feat: support moving view across sections (#5015)

frontend/appflowy_flutter/lib/workspace/application/view/view_bloc.dart

@@ -207,6 +207,13 @@ class ViewBloc extends Bloc<ViewEvent, ViewState> {
               ),
             );
           },
+          updateViewVisibility: (value) async {
+            final view = value.view;
+            await ViewBackendService.updateViewsVisibility(
+              [view],
+              value.isPublic,
+            );
+          },
         );
       },
     );
@@ -370,6 +377,8 @@ class ViewEvent with _$ViewEvent {
   ) = ViewDidUpdate;
   const factory ViewEvent.viewUpdateChildView(ViewPB result) =
       ViewUpdateChildView;
+  const factory ViewEvent.updateViewVisibility(ViewPB view, bool isPublic) =
+      UpdateViewVisibility;
 }
 
 @freezed

frontend/appflowy_flutter/lib/workspace/application/view/view_service.dart

@@ -280,4 +280,15 @@ class ViewBackendService {
       );
     });
   }
+
+  static Future<FlowyResult<void, FlowyError>> updateViewsVisibility(
+    List<ViewPB> views,
+    bool isPublic,
+  ) async {
+    final payload = UpdateViewVisibilityStatusPayloadPB(
+      viewIds: views.map((e) => e.id).toList(),
+      isPublic: isPublic,
+    );
+    return FolderEventUpdateViewVisibilityStatus(payload).send();
+  }
 }

frontend/appflowy_flutter/lib/workspace/presentation/home/menu/sidebar/folder/_section_folder.dart

@@ -2,6 +2,7 @@ import 'package:appflowy/generated/locale_keys.g.dart';
 import 'package:appflowy/workspace/application/menu/sidebar_sections_bloc.dart';
 import 'package:appflowy/workspace/application/sidebar/folder/folder_bloc.dart';
 import 'package:appflowy/workspace/application/tabs/tabs_bloc.dart';
+import 'package:appflowy/workspace/application/user/user_workspace_bloc.dart';
 import 'package:appflowy/workspace/presentation/home/menu/sidebar/folder/_folder_header.dart';
 import 'package:appflowy/workspace/presentation/home/menu/sidebar/rename_view_dialog.dart';
 import 'package:appflowy/workspace/presentation/home/menu/view/view_item.dart';
@@ -95,6 +96,25 @@ class SectionFolder extends StatelessWidget {
                     isHoverEnabled: isHoverEnabled,
                   ),
                 ),
+              if (views.isEmpty)
+                ViewItem(
+                  categoryType: categoryType,
+                  view: ViewPB(
+                    parentViewId: context
+                            .read<UserWorkspaceBloc>()
+                            .state
+                            .currentWorkspace
+                            ?.workspaceId ??
+                        '',
+                  ),
+                  level: 0,
+                  leftPadding: 16,
+                  isFeedback: false,
+                  onSelected: (_) {},
+                  onTertiarySelected: (_) {},
+                  isHoverEnabled: isHoverEnabled,
+                  isPlaceholder: true,
+                ),
             ],
           );
         },

frontend/appflowy_flutter/lib/workspace/presentation/home/menu/view/draggable_view_item.dart

@@ -26,6 +26,7 @@ class DraggableViewItem extends StatefulWidget {
     this.topHighlightColor,
     this.bottomHighlightColor,
     this.onDragging,
+    this.onMove,
   });
 
   final Widget child;
@@ -36,6 +37,7 @@ class DraggableViewItem extends StatefulWidget {
   final Color? topHighlightColor;
   final Color? bottomHighlightColor;
   final void Function(bool isDragging)? onDragging;
+  final void Function(ViewPB from, ViewPB to)? onMove;
 
   @override
   State<DraggableViewItem> createState() => _DraggableViewItemState();
@@ -189,6 +191,11 @@ class _DraggableViewItemState extends State<DraggableViewItem> {
       return;
     }
 
