join((f"{r}={getattr(self, r)!r}" for r in self.roles)),
-        )
-
-
-    @pyqtProperty(str, constant=True)
-    def _repr(self) -> str:
-        return repr(self)
-
-
-def prop(qt_type:       Union[str, Callable],
-         name:          str,
-         signal:        Optional[pyqtSignal] = None,
-         default_value: Any                  = None) -> pyqtProperty:
-
-    def fget(self, name=name, default_value=default_value):
-        if not hasattr(self, f"_{name}"):
-            setattr(self, f"_{name}", default_value)
-        return getattr(self, f"_{name}")
-
-    def fset(self, value, name=name, signal=signal):
-        setattr(self, f"_{name}", value)
-        if signal:
-            getattr(self, f"{name}Changed").emit(value)
-
-    kws = {"notify": signal} if signal else {"constant": True}
-
-    return pyqtProperty(qt_type, fget=fget, fset=fset, **kws)
+from .list_item import ListItem
 
 
 class User(ListItem):
-    roles = ("userId", "displayName", "avatarUrl", "statusMessage")
+    _required_init_values = {"userId"}
+    _constant             = {"userId"}
 
-    displayNameChanged   = pyqtSignal("QVariant")
-    avatarUrlChanged     = pyqtSignal("QVariant")
-    statusMessageChanged = pyqtSignal(str)
-
-    userId        = prop(str, "userId")
-    displayName   = prop("QVariant", "displayName", displayNameChanged)
-    avatarUrl     = prop(str, "avatarUrl", avatarUrlChanged)
-    statusMessage = prop(str, "statusMessage", statusMessageChanged, "")
+    userId:        str           = ""
+    displayName:   Optional[str] = None
+    avatarUrl:     Optional[str] = None
+    statusMessage: Optional[str] = None
 
 
 class Room(ListItem):
-    roles = ("roomId", "category", "displayName", "topic", "typingUsers",
-             "inviter", "leftEvent")
+    _required_init_values = {"roomId", "displayName"}
+    _constant             = {"roomId"}
 
-    categoryChanged    = pyqtSignal(str)
-    displayNameChanged = pyqtSignal("QVariant")
-    topicChanged       = pyqtSignal(str)
-    typingUsersChanged = pyqtSignal("QVariantList")
-    inviterChanged     = pyqtSignal("QVariant")
-    leftEventChanged   = pyqtSignal("QVariant")
-
-    roomId      = prop(str, "roomId")
-    category    = prop(str, "category", categoryChanged)
-    displayName = prop(str, "displayName", displayNameChanged)
-    topic       = prop(str, "topic", topicChanged, "")
-    typingUsers = prop(list, "typingUsers", typingUsersChanged, [])
-    inviter     = prop("QVariant", "inviter", inviterChanged)
-    leftEvent   = prop("QVariant", "leftEvent", leftEventChanged)
+    roomId:      str                      = ""
+    displayName: str                      = ""
+    category:    str                      = "Rooms"
+    topic:       Optional[str]            = None
+    typingUsers: List[str]                = []
+    inviter:     Optional[Dict[str, str]] = None
+    leftEvent:   Optional[Dict[str, str]] = None
 
 
 class RoomEvent(ListItem):
-    roles = ("type", "dateTime", "dict", "isLocalEcho")
+    _required_init_values = {"type", "dict"}
+    _constant             = {"type"}
 
-    type        = prop(str, "type")
-    dateTime    = prop("QVariant", "dateTime")
-    dict        = prop("QVariantMap", "dict")
-    isLocalEcho = prop(bool, "isLocalEcho", None, False)
+    type:        str            = ""
+    dict:        Dict[str, Any] = {}
+    dateTime:    QDateTime      = QDateTime.currentDateTime()
+    isLocalEcho: bool           = False