Add Option for Scanning Alt Text (#1169)

* Add Option for Scanning Alt Text

* Don't scan alt text if option disabled

* Add scanAltText to Options Schema

* Add `scanning.scanAltText` Update Function

* Bump Options Test Version

* Remove Param Annotation

9 files changed, 46 insertions, 2 deletions

diff --git a/ext/data/schemas/options-schema.json b/ext/data/schemas/options-schema.json
index 2fb1c9c3..85e02c02 100644
--- a/ext/data/schemas/options-schema.json
+++ b/ext/data/schemas/options-schema.json
@@ -437,6 +437,7 @@
                                     "hideDelay",
                                     "length",
                                     "deepDomScan",
+                                    "scanAltText",
                                     "popupNestingMaxDepth",
                                     "enablePopupSearch",
                                     "enableOnPopupExpressions",
@@ -688,6 +689,10 @@
                                         "type": "boolean",
                                         "default": false
                                     },
+                                    "scanAltText": {
+                                        "type": "boolean",
+                                        "default": true
+                                    },
                                     "popupNestingMaxDepth": {
                                         "type": "integer",
                                         "minimum": 0,
diff --git a/ext/js/app/frontend.js b/ext/js/app/frontend.js
index 8ac27979..c3022908 100644
--- a/ext/js/app/frontend.js
+++ b/ext/js/app/frontend.js
@@ -513,6 +513,7 @@ export class Frontend {
             matchTypePrefix: scanningOptions.matchTypePrefix,
             preventMiddleMouse,
             sentenceParsingOptions,
+            scanAltText: scanningOptions.scanAltText,
         });
         this._updateTextScannerEnabled();
 
diff --git a/ext/js/data/options-util.js b/ext/js/data/options-util.js
index 8af299d8..850ac81d 100644
--- a/ext/js/data/options-util.js
+++ b/ext/js/data/options-util.js
@@ -349,6 +349,7 @@ export class OptionsUtil {
                 enableOnSearchPage: true,
                 enableSearchTags: false,
                 layoutAwareScan: false,
+                scanAltText: true,
             },
 
             translation: {
@@ -549,6 +550,7 @@ export class OptionsUtil {
             this._updateVersion39,
             this._updateVersion40,
             this._updateVersion41,
+            this._updateVersion42,
         ];
         /* eslint-enable @typescript-eslint/unbound-method */
         if (typeof targetVersion === 'number' && targetVersion < result.length) {
@@ -1349,6 +1351,16 @@ export class OptionsUtil {
     }
 
     /**
+     * - Added scanning.scanAltText
+     * @type {import('options-util').UpdateFunction}
+     */
+    async _updateVersion42(options) {
+        for (const profile of options.profiles) {
+            profile.options.scanning.scanAltText = true;
+        }
+    }
+
+    /**
      * @param {string} url
      * @returns {Promise<chrome.tabs.Tab>}
      */
diff --git a/ext/js/display/display.js b/ext/js/display/display.js
index 3d18e416..01406382 100644
--- a/ext/js/display/display.js
+++ b/ext/js/display/display.js
@@ -461,6 +461,7 @@ export class Display extends EventDispatcher {
                 preventMiddleMouse: scanningOptions.preventMiddleMouse.onSearchQuery,
                 matchTypePrefix: false,
                 sentenceParsingOptions,
+                scanAltText: scanningOptions.scanAltText,
             },
         });
 
@@ -1984,6 +1985,7 @@ export class Display extends EventDispatcher {
             layoutAwareScan: scanningOptions.layoutAwareScan,
             preventMiddleMouse: false,
             sentenceParsingOptions,
+            scanAltText: scanningOptions.scanAltText,
         });
 
         this._contentTextScanner.setEnabled(true);
diff --git a/ext/js/language/text-scanner.js b/ext/js/language/text-scanner.js
index 249a2eda..759adf20 100644
--- a/ext/js/language/text-scanner.js
+++ b/ext/js/language/text-scanner.js
@@ -124,6 +124,8 @@ export class TextScanner extends EventDispatcher {
         this._sentenceBackwardQuoteMap = new Map();
         /** @type {import('text-scanner').InputConfig[]} */
         this._inputs = [];
+        /** @type {boolean} */
+        this._scanAltText = true;
 
