75 lines
2.1 KiB
Python
75 lines
2.1 KiB
Python
# SPDX-License-Identifier: LGPL-3.0-or-later
|
|
|
|
from typing import TYPE_CHECKING, Any, Dict, Optional
|
|
|
|
from ..pyotherside_events import ModelItemFieldChanged
|
|
from ..utils import serialize_value_for_qml
|
|
|
|
if TYPE_CHECKING:
|
|
from .model import Model
|
|
|
|
|
|
class ModelItem:
|
|
"""Base class for items stored inside a `Model`.
|
|
|
|
This class must be subclassed and not used directly.
|
|
All subclasses must be dataclasses.
|
|
|
|
Subclasses are also expected to implement `__lt__()`,
|
|
to provide support for comparisons with the `<`, `>`, `<=`, `=>` operators
|
|
and thus allow a `Model` to keep its data sorted.
|
|
"""
|
|
|
|
def __new__(cls, *_args, **_kwargs) -> "ModelItem":
|
|
cls.parent_model: Optional[Model] = None
|
|
return super().__new__(cls)
|
|
|
|
|
|
def __setattr__(self, name: str, value) -> None:
|
|
"""If this item is in a `Model`, alert it of attribute changes."""
|
|
|
|
if name == "parent_model" or self.parent_model is None:
|
|
super().__setattr__(name, value)
|
|
return
|
|
|
|
if getattr(self, name) == value:
|
|
return
|
|
|
|
with self.parent_model._write_lock:
|
|
super().__setattr__(name, value)
|
|
|
|
old_index = self.parent_model._sorted_data.index(self)
|
|
self.parent_model._sorted_data.sort()
|
|
new_index = self.parent_model._sorted_data.index(self)
|
|
|
|
ModelItemFieldChanged(
|
|
self.parent_model.sync_id,
|
|
old_index,
|
|
new_index,
|
|
name,
|
|
self.serialize_field(name),
|
|
)
|
|
|
|
|
|
def __delattr__(self, name: str) -> None:
|
|
raise NotImplementedError()
|
|
|
|
|
|
def serialize_field(self, field: str) -> Any:
|
|
return serialize_value_for_qml(
|
|
getattr(self, field),
|
|
json_list_dicts=True,
|
|
)
|
|
|
|
|
|
@property
|
|
def serialized(self) -> Dict[str, Any]:
|
|
"""Return this item as a dict ready to be passed to QML."""
|
|
|
|
return {
|
|
name: self.serialize_field(name) for name in dir(self)
|
|
if not (
|
|
name.startswith("_") or name in ("parent_model", "serialized")
|
|
)
|
|
}
|