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/OptionsConfigurationBlock.java
package org.eclipse.jdt.internal.ui.preferences;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.Map;