Document handling

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

src/bedit_gui/controllers/document_controller.py

@@ -0,0 +1,113 @@
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Protocol
+
+from PySide6.QtCore import QEvent, QObject
+
+from bedit_gui.documents import Document
+from bedit_gui.views.dialogs.document_dialogs import (
+    DocumentDialogs,
+    SaveChangesChoice,
+)
+from bedit_gui.views.main_window import MainWindow
+
+
+class DocumentDialogProvider(Protocol):
+    def choose_open_path(self, current_path: Path | None) -> Path | None: ...
+
+    def choose_save_path(self, current_path: Path | None) -> Path | None: ...
+
+    def ask_save_changes(self) -> SaveChangesChoice: ...
+
+    def show_file_error(self, title: str, error: Exception) -> None: ...
+
+
+class DocumentController(QObject):
+    """Coordinates the single-document workflow with the main window."""
+
+    def __init__(
+        self,
+        document: Document,
+        window: MainWindow,
+        dialogs: DocumentDialogProvider | None = None,
+    ) -> None:
+        super().__init__(window)
+        self.document = document
+        self.window = window
+        self.dialogs = dialogs or DocumentDialogs(window)
+
+        window.ui.actionNew_File.triggered.connect(self.new_document)
+        window.ui.actionOpen_File.triggered.connect(self.open_document)
+        window.ui.actionSave_File.triggered.connect(self.save_document)
+        window.ui.actionSave_File_As.triggered.connect(self.save_document_as)
+        window.ui.actionClose.triggered.connect(window.close)
+
+        document.path_changed.connect(self.update_window_title)
+        document.modified_changed.connect(self.update_window_title)
+        window.installEventFilter(self)
+        self.update_window_title()
+
+    def new_document(self) -> None:
+        if self.maybe_save_changes():
+            self.document.new()
+
+    def open_document(self) -> None:
+        if not self.maybe_save_changes():
+            return
+
+        path = self.dialogs.choose_open_path(self.document.path)
+        if path is None:
+            return
+
+        try:
+            self.document.open(path)
+        except (OSError, TypeError, ValueError) as exc:
+            self.dialogs.show_file_error("Could not open document", exc)
+
+    def save_document(self) -> bool:
+        if self.document.path is None:
+            return self.save_document_as()
+        try:
+            self.document.save()
+        except (OSError, TypeError, ValueError) as exc:
+            self.dialogs.show_file_error("Could not save document", exc)
+            return False
+        return True
+
+    def save_document_as(self) -> bool:
+        path = self.dialogs.choose_save_path(self.document.path)
+        if path is None:
+            return False
+
+        try:
+            self.document.save_as(path)
+        except (OSError, TypeError, ValueError) as exc:
+            self.dialogs.show_file_error("Could not save document", exc)
+            return False
+        return True
+
+    def maybe_save_changes(self) -> bool:
+        if not self.document.modified:
+            return True
+
+        choice = self.dialogs.ask_save_changes()
+        if choice is SaveChangesChoice.SAVE:
+            return self.save_document()
+        return choice is SaveChangesChoice.DISCARD
+
+    def update_window_title(self, *_args: object) -> None:
+        name = self.document.path.name if self.document.path else "Untitled"
+        marker = "*" if self.document.modified else ""
+        self.window.setWindowTitle(f"{name}{marker} — BEdit")
+
+    def eventFilter(self, watched: QObject, event: QEvent) -> bool:
+        window = getattr(self, "window", None)
+        if (
+            watched is window
+            and event.type() == QEvent.Type.Close
+            and not self.maybe_save_changes()
+        ):
+            event.ignore()
+            return True
+        return super().eventFilter(watched, event)