diff --git a/lib/src/core/transform/transaction.dart b/lib/src/core/transform/transaction.dart
index 21389a0ef..164483679 100644
--- a/lib/src/core/transform/transaction.dart
+++ b/lib/src/core/transform/transaction.dart
@@ -372,7 +372,7 @@ extension TextTransaction on Transaction {
           replaceText(
             node,
             selection.startIndex,
-            delta.length,
+            delta.length - selection.startIndex,
             texts.first,
           );
         } else if (i == length - 1) {
@@ -406,7 +406,7 @@ extension TextTransaction on Transaction {
           replaceText(
             node,
             selection.startIndex,
-            delta.length,
+            delta.length - selection.startIndex,
             texts.first,
           );
         } else if (i == length - 1 && texts.length >= 2) {
@@ -463,7 +463,7 @@ extension TextTransaction on Transaction {
           replaceText(
             nodes.first,
             selection.startIndex,
-            delta.length,
+            delta.length - selection.startIndex,
             text,
           );
           path = path.next;
@@ -538,6 +538,7 @@ extension TextTransaction on Transaction {
       final deltaQueue = entry.value;
       final composed =
           deltaQueue.fold<Delta>(node.delta!, (p, e) => p.compose(e));
+      assert(composed.every((element) => element is TextInsert));
       updateNode(node, {
         'delta': composed.toJson(),
       });
diff --git a/lib/src/editor/toolbar/desktop/items/icon_item_widget.dart b/lib/src/editor/toolbar/desktop/items/icon_item_widget.dart
index cd1a5b7f5..1e3653037 100644
--- a/lib/src/editor/toolbar/desktop/items/icon_item_widget.dart
+++ b/lib/src/editor/toolbar/desktop/items/icon_item_widget.dart
@@ -6,7 +6,8 @@ class IconItemWidget extends StatelessWidget {
     super.key,
     this.size = const Size.square(30.0),
     this.iconSize = const Size.square(18.0),
-    required this.iconName,
+    this.iconName,
+    this.iconBuilder,
     required this.isHighlight,
     this.highlightColor = Colors.lightBlue,
     this.tooltip,
@@ -15,7 +16,8 @@ class IconItemWidget extends StatelessWidget {
 
   final Size size;
   final Size iconSize;
-  final String iconName;
+  final String? iconName;
+  final WidgetBuilder? iconBuilder;
   final bool isHighlight;
   final Color highlightColor;
   final String? tooltip;
@@ -23,12 +25,14 @@ class IconItemWidget extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    Widget child = EditorSvg(
-      name: iconName,
-      color: isHighlight ? highlightColor : null,
-      width: iconSize.width,
-      height: iconSize.height,
-    );
+    Widget child = iconBuilder != null
+        ? iconBuilder!(context)
+        : EditorSvg(
+            name: iconName,
+            color: isHighlight ? highlightColor : null,
+            width: iconSize.width,
+            height: iconSize.height,
+          );
     if (onPressed != null) {
       child = MouseRegion(
         cursor: SystemMouseCursors.click,