add paste style

lib/src/models/documents/nodes/line.dart

@@ -393,12 +393,17 @@ class Line extends Container<Leaf?> {
     final data = queryChild(offset, true);
     var node = data.node as Leaf?;
     if (node != null) {
-      var pos = node.length - data.offset;
-      result.add(Tuple2(beg, node.style));
+      var pos = 0;
+      if (node is Text) {
+        pos = node.length - data.offset;
+        result.add(Tuple2(beg, node.style));
+      }
       while (!node!.isLast && pos < local) {
         node = node.next as Leaf;
-        result.add(Tuple2(pos + beg, node.style));
-        pos += node.length;
+        if (node is Text) {
+          result.add(Tuple2(pos + beg, node.style));
+          pos += node.length;
+        }
       }
     }
 
@@ -462,19 +467,23 @@ class Line extends Container<Leaf?> {
     // Adjust first node
     final firstNodeLen = res[1].item1;
     var text = res[0].item2;
-    total.add(text.substring(text.length - firstNodeLen));
+    if (text != Embed.kObjectReplacementCharacter) {
+      total.add(text.substring(text.length - firstNodeLen));
+    }
 
     for (var i = 1; i < res.length - 1; i++) {
-      total.add(res[i].item2);
+      if (res[i].item2 != Embed.kObjectReplacementCharacter) {
+        total.add(res[i].item2);
+      }
     }
 
     // Adjust last node
     final lastNodeLen = len - res[res.length - 1].item1;
     text = res[res.length - 1].item2;
-    total.add(text.substring(0, lastNodeLen));
-    return total
-        .skipWhile((value) => value == Embed.kObjectReplacementCharacter)
-        .join();
+    if (text != Embed.kObjectReplacementCharacter) {
+      total.add(text.substring(0, lastNodeLen));
+    }
+    return total.join();
   }
 
   List<Tuple2<int, String>> _getPlainText(int offset, int len, {int beg = 0}) {

lib/src/widgets/editor.dart

@@ -6,6 +6,8 @@ import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
+import '../models/documents/style.dart';
+import 'package:tuple/tuple.dart';
 
 import '../models/documents/document.dart';
 import '../models/documents/nodes/container.dart' as container_node;
@@ -48,6 +50,10 @@ abstract class EditorState extends State<RawEditor>
 
   EditorTextSelectionOverlay? get selectionOverlay;
 
+  List<Tuple2<int, Style>> get pasteStyle;
+
+  String get pastePlainText;
+
   /// Controls the floating cursor animation when it is released.
   /// The floating cursor is animated to merge with the regular cursor.
   AnimationController get floatingCursorResetController;

lib/src/widgets/raw_editor.dart

@@ -17,6 +17,7 @@ import '../models/documents/document.dart';
 import '../models/documents/nodes/block.dart';
 import '../models/documents/nodes/line.dart';
 import '../models/documents/nodes/node.dart';
+import '../models/documents/style.dart';
 import '../utils/platform.dart';
 import 'controller.dart';
 import 'cursor.dart';
@@ -259,6 +260,14 @@ class RawEditorState extends EditorState
   // Theme
   DefaultStyles? _styles;
 
+  // for pasting style
+  @override
+  List<Tuple2<int, Style>> get pasteStyle => _pasteStyle;
+  List<Tuple2<int, Style>> _pasteStyle = <Tuple2<int, Style>>[];
+  @override
+  String get pastePlainText => _pastePlainText;
+  String _pastePlainText = '';
+
   final ClipboardStatusNotifier _clipboardStatus = ClipboardStatusNotifier();
   final LayerLink _toolbarLayerLink = LayerLink();
   final LayerLink _startHandleLayerLink = LayerLink();
@@ -843,6 +852,8 @@ class RawEditorState extends EditorState
 
   @override
   void copySelection(SelectionChangedCause cause) {
+    _pastePlainText = widget.controller.getPlainText();
+    _pasteStyle = widget.controller.getAllIndividualSelectionStyles();
     // Copied straight from EditableTextState
     super.copySelection(cause);
     if (cause == SelectionChangedCause.toolbar) {
@@ -865,6 +876,8 @@ class RawEditorState extends EditorState
 
   @override
   void cutSelection(SelectionChangedCause cause) {
+    _pastePlainText = widget.controller.getPlainText();
+    _pasteStyle = widget.controller.getAllIndividualSelectionStyles();
     // Copied straight from EditableTextState
     super.cutSelection(cause);
     if (cause == SelectionChangedCause.toolbar) {

lib/src/widgets/raw_editor/raw_editor_state_selection_delegate_mixin.dart

@@ -4,6 +4,7 @@ import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
 import '../../models/documents/nodes/leaf.dart';
+import '../../models/documents/style.dart';
 import '../../utils/delta.dart';
 import '../editor.dart';
 
@@ -24,6 +25,21 @@ mixin RawEditorStateSelectionDelegateMixin on EditorState
 
     widget.controller.replaceText(
         diff.start, diff.deleted.length, insertedText, value.selection);
+
+    if (insertedText == pastePlainText && pastePlainText != '') {
+      var pos = diff.start;
+      for ( var i = 0; i < pasteStyle.length; i++){
+        int offset = pasteStyle[i].item1;
+        Style style = pasteStyle[i].item2;
+        if (i == pasteStyle.length - 1) {
+          style.attributes.forEach((k, v) => widget.controller
+              .formatText(pos + offset, pastePlainText.length - offset, v));
+        } else {
+          style.attributes.forEach((k, v) => widget.controller
+              .formatText(pos + offset, pasteStyle[i + 1].item1, v));
+        }
+      }
+    }
   }
 
   String _adjustInsertedText(String text) {