Scanning input generalization (#789)

* Add inputs to options.scanning

* Update CSS for mouse buttons

* Update list counters

* Set up HTML/CSS

* Add input controller

* Use new inputs

* Include mouse buttons

* Update how button inputs are detected

* Add index/empty fields to the input details object

* Update none check for scanning modifier

* Remove old settings

* Remove unused global

12 files changed, 417 insertions, 88 deletions

diff --git a/ext/bg/css/settings.css b/ext/bg/css/settings.css
index 2dc71d91..6d32c9c5 100644
--- a/ext/bg/css/settings.css
+++ b/ext/bg/css/settings.css
@@ -46,6 +46,21 @@ html:root:not([data-options-general-result-output-mode=merge]) #dict-main-group
     border-color: #f00000;
 }
 
+.mouse-button {
+    padding-left: 10px;
+    padding-right: 10px;
+}
+.mouse-button[hidden] {
+    display: none;
+}
+.mouse-button-icon {
+    width: 20px;
+    height: 20px;
+    display: block;
+    background: url(/mixed/img/mouse.svg) no-repeat center center;
+    background-size: 20px 20px;
+}
+
 .condition {
     display: flex;
     -flex-wrap: wrap;
@@ -113,21 +128,80 @@ html:root:not([data-options-general-result-output-mode=merge]) #dict-main-group
     display: none;
 }
 
-.condition-mouse-button[hidden] {
-    display: none;
+.scan-input-list {
+    counter-reset: scan-input-id;
+}
+.scan-input-table {
+    width: 100%;
+}
+.scan-input-list:not(:empty)+#scan-input-add {
+    border-top-left-radius: 0;
+    border-top-right-radius: 0;
+}
+.scan-input-index-cell {
+    position: relative;
+    min-width: 40px;
+}
+.scan-input-index {
+    position: absolute;
+    left: 0;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    font-size: 14px;
+    color: #555;
+    background-color: #eee;
+    border: 1px solid #ccc;
+    border-top-left-radius: 4px;
+    display: flex;
+    justify-content: center;
+    align-items: center;
+}
+.scan-input-index:after {
+    display: block;
+    counter-increment: scan-input-id;
+    content: counter(scan-input-id);
+}
+.scan-input-prefix {
+    padding: 6px 12px;
+    font-size: 14px;
+    color: #555;
+    text-align: center;
+    background-color: #eee;
+    border: 1px solid #ccc;
+    width: 100%;
+}
+.scan-input-input-cell {
+    width: 100%;
+}
+.scan-input-input-cell>input {
+    border-radius: 0;
+}
+.scan-input-mouse-button-cell>button {
+    border-radius: 0;
+}
+.scan-input-remove-button-cell>button {
+    border-top-left-radius: 0;
+    border-bottom-left-radius: 0;
+}
+.scan-input:nth-child(n+2) .scan-input-index {
+    border-top-left-radius: 0;
+}
+.scan-input:last-child tr:last-of-type .scan-input-mouse-button-cell>button {
+    border-bottom-right-radius: 4px;
 }
 
-.audio-source-list {
-    counter-reset: audio-source-id;
+.generic-input-list {
+    counter-reset: generic-input-id;
 }
-.audio-source-list .audio-source-prefix {
+.generic-input-list .generic-input-prefix {
     flex: 0 0 auto;
     width: 39px;
     text-align: center;
 }
-.audio-source-list .audio-source-prefix:after {
-    counter-increment: audio-source-id;
-    content: counter(audio-source-id);
+.generic-input-list .generic-input-prefix:after {
+    counter-increment: generic-input-id;
+    content: counter(generic-input-id);
 }
 
