SWT: A Developer's Notebook

Chapter 17. SWT Standard Dialogs

As GUI users, you are no doubt familiar with some of the complex windows used for common everyday operations such as opening files, choosing fonts or colors, and selecting which printer gets the output. If these windows had to be coded from scratch, the cost in development time would be high.

Recognizing this, the SWT provides us with predeveloped versions of these windows—known collectively as the Standard Dialogs. Six such dialogs are provided for your use:

• MessageBox

• DirectoryDialog

• FileDialog

• ColorDialog

• FontDialog

• PrintDialog

Each of these is represented by a single class that is located in the org.eclipse.swt.widgets package (except for PrintDialog, which resides in org.eclipse.swt.printing). The sections that follow discuss each in turn, showing how to incorporate them into your applications.

Using the SWT MessageBox Class

MessageBox is used to display some information to the user, such as an error condition, or to obtain simple input from the user, or both. The message box is displayed with a series of buttons, such as Yes, No, or Cancel. The program waits until the user makes a selection, then branches execution depending upon which selection was made.

How do I do that?

Perhaps the best example of using a MessageBox is seen when the user attempts to close an application by selecting File Exit from the program’s menu. Often a message box will appear asking the user for confirmation before actually exiting. Example 17-1 demonstrates ...