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> Unreal Engine API Reference > Editor > UnrealEd > Editor > UTransBuffer

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UTransBuffer

Transaction tracking system, manages the undo and redo buffer.

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Inheritance Hierarchy

UObjectBase

UObjectBaseUtility

UObject

UTransactor

UTransBuffer

UMatineeTransBuffer

References

Module	UnrealEd
Header	/Engine/Source/Editor/UnrealEd/Classes/Editor/TransBuffer.h
Include	#include "Editor/TransBuffer.h"

Syntax

class UTransBuffer : public UTransactor

Remarks

Transaction tracking system, manages the undo and redo buffer.

Variables

	Name	Description
int32	ActiveCount	Number of actions in the current transaction
TArray< int32 >	ActiveRecordCounts	The cached count of the number of object records each time a transaction is begun
SIZE_T	MaxMemory	Maximum number of bytes the transaction buffer is allowed to occupy
FText	ResetReason	Text describing the reason that the undo buffer is empty
TArray< int32 >	UndoBarrierStack	Undo barrier stack
TArray< TShared...	UndoBuffer	Variables.
int32	UndoCount	Number of transactions that have been undone, and are eligible to be redone

Functions

	Name	Description
void	AddReferencedObjects ( UObject* InThis, FReferenceCollector& Collector )
int32	BeginInternal ( const TCHAR* SessionContext, const FText& Description )	Implementation of the begin function. Used to create a specific transaction type
void	CheckState()	Validates the state of the transaction buffer.
void	Initialize ( SIZE_T InMaxMemory )	Constructor.
UTransBuffer...	OnBeforeRedoUndo()
UTransBuffer...	OnRedo()
UTransBuffer...	OnTransactionStateChanged()
UTransBuffer...	OnUndo()
UTransBuffer...	OnUndoBufferChanged()

Overridden from UTransactor

	Name	Description
int32	Begin ( const TCHAR* SessionContext, const FText& Description )	Begins a new undo transaction.
void	Cancel ( int32 StartIndex )	Cancels the current transaction, no longer capture actions to be placed in the undo buffer.
bool	CanRedo ( FText* Text )	Determines whether the redo option should be selectable.
bool	CanUndo ( FText* Text )	Determines whether the undo option should be selectable.
void	ClearUndoBarriers()	Clears all undo barriers.
bool	ContainsPieObjects()
bool	DisableObjectSerialization()	Disables the transaction buffer from serializing the set of objects it references.
bool	EnableObjectSerialization()	Enables the transaction buffer to serialize the set of objects it references.
int32	End()	Attempts to close an undo transaction. Only successful if the transaction's action counter is 1.
int32	FindTransactionIndex ( const FGuid& TransactionId )	Gets the transaction queue index from its TransactionId.
int32	GetQueueLength()	Gets the current length of the transaction queue.
FTransaction...	GetRedoContext()	Returns the description of the redo action that will be performed next.
const FTrans...	GetTransaction ( int32 QueueIndex )	Gets the transaction at the specified queue index.
FTransaction...	GetUndoContext ( bool bCheckWhetherUndoPossible )	Returns the description of the undo action that will be performed next.
int32	GetUndoCount()	Gets the number of transactions that were undone and can be redone.
SIZE_T	GetUndoSize()	Determines the amount of data currently stored by the transaction buffer.
bool	IsActive()	Returns whether there are any active actions; i.e. whether actions are currently being captured into the undo buffer.
bool	IsObjectInTransationBuffer ( const UObject* Object )	Checks if a specific object is referenced by the transaction buffer
bool	IsObjectSerializationEnabled()	Wrapper for checking if the transaction buffer is allowed to serialize object references.
bool	IsObjectTransacting ( const UObject* Object )	Checks if a specific object is in the transaction currently underway
bool	Redo()	Executes an redo transaction, redoing all actions contained by that transaction.
void	RemoveUndoBarrier()	Removes the last set undo barrier from the transaction buffer.
void	Reset ( const FText& Reason )	Resets the entire undo buffer; deletes all undo transactions.
void	SetPrimaryUndoObject ( UObject* Object )	Set passed object as the primary context object for transactions
void	SetUndoBarrier()	Sets an undo barrier at the current point in the transaction buffer.
bool	Undo ( bool bCanRedo )	Executes an undo transaction, undoing all actions contained by that transaction.

Overridden from UObject

		Name	Description
	void	FinishDestroy()	Called to finish destroying the object.
	void	Serialize ( FArchive& Ar )	Handles reading, writing, and reference collecting using FArchive.

Classes

	Name	Description
	FOnTransactorBeforeRedoUndo	Gets an event delegate that is executed when a redo operation is being attempted.
	FOnTransactorRedo	Gets an event delegate that is executed when a redo operation is being attempted.
	FOnTransactorTransactionStateChanged	Gets an event delegate that is executed when a transaction state changes.
	FOnTransactorUndo	Gets an event delegate that is executed when a undo operation is being attempted.
	FOnTransactorUndoBufferChanged	Gets an event delegate that is executed when the undo buffer changed.

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