 #custom-popup-css,
diff --git a/ext/bg/data/options-schema.json b/ext/bg/data/options-schema.json
index 52d96db9..17fe096c 100644
--- a/ext/bg/data/options-schema.json
+++ b/ext/bg/data/options-schema.json
@@ -318,7 +318,7 @@
                             "scanning": {
                                 "type": "object",
                                 "required": [
-                                    "middleMouse",
+                                    "inputs",
                                     "touchInputEnabled",
                                     "selectText",
                                     "alphanumeric",
@@ -336,9 +336,30 @@
                                     "layoutAwareScan"
                                 ],
                                 "properties": {
-                                    "middleMouse": {
-                                        "type": "boolean",
-                                        "default": true
+                                    "inputs": {
+                                        "type": "array",
+                                        "default": [
+                                            {
+                                                "include": "shift",
+                                                "exclude": ""
+                                            }
+                                        ],
+                                        "items": {
+                                            "required": [
+                                                "include",
+                                                "exclude"
+                                            ],
+                                            "properties": {
+                                                "include": {
+                                                    "type": "string",
+                                                    "default": "shift"
+                                                },
+                                                "exclude": {
+                                                    "type": "string",
+                                                    "default": ""
+                                                }
+                                            }
+                                        }
                                     },
                                     "touchInputEnabled": {
                                         "type": "boolean",
@@ -371,11 +392,6 @@
                                         "minimum": 1,
                                         "default": 10
                                     },
-                                    "modifier": {
-                                        "type": "string",
-                                        "enum": ["none", "alt", "ctrl", "shift", "meta"],
-                                        "default": "shift"
-                                    },
                                     "deepDomScan": {
                                         "type": "boolean",
                                         "default": false
diff --git a/ext/bg/js/options.js b/ext/bg/js/options.js
index 398fb95c..ab32bb11 100644
--- a/ext/bg/js/options.js
+++ b/ext/bg/js/options.js
@@ -474,6 +474,7 @@ class OptionsUtil {
         //  Added usePopupWindow.
         //  Updated handlebars templates to include "clipboard-image" definition.
         //  Added hideDelay.
+        //  Added inputs to profileOptions.scanning.
         for (const {conditionGroups} of options.profiles) {
             for (const {conditions} of conditionGroups) {
                 for (const condition of conditions) {
@@ -489,6 +490,24 @@ class OptionsUtil {
         for (const {options: profileOptions} of options.profiles) {
             profileOptions.general.usePopupWindow = false;
             profileOptions.scanning.hideDelay = 0;
+
+            const {modifier, middleMouse} = profileOptions.scanning;
+            const scanningInputs = [];
+            switch (modifier) {
+                case 'alt':
+                case 'ctrl':
+                case 'shift':
+                case 'meta':
+                    scanningInputs.push(modifier);
+                    break;
+                case 'none':
+                    scanningInputs.push('');
+                    break;
+            }
+            if (middleMouse) {
+                scanningInputs.push('mouse2');
+            }
+            profileOptions.scanning.inputs = scanningInputs;
         }
         await this._addFieldTemplatesToOptions(options, '/bg/data/anki-field-templates-upgrade-v4.handlebars');
         return options;
diff --git a/ext/bg/js/settings/keyboard-mouse-input-field.js b/ext/bg/js/settings/keyboard-mouse-input-field.js
index b1530c1b..4ba0d3ed 100644
--- a/ext/bg/js/settings/keyboard-mouse-input-field.js
+++ b/ext/bg/js/settings/keyboard-mouse-input-field.js
@@ -172,7 +172,7 @@ class KeyboardMouseInputField extends EventDispatcher {
 
     _onMouseButtonMouseDown(e) {
         e.preventDefault();
-        this._addInputs([`mouse${e.button}`]);
+        this._addInputs(DocumentUtil.getActiveButtons(e));
     }
 
