mecab refactoring and bugfix

ext/bg/js/backend.js

@@ -101,6 +101,8 @@ class Backend {
 
         if (options.parsing.enableMecabParser) {
             this.mecab.startListener();
+        } else {
+            this.mecab.stopListener();
         }
     }
 

ext/bg/js/mecab.js

@@ -34,15 +34,7 @@ class Mecab {
     startListener() {
         if (this.port !== null) { return; }
         this.port = chrome.runtime.connectNative('yomichan_mecab');
-        this.port.onMessage.addListener((message) => {
+        this.port.onMessage.addListener(this.onNativeMessage.bind(this));
-            const {sequence, data} = message;
-            const {callback, timer} = this.listeners[sequence] || {};
-            if (timer) {
-                clearTimeout(timer);
-                delete this.listeners[sequence];
-                callback(data);
-            }
-        });
     }
 
     stopListener() {
@@ -53,6 +45,15 @@ class Mecab {
         this.sequence = 0;
     }
 
+    onNativeMessage({sequence, data}) {
+        if (this.listeners.hasOwnProperty(sequence)) {
+            const {callback, timer} = this.listeners[sequence];
+            clearTimeout(timer);
+            callback(data);
+            delete this.listeners[sequence];
+        }
+    }
+
     invoke(action, params) {
         return new Promise((resolve, reject) => {
             const sequence = this.sequence++;

ext/bg/js/settings.js

@@ -154,7 +154,6 @@ async function formWrite(options) {
 
 function formSetupEventListeners() {
     $('input, select, textarea').not('.anki-model').not('.ignore-form-changes *').change(utilAsync(onFormOptionsChanged));
-    $('#parsing-mecab-enable').change(onParseMecabChanged);
     $('.anki-model').change(utilAsync(onAnkiModelChanged));
 }
 
@@ -441,20 +440,6 @@ function onMessage({action, params}, sender, callback) {
 }
 
 
-/*
- * Text parsing
- */
-
-function onParseMecabChanged(e) {
-    const mecab = utilBackend().mecab;
-    if (e.target.checked) {
-        mecab.startListener();
-    } else {
-        mecab.stopListener();
-    }
-}
-
-
 /*
  * Anki
  */