Customizable sentence parsing (#1217)

* Add new sentenceParsing options

* Update TextScanner.setOptions

* Assign terminator/quote maps

* Pass sentence parsing info to extractSentence

* Simplify setting

* Add setting for enableTerminationCharacters

* Create new settings for sentence termination characters

10 files changed, 600 insertions, 60 deletions

diff --git a/ext/bg/css/settings2.css b/ext/bg/css/settings2.css
index a74d0942..6ae9e335 100644
--- a/ext/bg/css/settings2.css
+++ b/ext/bg/css/settings2.css
@@ -1856,6 +1856,81 @@ input.translation-text-replacement-test-output {
     display: none;
 }
 
+.sentence-termination-character-list-table {
+    width: 100%;
+    table-layout: fixed;
+    border-spacing: 0.25em;
+    margin-top: 0.5em;
+    min-width: 400px;
+}
+.sentence-termination-character-list-table thead td {
+    white-space: nowrap;
+    font-size: var(--font-size-small);
+    line-height: 1;
+    text-align: left;
+    vertical-align: bottom;
+    font-weight: normal;
+}
+.sentence-termination-character-list-table td {
+    vertical-align: middle;
+    padding: 0;
+}
+.sentence-termination-character-list-table td:nth-child(1) {
+    width: 2em;
+}
+.sentence-termination-character-list-table td:nth-child(2) {
+    width: 4em;
+}
+.sentence-termination-character-list-table td:nth-child(3) {
+    width: 25%;
+}
+.sentence-termination-character-list-table td:nth-child(4) {
+    width: 18.5%;
+}
+.sentence-termination-character-list-table td:nth-child(5) {
+    width: 18.5%;
+}
+.sentence-termination-character-list-table td:nth-child(6) {
+    width: 40%;
+}
+.sentence-termination-character-list-table td:nth-child(7) {
+    width: 3em;
+}
+select.sentence-termination-character-type,
+input.sentence-termination-character-input1,
+input.sentence-termination-character-input2 {
+    width: 100%;
+}
+.sentence-termination-character-input2-alt {
+    text-align: center;
+}
+.sentence-termination-character-entry:not([data-type=quote]) .sentence-termination-character-input2 {
+    display: none;
+}
+.sentence-termination-character-entry[data-type=quote] .sentence-termination-character-input2-alt {
+    display: none;
+}
+.sentence-termination-character-include-list {
+    display: flex;
+    flex-flow: row nowrap;
+}
+.sentence-termination-character-include {
+    display: flex;
+    flex-flow: row nowrap;
+    white-space: nowrap;
+    align-items: center;
+}
+.sentence-termination-character-include>:first-child {
+    margin-right: 0.375em;
+}
+.sentence-termination-character-include+.sentence-termination-character-include {
+    margin-left: 1em;
+}
+#sentence-termination-character-list-empty {
+    flex: 0 1 auto;
+    margin-top: 0.5em;
+}
+
 