     _onMouseButtonMouseUp(e) {
diff --git a/ext/bg/js/settings/main.js b/ext/bg/js/settings/main.js
index 7fa8e502..4932586b 100644
--- a/ext/bg/js/settings/main.js
+++ b/ext/bg/js/settings/main.js
@@ -22,10 +22,10 @@
  * ClipboardPopupsController
  * DictionaryController
  * DictionaryImportController
- * DocumentUtil
  * GenericSettingController
  * PopupPreviewController
  * ProfileController
+ * ScanInputsController
  * SettingsBackup
  * SettingsController
  * StorageController
@@ -40,23 +40,6 @@ function showExtensionInformation() {
     node.textContent = `${manifest.name} v${manifest.version}`;
 }
 
-async function settingsPopulateModifierKeys() {
-    const scanModifierKeySelect = document.querySelector('#scan-modifier-key');
-    scanModifierKeySelect.textContent = '';
-
-    const {platform: {os}} = await api.getEnvironmentInfo();
-    const modifierKeys = [
-        ['none', 'None'],
-        ...DocumentUtil.getModifierKeys(os)
-    ];
-    for (const [value, name] of modifierKeys) {
-        const option = document.createElement('option');
-        option.value = value;
-        option.textContent = name;
-        scanModifierKeySelect.appendChild(option);
-    }
-}
-
 async function setupEnvironmentInfo() {
     const {browser, platform} = await api.getEnvironmentInfo();
     document.documentElement.dataset.browser = browser;
@@ -71,7 +54,6 @@ async function setupEnvironmentInfo() {
 
         setupEnvironmentInfo();
         showExtensionInformation();
-        settingsPopulateModifierKeys();
 
         const optionsFull = await api.optionsGetFull();
 
@@ -111,6 +93,9 @@ async function setupEnvironmentInfo() {
         const settingsBackup = new SettingsBackup(settingsController);
         settingsBackup.prepare();
 
+        const scanInputsController = new ScanInputsController(settingsController);
+        scanInputsController.prepare();
+
         yomichan.ready();
     } catch (e) {
         yomichan.logError(e);
diff --git a/ext/bg/js/settings/profile-conditions-ui.js b/ext/bg/js/settings/profile-conditions-ui.js
index d88f932b..419c35b3 100644
--- a/ext/bg/js/settings/profile-conditions-ui.js
+++ b/ext/bg/js/settings/profile-conditions-ui.js
@@ -441,7 +441,7 @@ class ProfileConditionUI {
         this._operatorOptionContainer = this._operatorInput.querySelector('optgroup');
         this._valueInput = this._node.querySelector('.condition-input-inner');
         this._removeButton = this._node.querySelector('.condition-remove');
-        this._mouseButton = this._node.querySelector('.condition-mouse-button');
+        this._mouseButton = this._node.querySelector('.mouse-button');
 
