If deck options are modified, ask before closing (#3410)

* If deck options are modified, ask before closing

This imitates the way the note editor behaves. If a user assumes by
error that chanhges are automatically saved, it ensures they won't
lose them.

Also, this will eventually allows to have the same feature on
AnkiDroid. While, currently, we always ask the user whether they want
to close the deck options, even when there are no modification, which
seems to regularly frustate users (including myself).

I'm new to Svelte, please let me know whether there is a better way to
obtain the information from Svelte state that I missed.

Note that I ensured that only a boolean can be obtained. I didn't
cause the whole state to be accessible. May be useful for some
add-ons, I guess, but risks breaking too much things.

Regarding the deckoptions.py, I tried to imitate addcards.py way to
check whether the add card view can be closed. Reusing the same
function and variable name when possible.

* Update qt/aqt/deckoptions.py (dae)

qt/aqt/deckoptions.py

@@ -14,6 +14,7 @@ from aqt.qt import *
 from aqt.utils import (
     KeyboardModifiersPressed,
     addCloseShortcut,
+    ask_user_dialog,
     disable_help_button,
     restoreGeom,
     saveGeom,
@@ -33,6 +34,8 @@ class DeckOptionsDialog(QDialog):
         self.mw = mw
         self._deck = deck
         self._setup_ui()
+        self._close_event_has_cleaned_up = False
+        self._ready = False
 
     def _setup_ui(self) -> None:
         self.setWindowModality(Qt.WindowModality.ApplicationModal)
@@ -57,8 +60,44 @@ class DeckOptionsDialog(QDialog):
 
     def _on_bridge_cmd(self, cmd: str) -> None:
         if cmd == "deckOptionsReady":
+            self.ready = True
             gui_hooks.deck_options_did_load(self)
 
+    def closeEvent(self, evt: QCloseEvent) -> None:
+        if self._close_event_has_cleaned_up:
+            evt.accept()
+            return
+        evt.ignore()
+        self.if_can_close()
+
+    def _close(self):
+        """Close. Ensure the closeEvent is not ignored."""
+        self._close_event_has_cleaned_up = True
+        self.close()
+
+    def if_can_close(self):
+        """Close if there was no modification. Otherwise ask for confirmation first."""
+
+        def callbackWithUserChoice(choice: int):
+            if choice == 0:
+                # The user accepted to discard current input.
+                self._close()
+
+        def if_can_close_callback_with_data_information(has_modified_dataData: bool):
+            if has_modified_dataData:
+                ask_user_dialog(
+                    tr.card_templates_discard_changes(),
+                    callback=callbackWithUserChoice,
+                    buttons=[
+                        QMessageBox.StandardButton.Discard,
+                        (tr.adding_keep_editing(), QMessageBox.ButtonRole.RejectRole),
+                    ],
+                )
+            else:
+                self._close()
+
+        self.has_modified_data(if_can_close_callback_with_data_information)
+
     def reject(self) -> None:
         self.mw.col.set_wants_abort()
         self.web.cleanup()
@@ -66,6 +105,15 @@ class DeckOptionsDialog(QDialog):
         saveGeom(self, self.TITLE)
         QDialog.reject(self)
 
+    def has_modified_data(self, callback: Callable[[bool], None]):
+        """Calls `callback` with the information of whether any deck options are modified."""
+        if self.ready:
+            self.web.evalWithCallback(
+                "anki.deckOptionsPendingChanges()", callback
+            )
+        else:
+            callback(False)
+
 
 def confirm_deck_then_display_options(active_card: Card | None = None) -> None:
     decks = [aqt.mw.col.decks.current()]

ts/routes/deck-options/[deckId]/+page.svelte

@@ -11,6 +11,10 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     export let data: PageData;
     let page: DeckOptionsPage;
 
+    globalThis.anki ||= {};
+    globalThis.anki.deckOptionsPendingChanges = () => {
+        return data.state.isModified();
+    };
     onMount(() => {
         globalThis.$deckOptions = new Promise((resolve, _reject) => {
             resolve(page);

ts/routes/deck-options/lib.ts

@@ -292,6 +292,10 @@ export class DeckOptionsState {
         });
         return list;
     }
+
+    isModified(): boolean {
+        return this.removedConfigs.length > 0 || this.modifiedConfigs.size > 0;
+    }
 }
 
 function bytesToObject(bytes: Uint8Array): Record<string, unknown> {