Use DOMTextScanner (#536)

* Use DOMTextScanner instead of TextSourceRange.seek*

* Move getNodesInRange to dom.js

* Move anyNodeMatchesSelector to dom.js

* Remove unused functions

* Update tests

* Add layoutAwareScan option

* Use layoutAwareScan for source and sentence scanning

* Remove unused IGNORE_TEXT_PATTERN

3 files changed, 50 insertions, 10 deletions

diff --git a/ext/mixed/js/display.js b/ext/mixed/js/display.js
index 90fd1037..1d699706 100644
--- a/ext/mixed/js/display.js
+++ b/ext/mixed/js/display.js
@@ -236,7 +236,9 @@ class Display {
             const {textSource, definitions} = termLookupResults;
 
             const scannedElement = e.target;
-            const sentence = docSentenceExtract(textSource, this.options.anki.sentenceExt);
+            const sentenceExtent = this.options.anki.sentenceExt;
+            const layoutAwareScan = this.options.scanning.layoutAwareScan;
+            const sentence = docSentenceExtract(textSource, sentenceExtent, layoutAwareScan);
 
             this.context.update({
                 index: this.entryIndexFind(scannedElement),
@@ -273,21 +275,22 @@ class Display {
         try {
             e.preventDefault();
 
-            const textSource = docRangeFromPoint(e.clientX, e.clientY, this.options.scanning.deepDomScan);
+            const {length: scanLength, deepDomScan: deepScan, layoutAwareScan} = this.options.scanning;
+            const textSource = docRangeFromPoint(e.clientX, e.clientY, deepScan);
             if (textSource === null) {
                 return false;
             }
 
             let definitions, length;
             try {
-                textSource.setEndOffset(this.options.scanning.length);
+                textSource.setEndOffset(scanLength, layoutAwareScan);
 
                 ({definitions, length} = await api.termsFind(textSource.text(), {}, this.getOptionsContext()));
                 if (definitions.length === 0) {
                     return false;
                 }
 
-                textSource.setEndOffset(length);
+                textSource.setEndOffset(length, layoutAwareScan);
             } finally {
                 textSource.cleanup();
             }
diff --git a/ext/mixed/js/dom.js b/ext/mixed/js/dom.js
index 0e8f4462..05764443 100644
--- a/ext/mixed/js/dom.js
+++ b/ext/mixed/js/dom.js
@@ -86,4 +86,42 @@ class DOM {
             null
         );
     }
+
+    static getNodesInRange(range) {
+        const end = range.endContainer;
+        const nodes = [];
+        for (let node = range.startContainer; node !== null; node = DOM.getNextNode(node)) {
+            nodes.push(node);
+            if (node === end) { break; }
+        }
+        return nodes;
+    }
+
+    static getNextNode(node) {
+        let next = node.firstChild;
+        if (next === null) {
+            while (true) {
+                next = node.nextSibling;
+                if (next !== null) { break; }
+
+                next = node.parentNode;
+                if (next === null) { break; }
+
+                node = next;
+            }
+        }
+        return next;
+    }
+
+    static anyNodeMatchesSelector(nodes, selector) {
+        const ELEMENT_NODE = Node.ELEMENT_NODE;
+        for (let node of nodes) {
+            for (; node !== null; node = node.parentNode) {
+                if (node.nodeType !== ELEMENT_NODE) { continue; }
+                if (node.matches(selector)) { return true; }
+                break;
+            }
+        }
+        return false;
+    }
 }
diff --git a/ext/mixed/js/text-scanner.js b/ext/mixed/js/text-scanner.js
index b8688b08..fb275452 100644
--- a/ext/mixed/js/text-scanner.js
+++ b/ext/mixed/js/text-scanner.js
@@ -17,7 +17,6 @@
 
 /* global
  * DOM
- * TextSourceRange
  * docRangeFromPoint
  */
 
@@ -119,20 +118,20 @@ class TextScanner extends EventDispatcher {
         }
     }
 
-    getTextSourceContent(textSource, length) {
+    getTextSourceContent(textSource, length, layoutAwareScan) {
         const clonedTextSource = textSource.clone();
 
-        clonedTextSource.setEndOffset(length);
+        clonedTextSource.setEndOffset(length, layoutAwareScan);
 
         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)) {
+                const nodes = DOM.getNodesInRange(clonedTextSource.range);
+                if (!DOM.anyNodeMatchesSelector(nodes, this._ignoreNodes)) {
                     break;
                 }
                 --length;
-                clonedTextSource.setEndOffset(length);
+                clonedTextSource.setEndOffset(length, layoutAwareScan);
             }
         }