         const operatorDetails = this._getOperatorDetails(type, operator);
         this._updateTypes(type);
diff --git a/ext/bg/js/settings/scan-inputs-controller.js b/ext/bg/js/settings/scan-inputs-controller.js
new file mode 100644
index 00000000..3b3945ff
--- /dev/null
+++ b/ext/bg/js/settings/scan-inputs-controller.js
@@ -0,0 +1,178 @@
+/*
+ * Copyright (C) 2020  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
+ * KeyboardMouseInputField
+ * api
+ */
+
+class ScanInputsController {
+    constructor(settingsController) {
+        this._settingsController = settingsController;
+        this._os = null;
+        this._container = null;
+        this._addButton = null;
+        this._entries = [];
+    }
+
+    async prepare() {
+        const {platform: {os}} = await api.getEnvironmentInfo();
+        this._os = os;
+
+        this._container = document.querySelector('#scan-input-list');
+        this._addButton = document.querySelector('#scan-input-add');
+
+        this._addButton.addEventListener('click', this._onAddButtonClick.bind(this), false);
+        this._settingsController.on('optionsChanged', this._onOptionsChanged.bind(this));
+
+        const options = await this._settingsController.getOptions();
+        this._onOptionsChanged({options});
+    }
+
+    removeInput(index) {
+        if (index < 0 || index >= this._entries.length) { return false; }
+        const input = this._entries[index];
+        input.cleanup();
+        this._entries.splice(index, 1);
+        for (let i = index, ii = this._entries.length; i < ii; ++i) {
+            this._entries[i].index = i;
+        }
+        this._settingsController.modifyProfileSettings([{
+            action: 'splice',
+            path: 'scanning.inputs',
+            start: index,
+            deleteCount: 1,
+            items: []
+        }]);
+    }
+
+    setProperty(index, property, value) {
+        const path = `scanning.inputs[${index}].${property}`;
+        this._settingsController.setProfileSetting(path, value);
+    }
+
+    // Private
+
+    _onOptionsChanged({options}) {
+        const {inputs} = options.scanning;
+
+        for (let i = this._entries.length - 1; i >= 0; --i) {
+            this._entries[i].cleanup();
+        }
+        this._entries.length = 0;
+
+        for (let i = 0, ii = inputs.length; i < ii; ++i) {
+            const {include, exclude} = inputs[i];
+            this._addOption(i, include, exclude);
+        }
+    }
+
+    _onAddButtonClick(e) {
+        e.preventDefault();
+
+        const index = this._entries.length;
+        const include = '';
+        const exclude = '';
+        this._addOption(index, include, exclude);
+        this._settingsController.modifyProfileSettings([{
+            action: 'splice',
+            path: 'scanning.inputs',
+            start: index,
+            deleteCount: 0,
+            items: [{include, exclude}]
+        }]);
+    }
+
+    _addOption(index, include, exclude) {
+        const field = new ScanInputField(this, index, this._os);
+        this._entries.push(field);
+        field.prepare(this._container, include, exclude);
+    }
+}
+
+class ScanInputField {
+    constructor(parent, index, os) {
+        this._parent = parent;
+        this._index = index;
+        this._os = os;
+        this._node = null;
+        this._includeInputField = null;
+        this._excludeInputField = null;
+        this._eventListeners = new EventListenerCollection();
+    }
+
+    get index() {
+        return this._index;
+    }
+
+    set index(value) {
+        this._index = value;
+    }
+
+    prepare(container, include, exclude) {
+        const node = this._instantiateTemplate('#scan-input-template');
+        const includeInputNode = node.querySelector('.scan-input-include .scan-input-field');
+        const includeMouseButton = node.querySelector('.scan-input-include .mouse-button');
+        const excludeInputNode = node.querySelector('.scan-input-exclude .scan-input-field');
+        const excludeMouseButton = node.querySelector('.scan-input-exclude .mouse-button');
+        const removeButton = node.querySelector('.scan-input-remove');
+
+        this._node = node;
+        container.appendChild(node);
+
+        this._includeInputField = new KeyboardMouseInputField(includeInputNode, includeMouseButton, this._os);
+        this._excludeInputField = new KeyboardMouseInputField(excludeInputNode, excludeMouseButton, this._os);
+        this._includeInputField.prepare(include, 'modifierInputs');
+        this._excludeInputField.prepare(exclude, 'modifierInputs');
+
+        this._eventListeners.on(this._includeInputField, 'change', this._onIncludeValueChange.bind(this));
+        this._eventListeners.on(this._excludeInputField, 'change', this._onExcludeValueChange.bind(this));
+        this._eventListeners.addEventListener(removeButton, 'click', this._onRemoveClick.bind(this));
+    }
+
+    cleanup() {
+        this._eventListeners.removeAllEventListeners();
+        if (this._includeInputField !== null) {
+            this._includeInputField.cleanup();
+            this._includeInputField = null;
+        }
+        if (this._node !== null) {
+            const parent = this._node.parentNode;
+            if (parent !== null) { parent.removeChild(this._node); }
+            this._node = null;
+        }
+    }
+
+    _onIncludeValueChange({value}) {
+        this._parent.setProperty(this._index, 'include', value);
+    }
+
+    _onExcludeValueChange({value}) {
+        this._parent.setProperty(this._index, 'exclude', value);
+    }
+
+    _onRemoveClick(e) {
+        e.preventDefault();
+        this._parent.removeInput(this._index);
+    }
+
+    _instantiateTemplate(templateSelector) {
+        const template = document.querySelector(templateSelector);
+        const content = document.importNode(template.content, true);
+        return content.firstChild;
+    }
+}
diff --git a/ext/bg/settings.html b/ext/bg/settings.html
index 3fa14f49..ae89ca1f 100644
--- a/ext/bg/settings.html
+++ b/ext/bg/settings.html
@@ -125,7 +125,7 @@
                     <div class="input-group-btn"><select class="form-control btn btn-default condition-operator"><optgroup label="Operator"></optgroup></select></div>
                     <div class="condition-line-break"></div>
                     <div class="condition-input"><input type="text" class="form-control condition-input-inner"></div>
-                    <div class="input-group-btn"><button class="btn btn-default condition-mouse-button" title="Mouse button" style="padding-left: 10px; padding-right: 10px;" hidden><span style="width: 20px; height: 20px; display: block; background: url(/mixed/img/mouse.svg) no-repeat center center; background-size: 20px 20px;"></span></button><button class="btn btn-danger condition-remove" title="Remove"><span class="glyphicon glyphicon-remove"></span></button></div>
+                    <div class="input-group-btn"><button class="btn btn-default mouse-button" title="Mouse button"><span class="mouse-button-icon"></span></button><button class="btn btn-danger condition-remove" title="Remove"><span class="glyphicon glyphicon-remove"></span></button></div>
                 </div></template>
             </div>
 
