Fix: Allow backspace at start of document to remove block elements an…

…d headers (#2198)

lib/src/editor/raw_editor/raw_editor_state.dart

@@ -761,6 +761,11 @@ class QuillRawEditorState extends EditorState
       return _handleSpaceKey(event);
     }
 
+    // Handles removing styles when pressing the backspace key at the beginning of the document.
+    if (event.logicalKey == LogicalKeyboardKey.backspace) {
+      return _handleBackspaceKey(event);
+    }
+
     return KeyEventResult.ignored;
   }
 
@@ -797,6 +802,49 @@ class QuillRawEditorState extends EditorState
     return KeyEventResult.handled;
   }
 
+  KeyEventResult _handleBackspaceKey(KeyEvent event) {
+    final child =
+        controller.document.queryChild(controller.selection.baseOffset);
+    if (child.node == null) {
+      return KeyEventResult.ignored;
+    }
+
+    if (child.node == null) {
+      return KeyEventResult.ignored;
+    }
+
+    // Only process when the backspace key is pressed at the beginning of the document.
+    if (controller.selection.baseOffset != 0) {
+      return KeyEventResult.ignored;
+    }
+
+    // Blocks and headers are targeted.
+    final node = child.node!;
+    final parent = node.parent;
+    if (parent == null && (parent is Block || parent is Root)) {
+      return KeyEventResult.ignored;
+    }
+
+    // Remove the parent's style.
+    // Block attributes are removed.
+    final style = parent!.style;
+    if (style.isNotEmpty) {
+      for (final attr in style.values) {
+        controller.formatSelection(Attribute.clone(attr, null));
+      }
+    }
+
+    // Remove the first child's style.
+    // Header attributes are removed.
+    final firstChildStyle = parent.first?.style;
+    if (firstChildStyle != null) {
+      for (final attr in firstChildStyle.values) {
+        controller.formatSelection(Attribute.clone(attr, null));
+      }
+    }
+    return KeyEventResult.handled;
+  }
+
   KeyEventResult _handleTabKey(KeyEvent event) {
     final child =
         controller.document.queryChild(controller.selection.baseOffset);