Allow the user to configure answer keys (#2502)

* add methods that allow the user to configure answer keys

* allow editing answer buttons in preferences

* import optional

* Give the layout referenced in code a clearer name (dae)

* Update placeholder text and make it translatable (dae)

The other items in the preferences screen don't have tooltips, so
placeholder text may be easier for the user to discover than a tooltip.

ftl/core/preferences.ftl

@@ -58,6 +58,7 @@ preferences-appearance = Appearance
 preferences-general = General
 preferences-style = Style
 preferences-review = Review
+preferences-answer-keys = Answer keys
 preferences-distractions = Distractions
 preferences-minimalist-mode = Minimalist mode
 preferences-editing = Editing
@@ -71,6 +72,7 @@ preferences-import-export = Import/Export
 preferences-network-timeout = Network timeout
 preferences-reset-window-sizes = Reset Window Sizes
 preferences-reset-window-sizes-complete = Window sizes and locations have been reset.
+preferences-shortcut-placeholder = Enter an unused shortcut key, or leave empty to disable.
 
 ## NO NEED TO TRANSLATE. This text is no longer used by Anki, and will be removed in the future.
 

qt/aqt/forms/preferences.ui

@@ -245,7 +245,7 @@
       <attribute name="title">
        <string>preferences_review</string>
       </attribute>
-      <layout class="QVBoxLayout" name="verticalLayout_6">
+      <layout class="QVBoxLayout" name="review_options_layout">
        <item>
         <widget class="QGroupBox" name="schedulerGroup">
          <property name="title">

qt/aqt/preferences.py

@@ -1,6 +1,7 @@
 # Copyright: Ankitects Pty Ltd and contributors
 # License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
+import functools
 import re
 from typing import Any, cast
 
@@ -47,8 +48,39 @@ class Preferences(QDialog):
         self.setup_collection()
         self.setup_profile()
         self.setup_global()
+        self.setup_configurable_answer_keys()
         self.show()
 
+    def setup_configurable_answer_keys(self):
+        """
+        Create a group box in Preferences with widgets that let the user edit answer keys.
+        """
+        ease_labels = (
+            (1, tr.studying_again()),
+            (2, tr.studying_hard()),
+            (3, tr.studying_good()),
+            (4, tr.studying_easy()),
+        )
+        self.form.review_options_layout.addWidget(
+            group := QGroupBox(tr.preferences_answer_keys())
+        )
+        group.setLayout(layout := QFormLayout())
+        for ease, label in ease_labels:
+            layout.addRow(
+                label,
+                line_edit := QLineEdit(self.mw.pm.get_answer_key(ease) or ""),
+            )
+            qconnect(
+                line_edit.textChanged,
+                functools.partial(self.mw.pm.set_answer_key, ease),
+            )
+            line_edit.setValidator(
+                QRegularExpressionValidator(
+                    QRegularExpression(r"^[a-z0-9\]\[=,./;\'\\-]$")
+                )
+            )
+            line_edit.setPlaceholderText(tr.preferences_shortcut_placeholder())
+
     def accept(self) -> None:
         # avoid exception if main window is already closed
         if not self.mw.col:

qt/aqt/profiles.py

@@ -10,7 +10,7 @@ import shutil
 import traceback
 from enum import Enum
 from pathlib import Path
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Optional
 
 import anki.lang
 import aqt.forms
@@ -116,6 +116,8 @@ class LoadMetaResult:
 
 
 class ProfileManager:
+    default_answer_keys = {ease_num: str(ease_num) for ease_num in range(1, 5)}
+
     def __init__(self, base: Path) -> None:  #
         "base should be retrieved via ProfileMangager.get_created_base_folder"
         ## Settings which should be forgotten each Anki restart
@@ -537,6 +539,12 @@ create table if not exists profiles
     def set_spacebar_rates_card(self, on: bool) -> None:
         self.meta["spacebar_rates_card"] = on
 
+    def get_answer_key(self, ease: int) -> Optional[str]:
+        return self.meta.setdefault("answer_keys", self.default_answer_keys).get(ease)
+
+    def set_answer_key(self, ease: int, key: str):
+        self.meta.setdefault("answer_keys", self.default_answer_keys)[ease] = key
+
     def hide_top_bar(self) -> bool:
         return self.meta.get("hide_top_bar", False)
 

qt/aqt/reviewer.py

@@ -3,6 +3,7 @@
 
 from __future__ import annotations
 
+import functools
 import json
 import random
 import re
@@ -507,14 +508,11 @@ class Reviewer:
             ("o", self.onOptions),
             ("i", self.on_card_info),
             ("Ctrl+Alt+i", self.on_previous_card_info),
-            ("1", lambda: self._answerCard(1)),
+            *(
-            ("2", lambda: self._answerCard(2)),
+                (key, functools.partial(self._answerCard, ease))
-            ("3", lambda: self._answerCard(3)),
+                for ease in aqt.mw.pm.default_answer_keys
-            ("4", lambda: self._answerCard(4)),
+                if (key := aqt.mw.pm.get_answer_key(ease))
-            ("h", lambda: self._answerCard(1)),
+            ),
-            ("j", lambda: self._answerCard(2)),
-            ("k", lambda: self._answerCard(3)),
-            ("l", lambda: self._answerCard(4)),
             ("u", self.mw.undo),
             ("5", self.on_pause_audio),
             ("6", self.on_seek_backward),