@@ -363,13 +363,13 @@
 
                 <div class="form-group ignore-form-changes">
                     <label>Audio playback sources</label>
-                    <div class="audio-source-list"></div>
+                    <div class="audio-source-list generic-input-list"></div>
                     <div class="input-group audio-source-options">
                         <button class="btn btn-default audio-source-add" title="Add audio playback source"><span class="glyphicon glyphicon-plus"></span></button>
                     </div>
 
                     <template id="audio-source-template"><div class="input-group audio-source">
-                        <div class="input-group-addon audio-source-prefix"></div>
+                        <div class="input-group-addon generic-input-prefix"></div>
                         <select class="form-control audio-source-select">
                             <option value="jpod101">JapanesePod101</option>
                             <option value="jpod101-alternate">JapanesePod101 (Alternate)</option>
@@ -387,10 +387,6 @@
                 <h3>Scanning Options</h3>
 
                 <div class="checkbox">
-                    <label><input type="checkbox" id="middle-mouse-button-scan" data-setting="scanning.middleMouse"> Middle mouse button scans</label>
-                </div>
-
-                <div class="checkbox">
                     <label><input type="checkbox" id="touch-input-enabled" data-setting="scanning.touchInputEnabled"> Touch input enabled</label>
                 </div>
 
@@ -433,8 +429,27 @@
                 </div>
 
                 <div class="form-group">
-                    <label for="scan-modifier-key">Scan modifier key</label>
-                    <select class="form-control" id="scan-modifier-key" data-setting="scanning.modifier"></select>
+                    <label>Scan inputs</label>
+                    <div class="scan-input-list" id="scan-input-list"></div>
+                    <button class="btn btn-default" id="scan-input-add" title="Add scan input"><span class="glyphicon glyphicon-plus"></span></button>
+
+                    <template id="scan-input-template"><div class="scan-input">
+                        <table class="scan-input-table"><tbody>
+                            <tr class="scan-input-include">
+                                <td class="scan-input-index-cell" rowspan="2"><div class="scan-input-index"></div></td>
+                                <td class="scan-input-prefix-cell"><div class="scan-input-prefix">Include</div></td>
+                                <td class="scan-input-input-cell"><input type="text" class="form-control scan-input-field" placeholder="No inputs"></td>
+                                <td class="scan-input-mouse-button-cell"><button class="btn btn-default mouse-button" title="Mouse button"><span class="mouse-button-icon"></span></button></td>
+                                <td class="scan-input-remove-button-cell"><button class="btn btn-danger scan-input-remove" title="Remove"><span class="glyphicon glyphicon-remove"></span></button></td>
+                            </tr>
+                            <tr class="scan-input-exclude">
+                                <td class="scan-input-prefix-cell"><div class="scan-input-prefix">Exclude</div></td>
+                                <td class="scan-input-input-cell"><input type="text" class="form-control scan-input-field" placeholder="No inputs"></td>
+                                <td class="scan-input-mouse-button-cell"><button class="btn btn-default mouse-button" title="Mouse button"><span class="mouse-button-icon"></span></button></td>
+                                <td class="scan-input-empty-cell"></td>
+                            </tr>
+                        </tbody></table>
+                    </div></template>
                 </div>
             </div>
 
