A dialog based user interface guides you through the steps necessary to execute a selected refactoring. A dialog based refactoring user interface consists of a short first dialog gathering information that is required to execute the refactoring, a separate problem dialog that pops up if any errors are detected and a preview dialog to preview the results of a refactoring.
This dialog gathers information that is required for the refactoring. For example, for a rename refactoring you will enter the new name for the Java element. You can either press OK to execute the refactoring or Preview > to preview the result of the refactoring.
The JDT allows you to preview the results of a refactoring action before you execute it.
The preview dialog consists of two parts:
The problem dialog indicates if there are suspected, potential, or definite problems with the refactoring action you are attempting.
Four types of problems are possible:
If there aren't any stop problems then the refactoring can be carried out by pressing the OK button. To preview the results of the refactoring action, press the Continue button.
Refactoring without preview
Refactoring with preview
Previewing refactoring changes
Undoing a refactoring operation
Redoing a refactoring operation