You can undo any editing actions that you perform on the Design Canvas, and you can redo any actions that you have previously undone. These options are not available for changes made in the Properties view.

To undo an action, select Edit > Undo or press Ctrl+Z. To redo, select Edit > Redo or press Ctrl+Y. (In some cases involving controls that have built-in design tools, you may need to use the Undo command multiple times before you see the desired result.)

The undo/redo stack for the Design Canvas is maintained separately from the stack for other Eclipse components. To undo or redo Visual Designer actions, you must have focus on the design window.
Note: Only editing actions that have occurred since the most recent save operation can be undone and redone; you cannot use Undo to return to a state earlier than the latest saved version of the file. To revert to an earlier saved version, right-click the class file in the Project Explorer view and select Replace With > Local History from the context menu.