 /* Generic layouts */
 .margin-above {
diff --git a/ext/bg/data/options-schema.json b/ext/bg/data/options-schema.json
index 9053ebb1..151a7fe3 100644
--- a/ext/bg/data/options-schema.json
+++ b/ext/bg/data/options-schema.json
@@ -846,13 +846,72 @@
                             "sentenceParsing": {
                                 "type": "object",
                                 "required": [
-                                    "scanExtent"
+                                    "scanExtent",
+                                    "enableTerminationCharacters",
+                                    "terminationCharacters"
                                 ],
                                 "properties": {
                                     "scanExtent": {
                                         "type": "integer",
                                         "minimum": 0,
                                         "default": 200
+                                    },
+                                    "enableTerminationCharacters": {
+                                        "type": "boolean",
+                                        "default": true
+                                    },
+                                    "terminationCharacters": {
+                                        "type": "array",
+                                        "items": {
+                                            "type": "object",
+                                            "required": [
+                                                "enabled",
+                                                "character1",
+                                                "character2",
+                                                "includeCharacterAtStart",
+                                                "includeCharacterAtEnd"
+                                            ],
+                                            "properties": {
+                                                "enabled": {
+                                                    "type": "boolean",
+                                                    "default": true
+                                                },
+                                                "character1": {
+                                                    "type": "string",
+                                                    "default": "\"",
+                                                    "minLength": 1,
+                                                    "maxLength": 1
+                                                },
+                                                "character2": {
+                                                    "type": ["string", "null"],
+                                                    "default": "\"",
+                                                    "minLength": 1,
+                                                    "maxLength": 1
+                                                },
+                                                "includeCharacterAtStart": {
+                                                    "type": "boolean",
+                                                    "default": false
+                                                },
+                                                "includeCharacterAtEnd": {
+                                                    "type": "boolean",
+                                                    "default": false
+                                                }
+                                            }
+                                        },
+                                        "default": [
+                                            {"enabled": true, "character1": "「", "character2": "」", "includeCharacterAtStart": false, "includeCharacterAtEnd": false},
+                                            {"enabled": true, "character1": "『", "character2": "』", "includeCharacterAtStart": false, "includeCharacterAtEnd": false},
+                                            {"enabled": true, "character1": "\"", "character2": "\"", "includeCharacterAtStart": false, "includeCharacterAtEnd": false},
+                                            {"enabled": true, "character1": "'", "character2": "'", "includeCharacterAtStart": false, "includeCharacterAtEnd": false},
+                                            {"enabled": true, "character1": ".", "character2": null, "includeCharacterAtStart": false, "includeCharacterAtEnd": true},
+                                            {"enabled": true, "character1": "!", "character2": null, "includeCharacterAtStart": false, "includeCharacterAtEnd": true},
+                                            {"enabled": true, "character1": "?", "character2": null, "includeCharacterAtStart": false, "includeCharacterAtEnd": true},
+                                            {"enabled": true, "character1": "．", "character2": null, "includeCharacterAtStart": false, "includeCharacterAtEnd": true},
+                                            {"enabled": true, "character1": "。", "character2": null, "includeCharacterAtStart": false, "includeCharacterAtEnd": true},
+                                            {"enabled": true, "character1": "！", "character2": null, "includeCharacterAtStart": false, "includeCharacterAtEnd": true},
+                                            {"enabled": true, "character1": "？", "character2": null, "includeCharacterAtStart": false, "includeCharacterAtEnd": true},
+                                            {"enabled": true, "character1": "…", "character2": null, "includeCharacterAtStart": false, "includeCharacterAtEnd": true}
+                                        ]
                                     }
                                 }
                             }
diff --git a/ext/bg/js/options.js b/ext/bg/js/options.js
index 441d56ec..6c335346 100644
--- a/ext/bg/js/options.js
+++ b/ext/bg/js/options.js
@@ -684,13 +684,30 @@ class OptionsUtil {
         // Version 8 changes:
         //  Added translation.textReplacements.
         //  Moved anki.sentenceExt to sentenceParsing.scanExtent.
