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  3. FTransaction

FTransaction

Base class for tracking transactions for undo/redo.

Unreal Engine C++ API Reference > Editor > UnrealEd > Editor

Inheritance Hierarchy

References

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

Syntax

class FTransaction : public ITransaction

Remarks

Base class for tracking transactions for undo/redo. A single transaction, representing a set of serialized, undo-able changes to a set of objects.

warning: The undo buffer cannot be made persistent because of its dependence on offsets of arrays from their owning UObjects.

warning: UObject::Serialize implicitly assumes that class properties do not change in between transaction resets.

Variables

  Type Name Description
Protected variable bool bFlip If true, on apply flip the direction of iteration over object records.
Protected variable TMap< UObject *, FChangedObjectValue > ChangedObjects Objects that will be changed directly by the transaction, empty when not transacting
Protected variable FString Context A text string describing the context for the transaction.
Protected variable FGuid Id Unique identifier for this transaction, used to track it during its lifetime
Protected variable int32 Inc Used to track direction to iterate over transaction's object records.
Protected variable TMap< UE::Transaction::FPersistentObjectRef, FObjectRecords > ObjectRecordsMap Map of object records (non-array), for optimized look-up and to prevent an object being serialized to a transaction more than once.
Protected variable FGuid OperationId Unique identifier for the active operation on this transaction (if any).
Protected variable TMap< UE::Transaction::FPersistentObjectRef, FPackageRecord > PackageRecordMap Map of package records for tracking and restoring the dirty state of packages on undo/redo.
Protected variable UObject * PrimaryObject The key object being edited in this transaction. For example the blueprint object. Can be NULL
Protected variable TIndirectArray< FObjectRecord > Records Transaction variables.
Protected variable FText Title Description of the transaction. Can be used by UI

Constructors

  Type Name Description
Public function  

FTransaction ( const TCHAR* InContext,
const FText& InTitle,
bool bInFlip
)

 Constructor.

Destructors

  Type Name Description
Public function Virtual    

Functions

  Type Name Description
Public function void Used by GC to collect referenced objects.
Public function Const SIZE_T  
Public function Const void Outputs the contents of the ObjectMap to the specified output device.
Public function Const FTransactionDiff Create a map that holds information about objects of a given transaction.
Public function Const FText Returns the description of each contained Object Record
Public function Const FGuid

GetId ()

 Returns the unique identifier for this transaction, used to track it during its lifetime
Public function Const FGuid Returns the unique identifier for the active operation on this transaction (if any)
Public function Const const UObject *  
Public function Const int32  
Public function Const FText Returns the descriptive text for the transaction
Public function Const void Get all the objects that are part of this transaction.
Public function Virtual Const const TCHAR * Returns a unique string to serve as a type ID for the FTranscationBase-derived type.
Public function Virtual Const bool  
Public function Const bool

IsObjectTransacting ( const UObject* Object
)

 Checks if a specific object is in the transaction currently underway

Overridden from ITransaction

  Type Name Description
Public function Virtual void

Apply ()

 Enacts the transaction.
Public function Virtual void BeginOperation should be called when a transaction or undo/redo starts
Public function Virtual Const bool

ContainsObject ( const UObject* Object
)

 Does the transaction know that the object is being modified.
Public function Virtual Const bool  
Public function Virtual void EndOperation should be called when a transaction is finalized or canceled or undo/redo ends
Public function Virtual void Finalize the transaction (try and work out what's changed).
Public function Virtual Const FTransactionContext Gets the full context for the transaction.
Public function Virtual Const bool Report if a transaction should be put in the undo buffer.
Public function Virtual void

SaveArray ( UObject* Object,
FScriptArray* Array,
int32 Index,
int32 Count,
int32 Oper,
int32 ElementSize,
uint32 ElementAlignment,
STRUCT_DC DefaultConstructor,
STRUCT_AR Serializer,
STRUCT_DTOR Destructor
)

 Saves an array to the transaction.
Public function Virtual void

SaveObject ( UObject* Object
)

 Saves an UObject to the transaction.
Public function Virtual void Sets the transaction's primary object.
Public function Virtual void

SnapshotObject ( UObject* Object,
TArrayView< const FProperty* > Properties
)

 Snapshots a UObject within the transaction.
Public function Virtual void

StoreUndo ( UObject* Object,
TUniquePtr< FChange > CustomChange
)

 Stores a command that can be used to undo a change to the specified object.

Classes

  Type Name Description
Protected struct FChangedObjectValue    
Protected class FObjectRecord Record of an object.  
Protected struct FObjectRecords    
Protected struct FPackageRecord    

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