Paste multiline selection

lib/src/controller/quill_controller.dart

@@ -477,10 +477,13 @@ class QuillController extends ChangeNotifier {
 
   /// Clipboard caches last copy to allow paste with styles. Static to allow paste between multiple instances of editor.
   static String _pastePlainText = '';
+  static Delta _pasteDelta = Delta();
   static List<OffsetValue> _pasteStyleAndEmbed = <OffsetValue>[];
 
   String get pastePlainText => _pastePlainText;
+  Delta get pasteDelta => _pasteDelta;
   List<OffsetValue> get pasteStyleAndEmbed => _pasteStyleAndEmbed;
+
   bool readOnly;
 
   /// Used to give focus to the editor following a toolbar action
@@ -507,6 +510,9 @@ class QuillController extends ChangeNotifier {
     /// Get the internal representation so it can be pasted into a QuillEditor with style retained.
     _pasteStyleAndEmbed = getAllIndividualSelectionStylesAndEmbed();
 
+    /// Get the deltas for the selection so they can be pasted into a QuillEditor with styles and embeds retained.
+    _pasteDelta = document.toDelta().slice(selection.start, selection.end);
+
     if (!selection.isCollapsed) {
       Clipboard.setData(ClipboardData(text: _pastePlainText));
       if (!copy) {
@@ -547,27 +553,13 @@ class QuillController extends ChangeNotifier {
     // See https://github.com/flutter/flutter/issues/11427
     final plainTextClipboardData =
         await Clipboard.getData(Clipboard.kTextPlain);
-    if (plainTextClipboardData != null) {
-      final lines = plainTextClipboardData.text!.split('\n');
-      for (var i = 0; i < lines.length; ++i) {
-        final line = lines[i];
-        if (line.isNotEmpty) {
-          replaceTextWithEmbeds(
-            selection.start,
-            selection.end - selection.start,
-            line,
-            TextSelection.collapsed(offset: selection.start + line.length),
-          );
-        }
-        if (i != lines.length - 1) {
-          document.insert(selection.extentOffset, '\n');
-          _updateSelection(
-            TextSelection.collapsed(
-              offset: selection.extentOffset + 1,
-            ),
-            insertNewline: true,
-          );
-        }
+    if (plainTextClipboardData?.text != null) {
+
+      /// Internal copy-paste preserves styles and embeds
+      if ( plainTextClipboardData!.text == _pastePlainText && _pastePlainText.isNotEmpty && _pasteDelta.isNotEmpty ) {
+        replaceText(selection.start, selection.end - selection.start, _pasteDelta, TextSelection.collapsed(offset: selection.end));
+      } else {
+        replaceText(selection.start, selection.end - selection.start, plainTextClipboardData.text, TextSelection.collapsed(offset: selection.end + plainTextClipboardData.text!.length));
       }
       updateEditor?.call();
       return true;

lib/src/delta/delta_diff.dart

@@ -70,19 +70,18 @@ int getPositionDelta(Delta user, Delta actual) {
       );
     }
     if (userOperation.key == actualOperation.key) {
+      /// Insertions must update diff allowing for type mismatch of Operation
+      if ( userOperation.key == Operation.insertKey) {
+        if ( userOperation.data is Delta && actualOperation.data is String ) {
+          diff += actualOperation.length!;
+        }
+      }
       continue;
     } else if (userOperation.isInsert && actualOperation.isRetain) {
       diff -= userOperation.length!;
     } else if (userOperation.isDelete && actualOperation.isRetain) {
       diff += userOperation.length!;
     } else if (userOperation.isRetain && actualOperation.isInsert) {
-      String? operationTxt = '';
-      if (actualOperation.data is String) {
-        operationTxt = actualOperation.data as String?;
-      }
-      if (operationTxt!.startsWith('\n')) {
-        continue;
-      }
       diff += actualOperation.length!;
     }
   }