[SuperEditor] Fixes the overlays obscuring editor view in devtools painting mode (Resolves #2610)

super_editor/lib/src/default_editor/document_caret_overlay.dart

@@ -7,6 +7,9 @@ import 'package:super_editor/src/infrastructure/documents/document_layers.dart';
 import 'package:super_editor/src/infrastructure/platforms/mobile_documents.dart';
 import 'package:super_text_layout/super_text_layout.dart';
 
+import '../infrastructure/flutter/build_nothing_box.dart';
+import 'document_gestures_touch_ios.dart';
+
 /// Document overlay that paints a caret with the given [caretStyle].
 class CaretDocumentOverlay extends DocumentLayoutLayerStatefulWidget {
   const CaretDocumentOverlay({
@@ -191,11 +194,11 @@ class CaretDocumentOverlayState extends DocumentLayoutLayerState<CaretDocumentOv
     // `displayOnAllPlatforms` to true.
     final platform = widget.platformOverride ?? defaultTargetPlatform;
     if (!widget.displayOnAllPlatforms && (platform == TargetPlatform.android || platform == TargetPlatform.iOS)) {
-      return const SizedBox();
+      return const BuildNothingBox();
     }
 
     if (_shouldHideCaretForExpandedSelection) {
-      return const SizedBox();
+      return const BuildNothingBox();
     }
 
     // Use a RepaintBoundary so that caret flashing doesn't invalidate our

super_editor/lib/src/default_editor/document_gestures_touch_android.dart

@@ -34,6 +34,8 @@ import 'package:super_editor/src/infrastructure/touch_controls.dart';
 
 import '../infrastructure/document_gestures.dart';
 import '../infrastructure/document_gestures_interaction_overrides.dart';
+import '../infrastructure/flutter/build_nothing_box.dart';
+import 'document_gestures_touch_ios.dart';
 import 'selection_upstream_downstream.dart';
 
 /// An [InheritedWidget] that provides shared access to a [SuperEditorAndroidControlsController],
@@ -366,7 +368,7 @@ class SuperEditorAndroidToolbarFocalPointDocumentLayerBuilder implements SuperEd
         SuperEditorAndroidControlsScope.maybeNearestOf(context) == null) {
       // There's no controls scope. This probably means SuperEditor is configured with
       // a non-Android gesture mode. Build nothing.
-      return const ContentLayerProxyWidget(child: SizedBox());
+      return const ContentLayerProxyWidget(child: BuildNothingBox());
     }
 
     return AndroidToolbarFocalPointDocumentLayer(
@@ -399,7 +401,7 @@ class SuperEditorAndroidHandlesDocumentLayerBuilder implements SuperEditorLayerB
         SuperEditorAndroidControlsScope.maybeNearestOf(context) == null) {
       // There's no controls scope. This probably means SuperEditor is configured with
       // a non-Android gesture mode. Build nothing.
-      return const ContentLayerProxyWidget(child: SizedBox());
+      return const ContentLayerProxyWidget(child: BuildNothingBox());
     }
 
     return AndroidHandlesDocumentLayer(

super_editor/lib/src/default_editor/document_gestures_touch_ios.dart

@@ -4,6 +4,7 @@ import 'dart:async';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
 import 'package:follow_the_leader/follow_the_leader.dart';
 import 'package:super_editor/src/core/document.dart';
 import 'package:super_editor/src/core/document_composer.dart';
@@ -34,6 +35,7 @@ import 'package:super_editor/src/infrastructure/touch_controls.dart';
 
 import '../infrastructure/document_gestures.dart';
 import '../infrastructure/document_gestures_interaction_overrides.dart';
+import '../infrastructure/flutter/build_nothing_box.dart';
 import 'selection_upstream_downstream.dart';
 
 /// An [InheritedWidget] that provides shared access to a [SuperEditorIosControlsController],
@@ -1943,7 +1945,7 @@ class SuperEditorIosToolbarFocalPointDocumentLayerBuilder implements SuperEditor
     if (defaultTargetPlatform != TargetPlatform.iOS || SuperEditorIosControlsScope.maybeNearestOf(context) == null) {
       // There's no controls scope. This probably means SuperEditor is configured with
       // a non-iOS gesture mode. Build nothing.
-      return const ContentLayerProxyWidget(child: SizedBox());
+      return const ContentLayerProxyWidget(child: BuildNothingBox());
     }
 
     return IosToolbarFocalPointDocumentLayer(
@@ -1976,7 +1978,7 @@ class SuperEditorIosHandlesDocumentLayerBuilder implements SuperEditorLayerBuild
     if (defaultTargetPlatform != TargetPlatform.iOS || SuperEditorIosControlsScope.maybeNearestOf(context) == null) {
       // There's no controls scope. This probably means SuperEditor is configured with
       // a non-iOS gesture mode. Build nothing.
-      return const ContentLayerProxyWidget(child: SizedBox());
+      return const ContentLayerProxyWidget(child: BuildNothingBox());
     }
 
     final controlsController = SuperEditorIosControlsScope.rootOf(context);

super_editor/lib/src/infrastructure/flutter/build_nothing_box.dart

@@ -0,0 +1,14 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
+
+/// A widget that builds and paints nothing.
+class BuildNothingBox extends LeafRenderObjectWidget {
+  const BuildNothingBox();
+
+  @override
+  RenderBuildNothingBox createRenderObject(BuildContext context) {
+    return RenderBuildNothingBox();
+  }
+}
+
+class RenderBuildNothingBox extends RenderProxyBox {}