+        //  Added sentenceParsing.enableTerminationCharacters.
+        //  Added sentenceParsing.terminationCharacters.
         for (const profile of options.profiles) {
             profile.options.translation.textReplacements = {
                 searchOriginal: true,
                 groups: []
             };
             profile.options.sentenceParsing = {
-                scanExtent: profile.options.anki.sentenceExt
+                scanExtent: profile.options.anki.sentenceExt,
+                enableTerminationCharacters: true,
+                terminationCharacters: [
+                    {enabled: true, character1: '「', character2: '」', includeCharacterAtStart: false, includeCharacterAtEnd: false},
+                    {enabled: true, character1: '『', character2: '』', includeCharacterAtStart: false, includeCharacterAtEnd: false},
+                    {enabled: true, character1: '"', character2: '"', includeCharacterAtStart: false, includeCharacterAtEnd: false},
+                    {enabled: true, character1: '\'', character2: '\'', includeCharacterAtStart: false, includeCharacterAtEnd: false},
+                    {enabled: true, character1: '.', character2: null, includeCharacterAtStart: false, includeCharacterAtEnd: true},
+                    {enabled: true, character1: '!', character2: null, includeCharacterAtStart: false, includeCharacterAtEnd: true},
+                    {enabled: true, character1: '?', character2: null, includeCharacterAtStart: false, includeCharacterAtEnd: true},
+                    {enabled: true, character1: '．', character2: null, includeCharacterAtStart: false, includeCharacterAtEnd: true},
+                    {enabled: true, character1: '。', character2: null, includeCharacterAtStart: false, includeCharacterAtEnd: true},
+                    {enabled: true, character1: '！', character2: null, includeCharacterAtStart: false, includeCharacterAtEnd: true},
+                    {enabled: true, character1: '？', character2: null, includeCharacterAtStart: false, includeCharacterAtEnd: true},
+                    {enabled: true, character1: '…', character2: null, includeCharacterAtStart: false, includeCharacterAtEnd: true}
+                ]
             };
             delete profile.options.anki.sentenceExt;
         }
diff --git a/ext/bg/js/settings2/sentence-termination-characters-controller.js b/ext/bg/js/settings2/sentence-termination-characters-controller.js
new file mode 100644
index 00000000..173c609b
--- /dev/null
+++ b/ext/bg/js/settings2/sentence-termination-characters-controller.js
@@ -0,0 +1,255 @@
+/*
+ * Copyright (C) 2021  Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/* global
+ * OptionsUtil
+ */
+
+class SentenceTerminationCharactersController {
+    constructor(settingsController) {
+        this._settingsController = settingsController;
+        this._entries = [];
+        this._addButton = null;
+        this._resetButton = null;
+        this._listTable = null;
+        this._listContainer = null;
+        this._emptyIndicator = null;
+    }
+
+    get settingsController() {
+        return this._settingsController;
+    }
+
+    async prepare() {
+        this._addButton = document.querySelector('#sentence-termination-character-list-add');
+        this._resetButton = document.querySelector('#sentence-termination-character-list-reset');
+        this._listTable = document.querySelector('#sentence-termination-character-list-table');
+        this._listContainer = document.querySelector('#sentence-termination-character-list');
+        this._emptyIndicator = document.querySelector('#sentence-termination-character-list-empty');
+
+        this._addButton.addEventListener('click', this._onAddClick.bind(this));
+        this._resetButton.addEventListener('click', this._onResetClick.bind(this));
+        this._settingsController.on('optionsChanged', this._onOptionsChanged.bind(this));
+
+        await this._updateOptions();
+    }
+
+    async addEntry(terminationCharacterEntry) {
+        const options = await this._settingsController.getOptions();
+        const {sentenceParsing: {terminationCharacters}} = options;
+
+        await this._settingsController.modifyProfileSettings([{
+            action: 'splice',
+            path: 'sentenceParsing.terminationCharacters',
+            start: terminationCharacters.length,
+            deleteCount: 0,
+            items: [terminationCharacterEntry]
+        }]);
+
+        await this._updateOptions();
+    }
+
+    async deleteEntry(index) {
+        const options = await this._settingsController.getOptions();
+        const {sentenceParsing: {terminationCharacters}} = options;
+
+        if (index < 0 || index >= terminationCharacters.length) { return false; }
+
+        await this._settingsController.modifyProfileSettings([{
+            action: 'splice',
+            path: 'sentenceParsing.terminationCharacters',
+            start: index,
+            deleteCount: 1,
+            items: []
+        }]);
+
+        await this._updateOptions();
+        return true;
+    }
+
+    async modifyProfileSettings(targets) {
+        return await this._settingsController.modifyProfileSettings(targets);
+    }
+
+    // Private
+
+    _onOptionsChanged({options}) {
+        for (const entry of this._entries) {
+            entry.cleanup();
+        }
+
+        this._entries = [];
+        const {sentenceParsing: {terminationCharacters}} = options;
+
+        for (let i = 0, ii = terminationCharacters.length; i < ii; ++i) {
+            const terminationCharacterEntry = terminationCharacters[i];
+            const node = this._settingsController.instantiateTemplate('sentence-termination-character-entry');
+            this._listContainer.appendChild(node);
+            const entry = new SentenceTerminationCharacterEntry(this, terminationCharacterEntry, i, node);
+            this._entries.push(entry);
+            entry.prepare();
+        }
+
+        this._listTable.hidden = (terminationCharacters.length === 0);
+        this._emptyIndicator.hidden = (terminationCharacters.length !== 0);
+    }
+
+    _onAddClick(e) {
