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
int value= Integer.parseInt(number);
				if (value < 0) {
					status.setError(PreferencesMessages.getFormattedString("CodeFormatterPreferencePage.invalid_input", number)); 
				}
			} catch (NumberFormatException e) {
				status.setError(PreferencesMessages.getFormattedString("CodeFormatterPreferencePage.invalid_input", number)); 
			}
		}
		return status;
	}
	
	private static int getPositiveIntValue(String string, int dflt) {
		try {
			int i= Integer.parseInt(string);
			if (i >= 0) {
				return i;
			}
		} catch (NumberFormatException e) {
		}
		return dflt;
	}		
	/* (non-Javadoc)
	 * @see org.eclipse.jdt.internal.ui.preferences.OptionsConfigurationBlock#getFullBuildDialogStrings(boolean)
	 */
	protected String[] getFullBuildDialogStrings(boolean workspaceSettings) {
		return null; 
	}
		
}