Extract textSource text inside TextScanner (#500)

* extract text inside TextScanner

* clone textSource before text extraction

3 files changed, 18 insertions, 20 deletions

diff --git a/ext/bg/js/search-query-parser.js b/ext/bg/js/search-query-parser.js
index 137234e8..935f01f2 100644
--- a/ext/bg/js/search-query-parser.js
+++ b/ext/bg/js/search-query-parser.js
@@ -51,8 +51,7 @@ class QueryParser extends TextScanner {
     async onSearchSource(textSource, cause) {
         if (textSource === null) { return null; }
 
-        this.setTextSourceScanLength(textSource, this.options.scanning.length);
-        const searchText = textSource.text();
+        const searchText = this.getTextSourceContent(textSource, this.options.scanning.length);
         if (searchText.length === 0) { return; }
 
         const {definitions, length} = await apiTermsFind(searchText, {}, this.getOptionsContext());
diff --git a/ext/fg/js/frontend.js b/ext/fg/js/frontend.js
index d979246d..b2cb0cd8 100644
--- a/ext/fg/js/frontend.js
+++ b/ext/fg/js/frontend.js
@@ -239,9 +239,7 @@ class Frontend {
     }
 
     async findTerms(textSource, optionsContext) {
-        this._textScanner.setTextSourceScanLength(textSource, this._options.scanning.length);
-
-        const searchText = textSource.text();
+        const searchText = this._textScanner.getTextSourceContent(textSource, this._options.scanning.length);
         if (searchText.length === 0) { return null; }
 
         const {definitions, length} = await apiTermsFind(searchText, {}, optionsContext);
@@ -253,9 +251,7 @@ class Frontend {
     }
 
     async findKanji(textSource, optionsContext) {
-        this._textScanner.setTextSourceScanLength(textSource, 1);
-
-        const searchText = textSource.text();
+        const searchText = this._textScanner.getTextSourceContent(textSource, 1);
         if (searchText.length === 0) { return null; }
 
         const definitions = await apiKanjiFind(searchText, optionsContext);
diff --git a/ext/mixed/js/text-scanner.js b/ext/mixed/js/text-scanner.js
index d74a04f8..9dcf6009 100644
--- a/ext/mixed/js/text-scanner.js
+++ b/ext/mixed/js/text-scanner.js
@@ -318,21 +318,24 @@ class TextScanner extends EventDispatcher {
         }
     }
 
-    setTextSourceScanLength(textSource, length) {
-        textSource.setEndOffset(length);
-        if (this.ignoreNodes === null || !textSource.range) {
-            return;
-        }
+    getTextSourceContent(textSource, length) {
+        const clonedTextSource = textSource.clone();
+
+        clonedTextSource.setEndOffset(length);
 
-        length = textSource.text().length;
-        while (textSource.range && length > 0) {
-            const nodes = TextSourceRange.getNodesInRange(textSource.range);
-            if (!TextSourceRange.anyNodeMatchesSelector(nodes, this.ignoreNodes)) {
-                break;
+        if (this.ignoreNodes !== null && clonedTextSource.range) {
+            length = clonedTextSource.text().length;
+            while (clonedTextSource.range && length > 0) {
+                const nodes = TextSourceRange.getNodesInRange(clonedTextSource.range);
+                if (!TextSourceRange.anyNodeMatchesSelector(nodes, this.ignoreNodes)) {
+                    break;
+                }
+                --length;
+                clonedTextSource.setEndOffset(length);
             }
-            --length;
-            textSource.setEndOffset(length);
         }
+
+        return clonedTextSource.text();
     }
 
     clearSelection(passive) {