Fix headers

lib/src/widgets/default_styles.dart

@@ -67,6 +67,9 @@ class InlineCodeStyle {
     this.header1,
     this.header2,
     this.header3,
+    this.header4,
+    this.header5,
+    this.header6,
     this.backgroundColor,
     this.radius,
   });
@@ -83,6 +86,15 @@ class InlineCodeStyle {
   /// Style override for inline code in headings level 3.
   final TextStyle? header3;
 
+  /// Style override for inline code in headings level 4.
+  final TextStyle? header4;
+
+  /// Style override for inline code in headings level 5.
+  final TextStyle? header5;
+
+  /// Style override for inline code in headings level 6.
+  final TextStyle? header6;
+
   /// Background color for inline code.
   final Color? backgroundColor;
 
@@ -101,6 +113,15 @@ class InlineCodeStyle {
     if (lineStyle.containsKey(Attribute.h3.key)) {
       return header3 ?? style;
     }
+    if (lineStyle.containsKey(Attribute.h4.key)) {
+      return header4 ?? style;
+    }
+    if (lineStyle.containsKey(Attribute.h5.key)) {
+      return header5 ?? style;
+    }
+    if (lineStyle.containsKey(Attribute.h6.key)) {
+      return header6 ?? style;
+    }
     return style;
   }
 
@@ -116,13 +137,16 @@ class InlineCodeStyle {
         other.header1 == header1 &&
         other.header2 == header2 &&
         other.header3 == header3 &&
+        other.header4 == header4 &&
+        other.header5 == header5 &&
+        other.header6 == header6 &&
         other.backgroundColor == backgroundColor &&
         other.radius == radius;
   }
 
   @override
-  int get hashCode =>
-      Object.hash(style, header1, header2, header3, backgroundColor, radius);
+  int get hashCode => Object.hash(style, header1, header2, header3, header4,
+      header5, header6, backgroundColor, radius);
 }
 
 @immutable

lib/src/widgets/raw_editor/raw_editor_state.dart

@@ -448,6 +448,21 @@ class QuillRawEditorState extends EditorState
               control: !isDesktopMacOS,
               meta: isDesktopMacOS,
             ): const QuillEditorApplyHeaderIntent(Attribute.h3),
+            SingleActivator(
+              LogicalKeyboardKey.digit4,
+              control: !isDesktopMacOS,
+              meta: isDesktopMacOS,
+            ): const QuillEditorApplyHeaderIntent(Attribute.h4),
+            SingleActivator(
+              LogicalKeyboardKey.digit5,
+              control: !isDesktopMacOS,
+              meta: isDesktopMacOS,
+            ): const QuillEditorApplyHeaderIntent(Attribute.h5),
+            SingleActivator(
+              LogicalKeyboardKey.digit6,
+              control: !isDesktopMacOS,
+              meta: isDesktopMacOS,
+            ): const QuillEditorApplyHeaderIntent(Attribute.h6),
             SingleActivator(
               LogicalKeyboardKey.digit0,
               control: !isDesktopMacOS,

lib/src/widgets/text_line.dart

@@ -271,6 +271,9 @@ class _TextLineState extends State<TextLine> {
       Attribute.h1: defaultStyles.h1!.style,
       Attribute.h2: defaultStyles.h2!.style,
       Attribute.h3: defaultStyles.h3!.style,
+      Attribute.h4: defaultStyles.h4!.style,
+      Attribute.h5: defaultStyles.h5!.style,
+      Attribute.h6: defaultStyles.h6!.style,
     };
 
     textStyle = textStyle.merge(m[header] ?? defaultStyles.paragraph!.style);