Bug 31395 Child window of Preferences dialog centers between screens
On the Preferences->Java->Code Generation->Names tab, the Edit button opens a dialog that is split between multiple monitors, instead of centering on the main Preference window like the rest of its child windows do.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/CodeFormatterConfigurationBlock.java
private static final String COMPACT= JavaCore.COMPACT;
	private static final String NORMAL= JavaCore.NORMAL;
	
	private static final String TAB= JavaCore.TAB;
	private static final String SPACE= JavaCore.SPACE;
	
	private static final String CLEAR_ALL= JavaCore.CLEAR_ALL;
	private static final String PRESERVE_ONE= JavaCore.PRESERVE_ONE;
			
	private String fPreviewText;
	private IDocument fPreviewDocument;
	
	private Text fTabSizeTextBox;
	private SourceViewer fSourceViewer;
	
	private PixelConverter fPixelConverter;
	
	private IStatus fLineLengthStatus;
	private IStatus fTabSizeStatus;	
	
	public CodeFormatterConfigurationBlock(IStatusChangeListener context, IJavaProject project) {
		super(context, project);
			
		fPreviewDocument= new Document();
		fPreviewText= loadPreviewFile("CodeFormatterPreviewCode.txt");		
		fLineLengthStatus= new StatusInfo();
		fTabSizeStatus= new StatusInfo();
	}
	
	protected String[] getAllKeys() {