From d42a0be080ed6b1cce4a65de008279318c8844dc Mon Sep 17 00:00:00 2001
From: Daniel Eder <danieleder@outlook.at>
Date: Mon, 1 Aug 2022 15:55:10 +0200
Subject: [PATCH] Add quill paste matchers for MS Word

for bullet and ordered lists
---
 frontend/components/Editor/index.js           |  5 ++
 .../services/quill/msWordPasteMatchers.js     | 52 +++++++++++++++++++
 2 files changed, 57 insertions(+)
 create mode 100644 frontend/services/quill/msWordPasteMatchers.js

diff --git a/frontend/components/Editor/index.js b/frontend/components/Editor/index.js
index a5c00171..2991fac7 100644
--- a/frontend/components/Editor/index.js
+++ b/frontend/components/Editor/index.js
@@ -1,5 +1,6 @@
 import standardToolbarContainer from '~/services/quill/standardToolbarContainer';
 import dropOrPasteImageHandler from '~/services/quill/handlers/dropOrPasteImageHandler';
+import msWordPasteMatchers     from '~/services/quill/msWordPasteMatchers';
 import uploadImageHandler      from '~/services/quill/handlers/uploadImageHandler';
 import markAsAnswerHandler     from '~/services/quill/handlers/markAsAnswerHandler';
 import codeBlockHandler        from '~/services/quill/handlers/codeBlockHandler';
@@ -73,6 +74,10 @@ const bindings = {
     handler: formulaHandler
   },
 
+  clipboard: {
+    matchers: msWordPasteMatchers
+  }
+
   // blurOnEsc: {
   //   key: 'Escape',
   //   handler: () => {
diff --git a/frontend/services/quill/msWordPasteMatchers.js b/frontend/services/quill/msWordPasteMatchers.js
new file mode 100644
index 00000000..c8041783
--- /dev/null
+++ b/frontend/services/quill/msWordPasteMatchers.js
@@ -0,0 +1,52 @@
+// See https://github.com/quilljs/quill/issues/1225#issuecomment-1000785590
+
+import Delta from 'quill-delta';
+
+function matchMsWordList(node, delta) {
+    // Clone the operations
+    let ops = delta.ops.map((op) => Object.assign({}, op));
+
+    // Trim the front of the first op to remove the bullet/number
+    let bulletOp = ops.find((op) => op.insert && op.insert.trim().length);
+    if (!bulletOp) { return delta }
+
+    bulletOp.insert = bulletOp.insert.trimLeft();
+    let listPrefix = bulletOp.insert.match(/^.*?(^·|\.)/) || bulletOp.insert[0];
+    bulletOp.insert = bulletOp.insert.substring(listPrefix[0].length, bulletOp.insert.length);
+
+    // Trim the newline off the last op
+    let last = ops[ops.length-1];
+    last.insert = last.insert.substring(0, last.insert.length - 1);
+
+    // Determine the list type
+    let listType = listPrefix[0].length === 1 ? 'bullet' : 'ordered';
+
+    // Determine the list indent
+    let style = node.getAttribute('style').replace(/\n+/g, '');
+    let levelMatch = style.match(/level(\d+)/);
+    let indent = levelMatch ? levelMatch[1] - 1 : 0;
+
+    // Add the list attribute
+    ops.push({insert: '\n', attributes: {list: listType, indent}})
+
+    return new Delta(ops);
+}
+
+function maybeMatchMsWordList(node, delta) {
+    if (delta.ops[0].insert.trimLeft()[0] === '·') {
+        return matchMsWordList(node, delta);
+    }
+
+    return delta;
+}
+
+const msWordPasteMatchers = [
+    ['p.MsoListParagraphCxSpFirst', matchMsWordList],
+    ['p.MsoListParagraphCxSpMiddle', matchMsWordList],
+    ['p.MsoListParagraphCxSpLast', matchMsWordList],
+    ['p.MsoListParagraph', matchMsWordList],
+    ['p.msolistparagraph', matchMsWordList],
+    ['p.MsoNormal', maybeMatchMsWordList]
+];
+
+export default msWordPasteMatchers;