+    if (widget.onMove != null) {
+      widget.onMove?.call(from, to);
+      return;
+    }
+
     final fromSection = getViewSection(from);
     final toSection = getViewSection(to);
 

frontend/appflowy_flutter/lib/workspace/presentation/home/menu/view/view_item.dart

@@ -43,6 +43,7 @@ class ViewItem extends StatelessWidget {
     required this.isFeedback,
     this.height = 28.0,
     this.isHoverEnabled = true,
+    this.isPlaceholder = false,
   });
 
   final ViewPB view;
@@ -78,6 +79,10 @@ class ViewItem extends StatelessWidget {
 
   final bool isHoverEnabled;
 
+  // all the view movement depends on the [ViewItem] widget, so we have to add a
+  // placeholder widget to receive the drop event when moving view across sections.
+  final bool isPlaceholder;
+
   @override
   Widget build(BuildContext context) {
     return BlocProvider(
@@ -105,6 +110,7 @@ class ViewItem extends StatelessWidget {
             isFeedback: isFeedback,
             height: height,
             isHoverEnabled: isHoverEnabled,
+            isPlaceholder: isPlaceholder,
           );
         },
       ),
@@ -132,6 +138,7 @@ class InnerViewItem extends StatelessWidget {
     required this.isFeedback,
     required this.height,
     this.isHoverEnabled = true,
+    this.isPlaceholder = false,
   });
 
   final ViewPB view;
@@ -154,6 +161,7 @@ class InnerViewItem extends StatelessWidget {
   final double height;
 
   final bool isHoverEnabled;
+  final bool isPlaceholder;
 
   @override
   Widget build(BuildContext context) {
@@ -170,6 +178,7 @@ class InnerViewItem extends StatelessWidget {
       leftPadding: leftPadding,
       isFeedback: isFeedback,
       height: height,
+      isPlaceholder: isPlaceholder,
     );
 
     // if the view is expanded and has child views, render its child views
@@ -188,6 +197,7 @@ class InnerViewItem extends StatelessWidget {
             isDraggable: isDraggable,
             leftPadding: leftPadding,
             isFeedback: isFeedback,
+            isPlaceholder: isPlaceholder,
           );
         }).toList();
 
@@ -222,14 +232,17 @@ class InnerViewItem extends StatelessWidget {
     }
 
     // wrap the child with DraggableItem if isDraggable is true
-    if (isDraggable && !isReferencedDatabaseView(view, parentView)) {
+    if ((isDraggable || isPlaceholder) &&
+        !isReferencedDatabaseView(view, parentView)) {
       child = DraggableViewItem(
         isFirstChild: isFirstChild,
         view: view,
-        child: child,
         onDragging: (isDragging) {
           _isDragging = isDragging;
         },
+        onMove: isPlaceholder
+            ? (from, to) => _moveViewCrossSection(context, from, to)
+            : null,
         feedback: (context) {
           return ViewItem(
             view: view,
@@ -243,6 +256,7 @@ class InnerViewItem extends StatelessWidget {
             isFeedback: true,
           );
         },
+        child: child,
       );
     } else {
       // keep the same height of the DraggableItem
@@ -254,6 +268,37 @@ class InnerViewItem extends StatelessWidget {
 
     return child;
   }
+
+  void _moveViewCrossSection(
+    BuildContext context,
+    ViewPB from,
+    ViewPB to,
+  ) {
+    if (isReferencedDatabaseView(view, parentView)) {
+      return;
+    }
+    final fromSection = categoryType == FolderCategoryType.public
+        ? ViewSectionPB.Private
+        : ViewSectionPB.Public;
+    final toSection = categoryType == FolderCategoryType.public
+        ? ViewSectionPB.Public
+        : ViewSectionPB.Private;
+    context.read<ViewBloc>().add(
+          ViewEvent.move(
+            from,
+            to.parentViewId,
+            null,
+            fromSection,
+            toSection,
+          ),
+        );
+    context.read<ViewBloc>().add(
+          ViewEvent.updateViewVisibility(
+            from,
+            categoryType == FolderCategoryType.public,
+          ),
+        );
+  }
 }
 
 class SingleInnerViewItem extends StatefulWidget {
@@ -272,6 +317,7 @@ class SingleInnerViewItem extends StatefulWidget {
     required this.isFeedback,
     required this.height,
     this.isHoverEnabled = true,
+    this.isPlaceholder = false,
   });
 
   final ViewPB view;
@@ -291,6 +337,7 @@ class SingleInnerViewItem extends StatefulWidget {
   final double height;
 
   final bool isHoverEnabled;
+  final bool isPlaceholder;
 