@@ -1176,6 +1191,7 @@
         <script src="/bg/js/settings/popup-preview.js"></script>
         <script src="/bg/js/settings/profiles.js"></script>
         <script src="/bg/js/settings/profile-conditions-ui.js"></script>
+        <script src="/bg/js/settings/scan-inputs-controller.js"></script>
         <script src="/bg/js/settings/settings-controller.js"></script>
         <script src="/bg/js/settings/storage.js"></script>
         <script src="/mixed/js/dictionary-data-util.js"></script>
diff --git a/ext/fg/js/frontend.js b/ext/fg/js/frontend.js
index 3ddf0d25..8189b8ad 100644
--- a/ext/fg/js/frontend.js
+++ b/ext/fg/js/frontend.js
@@ -254,12 +254,12 @@ class Frontend {
         await this.updateOptions();
     }
 
-    _onSearched({type, definitions, sentence, input: {cause}, textSource, optionsContext, error}) {
+    _onSearched({type, definitions, sentence, input: {cause, empty}, textSource, optionsContext, error}) {
         const scanningOptions = this._options.scanning;
 
         if (error !== null) {
             if (yomichan.isExtensionUnloaded) {
-                if (textSource !== null && scanningOptions.modifier !== 'none') {
+                if (textSource !== null && !empty) {
                     this._showExtensionUnloaded(textSource);
                 }
             } else {
@@ -321,10 +321,9 @@ class Frontend {
         await this._updatePopup();
 
         this._textScanner.setOptions({
+            inputs: scanningOptions.inputs,
             deepContentScan: scanningOptions.deepDomScan,
             selectText: scanningOptions.selectText,
-            modifier: scanningOptions.modifier,
-            useMiddleMouse: scanningOptions.middleMouse,
             delay: scanningOptions.delay,
             touchInputEnabled: scanningOptions.touchInputEnabled,
             scanLength: scanningOptions.length,
diff --git a/ext/mixed/js/display.js b/ext/mixed/js/display.js
index 70b3895a..ea6b52c0 100644
--- a/ext/mixed/js/display.js
+++ b/ext/mixed/js/display.js
@@ -239,10 +239,9 @@ class Display extends EventDispatcher {
             selectedParser: options.parsing.selectedParser,
             termSpacing: options.parsing.termSpacing,
             scanning: {
+                inputs: scanning.inputs,
                 deepContentScan: scanning.deepDomScan,
                 selectText: scanning.selectText,
-                modifier: scanning.modifier,
-                useMiddleMouse: scanning.middleMouse,
                 delay: scanning.delay,
                 touchInputEnabled: scanning.touchInputEnabled,
                 scanLength: scanning.length,
diff --git a/ext/mixed/js/document-util.js b/ext/mixed/js/document-util.js
index 0b72ff9a..58b0c759 100644
--- a/ext/mixed/js/document-util.js
+++ b/ext/mixed/js/document-util.js
@@ -188,6 +188,18 @@ class DocumentUtil {
         return modifiers;
     }
 
