5 files changed, 33 insertions, 10 deletions

diff --git a/ext/bg/js/options.js b/ext/bg/js/options.js
index 49544840..1ea6ed68 100644
--- a/ext/bg/js/options.js
+++ b/ext/bg/js/options.js
@@ -40,6 +40,7 @@ function formRead() {
         optionsNew.scanning.middleMouse = $('#middle-mouse-button-scan').prop('checked');
         optionsNew.scanning.selectText = $('#select-matched-text').prop('checked');
         optionsNew.scanning.imposter = $('#search-form-text-fields').prop('checked');
+        optionsNew.scanning.alphanumeric = $('#search-alphanumeric').prop('checked');
         optionsNew.scanning.delay = parseInt($('#scan-delay').val(), 10);
         optionsNew.scanning.length = parseInt($('#scan-length').val(), 10);
 
@@ -127,6 +128,7 @@ $(document).ready(() => {
         $('#middle-mouse-button-scan').prop('checked', options.scanning.middleMouse);
         $('#select-matched-text').prop('checked', options.scanning.selectText);
         $('#search-form-text-fields').prop('checked', options.scanning.imposter);
+        $('#search-alphanumeric').prop('checked', options.scanning.alphanumeric);
         $('#scan-delay').val(options.scanning.delay);
         $('#scan-length').val(options.scanning.length);
 
diff --git a/ext/bg/js/translator.js b/ext/bg/js/translator.js
index 67430aef..b3b90641 100644
--- a/ext/bg/js/translator.js
+++ b/ext/bg/js/translator.js
@@ -41,10 +41,17 @@ class Translator {
         });
     }
 
-    findTerms(text, dictionaries, softKatakana) {
+    findTerms(text, dictionaries, softKatakana, alphanumeric) {
         const titles = Object.keys(dictionaries);
         const cache = {};
 
+        if (!alphanumeric && text.length > 0) {
+            const c = text[0];
+            if (!jpIsKana(c) && !jpIsKanji(c)) {
+                return Promise.resolve({length: 0, definitions: []});
+            }
+        }
+
         return this.findTermsDeinflected(text, titles, cache).then(deinfLiteral => {
             const textHiragana = wanakana._katakanaToHiragana(text);
             if (text !== textHiragana && softKatakana) {
@@ -84,8 +91,8 @@ class Translator {
         });
     }
 
-    findTermsGrouped(text, dictionaries, softKatakana) {
-        return this.findTerms(text, dictionaries, softKatakana).then(({length, definitions}) => {
+    findTermsGrouped(text, dictionaries, softKatakana, alphanumeric) {
+        return this.findTerms(text, dictionaries, softKatakana, alphanumeric).then(({length, definitions}) => {
             return {length, definitions: dictTermsGroup(definitions, dictionaries)};
         });
     }
diff --git a/ext/bg/js/util.js b/ext/bg/js/util.js
index 64143ffe..09337c63 100644
--- a/ext/bg/js/util.js
+++ b/ext/bg/js/util.js
@@ -31,6 +31,20 @@ function promiseCallback(promise, callback) {
 
 
 /*
+ * Japanese
+ */
+
+function jpIsKanji(c) {
+    const code = c.charCodeAt(0);
+    return code >= 0x4e00 && code < 0x9fb0 || code >= 0x3400 && code < 0x4dc0;
+}
+
+function jpIsKana(c) {
+    return wanakana.isKana(c);
+}
+
+
+/*
  * Commands
  */
 
@@ -98,6 +112,7 @@ function optionsSetDefaults(options) {
             middleMouse: true,
             selectText: true,
             imposter: true,
+            alphanumeric: true,
             delay: 15,
             length: 10
         },
@@ -489,14 +504,9 @@ function jsonLoadDb(indexUrl, indexLoaded, termsLoaded, kanjiLoaded) {
  */
 
 function handlebarsKanjiLinks(options) {
-    const isKanji = c => {
-        const code = c.charCodeAt(0);
-        return code >= 0x4e00 && code < 0x9fb0 || code >= 0x3400 && code < 0x4dc0;
-    };
-
     let result = '';
     for (const c of options.fn(this)) {
-        if (isKanji(c)) {
+        if (jpIsKanji(c)) {
             result += `<a href="#" class="kanji-link">${c}</a>`;
         } else {
             result += c;
diff --git a/ext/bg/js/yomichan.js b/ext/bg/js/yomichan.js
index 51e05c80..172bb1d3 100644
--- a/ext/bg/js/yomichan.js
+++ b/ext/bg/js/yomichan.js
@@ -107,7 +107,7 @@ window.yomichan = new class {
             this.translator.findTermsGrouped.bind(this.translator) :
             this.translator.findTerms.bind(this.translator);
 
-        return searcher(text, dictEnabledSet(this.options), this.options.general.softKatakana).then(({definitions, length}) => {
+        return searcher(text, dictEnabledSet(this.options), this.options.general.softKatakana, this.options.scanning.alphanumeric).then(({definitions, length}) => {
             return {length, definitions: definitions.slice(0, this.options.general.maxResults)};
         });
     }
diff --git a/ext/bg/options.html b/ext/bg/options.html
index e3168ca1..3595cda4 100644
--- a/ext/bg/options.html
+++ b/ext/bg/options.html
@@ -93,6 +93,10 @@
                     <label><input type="checkbox" id="search-form-text-fields"> Search form text fields</label>
                 </div>
 
+                <div class="checkbox">
+                    <label><input type="checkbox" id="search-alphanumeric"> Search alphanumeric text</label>
+                </div>
+
                 <div class="form-group options-advanced">
                     <label for="scan-delay">Scan delay</label>
                     <input type="number" min="1" id="scan-delay" class="form-control">