SWT: A Developer's Notebook

Using the SWT FileDialog Class

If your application deals with files in any manner, you need a mechanism to ask the user for a filename (to open or save). You have no doubt seen examples of file open dialogs in your favorite development environment or text editor, and you know that they can be fairly complex. A file open dialog will contain many buttons, and a list box or tree view (or both) that enables the user to navigate through the filesystem.

Developing such a dialog from scratch would take many hours of programming time. Fortunately, the SWT FileDialog class does all the heavy lifting for you—all you need to do is create an instance of FileDialog and specify a few parameters.

How do I do that?

FileDialog works almost exactly like MessageBox, with just a few different settings to work with. The most logical example of the use of FileDialog is to prompt the user for File Open and File Save information, as demonstrated in Example 17-3.

Example 17-3. Using FileDialog

import org.eclipse.swt.widgets.*; import org.eclipse.swt.SWT; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.graphics.Image; public class FileDialogExample { Display d; Shell s; FileDialogExample( ) { d = new Display( ); s = new Shell(d); s.setSize(400,400); s.setImage(new Image(d, "c:\\icons\\JavaCup.ico")); s.setText("A MessageBox Example"); // create the menu system Menu m = new Menu(s,SWT.BAR); ...