Using Undo and Redo

You can undo the last 20 operations, and to redo the operation that was most recently undone.

To undo the last operation, do one of the following actions:

• Choose Edit > Undo.
• Click the Undo tool.

To redo an operation, do one of the following actions:

• Choose Edit > Redo.
• Click the Redo tool.

The Undo menu command does not become active until you perform at least one operation that can be undone. Similarly, the Redo menu command is not active until you have used the Undo command at least once.

By default, you can undo the last 20 operations, but you can set this value in the General::Model::UndoBufferSize property. Setting this property to a value of zero disables the Undo/Redo feature.

You cannot use the Undo command after large operations that affect the file system. The undo operation buffer is cleared and the Undo and Redo tools are deactivated. The following operations cannot be undone:

• Saving, opening, or closing a project
• Automatic diagram layout
• Roundtripping code with the generated code in browser option
• Loading a unit into a workspace
• Configuration management operations
• Importing IBM® Rational Rose® models
• Reverse engineering
• Adding a file unit to the model (choose File > > Add to Model)
• Code generation with the generated code in browser option