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/NameConventionConfigurationBlock.java
private boolean canEdit(ListDialogField field) {
			return field.getSelectedElements().size() == 1;
		}
		public void customButtonPressed(ListDialogField field, int index) {
			doEditButtonPressed(index);
		}
		public void selectionChanged(ListDialogField field) {