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  3. FHierarchyElementViewModel

FHierarchyElementViewModel

The base view model for all elements in the hierarchy.

API > API/Editor > API/Editor/DataHierarchyEditor

The base view model for all elements in the hierarchy. There are four base view models inheriting from this; for roots, items, categories, and sections. When creating a new view model, you should inherit from one of those four base view models.

   
Name FHierarchyElementViewModel
Type struct
Header File /Engine/Source/Editor/DataHierarchyEditor/Public/DataHierarchyViewModelBase.h
Include Path #include "DataHierarchyViewModelBase.h"

Syntax

struct FHierarchyElementViewModel :  
    public TSharedFromThis< FHierarchyElementViewModel > ,  
    public FTickableEditorObject

Inheritance Hierarchy

Derived Classes

Constructors

Name Remarks Include Path Unreal Specifiers

FHierarchyElementViewModel ( UHierarchyElement* InElement,
TSharedPtr< FHierarchyElementViewModel > InParent,
TWeakObjectPtr< UDataHierarchyViewModelBase > InHierarchyViewModel,
bool bInIsForHierarchy
)

   DataHierarchyViewModelBase.h  

Destructors

Name Remarks Include Path Unreal Specifiers

virtual ~FHierarchyElementViewModel()

   DataHierarchyViewModelBase.h  

Structs

Name Remarks
FDefaultUserFeedback  
FResultWithUserFeedback  

Typedefs

Name Type Remarks Include Path
FOnChildRequestedDeletion TBaseDelegate_OneParam< void, TSharedPtr< FHierarchyElementViewModel > Child >   DataHierarchyViewModelBase.h
FOnFilterChild TBaseDelegate_OneParam< bool, const TSharedPtr< const FHierarchyElementViewModel > Child >   DataHierarchyViewModelBase.h
FOnSynced TBaseDelegate_NoParams< void >   DataHierarchyViewModelBase.h

Functions

Public

Name Remarks Include Path Unreal Specifiers

TSharedPtr< FHierarchyElementViewModel > AddChild ( TSubclassOf< UHierarchyElement > NewChildClass,
int32 InsertIndex,
FHierarchyElementIdentity ChildIdentity
)

   DataHierarchyViewModelBase.h  

void AddChildFilter ( FOnFilterChild InFilterChild
)

   DataHierarchyViewModelBase.h  

virtual bool AllowEditingInDetailsPanel ()

 Source items are transient, which is why we don't allow editing by default. DataHierarchyViewModelBase.h  

virtual void AppendDynamicContextMenuForSingleElement ( UToolMenu* ToolMenu
)

 Override this to register dynamic context menu entries when right clicking a single hierarchy item DataHierarchyViewModelBase.h  

FResultWithUserFeedback CanContain ( TSubclassOf< UHierarchyElement > HierarchyElementType
)

 Returns true if this element can add a new element via the add menu. DataHierarchyViewModelBase.h  

bool CanDelete()

 Returns true if deletable DataHierarchyViewModelBase.h  
Should return true if an item should be draggable. DataHierarchyViewModelBase.h  

FResultWithUserFeedback CanDropOn ( TSharedPtr< FHierarchyElementViewModel > DraggedElement,
EItemDropZone ItemDropZone
)

 Returns true if the given item can be dropped on the given target area. DataHierarchyViewModelBase.h  
Lets you completely customize the OnDroppedOn behavior. DataHierarchyViewModelBase.h  

virtual FResultWithUserFeedback CanHaveChildren()

 Needs to be true in order to allow drag & drop operations to parent items to this item DataHierarchyViewModelBase.h  

bool CanRename()

 Returns true if renamable DataHierarchyViewModelBase.h  

void Delete()

 Deleting will ask the parent to delete its child DataHierarchyViewModelBase.h  

void DeleteChild ( TSharedPtr< FHierarchyElementViewModel > Child
)

   DataHierarchyViewModelBase.h  

virtual bool DoesExternalDataStillExist ( const UHierarchyDataRefreshContext* Context
) const

 This function determines whether a hierarchy item that represents that external data should be maintained during data refresh Needs to be implemented if RepresentsExternalData return true. DataHierarchyViewModelBase.h  

TSharedRef< FHierarchyElementViewModel > DuplicateToThis ( TSharedPtr< FHierarchyElementViewModel > ItemToDuplicate,
int32 InsertIndex
)

   DataHierarchyViewModelBase.h  

int32 FindIndexOfChild ( const UHierarchyElement* Child
) const

   DataHierarchyViewModelBase.h  
  DataHierarchyViewModelBase.h  

int32 FindIndexOfDataChild ( const UHierarchyElement* Child
) const

   DataHierarchyViewModelBase.h  

TSharedPtr< FHierarchyElementViewModel > FindViewModelForChild ( FHierarchyElementIdentity ChildIdentity,
bool bSearchRecursively
) const

   DataHierarchyViewModelBase.h  

TSharedPtr< FHierarchyElementViewModel > FindViewModelForChild ( const UHierarchyElement* Child,
bool bSearchRecursively
) const

   DataHierarchyViewModelBase.h  

const TArray< TSharedPtr< FHierarchyElementViewModel > > & GetChildren()

   DataHierarchyViewModelBase.h  

TArray< TSharedPtr< FHierarchyElementViewModel > > & GetChildrenMutable()

   DataHierarchyViewModelBase.h  

void GetChildrenViewModelsForType ( TArray< TSharedPtr< ViewModelClass > >& OutChildren,
bool bRecursive
) const

