moment/harmonyqml/backend/model/list_model.py
miruka 4607f53b7a Show special text when room has no events yet
e.g. if invited to a room but there's no history provided by
another account.

Also add a signal for the ListModel.count property.
2019-04-22 11:31:06 -04:00

248 lines
7.0 KiB
Python

import logging
from typing import (
Any, Callable, Dict, Iterable, List, Mapping, MutableSequence, Optional,
Sequence, Tuple, Union
)
from PyQt5.QtCore import (
QAbstractListModel, QModelIndex, QObject, Qt, pyqtProperty, pyqtSignal,
pyqtSlot
)
from .items import ListItem
NewItem = Union[ListItem, Mapping[str, Any], Sequence]
class ListModel(QAbstractListModel):
changed = pyqtSignal()
countChanged = pyqtSignal(int)
def __init__(self,
initial_data: Optional[List[NewItem]] = None,
container: Callable[..., MutableSequence] = list,
parent: Optional[QObject] = None) -> None:
super().__init__(parent)
self._data: MutableSequence[ListItem] = container()
if initial_data:
self.extend(initial_data)
def __repr__(self) -> str:
return "%s(%r)" % (type(self).__name__, self._data)
def __getitem__(self, index):
return self._data[index]
def __setitem__(self, index, value) -> None:
self.set(index, value)
def __delitem__(self, index) -> None:
self.remove(index)
def __len__(self) -> int:
return len(self._data)
def __iter__(self):
return iter(self._data)
@pyqtProperty(list, constant=True)
def roles(self) -> Tuple[str, ...]:
return self._data[0].roles if self._data else () # type: ignore
def roleNames(self) -> Dict[int, bytes]:
return {Qt.UserRole + i: bytes(f, "utf-8")
for i, f in enumerate(self.roles, 1)} \
if self._data else {}
def data(self, index: QModelIndex, role: int = Qt.DisplayRole) -> Any:
if role <= Qt.UserRole:
return None
return getattr(self._data[index.row()],
str(self.roleNames()[role], "utf8"))
def rowCount(self, _: QModelIndex = QModelIndex()) -> int:
return len(self)
def _convert_new_value(self, value: NewItem) -> ListItem:
def convert() -> ListItem:
if self._data and isinstance(value, Mapping):
if not set(value.keys()) <= set(self.roles):
raise ValueError(
f"{value}: must have all these keys: {self.roles}"
)
return type(self._data[0])(**value)
if not self._data and isinstance(value, Mapping):
raise NotImplementedError("First item must be set from Python")
if self._data and isinstance(value, type(self._data[0])):
return value
if not self._data and isinstance(value, ListItem):
return value
raise TypeError("%r: must be mapping or %s" % (
value,
type(self._data[0]).__name__ if self._data else "ListItem"
))
value = convert()
value.setParent(self)
return value
@pyqtProperty(int, notify=countChanged)
def count(self) -> int:
return len(self)
@pyqtSlot(int, result="QVariant")
def get(self, index: int) -> ListItem:
return self._data[index]
@pyqtSlot(str, "QVariant", result=int)
def indexWhere(self, prop: str, is_value: Any) -> int:
for i, item in enumerate(self._data):
if getattr(item, prop) == is_value:
return i
raise ValueError(f"No item in model data with "
f"property {prop!r} set to {is_value!r}.")
@pyqtSlot(str, "QVariant", result="QVariant")
def getWhere(self, prop: str, is_value: Any) -> ListItem:
return self.get(self.indexWhere(prop, is_value))
@pyqtSlot(int, "QVariantMap")
def insert(self, index: int, value: NewItem) -> None:
value = self._convert_new_value(value)
self.beginInsertRows(QModelIndex(), index, index)
self._data.insert(index, value)
self.endInsertRows()
self.countChanged.emit(len(self))
self.changed.emit()
@pyqtSlot("QVariantMap")
def append(self, value: NewItem) -> None:
self.insert(len(self), value)
@pyqtSlot(list)
def extend(self, values: Iterable[NewItem]) -> None:
for val in values:
self.append(val)
@pyqtSlot("QVariantMap")
def update(self, index: int, value: NewItem) -> None:
value = self._convert_new_value(value)
for role in self.roles:
if role in value.no_update:
continue
setattr(self._data[index], role, getattr(value, role))
qidx = QAbstractListModel.index(self, index, 0)
self.dataChanged.emit(qidx, qidx, self.roleNames())
self.changed.emit()
@pyqtSlot(str, "QVariant", "QVariantMap")
def updateOrAppendWhere(
self, prop: str, is_value: Any, update_with: NewItem
) -> None:
try:
index = self.indexWhere(prop, is_value)
self.update(index, update_with)
except ValueError:
index = len(self)
self.append(update_with)
@pyqtSlot(int, list)
def set(self, index: int, value: NewItem) -> None:
qidx = QAbstractListModel.index(self, index, 0)
value = self._convert_new_value(value)
self._data[index] = value
self.dataChanged.emit(qidx, qidx, self.roleNames())
self.changed.emit()
@pyqtSlot(int, str, "QVariant")
def setProperty(self, index: int, prop: str, value: Any) -> None:
setattr(self._data[index], prop, value)
qidx = QAbstractListModel.index(self, index, 0)
self.dataChanged.emit(qidx, qidx, self.roleNames())
self.changed.emit()
@pyqtSlot(int, int)
@pyqtSlot(int, int, int)
def move(self, from_: int, to: int, n: int = 1) -> None:
# pylint: disable=invalid-name
qlast = from_ + n - 1
if (n <= 0) or (from_ == to) or (qlast == to) or \
not (len(self) > qlast >= 0) or \
not len(self) >= to >= 0:
return
qidx = QModelIndex()
qto = min(len(self), to + n if to > from_ else to)
# print(f"self.beginMoveRows(qidx, {from_}, {qlast}, qidx, {qto})")
valid = self.beginMoveRows(qidx, from_, qlast, qidx, qto)
if not valid:
logging.warning("Invalid move operation - %r", locals())
return
last = from_ + n
cut = self._data[from_:last]
del self._data[from_:last]
self._data[to:to] = cut
self.endMoveRows()
self.changed.emit()
@pyqtSlot(int)
def remove(self, index: int) -> None:
self.beginRemoveRows(QModelIndex(), index, index)
del self._data[index]
self.endRemoveRows()
self.countChanged.emit(len(self))
self.changed.emit()
@pyqtSlot()
def clear(self) -> None:
# Reimplemented for performance reasons (begin/endRemoveRows)
self.beginRemoveRows(QModelIndex(), 0, len(self))
self._data.clear()
self.endRemoveRows()
self.countChanged.emit(len(self))
self.changed.emit()