+        e.preventDefault();
+        this._addNewEntry();
+    }
+
+    _onResetClick(e) {
+        e.preventDefault();
+        this._reset();
+    }
+
+    async _addNewEntry() {
+        const newEntry = {
+            enabled: true,
+            character1: '"',
+            character2: '"',
+            includeCharacterAtStart: false,
+            includeCharacterAtEnd: false
+        };
+        return await this.addEntry(newEntry);
+    }
+
+    async _updateOptions() {
+        const options = await this._settingsController.getOptions();
+        this._onOptionsChanged({options});
+    }
+
+    async _reset() {
+        const defaultOptions = await this._getDefaultOptions();
+        const value = defaultOptions.profiles[0].options.sentenceParsing.terminationCharacters;
+        await this._settingsController.setProfileSetting('sentenceParsing.terminationCharacters', value);
+        await this._updateOptions();
+    }
+
+    async _getDefaultOptions() {
+        const optionsUtil = new OptionsUtil();
+        await optionsUtil.prepare();
+        const optionsFull = optionsUtil.getDefault();
+        return optionsFull;
+    }
+}
+
+class SentenceTerminationCharacterEntry {
+    constructor(parent, data, index, node) {
+        this._parent = parent;
+        this._data = data;
+        this._index = index;
+        this._node = node;
+        this._eventListeners = new EventListenerCollection();
+        this._character1Input = null;
+        this._character2Input = null;
+        this._basePath = `sentenceParsing.terminationCharacters[${this._index}]`;
+    }
+
+    prepare() {
+        const {enabled, character1, character2, includeCharacterAtStart, includeCharacterAtEnd} = this._data;
+        const node = this._node;
+
+        const enabledToggle = node.querySelector('.sentence-termination-character-enabled');
+        const typeSelect = node.querySelector('.sentence-termination-character-type');
+        const character1Input = node.querySelector('.sentence-termination-character-input1');
+        const character2Input = node.querySelector('.sentence-termination-character-input2');
+        const includeAtStartCheckbox = node.querySelector('.sentence-termination-character-include-at-start');
+        const includeAtEndheckbox = node.querySelector('.sentence-termination-character-include-at-end');
+        const menuButton = node.querySelector('.sentence-termination-character-entry-button');
+
+        this._character1Input = character1Input;
+        this._character2Input = character2Input;
+
+        const type = (character2 === null ? 'terminator' : 'quote');
+        node.dataset.type = type;
+
+        enabledToggle.checked = enabled;
+        typeSelect.value = type;
+        character1Input.value = character1;
+        character2Input.value = (character2 !== null ? character2 : '');
+        includeAtStartCheckbox.checked = includeCharacterAtStart;
+        includeAtEndheckbox.checked = includeCharacterAtEnd;
+
+        enabledToggle.dataset.setting = `${this._basePath}.enabled`;
+        includeAtStartCheckbox.dataset.setting = `${this._basePath}.includeCharacterAtStart`;
+        includeAtEndheckbox.dataset.setting = `${this._basePath}.includeCharacterAtEnd`;
+
+        this._eventListeners.addEventListener(typeSelect, 'change', this._onTypeSelectChange.bind(this), false);
+        this._eventListeners.addEventListener(character1Input, 'change', this._onCharacterChange.bind(this, 1), false);
+        this._eventListeners.addEventListener(character2Input, 'change', this._onCharacterChange.bind(this, 2), false);
+        this._eventListeners.addEventListener(menuButton, 'menuClosed', this._onMenuClosed.bind(this), false);
+    }
+
+    cleanup() {
+        this._eventListeners.removeAllEventListeners();
+        if (this._node.parentNode !== null) {
+            this._node.parentNode.removeChild(this._node);
+        }
+    }
+
+    // Private
+
+    _onTypeSelectChange(e) {
+        this._setHasCharacter2(e.currentTarget.value === 'quote');
+    }
+
+    _onCharacterChange(characterNumber, e) {
+        const node = e.currentTarget;
+        if (characterNumber === 2 && this._data.character2 === null) {
+            node.value = '';
+        }
+
+        const value = node.value.substring(0, 1);
+        this._setCharacterValue(node, characterNumber, value);
+    }
+
+    _onMenuClosed(e) {
+        const {detail: {action}} = e;
+        switch (action) {
+            case 'delete':
+                this._delete();
+                break;
+        }
+    }
+
+    async _delete() {
+        this._parent.deleteEntry(this._index);
+    }
+
+    async _setHasCharacter2(has) {
+        const okay = await this._setCharacterValue(this._character2Input, 2, has ? this._data.character1 : null);
+        if (okay) {
+            const type = (!has ? 'terminator' : 'quote');
+            this._node.dataset.type = type;
+        }
+    }
+
+    async _setCharacterValue(inputNode, characterNumber, value) {
+        const pathEnd = `character${characterNumber}`;
+        const r = await this._parent.settingsController.setProfileSetting(`${this._basePath}.${pathEnd}`, value);
+        const okay = !r[0].error;
+        if (okay) {
+            this._data[pathEnd] = value;
+        } else {
+            value = this._data[pathEnd];
+        }
+        inputNode.value = (value !== null ? value : '');
+        return okay;
+    }
+}
diff --git a/ext/bg/js/settings2/settings-main.js b/ext/bg/js/settings2/settings-main.js
index 1b3bfaa0..fc003ac8 100644
--- a/ext/bg/js/settings2/settings-main.js
+++ b/ext/bg/js/settings2/settings-main.js
@@ -32,6 +32,7 @@
  * ScanInputsController
  * ScanInputsSimpleController
  * SecondarySearchDictionaryController
+ * SentenceTerminationCharactersController
  * SettingsController
  * SettingsDisplayController
  * StatusFooter
@@ -124,6 +125,9 @@ async function setupGenericSettingsController(genericSettingController) {
         const translationTextReplacementsController = new TranslationTextReplacementsController(settingsController);
         translationTextReplacementsController.prepare();
 