   @override
   State<SingleInnerViewItem> createState() => _SingleInnerViewItemState();
@@ -305,6 +352,13 @@ class _SingleInnerViewItemState extends State<SingleInnerViewItem> {
     final isSelected =
         getIt<MenuSharedState>().latestOpenView?.id == widget.view.id;
 
+    if (widget.isPlaceholder) {
+      return const SizedBox(
+        height: 4,
+        width: double.infinity,
+      );
+    }
+
     if (widget.isFeedback || !widget.isHoverEnabled) {
       return _buildViewItem(
         false,

frontend/rust-lib/flowy-folder/src/entities/view.rs

@@ -475,6 +475,15 @@ pub struct UpdateRecentViewPayloadPB {
   pub add_in_recent: bool,
 }
 
+#[derive(Default, ProtoBuf)]
+pub struct UpdateViewVisibilityStatusPayloadPB {
+  #[pb(index = 1)]
+  pub view_ids: Vec<String>,
+
+  #[pb(index = 2)]
+  pub is_public: bool,
+}
+
 // impl<'de> Deserialize<'de> for ViewDataType {
 //     fn deserialize<D>(deserializer: D) -> Result<Self, <D as Deserializer<'de>>::Error>
 //     where

frontend/rust-lib/flowy-folder/src/event_handler.rs

@@ -363,3 +363,14 @@ pub(crate) async fn reload_workspace_handler(
   folder.reload_workspace().await?;
   Ok(())
 }
+
+#[tracing::instrument(level = "debug", skip(data, folder), err)]
+pub(crate) async fn update_view_visibility_status_handler(
+  data: AFPluginData<UpdateViewVisibilityStatusPayloadPB>,
+  folder: AFPluginState<Weak<FolderManager>>,
+) -> Result<(), FlowyError> {
+  let folder = upgrade_folder(folder)?;
+  let params = data.into_inner();
+  folder.set_views_visibility(params.view_ids, params.is_public);
+  Ok(())
+}

frontend/rust-lib/flowy-folder/src/event_map.rs

@@ -40,6 +40,7 @@ pub fn init(folder: Weak<FolderManager>) -> AFPlugin {
     .event(FolderEvent::ReloadWorkspace, reload_workspace_handler)
     .event(FolderEvent::ReadPrivateViews, read_private_views_handler)
     .event(FolderEvent::ReadCurrentWorkspaceViews, get_current_workspace_views_handler)
+    .event(FolderEvent::UpdateViewVisibilityStatus, update_view_visibility_status_handler)
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Display, Hash, ProtoBuf_Enum, Flowy_Event)]
@@ -166,4 +167,7 @@ pub enum FolderEvent {
   /// Only the first level of child views are included.
   #[event(output = "RepeatedViewPB")]
   ReadCurrentWorkspaceViews = 40,
+
+  #[event(input = "UpdateViewVisibilityStatusPayloadPB")]
+  UpdateViewVisibilityStatus = 41,
 }

frontend/rust-lib/flowy-folder/src/manager.rs

@@ -1120,6 +1120,19 @@ impl FolderManager {
     &self.cloud_service
   }
 
+  pub fn set_views_visibility(&self, view_ids: Vec<String>, is_public: bool) {
+    self.with_folder(
+      || (),
+      |folder| {
+        if is_public {
+          folder.delete_private_view_ids(view_ids);
+        } else {
+          folder.add_private_view_ids(view_ids);
+        }
+      },
+    );
+  }
+
   fn get_sections(&self, section_type: Section) -> Vec<SectionItem> {
     self.with_folder(Vec::new, |folder| {
       let trash_ids = folder