Add toPlainText method to `EmbedBuilder`

lib/src/models/documents/document.dart

@@ -1,5 +1,6 @@
 import 'dart:async';
 
+import '../../widgets/embeds.dart';
 import '../quill_delta.dart';
 import '../rules/rule.dart';
 import '../structs/doc_change.dart';
@@ -349,7 +350,13 @@ class Document {
   }
 
   /// Returns plain text representation of this document.
-  String toPlainText() => _root.children.map((e) => e.toPlainText()).join();
+  String toPlainText([
+    Iterable<EmbedBuilder>? embedBuilders,
+    EmbedBuilder? unknownEmbedBuilder,
+  ]) =>
+      _root.children
+          .map((e) => e.toPlainText(embedBuilders, unknownEmbedBuilder))
+          .join();
 
   void _loadDocument(Delta doc) {
     if (doc.isEmpty) {

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

@@ -1,5 +1,6 @@
 import 'dart:collection';
 
+import '../../../widgets/embeds.dart';
 import '../style.dart';
 import 'leaf.dart';
 import 'line.dart';
@@ -103,7 +104,13 @@ abstract class Container<T extends Node?> extends Node {
   }
 
   @override
-  String toPlainText() => children.map((child) => child.toPlainText()).join();
+  String toPlainText([
+    Iterable<EmbedBuilder>? embedBuilders,
+    EmbedBuilder? unknownEmbedBuilder,
+  ]) =>
+      children
+          .map((e) => e.toPlainText(embedBuilders, unknownEmbedBuilder))
+          .join();
 
   /// Content length of this node's children.
   ///

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

@@ -1,5 +1,6 @@
 import 'dart:math' as math;
 
+import '../../../widgets/embeds.dart';
 import '../../quill_delta.dart';
 import '../style.dart';
 import 'embeddable.dart';
@@ -224,7 +225,11 @@ class Text extends Leaf {
   String get value => _value as String;
 
   @override
-  String toPlainText() => value;
+  String toPlainText([
+    Iterable<EmbedBuilder>? embedBuilders,
+    EmbedBuilder? unknownEmbedBuilder,
+  ]) =>
+      value;
 }
 
 /// An embed node inside of a line in a Quill document.
@@ -257,7 +262,29 @@ class Embed extends Leaf {
   // Embed nodes are represented as unicode object replacement character in
   // plain text.
   @override
-  String toPlainText() => kObjectReplacementCharacter;
+  String toPlainText([
+    Iterable<EmbedBuilder>? embedBuilders,
+    EmbedBuilder? unknownEmbedBuilder,
+  ]) {
+    final builders = embedBuilders;
+
+    print('这里是 ${toString()}');
+
+    if (builders != null) {
+      for (final builder in builders) {
+        print('${builder.key} ${value.type}');
+        if (builder.key == value.type) {
+          return builder.toPlainText(this);
+        }
+      }
+    }
+
+    if (unknownEmbedBuilder != null) {
+      return unknownEmbedBuilder.toPlainText(this);
+    }
+
+    return Embed.kObjectReplacementCharacter;
+  }
 
   @override
   String toString() => '${super.toString()} ${value.type}';

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

@@ -2,6 +2,7 @@ import 'dart:math' as math;
 
 import 'package:collection/collection.dart';
 
+import '../../../widgets/embeds.dart';
 import '../../quill_delta.dart';
 import '../../structs/offset_value.dart';
 import '../attribute.dart';
@@ -65,7 +66,11 @@ class Line extends Container<Leaf?> {
   }
 
   @override
-  String toPlainText() => '${super.toPlainText()}\n';
+  String toPlainText([
+    Iterable<EmbedBuilder>? embedBuilders,
+    EmbedBuilder? unknownEmbedBuilder,
+  ]) =>
+      '${super.toPlainText(embedBuilders, unknownEmbedBuilder)}\n';
 
   @override
   String toString() {

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

@@ -1,5 +1,6 @@
 import 'dart:collection';
 
+import '../../../widgets/embeds.dart';
 import '../../quill_delta.dart';
 import '../attribute.dart';
 import '../style.dart';
@@ -109,7 +110,10 @@ abstract class Node extends LinkedListEntry<Node> {
 
   Node newInstance();
 
-  String toPlainText();
+  String toPlainText([
+    Iterable<EmbedBuilder>? embedBuilders,
+    EmbedBuilder? unknownEmbedBuilder,
+  ]);
 
   Delta toDelta();
 

lib/src/widgets/embeds.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 
+import '../../extensions.dart';
 import '../models/documents/nodes/leaf.dart' as leaf;
 import '../models/themes/quill_dialog_theme.dart';
 import '../models/themes/quill_icon_theme.dart';
@@ -15,6 +16,8 @@ abstract class EmbedBuilder {
     return WidgetSpan(child: widget);
   }
 
+  String toPlainText(Embed node) => Embed.kObjectReplacementCharacter;
+
   Widget build(
     BuildContext context,
     QuillController controller,