+    static getActiveModifiersAndButtons(event) {
+        const modifiers = this.getActiveModifiers(event);
+        this._getActiveButtons(event, modifiers);
+        return modifiers;
+    }
+
+    static getActiveButtons(event) {
+        const buttons = new Set();
+        this._getActiveButtons(event, buttons);
+        return buttons;
+    }
+
     static getKeyFromEvent(event) {
         const key = event.key;
         return (typeof key === 'string' ? (key.length === 1 ? key.toUpperCase() : key) : '');
@@ -299,6 +311,19 @@ class DocumentUtil {
         return !(browser === 'firefox' || browser === 'firefox-mobile') || os === 'mac';
     }
 
+    static _getActiveButtons(event, set) {
+        const {buttons} = event;
+        if (typeof buttons === 'number') {
+            for (let i = 0; i < 6; ++i) {
+                const buttonFlag = (1 << i);
+                if ((buttons & buttonFlag) !== 0) {
+                    set.add(`mouse${i}`);
+                }
+            }
+        }
+        return set;
+    }
+
     // Private
 
     _setImposterStyle(style, propertyName, value) {
diff --git a/ext/mixed/js/text-scanner.js b/ext/mixed/js/text-scanner.js
index f3e99577..6eafc82c 100644
--- a/ext/mixed/js/text-scanner.js
+++ b/ext/mixed/js/text-scanner.js
@@ -43,13 +43,12 @@ class TextScanner extends EventDispatcher {
 
         this._deepContentScan = false;
         this._selectText = false;
-        this._modifier = 'none';
-        this._useMiddleMouse = false;
         this._delay = 0;
         this._touchInputEnabled = false;
         this._scanLength = 1;
         this._sentenceExtent = 1;
         this._layoutAwareScan = false;
+        this._inputs = [];
 
         this._enabled = false;
         this._eventListeners = new EventListenerCollection();
@@ -94,19 +93,19 @@ class TextScanner extends EventDispatcher {
         }
     }
 
-    setOptions({deepContentScan, selectText, modifier, useMiddleMouse, delay, touchInputEnabled, scanLength, sentenceExtent, layoutAwareScan}) {
+    setOptions({inputs, deepContentScan, selectText, delay, touchInputEnabled, scanLength, sentenceExtent, layoutAwareScan}) {
+        if (Array.isArray(inputs)) {
+            this._inputs = inputs.map(({include, exclude}) => ({
+                include: this._getInputArray(include),
+                exclude: this._getInputArray(exclude)
+            }));
+        }
         if (typeof deepContentScan === 'boolean') {
             this._deepContentScan = deepContentScan;
         }
         if (typeof selectText === 'boolean') {
             this._selectText = selectText;
         }
-        if (typeof modifier === 'string') {
-            this._modifier = modifier;
-        }
-        if (typeof useMiddleMouse === 'boolean') {
-            this._useMiddleMouse = useMiddleMouse;
-        }
         if (typeof delay === 'number') {
             this._delay = delay;
         }
@@ -184,7 +183,7 @@ class TextScanner extends EventDispatcher {
     }
 
     async search(textSource) {
-        return await this._search(textSource, {cause: 'script'});
+        return await this._search(textSource, {cause: 'script', index: -1, empty: false});
     }
 
     // Private
@@ -242,17 +241,14 @@ class TextScanner extends EventDispatcher {
             return;
         }
 
-        const modifiers = DocumentUtil.getActiveModifiers(e);
+        const modifiers = DocumentUtil.getActiveModifiersAndButtons(e);
         this.trigger('activeModifiersChanged', {modifiers});
 
-        if (!(
-            this._isScanningModifierPressed(this._modifier, e) ||
-            (this._useMiddleMouse && DocumentUtil.isMouseButtonDown(e, 'auxiliary'))
-        )) {
-            return;
-        }
+        const inputInfo = this._getMatchingInputGroup(modifiers);
+        if (inputInfo === null) { return; }
 
