Document handling

New/Open/Save/Save as and Undo/Redo

src/bedit_gui/documents/document.py

@@ -0,0 +1,80 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+from PySide6.QtCore import QObject, Signal
+from PySide6.QtGui import QUndoStack
+
+from bedit_core.models import ID
+from bedit_core.models import Document as CoreDocument
+from bedit_gui.services import document_files
+
+
+class Document(QObject):
+    """The editable document currently owned by the GUI application."""
+
+    model_changed = Signal(object)
+    path_changed = Signal(object)
+    modified_changed = Signal(bool)
+
+    def __init__(self, parent: QObject | None = None) -> None:
+        super().__init__(parent)
+        self.undo_stack = QUndoStack(self)
+        self.undo_stack.cleanChanged.connect(self._on_clean_changed)
+        self._model = self._new_model()
+        self._path: Path | None = None
+        self.undo_stack.setClean()
+
+    @property
+    def model(self) -> CoreDocument:
+        return self._model
+
+    @property
+    def path(self) -> Path | None:
+        return self._path
+
+    @property
+    def modified(self) -> bool:
+        return not self.undo_stack.isClean()
+
+    def new(self) -> None:
+        self._replace(self._new_model(), None)
+
+    def open(self, path: str | Path) -> None:
+        file_path = Path(path)
+        model = document_files.load(file_path)
+        self._replace(model, file_path)
+
+    def save(self) -> None:
+        if self._path is None:
+            raise ValueError("the document does not have a file path")
+        document_files.save(self._model, self._path)
+        self.undo_stack.setClean()
+
+    def save_as(self, path: str | Path) -> None:
+        file_path = Path(path)
+        document_files.save(self._model, file_path)
+        if file_path != self._path:
+            self._path = file_path
+            self.path_changed.emit(file_path)
+        self.undo_stack.setClean()
+
+    def _replace(self, model: CoreDocument, path: Path | None) -> None:
+        self.undo_stack.clear()
+        self._model = model
+        self._path = path
+        self.model_changed.emit(model)
+        self.path_changed.emit(path)
+        self.undo_stack.setClean()
+
+    def _on_clean_changed(self, clean: bool) -> None:
+        self.modified_changed.emit(not clean)
+
+    @staticmethod
+    def _new_model() -> CoreDocument:
+        return CoreDocument(
+            format_version=1,
+            id=ID(),
+            name="Untitled",
+            root={},
+        )