IDLitDataOperation::UndoExecute
Syntax | Return Value | Arguments | Keywords | Version History | See Also
The IDLitDataOperation::UndoExecute function method is called when a user selects the Undo operation after executing an IDLitDataOperation that sets the value of the REVERSIBLE_OPERATION property to 1. (If the IDLitDataOperation does not set this property, the UndoExecute method is not called.) If implemented, this method generally applies the inverse of the operation performed by the Execute method.
Note
An operation based on the IDLitDataOperation class must implement this method if the operation sets the REVERSIBLE_OPERATION property. See Creating an Operation (iTool Developer's Guide) for details.
When the iTool system undoes an IDLitDataOperation, it passes the raw data (of the appropriate iTools data type) from the selected objects to the UndoExecute method. This means that the UndoExecute method itself does not need to "unpack" a data object before performing the operations, allowing rapid and simple operation execution. For example, if the operation expects data of the iTools data type IDLARRAY2D, the iTool system will include the selected two-dimensional array as the Data argument.
Syntax
Result = Obj->[IDLitDataOperation::]UndoExecute(Data)
Return Value
The return value is 1 if the operation was undone successfully, or 0 otherwise.
Arguments
Data
A single data item on which the operation should be performed. Note that Data is not an IDLitData object, but actual data.
Keywords
None
Version History
