IOleUndoManager::RedoTo method (ocidl.h)

Instructs the undo manager to invoke undo actions back through the redo stack, down to and including the specified undo unit.

Syntax

HRESULT RedoTo(
  [in] IOleUndoUnit *pUU
);

Parameters

[in] pUU

An IOleUndoUnit pointer to the top level unit to redo. If this parameter is NULL, the most recently added top level unit is used.

Return value

This method returns S_OK on success. Other possible return values include the following.

Remarks

This method calls the IOleUndoUnit::Do method on each top-level undo unit. Then, it releases that undo unit.

Note that the specified undo unit must be a top-level unit, typically retrieved through IOleUndoManager::EnumRedoable.

In case an error is returned from the undo unit, the undo manager needs to attempt to rollback the state of the document to recover from the error by performing actions on the undo stack.

No matter what the success of the rollback, the undo manager should always clear both stacks before returning the error.

If the undo manager has called the IOleUndoUnit::Do method on more than one top-level unit, it should only rollback the unit that returned the error. The top-level units that succeeded should not be rolled back.

The undo manager must also keep track of whether units were added to the opposite stack so it won't attempt rollback if nothing was added. See the IOleUndoManager interface for detailed description of error handling.

Requirements

See also

IOleUndoManager

IOleUndoManager::EnumRedoable

IOleUndoManager::UndoTo

IOleUndoUnit::Do