+        const sentenceTerminationCharactersController = new SentenceTerminationCharactersController(settingsController);
+        sentenceTerminationCharactersController.prepare();
+
         await Promise.all(preparePromises);
 
         document.documentElement.dataset.loaded = 'true';
diff --git a/ext/bg/settings2.html b/ext/bg/settings2.html
index e5f105f0..81b91bf0 100644
--- a/ext/bg/settings2.html
+++ b/ext/bg/settings2.html
@@ -1125,29 +1125,31 @@
         </div>
     </div>
     <div class="settings-group advanced-only">
-        <div class="settings-item">
-            <div class="settings-item-inner settings-item-inner-wrappable">
-                <div class="settings-item-left">
-                    <div class="settings-item-label">
-                        Sentence scanning extent
-                        <a class="more-toggle more-only" data-parent-distance="4">(?)</a>
-                    </div>
-                </div>
-                <div class="settings-item-right">
-                    <input type="number" data-setting="sentenceParsing.scanExtent" min="0" step="1">
-                </div>
+        <div class="settings-item"><div class="settings-item-inner settings-item-inner-wrappable">
+            <div class="settings-item-left">
+                <div class="settings-item-label">Sentence scanning extent</div>
+                <div class="settings-item-description">Adjust how many characters are bidirectionally scanned to form a sentence.</div>
             </div>
-            <div class="settings-item-children more" hidden>
-                <p>
-                    This option controls the maximum scanning distance used to determine the bounds of a sentence,
-                    in number of characters.
-                    Sentence scanning is bidirectional and begins from both the start and end of the source term.
-                </p>
-                <p>
-                    <a class="more-toggle" data-parent-distance="3">Less&hellip;</a>
-                </p>
+            <div class="settings-item-right">
+                <input type="number" data-setting="sentenceParsing.scanExtent" min="0" step="1">
             </div>
-        </div>
+        </div></div>
+        <div class="settings-item"><div class="settings-item-inner settings-item-inner-wrappable">
+            <div class="settings-item-left">
+                <div class="settings-item-label">Enable sentence termination characters</div>
+            </div>
+            <div class="settings-item-right">
+                <label class="toggle"><input type="checkbox" data-setting="sentenceParsing.enableTerminationCharacters"><span class="toggle-body"><span class="toggle-track"></span><span class="toggle-knob"></span></span></label>
+            </div>
+        </div></div>
+        <div class="settings-item settings-item-button" data-modal-action="show,sentence-termination-characters"><div class="settings-item-inner">
+            <div class="settings-item-left">
+                <div class="settings-item-label">Configure sentence termination characters&hellip;</div>
+            </div>
+            <div class="settings-item-right open-panel-button-container">
+                <button class="icon-button"><span class="icon-button-inner"><span class="icon" data-icon="material-right-arrow"></span></span></button>
+            </div>
+        </div></div>
     </div>
 