         /** @type {boolean} */
         this._enabled = false;
@@ -255,6 +257,7 @@ export class TextScanner extends EventDispatcher {
         preventMiddleMouse,
         sentenceParsingOptions,
         matchTypePrefix,
+        scanAltText,
     }) {
         if (Array.isArray(inputs)) {
             this._inputs = inputs.map((input) => this._convertInput(input));
@@ -289,6 +292,9 @@ export class TextScanner extends EventDispatcher {
         if (typeof matchTypePrefix === 'boolean') {
             this._matchTypePrefix = matchTypePrefix;
         }
+        if (typeof scanAltText === 'boolean') {
+            this._scanAltText = scanAltText;
+        }
         if (typeof sentenceParsingOptions === 'object' && sentenceParsingOptions !== null) {
             const {scanExtent, terminationCharacterMode, terminationCharacters} = sentenceParsingOptions;
             if (typeof scanExtent === 'number') {
@@ -443,6 +449,11 @@ export class TextScanner extends EventDispatcher {
      */
     async _search(textSource, searchTerms, searchKanji, inputInfo, showEmpty = false) {
         try {
+            const isAltText = textSource instanceof TextSourceElement;
+            if (isAltText && !this._scanAltText) {
+                return;
+            }
+
             const inputInfoDetail = inputInfo.detail;
             const selectionRestoreInfo = (
                 (typeof inputInfoDetail === 'object' && inputInfoDetail !== null && inputInfoDetail.restoreSelection) ?
@@ -468,7 +479,7 @@ export class TextScanner extends EventDispatcher {
             const result = await this._findDictionaryEntries(textSource, searchTerms, searchKanji, optionsContext);
             if (result !== null) {
                 ({dictionaryEntries, sentence, type} = result);
-            } else if (showEmpty || (textSource !== null && textSource instanceof TextSourceElement && await this._isTextLookupWorthy(textSource.fullContent))) {
+            } else if (showEmpty || (textSource !== null && isAltText && await this._isTextLookupWorthy(textSource.fullContent))) {
                 // Shows a "No results found" message
                 dictionaryEntries = [];
                 sentence = {text: '', offset: 0};
diff --git a/ext/settings.html b/ext/settings.html
index dfd562a9..ccd6dc9b 100644
--- a/ext/settings.html
+++ b/ext/settings.html
@@ -415,6 +415,15 @@
                 <label class="toggle"><input type="checkbox" data-setting="scanning.deepDomScan"><span class="toggle-body"><span class="toggle-track"></span><span class="toggle-knob"></span></span></label>
             </div>
         </div></div>
+        <div class="settings-item"><div class="settings-item-inner">
+            <div class="settings-item-left">
+                <div class="settings-item-label">Scan alt text</div>
+                <div class="settings-item-description">Scan text that is used for image and button descriptions.</div>
+            </div>
+            <div class="settings-item-right">
+                <label class="toggle"><input type="checkbox" data-setting="scanning.scanAltText"><span class="toggle-body"><span class="toggle-track"></span><span class="toggle-knob"></span></span></label>
+            </div>
+        </div></div>
         <div class="settings-item advanced-only">
             <div class="settings-item-inner">
                 <div class="settings-item-left">
diff --git a/test/options-util.test.js b/test/options-util.test.js
index 253b9650..60d44470 100644
--- a/test/options-util.test.js
+++ b/test/options-util.test.js
@@ -95,6 +95,7 @@ function createProfileOptionsTestData1() {
             enableOnSearchPage: true,
             enableSearchTags: false,
             layoutAwareScan: false,
+            scanAltText: true,
         },
         translation: {
             convertHalfWidthCharacters: 'false',
@@ -325,6 +326,7 @@ function createProfileOptionsUpdatedTestData1() {
             hidePopupOnCursorExit: false,
             hidePopupOnCursorExitDelay: 0,
             normalizeCssZoom: true,
+            scanAltText: true,
             preventMiddleMouse: {
                 onWebPages: false,
                 onPopupPages: false,
@@ -606,7 +608,7 @@ function createOptionsUpdatedTestData1() {
             },
         ],
         profileCurrent: 0,
-        version: 41,
+        version: 42,
         global: {
             database: {
                 prefixWildcardsSupported: false,
diff --git a/types/ext/settings.d.ts b/types/ext/settings.d.ts
index 559a27c4..b84942b1 100644
--- a/types/ext/settings.d.ts
+++ b/types/ext/settings.d.ts
@@ -190,6 +190,7 @@ export type ScanningOptions = {
     hidePopupOnCursorExit: boolean;
     hidePopupOnCursorExitDelay: number;
     normalizeCssZoom: boolean;
+    scanAltText: boolean;
 };
 
 export type ScanningInput = {
diff --git a/types/ext/text-scanner.d.ts b/types/ext/text-scanner.d.ts
index 4277d49a..0af55d72 100644
--- a/types/ext/text-scanner.d.ts
+++ b/types/ext/text-scanner.d.ts
@@ -41,6 +41,7 @@ export type Options = {
     preventMiddleMouse?: boolean;
     matchTypePrefix?: boolean;
     sentenceParsingOptions?: SentenceParsingOptions;
+    scanAltText?: boolean;
 };
 
 export type InputOptionsOuter = {