ReadActionState

Inside Macintosh: OpenDoc Class Reference /: Part 1 - Classes and Methods / ODPart

ReadActionState
The ReadActionState method should read the undo action data from the specified storage-unit view object.
ODActionData ReadActionState (
                     in ODStorageUnitView storageUnitView);
storageUnitView
A reference to a storage-unit view object that contains the action data.
return value
A byte array whose buffer contains the data previously logged by this part to allow it to undo the action.

DISCUSSION
OpenDoc calls this method when it reads the undo action data from persistent storage. Your part's ReadActionState method will not be called in OpenDoc 1.0 due to the lack of a persistent undo model; it is provided here for compatibility with future versions of OpenDoc.

OVERRIDING
When you subclass ODPart, you can override this method. Your override method must not call its inherited method; that is, your override method must implement this method's functionality completely.

EXCEPTIONS

kODErrDoesNotUndo
The specified action is not an undo action of this part.
kODErrOutOfMemory
There is not enough memory to read the data.

SEE ALSO
The ODActionData type (page 898).
The ODPart::DisposeActionState method (page 499).
The ODPart::WriteActionState method (page 552).
Table 2-1 on page 89 in OpenDoc Programmer's Guide.
"Implementing Undo" on page 258 in OpenDoc Programmer's Guide.