-        this._searchAtFromMouse(e.clientX, e.clientY);
+        const {index, empty} = inputInfo;
+        this._searchAtFromMouse(e.clientX, e.clientY, index, empty);
     }
 
     _onMouseDown(e) {
@@ -276,7 +272,7 @@ class TextScanner extends EventDispatcher {
 
     _onClick(e) {
         if (this._searchOnClick) {
-            this._searchAt(e.clientX, e.clientY, {cause: 'click'});
+            this._searchAt(e.clientX, e.clientY, {cause: 'click', index: -1, empty: false});
         }
 
         if (this._preventNextClick) {
@@ -349,7 +345,7 @@ class TextScanner extends EventDispatcher {
             return;
         }
 
-        this._searchAt(primaryTouch.clientX, primaryTouch.clientY, {cause: 'touchMove'});
+        this._searchAt(primaryTouch.clientX, primaryTouch.clientY, {cause: 'touchMove', index: -1, empty: false});
 
         e.preventDefault(); // Disable scroll
     }
@@ -406,17 +402,6 @@ class TextScanner extends EventDispatcher {
         ];
     }
 
-    _isScanningModifierPressed(scanningModifier, mouseEvent) {
-        switch (scanningModifier) {
-            case 'alt': return mouseEvent.altKey;
-            case 'ctrl': return mouseEvent.ctrlKey;
-            case 'shift': return mouseEvent.shiftKey;
-            case 'meta': return mouseEvent.metaKey;
-            case 'none': return true;
-            default: return false;
-        }
-    }
-
     _getTouch(touchList, identifier) {
         for (const touch of touchList) {
             if (touch.identifier === identifier) {
@@ -498,17 +483,17 @@ class TextScanner extends EventDispatcher {
         }
     }
 
-    async _searchAtFromMouse(x, y) {
+    async _searchAtFromMouse(x, y, inputIndex, inputEmpty) {
         if (this._pendingLookup) { return; }
 
-        if (this._modifier === 'none') {
+        if (inputEmpty) {
             if (!await this._scanTimerWait()) {
                 // Aborted
                 return;
             }
         }
 
-        await this._searchAt(x, y, {cause: 'mouse'});
+        await this._searchAt(x, y, {cause: 'mouse', index: inputIndex, empty: inputEmpty});
     }
 
     async _searchAtFromTouchStart(x, y) {
@@ -516,7 +501,7 @@ class TextScanner extends EventDispatcher {
 
         const textSourceCurrentPrevious = this._textSourceCurrent !== null ? this._textSourceCurrent.clone() : null;
 
-        await this._searchAt(x, y, {cause: 'touchStart'});
+        await this._searchAt(x, y, {cause: 'touchStart', index: -1, empty: false});
 
         if (
             this._textSourceCurrent !== null &&
@@ -527,4 +512,37 @@ class TextScanner extends EventDispatcher {
             this._preventNextMouseDown = true;
         }
     }
+
+    _getMatchingInputGroup(modifiers) {
+        let fallback = null;
+        for (let i = 0, ii = this._inputs.length; i < ii; ++i) {
+            const input = this._inputs[i];
+            const {include, exclude} = input;
+            if (this._setHasAll(modifiers, include) && (exclude.length === 0 || !this._setHasAll(modifiers, exclude))) {
+                if (include.length > 0) {
+                    return {index: i, empty: false, input};
+                } else if (fallback === null) {
+                    fallback = {index: i, empty: true, input};
+                }
+            }
+        }
+        return fallback;
+    }
+
+    _setHasAll(set, values) {
+        for (const value of values) {
+            if (!set.has(value)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    _getInputArray(value) {
+        return (
+            typeof value === 'string' ?
+            value.split(/[,;\s]+/).map((v) => v.trim().toLowerCase()).filter((v) => v.length > 0) :
+            []
+        );
+    }
 }