     <!-- Translation -->
@@ -2725,6 +2727,86 @@
 </div></div></template>
 
 
+<!-- Sentence parsing modal -->
+<div id="sentence-termination-characters" class="modal-container" tabindex="-1" role="dialog" hidden><div class="modal-content">
+    <div class="modal-header">
+        <div class="modal-title">Sentence Termination Characters</div>
+        <div class="modal-header-button-container">
+            <div class="modal-header-button-group">
+                <button class="icon-button modal-header-button" data-modal-action="expand"><span class="icon-button-inner"><span class="icon" data-icon="expand"></span></span></button>
+                <button class="icon-button modal-header-button" data-modal-action="collapse"><span class="icon-button-inner"><span class="icon" data-icon="collapse"></span></span></button>
+            </div>
+        </div>
+    </div>
+    <div class="modal-body">
+        <p>
+            Sentences are terminated by punctuation and quotation marks, which can both be configured below.
+        </p>
+        <table class="sentence-termination-character-list-table" id="sentence-termination-character-list-table" hidden>
+            <thead><tr>
+                <td>#</td>
+                <td>Enabled</td>
+                <td>Type</td>
+                <td>Character 1</td>
+                <td>Character 2</td>
+                <td>Include character in sentence</td>
+                <td></td>
+            </tr></thead>
+            <tbody class="sentence-termination-character-list generic-list" id="sentence-termination-character-list"></tbody>
+        </table>
+        <div id="sentence-termination-character-list-empty" hidden>
+            No terminators defined.
+        </div>
+    </div>
+    <div class="modal-footer">
+        <button class="low-emphasis danger" id="sentence-termination-character-list-reset">Reset</button>
+        <button class="low-emphasis" id="sentence-termination-character-list-add">Add</button>
+        <button data-modal-action="hide">Close</button>
+    </div>
+</div></div>
+
+
+<!-- Sentence parsing templates -->
+<template id="sentence-termination-character-entry-template"><tr class="sentence-termination-character-entry">
+    <td class="generic-list-index-prefix"></td>
+    <td>
+        <label class="toggle"><input type="checkbox" class="sentence-termination-character-enabled"><span class="toggle-body"><span class="toggle-track"></span><span class="toggle-knob"></span></span></label>
+    </td>
+    <td>
+        <select class="sentence-termination-character-type">
+            <option value="terminator">Terminator</option>
+            <option value="quote">Quote</option>
+        </select>
+    </td>
+    <td>
+        <input type="text" class="sentence-termination-character-input1" maxlength="1">
+    </td>
+    <td>
+        <input type="text" class="sentence-termination-character-input2" maxlength="1">
+        <div class="sentence-termination-character-input2-alt">&mdash;</div>
+    </td>
+    <td>
+        <div class="sentence-termination-character-include-list">
+            <label class="sentence-termination-character-include">
+                <label class="checkbox"><input type="checkbox" class="sentence-termination-character-include-at-start"><span class="checkbox-body"><span class="checkbox-fill"></span><span class="checkbox-border"></span><span class="checkbox-check"></span></span></label>
+                <span>At start</span>
+            </label>
+            <label class="sentence-termination-character-include">
+                <label class="checkbox"><input type="checkbox" class="sentence-termination-character-include-at-end"><span class="checkbox-body"><span class="checkbox-fill"></span><span class="checkbox-border"></span><span class="checkbox-check"></span></span></label>
+                <span>At end</span>
+            </label>
+        </div>
+    </td>
+    <td>
+        <button class="icon-button sentence-termination-character-entry-button" data-menu="sentence-termination-character-entry-menu" data-menu-position="below,left"><span class="icon-button-inner"><span class="icon" data-icon="kebab-menu"></span></span></button>
+    </td>
+</tr></template>
+
+<template id="sentence-termination-character-entry-menu-template"><div class="popup-menu-container" tabindex="-1" role="dialog"><div class="popup-menu">
+    <button class="popup-menu-item" data-menu-action="delete">Delete</button>
+</div></div></template>
+
+
 <!-- Scripts -->
 <script src="/mixed/lib/jszip.min.js"></script>
 <script src="/mixed/lib/wanakana.min.js"></script>
@@ -2783,6 +2865,7 @@
 
 <script src="/bg/js/settings2/nested-popups-controller.js"></script>
 <script src="/bg/js/settings2/secondary-search-dictionary-controller.js"></script>
+<script src="/bg/js/settings2/sentence-termination-characters-controller.js"></script>
 <script src="/bg/js/settings2/settings-display-controller.js"></script>
 <script src="/bg/js/settings2/translation-text-replacements-controller.js"></script>
 
diff --git a/ext/fg/js/frontend.js b/ext/fg/js/frontend.js
index a206e3fb..4ca7874a 100644
--- a/ext/fg/js/frontend.js
+++ b/ext/fg/js/frontend.js
@@ -326,9 +326,9 @@ class Frontend {
             touchInputEnabled: scanningOptions.touchInputEnabled,
             pointerEventsEnabled: scanningOptions.pointerEventsEnabled,
             scanLength: scanningOptions.length,
-            sentenceScanExtent: sentenceParsingOptions.scanExtent,
             layoutAwareScan: scanningOptions.layoutAwareScan,
-            preventMiddleMouse
+            preventMiddleMouse,
+            sentenceParsingOptions
         });
         this._updateTextScannerEnabled();
 
diff --git a/ext/mixed/js/display.js b/ext/mixed/js/display.js
index 4c8d2f91..2b3ea21c 100644
--- a/ext/mixed/js/display.js
+++ b/ext/mixed/js/display.js
@@ -327,9 +327,9 @@ class Display extends EventDispatcher {
                 touchInputEnabled: scanningOptions.touchInputEnabled,
                 pointerEventsEnabled: scanningOptions.pointerEventsEnabled,
                 scanLength: scanningOptions.length,
-                sentenceScanExtent: sentenceParsingOptions.scanExtent,
                 layoutAwareScan: scanningOptions.layoutAwareScan,
-                preventMiddleMouse: scanningOptions.preventMiddleMouse.onSearchQuery
+                preventMiddleMouse: scanningOptions.preventMiddleMouse.onSearchQuery,
+                sentenceParsingOptions
             }
         });
 
