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/CompilerConfigurationBlock.java
item.setText(PreferencesMessages.getString("CompilerConfigurationBlock.problems.tabtitle")); 
		item.setControl(problemsComposite);
		item= new TabItem(folder, SWT.NONE);
		item.setText(PreferencesMessages.getString("CompilerConfigurationBlock.style.tabtitle")); 
		item.setControl(styleComposite);
	
		item= new TabItem(folder, SWT.NONE);
		item.setText(PreferencesMessages.getString("CompilerConfigurationBlock.compliance.tabtitle")); 
		item.setControl(complianceComposite);
		
		item= new TabItem(folder, SWT.NONE);
		item.setText(PreferencesMessages.getString("CompilerConfigurationBlock.others.tabtitle")); 
		item.setControl(othersComposite);		
		
		validateSettings(null, null);
	
		return folder;
	}
	private Composite createStyleTabContent(TabFolder folder) {
		String[] errorWarningIgnore= new String[] { ERROR, WARNING, IGNORE };
		
		String[] errorWarningIgnoreLabels= new String[] {
			PreferencesMessages.getString("CompilerConfigurationBlock.error"),  
			PreferencesMessages.getString("CompilerConfigurationBlock.warning"), 
			PreferencesMessages.getString("CompilerConfigurationBlock.ignore") 
		};
		
		GridLayout layout= new GridLayout();
		layout.numColumns= 2;