diff --git a/lib/widgets/editor.dart b/lib/widgets/editor.dart
index 12b698bf..b382ca20 100644
--- a/lib/widgets/editor.dart
+++ b/lib/widgets/editor.dart
@@ -149,7 +149,7 @@ class QuillEditor extends StatefulWidget {
   final bool? showCursor;
   final bool readOnly;
   final String? placeholder;
-  final bool? enableInteractiveSelection;
+  final bool enableInteractiveSelection;
   final double? minHeight;
   final double? maxHeight;
   final DefaultStyles? customStyles;
@@ -161,8 +161,7 @@ class QuillEditor extends StatefulWidget {
   final EmbedBuilder embedBuilder;
 
   QuillEditor(
-      {Key? key,
-      required this.controller,
+      {required this.controller,
       required this.focusNode,
       required this.scrollController,
       required this.scrollable,
@@ -171,7 +170,7 @@ class QuillEditor extends StatefulWidget {
       this.showCursor,
       required this.readOnly,
       this.placeholder,
-      this.enableInteractiveSelection,
+      this.enableInteractiveSelection = true,
       this.minHeight,
       this.maxHeight,
       this.customStyles,
@@ -184,7 +183,7 @@ class QuillEditor extends StatefulWidget {
           kIsWeb ? _defaultEmbedBuilderWeb : _defaultEmbedBuilder});
 
   factory QuillEditor.basic(
-      {Key? key, required QuillController controller, required bool readOnly}) {
+      {required QuillController controller, required bool readOnly}) {
     return QuillEditor(
         controller: controller,
         scrollController: ScrollController(),
@@ -296,7 +295,7 @@ class _QuillEditorState extends State<QuillEditor>
           selectionColor,
           textSelectionControls,
           widget.keyboardAppearance,
-          widget.enableInteractiveSelection!,
+          widget.enableInteractiveSelection ?? true,
           widget.scrollPhysics,
           widget.embedBuilder),
     );
@@ -313,7 +312,7 @@ class _QuillEditorState extends State<QuillEditor>
   }
 
   @override
-  bool? getSelectionEnabled() {
+  bool getSelectionEnabled() {
     return widget.enableInteractiveSelection;
   }
 
@@ -341,7 +340,7 @@ class _QuillEditorSelectionGestureDetectorBuilder
 
   @override
   void onSingleLongTapMoveUpdate(LongPressMoveUpdateDetails details) {
-    if (!delegate.getSelectionEnabled()!) {
+    if (!delegate.getSelectionEnabled()) {
       return;
     }
     switch (Theme.of(_state.context).platform) {
@@ -470,7 +469,7 @@ class _QuillEditorSelectionGestureDetectorBuilder
 
     bool positionSelected = _onTapping(details);
 
-    if (delegate.getSelectionEnabled()! && !positionSelected) {
+    if (delegate.getSelectionEnabled() && !positionSelected) {
       switch (Theme.of(_state.context).platform) {
         case TargetPlatform.iOS:
         case TargetPlatform.macOS:
diff --git a/lib/widgets/raw_editor.dart b/lib/widgets/raw_editor.dart
index 24f9c397..9fb46152 100644
--- a/lib/widgets/raw_editor.dart
+++ b/lib/widgets/raw_editor.dart
@@ -29,6 +29,7 @@ import 'delegate.dart';
 import 'editor.dart';
 import 'keyboard_listener.dart';
 
+
 class RawEditor extends StatefulWidget {
   final QuillController controller;
   final FocusNode focusNode;
@@ -1176,4 +1177,4 @@ class _Editor extends MultiChildRenderObjectWidget {
     renderObject.onSelectionChanged = onSelectionChanged;
     renderObject.setPadding(padding);
   }
-}
+}
\ No newline at end of file
diff --git a/lib/widgets/text_line.dart b/lib/widgets/text_line.dart
index 8eb7207e..ea676d64 100644
--- a/lib/widgets/text_line.dart
+++ b/lib/widgets/text_line.dart
@@ -101,7 +101,7 @@ class TextLine extends StatelessWidget {
       Attribute.h3: defaultStyles.h3!.style,
     };
 
-    textStyle = textStyle.merge(m[header!] ?? defaultStyles.paragraph!.style);
+    textStyle = textStyle.merge(m[header] ?? defaultStyles.paragraph!.style);
 
     Attribute? block = line.style.getBlockExceptHeader();
     TextStyle? toMerge;
@@ -187,8 +187,8 @@ class TextLine extends StatelessWidget {
       decorations.add(b.decoration);
     }
     return a.merge(b).apply(
-        decoration:
-            TextDecoration.combine(decorations as List<TextDecoration>));
+        decoration: TextDecoration.combine(
+            List.castFrom<dynamic, TextDecoration>(decorations)));
   }
 }
 
@@ -824,8 +824,8 @@ class _TextLineElement extends RenderObjectElement {
   }
 
   @override
-  insertRenderObjectChild(RenderObject child, TextLineSlot? slot) {
-    assert(child is RenderBox);
+  insertRenderObjectChild(RenderBox child, TextLineSlot? slot) {
+    // assert(child is RenderBox);
     _updateRenderObject(child, slot);
     assert(renderObject.children.keys.contains(slot));
   }
@@ -854,13 +854,13 @@ class _TextLineElement extends RenderObjectElement {
     }
   }
 
-  _updateRenderObject(RenderObject? child, TextLineSlot? slot) {
+  _updateRenderObject(RenderBox? child, TextLineSlot? slot) {
     switch (slot) {
       case TextLineSlot.LEADING:
-        renderObject.setLeading(child as RenderBox?);
+        renderObject.setLeading(child);
         break;
       case TextLineSlot.BODY:
-        renderObject.setBody((child as RenderBox?) as RenderContentProxyBox?);
+        renderObject.setBody((child) as RenderContentProxyBox?);
         break;
       default:
         throw UnimplementedError();