@@ -1832,9 +1832,9 @@ class Display extends EventDispatcher {
             touchInputEnabled: false,
             pointerEventsEnabled: false,
             scanLength: scanningOptions.length,
-            sentenceScanExtent: sentenceParsingOptions.scanExtent,
             layoutAwareScan: scanningOptions.layoutAwareScan,
-            preventMiddleMouse: false
+            preventMiddleMouse: false,
+            sentenceParsingOptions
         });
 
         this._definitionTextScanner.setEnabled(true);
diff --git a/ext/mixed/js/document-util.js b/ext/mixed/js/document-util.js
index 647cbedc..42d3556b 100644
--- a/ext/mixed/js/document-util.js
+++ b/ext/mixed/js/document-util.js
@@ -24,24 +24,6 @@
 class DocumentUtil {
     constructor() {
         this._transparentColorPattern = /rgba\s*\([^)]*,\s*0(?:\.0+)?\s*\)/;
-
-        const quoteArray = [
-            ['「', '」'],
-            ['『', '』'],
-            ['\'', '\''],
-            ['"', '"']
-        ];
-        const terminatorString = '…。．.？?！!';
-        this._terminatorMap = new Map();
-        for (const char of terminatorString) {
-            this._terminatorMap.set(char, [false, true]);
-        }
-        this._forwardQuoteMap = new Map();
-        this._backwardQuoteMap = new Map();
-        for (const [char1, char2] of quoteArray) {
-            this._forwardQuoteMap.set(char1, [char2, false]);
-            this._backwardQuoteMap.set(char2, [char1, false]);
-        }
     }
 
     getRangeFromPoint(x, y, deepContentScan) {
@@ -81,11 +63,30 @@ class DocumentUtil {
         }
     }
 
-    extractSentence(source, layoutAwareScan, extent) {
-        const terminatorMap = this._terminatorMap;
-        const forwardQuoteMap = this._forwardQuoteMap;
-        const backwardQuoteMap = this._backwardQuoteMap;
-
+    /**
+     * Extract a sentence from a document.
+     * @param source The text source object, either `TextSourceRange` or `TextSourceElement`.
+     * @param layoutAwareScan Whether or not layout-aware scan mode should be used.
+     * @param extent The length of the sentence to extract.
+     * @param terminatorMap A mapping of characters that terminate a sentence.
+     *   Format:
+     *   ```js
+     *   new Map([ [character: string, [includeCharacterAtStart: boolean, includeCharacterAtEnd: boolean]], ... ])
+     *   ```
+     * @param forwardQuoteMap A mapping of quote characters that delimit a sentence.
+     *   Format:
+     *   ```js
+     *   new Map([ [character: string, [otherCharacter: string, includeCharacterAtStart: boolean]], ... ])
+     *   ```
+     * @param backwardQuoteMap A mapping of quote characters that delimit a sentence,
+     *   which is the inverse of forwardQuoteMap.
+     *   Format:
+     *   ```js
+     *   new Map([ [character: string, [otherCharacter: string, includeCharacterAtEnd: boolean]], ... ])
+     *   ```
+     * @returns The sentence and the offset to the original source: `{sentence: string, offset: integer}`.
+     */
+    extractSentence(source, layoutAwareScan, extent, terminatorMap, forwardQuoteMap, backwardQuoteMap) {
         // Scan text
         source = source.clone();
         const startLength = source.setStartOffset(extent, layoutAwareScan);
diff --git a/ext/mixed/js/text-scanner.js b/ext/mixed/js/text-scanner.js
index f26bcf0e..11a6f88f 100644
--- a/ext/mixed/js/text-scanner.js
+++ b/ext/mixed/js/text-scanner.js
@@ -59,9 +59,12 @@ class TextScanner extends EventDispatcher {
         this._touchInputEnabled = false;
         this._pointerEventsEnabled = false;
         this._scanLength = 1;
-        this._sentenceScanExtent = 1;
         this._layoutAwareScan = false;
         this._preventMiddleMouse = false;
+        this._sentenceScanExtent = 0;
+        this._sentenceTerminatorMap = new Map();
+        this._sentenceForwardQuoteMap = new Map();
+        this._sentenceBackwardQuoteMap = new Map();
         this._inputs = [];
 
