chore: disable children receive events under fake drag target

Author: appflowy

frontend/app_flowy/packages/appflowy_board/lib/src/widgets/reorder_flex/drag_target.dart

@@ -277,6 +277,31 @@ class IgnorePointerWidget extends StatelessWidget {
   }
 }
 
+class AbsorbPointerWidget extends StatelessWidget {
+  final Widget? child;
+  final bool useIntrinsicSize;
+  const AbsorbPointerWidget({
+    required this.child,
+    this.useIntrinsicSize = false,
+    Key? key,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    final sizedChild = useIntrinsicSize
+        ? child
+        : SizedBox(width: 0.0, height: 0.0, child: child);
+
+    final opacity = useIntrinsicSize ? 0.3 : 0.0;
+    return AbsorbPointer(
+      child: Opacity(
+        opacity: opacity,
+        child: sizedChild,
+      ),
+    );
+  }
+}
+
 class PhantomWidget extends StatelessWidget {
   final Widget? child;
   final double opacity;
@@ -442,15 +467,15 @@ class _FakeDragTargetState<T extends DragTargetData>
       return SizeTransitionWithIntrinsicSize(
         sizeFactor: widget.deleteAnimationController,
         axis: Axis.vertical,
-        child: IgnorePointerWidget(
+        child: AbsorbPointerWidget(
           child: widget.child,
         ),
       );
     } else {
       return SizeTransitionWithIntrinsicSize(
         sizeFactor: widget.insertAnimationController,
         axis: Axis.vertical,
-        child: IgnorePointerWidget(
+        child: AbsorbPointerWidget(
           useIntrinsicSize: true,
           child: widget.child,
         ),

frontend/app_flowy/packages/appflowy_board/lib/src/widgets/reorder_phantom/phantom_controller.dart

@@ -204,16 +204,16 @@ class BoardPhantomController extends OverlapDragTargetDelegate
 
   @override
   int canMoveTo(String dragTargetId) {
-    // if (columnsState.isDragging(dragTargetId)) {
-    //   return -1;
-    // }
-
-    // final controller = delegate.controller(dragTargetId);
-    // if (controller != null) {
-    //   return controller.columnData.items.length;
-    // } else {
-    //   return 0;
-    // }
+    if (columnsState.isDragging(dragTargetId)) {
+      return -1;
+    }
+
+    final controller = delegate.controller(dragTargetId);
+    if (controller != null) {
+      return controller.columnData.items.length;
+    } else {
+      return 0;
+    }
 
     if (delegate.controller(dragTargetId)?.columnData.items.isEmpty ?? false) {
       return 0;