   DataHierarchyViewModelBase.h  

void GetChildrenViewModelsForType ( TArray< TSharedPtr< ViewModelChildClass > >& OutChildren,
bool bRecursive
) const

   DataHierarchyViewModelBase.h  

const T * GetData ()

   DataHierarchyViewModelBase.h  
  DataHierarchyViewModelBase.h  
  DataHierarchyViewModelBase.h  
  DataHierarchyViewModelBase.h  

const TArray< TSharedPtr< FHierarchyElementViewModel > > & GetFilteredChildren()

   DataHierarchyViewModelBase.h  

int32 GetHierarchyDepth()

 Returns the hierarchy depth via number of parents above. DataHierarchyViewModelBase.h  

TWeakObjectPtr< UDataHierarchyViewModelBase > GetHierarchyViewModel()

   DataHierarchyViewModelBase.h  
The UObject we display in the details panel when this item is selected. DataHierarchyViewModelBase.h  

FSimpleDelegate & GetOnRequestRename()

   DataHierarchyViewModelBase.h  

FOnSynced & GetOnSynced()

   DataHierarchyViewModelBase.h  
Returns the parent view model of the hierarchical parent DataHierarchyViewModelBase.h  

virtual const FTableRowStyle * GetRowStyle()

   DataHierarchyViewModelBase.h  

virtual TArray< FString > GetSearchTerms()

   DataHierarchyViewModelBase.h  

virtual TStatId GetStatId()

   DataHierarchyViewModelBase.h  

bool HasParent ( TSharedPtr< FHierarchyElementViewModel > ParentCandidate,
bool bRecursive
) const

   DataHierarchyViewModelBase.h  

virtual void Initialize()

 Can be implemented for additional logic that the constructor isn't valid for. DataHierarchyViewModelBase.h  

virtual FResultWithUserFeedback IsEditableByUser()

 Should return true if properties are supposed to be editable & needs to be true if typical operations should work on it (renaming, dragging, deleting etc.) DataHierarchyViewModelBase.h  

bool IsExpandedByDefault()

   DataHierarchyViewModelBase.h  

bool IsForHierarchy()

   DataHierarchyViewModelBase.h  

TOptional< EItemDropZone > OnCanRowAcceptDrop ( const FDragDropEvent& DragDropEvent,
EItemDropZone ItemDropZone,
TSharedPtr< FHierarchyElementViewModel > Item
)

 Returns a set result if the item can accept a drop either above/onto/below the item. DataHierarchyViewModelBase.h  

FOnChildRequestedDeletion & OnChildRequestedDeletion()

   DataHierarchyViewModelBase.h  

FReply OnDragDetected ( const FGeometry& Geometry,
const FPointerEvent& PointerEvent,
bool bIsSource
)

   DataHierarchyViewModelBase.h  

void OnDroppedOn ( TSharedPtr< FHierarchyElementViewModel > DroppedItem,
EItemDropZone ItemDropZone
)

 Gets executed when an item was dropped on this. DataHierarchyViewModelBase.h  

virtual TOptional< bool > OnDroppedOnOverride ( TSharedPtr< FHierarchyElementViewModel > DroppedElement,
EItemDropZone ItemDropZone
)

   DataHierarchyViewModelBase.h  

virtual FReply OnDroppedOnRow ( const FDragDropEvent& DragDropEvent,
EItemDropZone ItemDropZone,
TSharedPtr< FHierarchyElementViewModel > Item
)

   DataHierarchyViewModelBase.h  

void OnRowDragLeave ( const FDragDropEvent& DragDropEvent
)

   DataHierarchyViewModelBase.h  

virtual void PostEditChange ( const FPropertyChangedEvent& PropertyChangedEvent,
FProperty* PropertyThatChanged
)

 Called when a property on the underlying data changes. DataHierarchyViewModelBase.h  

void RefreshChildrenData()

   DataHierarchyViewModelBase.h  

void Rename ( FName NewName
)

   DataHierarchyViewModelBase.h  

TSharedRef< FHierarchyElementViewModel > ReparentToThis ( TSharedPtr< FHierarchyElementViewModel > ItemToMove,
int32 InsertIndex
)

   DataHierarchyViewModelBase.h  

virtual bool RepresentsExternalData()

 For data cleanup that represents external data, this needs to return true in order for live cleanup to work. DataHierarchyViewModelBase.h  

void RequestRename()

   DataHierarchyViewModelBase.h  

void RequestRenamePending()

   DataHierarchyViewModelBase.h  

virtual void SortChildrenData ()

 Every item view model can define its own sort order for its children. DataHierarchyViewModelBase.h  

void SyncViewModelsToData()

   DataHierarchyViewModelBase.h  

virtual void Tick ( float DeltaTime
)

   DataHierarchyViewModelBase.h  

virtual FString ToString()

   DataHierarchyViewModelBase.h  

FText ToStringAsText()

   DataHierarchyViewModelBase.h  

Protected

Name Remarks Include Path Unreal Specifiers

virtual void PostAddFixup()

 Override this to handle post-add logic (for example when dropping an element on another element, or using the add button). DataHierarchyViewModelBase.h  

virtual void PostOnDroppedOn ( TSharedPtr< FHierarchyElementViewModel > DroppedElementViewModel
)

 Called after an element was dropped onto the calling element. DataHierarchyViewModelBase.h  

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