         this._enabled = false;
@@ -142,9 +145,9 @@ class TextScanner extends EventDispatcher {
         touchInputEnabled,
         pointerEventsEnabled,
         scanLength,
-        sentenceScanExtent,
         layoutAwareScan,
-        preventMiddleMouse
+        preventMiddleMouse,
+        sentenceParsingOptions
     }) {
         if (Array.isArray(inputs)) {
             this._inputs = inputs.map(({
@@ -193,15 +196,38 @@ class TextScanner extends EventDispatcher {
         if (typeof scanLength === 'number') {
             this._scanLength = scanLength;
         }
-        if (typeof sentenceScanExtent === 'number') {
-            this._sentenceScanExtent = sentenceScanExtent;
-        }
         if (typeof layoutAwareScan === 'boolean') {
             this._layoutAwareScan = layoutAwareScan;
         }
         if (typeof preventMiddleMouse === 'boolean') {
             this._preventMiddleMouse = preventMiddleMouse;
         }
+        if (typeof sentenceParsingOptions === 'object' && sentenceParsingOptions !== null) {
+            const {scanExtent, enableTerminationCharacters, terminationCharacters} = sentenceParsingOptions;
+            const hasTerminationCharacters = (typeof terminationCharacters === 'object' && Array.isArray(terminationCharacters));
+            if (typeof scanExtent === 'number') {
+                this._sentenceScanExtent = sentenceParsingOptions.scanExtent;
+            }
+            if (typeof enableTerminationCharacters === 'boolean' || hasTerminationCharacters) {
+                const sentenceTerminatorMap = this._sentenceTerminatorMap;
+                const sentenceForwardQuoteMap = this._sentenceForwardQuoteMap;
+                const sentenceBackwardQuoteMap = this._sentenceBackwardQuoteMap;
+                sentenceTerminatorMap.clear();
+                sentenceForwardQuoteMap.clear();
+                sentenceBackwardQuoteMap.clear();
+                if (enableTerminationCharacters !== false && hasTerminationCharacters) {
+                    for (const {enabled, character1, character2, includeCharacterAtStart, includeCharacterAtEnd} of terminationCharacters) {
+                        if (!enabled) { continue; }
+                        if (character2 === null) {
+                            sentenceTerminatorMap.set(character1, [includeCharacterAtStart, includeCharacterAtEnd]);
+                        } else {
+                            sentenceForwardQuoteMap.set(character1, [character2, includeCharacterAtStart]);
+                            sentenceBackwardQuoteMap.set(character2, [character1, includeCharacterAtEnd]);
+                        }
+                    }
+                }
+            }
+        }
     }
 
     getTextSourceContent(textSource, length, layoutAwareScan) {
@@ -723,6 +749,9 @@ class TextScanner extends EventDispatcher {
     async _findTerms(textSource, optionsContext) {
         const scanLength = this._scanLength;
         const sentenceScanExtent = this._sentenceScanExtent;
+        const sentenceTerminatorMap = this._sentenceTerminatorMap;
+        const sentenceForwardQuoteMap = this._sentenceForwardQuoteMap;
+        const sentenceBackwardQuoteMap = this._sentenceBackwardQuoteMap;
         const layoutAwareScan = this._layoutAwareScan;
         const searchText = this.getTextSourceContent(textSource, scanLength, layoutAwareScan);
         if (searchText.length === 0) { return null; }
@@ -731,13 +760,23 @@ class TextScanner extends EventDispatcher {
         if (definitions.length === 0) { return null; }
 
         textSource.setEndOffset(length, layoutAwareScan);
-        const sentence = this._documentUtil.extractSentence(textSource, layoutAwareScan, sentenceScanExtent);
+        const sentence = this._documentUtil.extractSentence(
+            textSource,
+            layoutAwareScan,
+            sentenceScanExtent,
+            sentenceTerminatorMap,
+            sentenceForwardQuoteMap,
+            sentenceBackwardQuoteMap
+        );
 
         return {definitions, sentence, type: 'terms'};
     }
 
     async _findKanji(textSource, optionsContext) {
         const sentenceScanExtent = this._sentenceScanExtent;
+        const sentenceTerminatorMap = this._sentenceTerminatorMap;
+        const sentenceForwardQuoteMap = this._sentenceForwardQuoteMap;
+        const sentenceBackwardQuoteMap = this._sentenceBackwardQuoteMap;
         const layoutAwareScan = this._layoutAwareScan;
         const searchText = this.getTextSourceContent(textSource, 1, layoutAwareScan);
         if (searchText.length === 0) { return null; }
@@ -746,7 +785,14 @@ class TextScanner extends EventDispatcher {
         if (definitions.length === 0) { return null; }
 
         textSource.setEndOffset(1, layoutAwareScan);
-        const sentence = this._documentUtil.extractSentence(textSource, layoutAwareScan, sentenceScanExtent);
+        const sentence = this._documentUtil.extractSentence(
+            textSource,
+            layoutAwareScan,
+            sentenceScanExtent,
+            sentenceTerminatorMap,
+            sentenceForwardQuoteMap,
+            sentenceBackwardQuoteMap
+        );
 
         return {definitions, sentence, type: 'kanji'};
     }